[{"awards": "2149070 Hawco, Nicholas", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 13 Mar 2023 00:00:00 GMT", "description": "This proposal represents collaborative research to explore manganese (Mn) limitation in Antarctic diatoms by two early career investigators. Diatoms are central players in the Southern Ocean carbon cycle, where the micronutrient chemistry is fundamentally different from other oceans. The Southern Ocean is characterized by widespread low Mn, coupled with high zinc (Zn). High Zn levels are potentially toxic to diatoms as Zn can competitively inhibit Mn uptake and metabolism, compromising the ability of building critical cellular components, thus impacting the biological pump. Using culture experiments with a matrix of micronutrient treatments (Mn, Zn, Fe) and irradiances, and using physiological and transcriptomic approaches, along with biochemical principles, the Principal Investigators will address the central hypothesis (that diatoms from the Southern Ocean possess unique physiological mechanisms to adapt to low Mn/high Zn) by quantifying rates of uptake and transporter binding constants. The transcriptomics approach will help to identify candidate genes that may provide Antarctic diatoms physiological mechanisms in low Mn/high Zn environment. The project does not require fieldwork but instead would make use of culture experiments with 4 diatom species (3 Antarctic, and 1 temperate). The proposed approach will also enable the goal of developing biomarker(s) for assessing Mn stress or Zn toxicity and results from the physiological experiments will help parameterize models of micronutrient limitation in the Southern Ocean.\r\n\r\nThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Southern Ocean; BIOGEOCHEMICAL CYCLES; Iron; Phytoplankton; TRACE ELEMENTS; DIATOMS", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Hawco, Nicholas; Cohen, Natalie", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "ANT LIA: Collaborative Research: Adaptations of Southern Ocean Diatoms to Manganese Scarcity: Can Physiological Ingenuity Overcome Unfavorable Chemistry?", "uid": "p0010412", "west": -180.0}, {"awards": "2240780 Cohen, Natalie", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 13 Mar 2023 00:00:00 GMT", "description": "Mixotrophic microorganisms that are capable of both photosynthetic and heterotrophic forms of metabolism are key contributors to primary productivity and organic carbon remineralization in the Southern Ocean. However, uncertainties in their grazing behavior and physiology prevent an accurate understanding of microbial food web dynamics and biogeochemical cycling in the Antarctic ecosystem. Polar mixotrophs have evolved to withstand extreme seasonality, including variable light, sea ice, temperature, and micronutrient concentrations. In particular, the Southern Ocean appears to be the only region of the world\u2019s ocean where the bioessential trace metals iron (Fe) and manganese (Mn) are low enough to inhibit photosynthetic growth. The molecular physiology of mixotrophs experiencing Fe and Mn growth limitation has not yet been examined, and we lack an understanding of how seasonal changes in the availability of these micronutrients influence mixotrophic growth dynamics. We aim to examine whether grazing affords mixotrophs an ecological advantage in the Fe and Mn-deficient Southern Ocean, and to characterize the shifts in metabolic processes that occur during transitions in micronutrient conditions. Culture studies will directly measure growth responses, grazing behavior, and changes in elemental stoichiometry in response to Fe and Mn limitation. Transcriptomic analyses will reveal the metabolic underpinnings of trophic behavior and micronutrient stress responses, with implications for key biogeochemical processes such as carbon fixation, remineralization, and nutrient cycling. ", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "PHYTOPLANKTON; PLANKTON; Georgia", "locations": "Georgia", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Cohen, Natalie; Millette, Nicole", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "ANT LIA: Collaborative Research: Mixotrophic Grazing as a Strategy to meet Nutritional Requirements in the Iron and Manganese Deficient Southern Ocean", "uid": "p0010411", "west": -180.0}, {"awards": "1643961 Anandakrishnan, Sridhar", "bounds_geometry": "POLYGON((-80 -83,-79.8 -83,-79.6 -83,-79.4 -83,-79.2 -83,-79 -83,-78.8 -83,-78.6 -83,-78.4 -83,-78.2 -83,-78 -83,-78 -83.2,-78 -83.4,-78 -83.6,-78 -83.8,-78 -84,-78 -84.2,-78 -84.4,-78 -84.6,-78 -84.8,-78 -85,-78.2 -85,-78.4 -85,-78.6 -85,-78.8 -85,-79 -85,-79.2 -85,-79.4 -85,-79.6 -85,-79.8 -85,-80 -85,-80 -84.8,-80 -84.6,-80 -84.4,-80 -84.2,-80 -84,-80 -83.8,-80 -83.6,-80 -83.4,-80 -83.2,-80 -83))", "dataset_titles": "Rutford Ice Stream short period data", "datasets": [{"dataset_uid": "200336", "doi": "https://doi.org/10.7914/SN/5B_2018", "keywords": null, "people": null, "repository": "IRIS DMC", "science_program": null, "title": "Rutford Ice Stream short period data", "url": "http://fdsn.adc1.iris.edu/networks/detail/5B_2018/"}], "date_created": "Wed, 16 Nov 2022 00:00:00 GMT", "description": "Anandakrishnan/1643961\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to study conditions under the Rutford Ice Stream, a large glacier that flows from the interior of the West Antarctic Ice Sheet to the Filchner Ronne Ice Shelf and then on to the ocean. The speed and volume of ice delivered to the ocean by this and similar glaciers is central to the question of sea-level change in the coming decades: if the volume of ice carried by Rutford to the ocean increases, then it will contribute to a rise in sea level. Numerical models of glacier flow that are used to forecast future conditions must include a component that accounts for the sliding of the ice over its bed. The sliding process is poorly modeled because of lack of detailed information about the bottom of glaciers, leading to increased uncertainty in the ice-flow models. Data from this project will provide such information. \u003cbr/\u003e\u003cbr/\u003eDuring this project, in collaboration with researchers at the British Antarctic Survey, a detailed survey of the properties of the bed of Rutford Ice Stream will be carried out. These surveys include using seismic instruments (which are sensitive to naturally occurring earthquakes within glaciers--called icequakes) to monitor the distribution of those icequakes at the bed. The locations, size, and timing of icequakes are controlled by the properties of the bed such as porosity, water pressure, and stress. As part of this project, a hole will be drilled to the bed of the glacier to monitor water pressures and to extract a sample of the basal material. By comparing the pressure variations with icequake production, the properties of the basal material over a large area can be better determined. Those results will aid in the application of numerical models by informing their description of the sliding process. This award requires field work in Antarctica.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -78.0, "geometry": "POINT(-79 -84)", "instruments": null, "is_usap_dc": true, "keywords": "SEISMICITY; GLACIERS/ICE SHEETS; Ice Dynamics; Rutford Ice Stream", "locations": "Rutford Ice Stream", "north": -83.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Anandakrishnan, Sridhar", "platforms": null, "repo": "IRIS DMC", "repositories": "Other", "science_programs": null, "south": -85.0, "title": "Rutford Ice Stream Cooperative Research Program with British Antarctic Survey", "uid": "p0010392", "west": -80.0}, {"awards": "1645087 Catchen, Julian", "bounds_geometry": null, "dataset_titles": "Evaluating Illumina-, Nanopore-, and PacBio-based genome assembly strategies with the bald notothen, Trematomus borchgrevinki", "datasets": [{"dataset_uid": "200330", "doi": "", "keywords": null, "people": null, "repository": "NCBI ", "science_program": null, "title": "Evaluating Illumina-, Nanopore-, and PacBio-based genome assembly strategies with the bald notothen, Trematomus borchgrevinki", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA861284"}, {"dataset_uid": "200331", "doi": "10.5061/dryad.ghx3ffbs3", "keywords": null, "people": null, "repository": "Dryad", "science_program": null, "title": "Evaluating Illumina-, Nanopore-, and PacBio-based genome assembly strategies with the bald notothen, Trematomus borchgrevinki", "url": "https://datadryad.org/stash/dataset/doi:10.5061/dryad.ghx3ffbs3"}], "date_created": "Mon, 10 Oct 2022 00:00:00 GMT", "description": "As plate tectonics pushed Antarctica into a polar position, by ~34 million years ago, the continent and its surrounding Southern Ocean (SO) became geographically and thermally isolated by the Antarctic Circumpolar Current. Terrestrial and marine glaciation followed, resulting in extinctions as well as the survival and radiation of unique flora and fauna. The notothenioid fish survived and arose from a common ancestral stock into tax with 120 species that dominates today\u0027s SO fish fauna. The Notothenioids evolved adaptive traits including novel antifreeze proteins for survival in extreme cold, but also suffered seemingly adverse trait loss including red blood cells in the icefish family, and the ability to mount cellular responses to mitigate heat stress ? otherwise ubiquitous across all life. This project aims to understand how the notothenoid genomes have changed and contributed to their evolution in the cold. The project will sequence, analyze and compare the genomes of two strategic pairs of notothenioid fishes representing both red-blooded and white-blooded species. Each pair will consist of one Antarctic species and one that has readapted to the temperate waters of S. America or New Zealand. The project will also compare the Antarctic species genomes to a genome of the closet non-Antarctic relative representing the temperate notothenioid ancestor. The work aims to uncover the mechanisms that enabled the adaptive evolution of this ecologically vital group of fish in the freezing Southern Ocean, and shed light on their adaptability to a warming world. The finished genomes will be made available to promote and advance Antarctic research and the project will host a symposium of Polar researchers to discuss the cutting edge developments regarding of genomic adaptations in the polar region.\u003cbr/\u003eDespite subzero, icy conditions that are perilous to teleost fish, the fish fauna of the isolated Southern Ocean (SO) surrounding Antarctica is remarkably bountiful. A single teleost group - the notothenioid fishes - dominate the fauna, comprising over 120 species that arose from a common ancestor. When Antarctica became isolated and SO temperatures began to plunge in early Oligocene, the prior temperate fishes became extinct. The ancestor of Antarctic notothenioids overcame forbidding polar conditions and, absent niche competition, it diversified and filled the SO. How did notothenioids adapt to freezing environmental selection pressures and achieve such extraordinary success? And having specialized to life in chronic cold for 30 myr, can they evolve in pace with today\u0027s warming climate to stay viable? Past studies of Antarctic notothenioid evolutionary adaptation have discovered various remarkable traits including the key, life-saving antifreeze proteins. But life specialized to cold also led to paradoxical trait changes such as the loss of the otherwise universal heat shock response, and of the O2-transporting hemoglobin and red blood cells in the icefish family. A few species interestingly regained abilities to live in temperate waters following the escape of their ancestor out of the freezing SO. \u003cbr/\u003eThis proposed project is the first major effort to advance the field from single trait studies to understanding the full spectrum of genomic and genetic responses to climatic and environmental change during notothenioid evolution, and to evaluate their adaptability to continuing climate change. To this end, the project will sequence the genomes of four key species that embody genomic responses to different thermal selection regimes during notothenioids\u0027 evolutionary history, and by comparative analyses of genomic structure, architecture and content, deduce the responding changes. Specifically, the project will (i) obtain whole genome assemblies of the red-blooded T. borchgrevinki and the S. American icefish C. esox; (ii) using the finished genomes from (i) as template, obtain assemblies of the New Zealand notothenioid N. angustata, and the white-blooded icefish C. gunnari, representing a long (11 myr) and recent (1 myr) secondarily temperate evolutionary history respectively. Genes that are under selection in the temperate environment but not in the Antarctic environment can be inferred to be directly necessary for that environment and the reverse is also true for genes under selection in the Antarctic but not in the temperate environment. Further, genes important for survival in temperate waters will show parallel selection between N. angustata and C. esox despite the fact that the two fish left the Antarctic at far separated time points. Finally, gene families that expanded due to strong selection within the cold Antarctic should show a degradation of duplicates in the temperate environment. The project will test these hypotheses using a number of techniques to compare the content and form of genes, the structure of the chromosomes containing those genes, and through the identification of key characters, such as selfish genetic elements, introns, and structural variants.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "McMurdo Sound; icefishes; SHIPS; genome assembly; Notothenioids; Puerto Natales, Chile; FISH", "locations": "McMurdo Sound; Puerto Natales, Chile", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Catchen, Julian; Cheng, Chi-Hing", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "NCBI ", "repositories": "Other", "science_programs": null, "south": null, "title": "Evolutionary Genomic Responses in Antarctic Notothenioid Fishes", "uid": "p0010384", "west": null}, {"awards": "1744649 Christianson, Knut", "bounds_geometry": "POLYGON((-120 -85.5,-117.5 -85.5,-115 -85.5,-112.5 -85.5,-110 -85.5,-107.5 -85.5,-105 -85.5,-102.5 -85.5,-100 -85.5,-97.5 -85.5,-95 -85.5,-95 -85.62,-95 -85.74,-95 -85.86,-95 -85.98,-95 -86.1,-95 -86.22,-95 -86.34,-95 -86.46000000000001,-95 -86.58,-95 -86.7,-97.5 -86.7,-100 -86.7,-102.5 -86.7,-105 -86.7,-107.5 -86.7,-110 -86.7,-112.5 -86.7,-115 -86.7,-117.5 -86.7,-120 -86.7,-120 -86.58,-120 -86.46000000000001,-120 -86.34,-120 -86.22,-120 -86.1,-120 -85.98,-120 -85.86,-120 -85.74,-120 -85.62,-120 -85.5))", "dataset_titles": "Ice Dynamics at the Intersection of the West and East Antarctic Ice Sheets", "datasets": [{"dataset_uid": "601606", "doi": "10.15784/601606", "keywords": "Antarctica; Cryosphere; Glaciers/Ice Sheet; Glaciology; Ground Penetrating Radar; Ice Penetrating Radar; Snow/Ice", "people": "Christianson, Knut", "repository": "USAP-DC", "science_program": null, "title": "Ice Dynamics at the Intersection of the West and East Antarctic Ice Sheets", "url": "https://www.usap-dc.org/view/dataset/601606"}], "date_created": "Tue, 02 Aug 2022 00:00:00 GMT", "description": "The response of the Antarctic ice sheet to climate change is a central issue in projecting global sea-level rise. While much attention is focused on the ongoing rapid changes at the coastal margin of the West Antarctic Ice Sheet, obtaining records of past ice-sheet and climate change is the only way to constrain how an ice sheet changes over millennial timescales. Whether the West Antarctic Ice Sheet collapsed during the last interglacial period (~130,000 to 116,000 years ago), when temperatures were slightly warmer than today, remains a major unsolved problem in Antarctic glaciology. Hercules Dome is an ice divide located at the intersection of the East Antarctic and West Antarctic ice sheets. It is ideally situated to record the glaciological and climatic effects of changes in the West Antarctic Ice Sheet. This project will establish whether Hercules Dome experienced major changes in flow due to changes in the elevation of the two ice sheets. The project will also ascertain whether Hercules Domes is a suitable site from which to recover climate records from the last interglacial period. These records could be used to determine whether the West Antarctic Ice Sheet collapsed during that period. The project will support two early-career researchers and train students at the University of Washington. Results will be communicated through outreach programs in coordination the Ice Drilling Project Office, the University of Washington\u0027s annual Polar Science Weekend in Seattle, and art-science collaboration.\u003cbr/\u003e\u003cbr/\u003eThis project will develop a history of ice dynamics at the intersection of the East and West Antarctic ice sheets, and ascertain whether the site is suitable for a deep ice-coring operation. Ice divides provide a unique opportunity to assess the stability of past ice flow. The low deviatoric stresses and non-linearity of ice flow causes an arch (a \"Raymond Bump\") in the internal layers beneath a stable ice divide. This information can be used to determine the duration of steady ice flow. Due to the slow horizontal ice-flow velocities, ice divides also preserve old ice with internal layering that reflects past flow conditions caused by divide migration. Hercules Dome is an ice divide that is well positioned to retain information of past variations in the geometry of both the East and West Antarctic Ice Sheets. This dome is also the most promising location at which to recover an ice core that can be used to determine whether the West Antarctic Ice Sheet collapsed during the last interglacial period. Limited ice-penetrating radar data collected along a previous scientific surface traverse indicate well-preserved englacial stratigraphy and evidence suggestive of a Raymond Bump, but the previous survey was not sufficiently extensive to allow thorough characterization or determination of past changes in ice dynamics. This project will conduct a dedicated survey to map the englacial stratigraphy and subglacial topography as well as basal properties at Hercules Dome. The project will use ground-based ice-penetrating radar to 1) image internal layers and the ice-sheet basal interface, 2) accurately measure englacial attenuation, and 3) determine englacial vertical strain rates. The radar data will be combined with GPS observations for detailed topography and surface velocities and ice-flow modeling to constrain the basal characteristics and the history of past ice flow.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -95.0, "geometry": "POINT(-107.5 -86.1)", "instruments": null, "is_usap_dc": true, "keywords": "ICE DEPTH/THICKNESS; East Antarctica; West Antarctica", "locations": " East Antarctica; West Antarctica", "north": -85.5, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Christianson, Knut", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -86.7, "title": "Ice Dynamics at the Intersection of the West and East Antarctic Ice Sheets", "uid": "p0010359", "west": -120.0}, {"awards": "2053726 Hofmann, Gretchen", "bounds_geometry": "POLYGON((163 -77,163.4 -77,163.8 -77,164.2 -77,164.6 -77,165 -77,165.4 -77,165.8 -77,166.2 -77,166.6 -77,167 -77,167 -77.1,167 -77.2,167 -77.3,167 -77.4,167 -77.5,167 -77.6,167 -77.7,167 -77.8,167 -77.9,167 -78,166.6 -78,166.2 -78,165.8 -78,165.4 -78,165 -78,164.6 -78,164.2 -78,163.8 -78,163.4 -78,163 -78,163 -77.9,163 -77.8,163 -77.7,163 -77.6,163 -77.5,163 -77.4,163 -77.3,163 -77.2,163 -77.1,163 -77))", "dataset_titles": "Analyses combining ATAC-seq, RRBS, and RNA-seq data for purple urchins", "datasets": [{"dataset_uid": "200288", "doi": "", "keywords": null, "people": null, "repository": "github", "science_program": null, "title": "Analyses combining ATAC-seq, RRBS, and RNA-seq data for purple urchins", "url": "https://github.com/snbogan/Sp_RRBS_ATAC"}], "date_created": "Thu, 14 Apr 2022 00:00:00 GMT", "description": "Part 1: Non-technical description:\r\n\tWith support from the Office of Polar Programs, this project will evaluate how an important part of the food web in the coastal ocean of Antarctica will respond to climate change. The focal study organism in the plankton is a shelled mollusk, the Antarctic pteropod, Limacina helicina antarctica, a Southern Ocean organism that this known to respond to climate driven changes in ocean acidification and ocean warming. Ocean acidification, the lowering of ocean pH via the absorption of atmospheric carbon dioxide in the surface of the ocean, is a change in the ocean that is expected to cross deleterious thresholds of pH within decades. This study will improve understanding of how pteropods will respond, which will provide insight into predicting the resilience of the Antarctic marine ecosystem during future changes, one of the planets last marine wildernesses. The project will use tools of molecular biology to examine specifically how gene expression is modulated in the pteropods, and further, how the changes and regulation of genes act to resist the stress of low pH and high temperature. In addition, this project supports the training of Ph.D. graduate students and advances the goal of inclusive excellence in STEM and in marine sciences, in particular. The students involved in this project are from groups traditionally under-represented in marine science including first-generation college students. Overall, the project contributes to the development of the U.S. work force and contributes to diversity and inclusive excellence in the geosciences.\r\n\r\nPart 2: Technical description: \r\nThe overarching goal of this project is to investigate the molecular response of the Antarctic thecosome pteropod, Limacina helicina antarctica to ocean acidification (OA) and ocean warming. The project will investigate changes in the epigenome of juvenile L. h. antarctica, by assessing the dynamics of DNA methylation in response to three scenarios of environmental conditions that were simulated in laboratory mesocosm CO2 experiments: (1) present-day pCO2 conditions for summer and winter, (2) future ocean acidification expected within 10-15 years, and (3) a multiple stressor experiment to investigate synergistic interaction of OA and high temperature stress. Recent lab-based mesocosm experiment research showed significant changes in the dynamics of global DNA methylation in the pteropod genome, along with variation in gene expression in response to abiotic changes. Thus, it is clear that juvenile L. h. antarctica are capable of mounting a substantial epigenetic response to ocean acidification. However, it is not known how DNA methylation, as an epigenetic process, is modulating changes in the transcriptome. In order to address this gap in the epigenetic knowledge regarding pteropods, the project will use next-generation sequencing approaches (e.g., RNA sequencing and reduced representation bisulfite sequencing) to integrate changes in methylation status with changes in gene expression in juvenile pteropods. Overall, this investigation is an important step in exploring environmental transcriptomics and phenotypic plasticity of an ecologically important member of Southern Ocean macrozoooplankton in response to anthropogenic climate change.\r\n\r\nThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 167.0, "geometry": "POINT(165 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; USAP-DC; McMurdo Sound; FIELD INVESTIGATION; AMD/US; MARINE ECOSYSTEMS; USA/NSF; ANIMALS/INVERTEBRATES", "locations": "McMurdo Sound", "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Hofmann, Gretchen", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "github", "repositories": "Other", "science_programs": null, "south": -78.0, "title": "The Role of the Epigenetic Mechanism, DNA Methylation, in the Tolerance and Resistance of Antarctic Pteropods to Ocean Acidification and Warming", "uid": "p0010313", "west": 163.0}, {"awards": "2139002 Huth, Alexander", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 05 Nov 2021 00:00:00 GMT", "description": "Icebergs influence climate by controlling how freshwater from ice sheets is distributed into the ocean, where roughly half of ice sheet mass loss is attributed to iceberg calving in the current climate. The freshwater deposited by icebergs as they drift and melt can affect ocean circulation, sea-ice formation, and biological primary productivity. Furthermore, calving of icebergs from ice shelves, the floating extensions of ice sheets, can influence ice sheet evolution and sea-level rise by reducing the resistive stresses provided by ice shelves on the seaward flow of upstream grounded ice. The majority of mass calved from ice shelves occurs in the form of tabular icebergs, which are typically hundreds of meters thick and on the order of tens to hundreds of kilometers in length and width. Tabular calving occurs when full-thickness ice shelf fractures known as rifts propagate to the edges of the ice shelf. These calving events are infrequent, often with decades between events on an individual ice shelf. Changes in tabular calving behavior, i.e., the size and frequency of calving events, can strongly influence climate and ice sheet evolution. However, tabular calving behavior, and how it responds to changes in climate, is neither well understood nor accurately represented in climate models.\r\n\r\nIn this project, a tabular calving parameterization for climate models will be developed. The parameterization will be derived according to data generated from a series of realistic and idealized century-scale tabular calving simulations, which will be performed with a novel ice flow and damage framework that can be applied at the scale of individual ice sheet-ice shelf systems: the CD-MPM-SSA (Continuum Damage Material Point Method for Shelfy-Stream Approximation). During these simulations, the geometry of the ice shelf, mechanical/rheological properties of the ice, and climate forcings such as ocean temperature will be varied to determine the rifting and calving response. The calving parameterization derived from these experiments will be implemented in a Geophysical Fluid Dynamics Laboratory (GFDL) climate model, where it will be coupled with a bonded-particle iceberg model. Then, experiments will be run to study the feedback between changes in iceberg calving behavior and climate. Success of this project will improve our understanding and representation of the ice mass budget, ice sheet evolution, and ocean freshwater fluxes, and will improve projections of climate change and sea-level rise.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; GLACIERS/ICE SHEETS; USAP-DC; ICEBERGS; AMD; AMD/US; Antarctic Ice Sheet; MODELS", "locations": "Antarctic Ice Sheet", "north": -60.0, "nsf_funding_programs": "Post Doc/Travel", "paleo_time": null, "persons": "Huth, Alex", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repositories": null, "science_programs": null, "south": -90.0, "title": "OPP-PRF Calving, Icebergs, and Climate", "uid": "p0010276", "west": -180.0}, {"awards": "1921418 Yan, Stephen", "bounds_geometry": null, "dataset_titles": "2019 initial L-band radar data for Dome Concordia; 2019 initial L-band radar data for EGRIP", "datasets": [{"dataset_uid": "601489", "doi": "10.15784/601489", "keywords": "Antarctica; Cryosphere", "people": "O\u0027Neill, Charles; Taylor, Ryan; Gogineni, Prasad; Taylor, Drew", "repository": "USAP-DC", "science_program": null, "title": "2019 initial L-band radar data for Dome Concordia", "url": "https://www.usap-dc.org/view/dataset/601489"}, {"dataset_uid": "601488", "doi": "10.15784/601488", "keywords": "Antarctica; Cryosphere; Greenland", "people": "Taylor, Ryan; O\u0027Neill, Charles; Gogineni, Prasad; Taylor, Drew", "repository": "USAP-DC", "science_program": null, "title": "2019 initial L-band radar data for EGRIP", "url": "https://www.usap-dc.org/view/dataset/601488"}], "date_created": "Mon, 11 Oct 2021 00:00:00 GMT", "description": "Predicting the response of ice sheets to changing climate and their contribution to sea level requires accurate representation in numerical models of basal conditions under the ice. There remain large data gaps for these basal boundary conditions under the East Antarctic Ice Sheet as well as in West Antarctica, including basal melt rates under ice shelves. This project developed and tested a prototype ground-based radar system to sound and image ice more than 4km thick, detect thin water films at the ice bed, and determine basal melt rates under ice shelves. The team worked with European partners (France, Italy, Germany) at Dome C to conduct deep-field Antarctic testing of the new radar.\r\n\r\nThe project built and tested an L-band radar system (1.2-1.4GHz) with peak transmit power of 2kW. In addition to sounding and imaging thick ice, detection goals included resolving thin water films (\u003e0.5mm). Such a system targets glaciological problems including site selection for ice in the 1.5-million-year age range, basal stress boundary conditions under grounded ice, and melt rates under floating shelves. By demonstrating feasibility, the project aims to influence sensor selection for satellite missions.\r\n\r\nThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; AMD; Greenland; GLACIER TOPOGRAPHY/ICE SHEET TOPOGRAPHY; GLACIER THICKNESS/ICE SHEET THICKNESS; FIELD INVESTIGATION; USA/NSF; AMD/US; Antarctica", "locations": "Antarctica; Greenland", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Science and Technology", "paleo_time": null, "persons": "Gogineni, Prasad; O\u0027Neill, Charles; Yan, Stephen; Taylor, Drew", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "EAGER: L-Band Radar Ice Sounder for Measuring Ice Basal Conditions and Ice-Shelf Melt Rate", "uid": "p0010271", "west": null}, {"awards": "2020706 Hindle, Allyson; 2020664 Vazquez-Medina, Jose Pablo", "bounds_geometry": "POLYGON((164 -77.2,164.3 -77.2,164.6 -77.2,164.9 -77.2,165.2 -77.2,165.5 -77.2,165.8 -77.2,166.1 -77.2,166.4 -77.2,166.7 -77.2,167 -77.2,167 -77.265,167 -77.33,167 -77.395,167 -77.46,167 -77.525,167 -77.59,167 -77.655,167 -77.72,167 -77.785,167 -77.85,166.7 -77.85,166.4 -77.85,166.1 -77.85,165.8 -77.85,165.5 -77.85,165.2 -77.85,164.9 -77.85,164.6 -77.85,164.3 -77.85,164 -77.85,164 -77.785,164 -77.72,164 -77.655,164 -77.59,164 -77.525,164 -77.46,164 -77.395,164 -77.33,164 -77.265,164 -77.2))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 09 Sep 2021 00:00:00 GMT", "description": "The Weddell seal is a champion diver with high natural tolerance for low blood oxygen concentration (hypoxemia) and inadequate blood supply (ischemia). The processes unique to this species protects their tissues from inflammation and oxidative stress observed in other mammalian tissues exposed to such physiological conditions. This project aims to understand the signatures of the processes that protect seals from inflammation and oxidant stress, using molecular, cellular and metabolic tools. Repetitive short dives before long ones are hypothesized to precondition seal tissues and activate the protective processes. The new aspect of this work is the study of endothelial cells, which sense changes in oxygen and blood flow, providing a link between breath-holding and cellular function. The approach is one of laboratory experiments combined with 2-years of field work in an ice camp off McMurdo Station in Antarctica. The study is structured by three main objectives: 1) laboratory experiments with arterial endothelial cells exposed to changes in oxygen and flow to identify molecular pathways responsible for tolerance of hypoxia and ischemia using several physiological, biochemical and genomic tools including CRSPR/Cas9 knockout and knockdown approaches. 2) Metabolomic analyses of blood metabolites produced by seals during long dives. And 3) Metabolomic and genomic determinations of seal physiology during short dives hypothesized to pre-condition tolerance responses. In the field, blood samples will be taken after seals dive in an isolated ice hole and its diving performance recorded. It is expected that the blood will contain metabolites that can be related to molecular pathways identified in lab experiments. ", "east": 167.0, "geometry": "POINT(165.5 -77.525)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; AMD/US; AMD; MAMMALS; FIELD INVESTIGATION; McMurdo Sound", "locations": "McMurdo Sound", "north": -77.2, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Hindle, Allyson", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": -77.85, "title": "Collaborative Research: Role of Endothelial Cell Activation in Hypoxia Tolerance of an Elite Diver, the Weddell Seal", "uid": "p0010257", "west": 164.0}, {"awards": "2122248 Waters, Laura", "bounds_geometry": "POLYGON((-127.143608 -77.1380528,-127.1012394 -77.1380528,-127.0588708 -77.1380528,-127.0165022 -77.1380528,-126.9741336 -77.1380528,-126.931765 -77.1380528,-126.8893964 -77.1380528,-126.8470278 -77.1380528,-126.8046592 -77.1380528,-126.7622906 -77.1380528,-126.719922 -77.1380528,-126.719922 -77.14809141,-126.719922 -77.15813002,-126.719922 -77.16816863,-126.719922 -77.17820724,-126.719922 -77.18824585,-126.719922 -77.19828446,-126.719922 -77.20832307,-126.719922 -77.21836168,-126.719922 -77.22840029,-126.719922 -77.2384389,-126.7622906 -77.2384389,-126.8046592 -77.2384389,-126.8470278 -77.2384389,-126.8893964 -77.2384389,-126.931765 -77.2384389,-126.9741336 -77.2384389,-127.0165022 -77.2384389,-127.0588708 -77.2384389,-127.1012394 -77.2384389,-127.143608 -77.2384389,-127.143608 -77.22840029,-127.143608 -77.21836168,-127.143608 -77.20832307,-127.143608 -77.19828446,-127.143608 -77.18824585,-127.143608 -77.17820724,-127.143608 -77.16816863,-127.143608 -77.15813002,-127.143608 -77.14809141,-127.143608 -77.1380528))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 19 Aug 2021 00:00:00 GMT", "description": "Isotopic and sedimentary datasets reveal that volcanic activity typically increases during interglacial periods. However, the physical mechanisms through which changes in the surface loading affect volcanic magmatic plumbing systems remain unconstrained. Recently generated 40Ar/39Ar eruption ages indicate that 86% of the dated samples from Mt. Waesche, a late Quaternary volcano in Marie Byrd land, correlate with interglacial periods, suggesting this volcano uniquely responds to changes in the West Antarctic Ice Sheet. We propose to combine the petrology of Mount Waesche\u2019s volcanic record, constraints on changing ice loads through time, and geodynamic modelling to: (1) Determine how pre-eruptive storage conditions change during glacial and interglacial periods using whole rock and mineral compositions of volcanic rocks; (2) Conduct geodynamic modeling to elucidate the relationship between lithospheric structure, temporal variations in ice sheet thickness, and subsequent changes in crustal stresses and magmatic transport and, therefore, the mechanism(s) by which deglaciation impacts magmatic plumbing systems; (3) Use the outcomes of objectives (1) and (2) to provide new constraints on the changes in ice sheet thickness through time that could plausibly trigger future volcanic and magmatic activity in West Antarctica. This collaborative approach will provide a novel methodology to determine prior magnitudes and rates of ice load changes within the Marie Byrd Land region of Antarctica. Lastly, estimates of WAIS elevation changes from this study will be compared to ongoing studies at Mount Waesche focused on constraining last interglacial ice sheet draw down using cosmogenic exposure ages obtained from shallow drilling. The scope of work also includes a partnership with Mentoring Kids Works to develop several Polar and Earth Science Educational Modules aimed at improving reading skills in third grade students in New Mexico. The proposed Polar and Earth Science program consists of modules that include readings of books introducing students to Earth and Polar science themes, paired with Earth and Polar Science activities, followed by simple experiments, where students make predictions and collect data. Information required to implement our Polar and Earth Science curriculum will be made available online.", "east": -126.719922, "geometry": "POINT(-126.931765 -77.18824585)", "instruments": null, "is_usap_dc": true, "keywords": "Mt. Waesche; AMD/US; GEOCHEMISTRY; West Antarctica; Executive Committee Range; NOT APPLICABLE; USAP-DC; AMD; LITHOSPHERIC PLATE MOTION; MAJOR ELEMENTS; STRESS; USA/NSF; ROCKS/MINERALS/CRYSTALS", "locations": "West Antarctica; Mt. Waesche; Executive Committee Range", "north": -77.1380528, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Waters, Laura; Naliboff, John; Zimmerer, Matthew", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repositories": null, "science_programs": null, "south": -77.2384389, "title": "Integrating petrologic records and geodynamics: Quantifying the effects of glaciation on crustal stress and eruptive patterns at Mt. Waesche, Executive Committee Range, Antarctica", "uid": "p0010248", "west": -127.143608}, {"awards": "1744999 Todgham, Anne", "bounds_geometry": "POLYGON((162 -77,162.8 -77,163.6 -77,164.4 -77,165.2 -77,166 -77,166.8 -77,167.6 -77,168.4 -77,169.2 -77,170 -77,170 -77.1,170 -77.2,170 -77.3,170 -77.4,170 -77.5,170 -77.6,170 -77.7,170 -77.8,170 -77.9,170 -78,169.2 -78,168.4 -78,167.6 -78,166.8 -78,166 -78,165.2 -78,164.4 -78,163.6 -78,162.8 -78,162 -78,162 -77.9,162 -77.8,162 -77.7,162 -77.6,162 -77.5,162 -77.4,162 -77.3,162 -77.2,162 -77.1,162 -77))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 12 Aug 2021 00:00:00 GMT", "description": "This project fits within the second of three major themes identified by the National Academy of Science report \u201cA Strategic Vision for NSF Investments in Antarctic and Southern Ocean Research\u201d. How do Antarctic biota evolve and adapt to the changing environment? Decoding the genomic and transcriptomic bases of biological adaptation and response across Antarctic organisms and ecosystems. Central in this theme is the physiological capacity of animals to cope with changes in environmental conditions over their lifetime, which this research firmly addresses. In the Southern Ocean surrounding Antarctica there is an extraordinary diversity of marine life. Much of our understanding of the biology of these animals comes from studies of the adaptations of these animals to sub-zero ocean conditions. Antarctic marine organisms have evolved to survive in stable, cold ocean conditions and possess a limited capacity to respond to environmental change. Research to date on Antarctic fishes has focused on adult life stages with much less research on early life stages that likely prioritize growth and development and not physiological mechanisms of stress tolerance. This project addresses the mechanisms that early life stages (embryos, larvae and juveniles) of Antarctic fishes use to respond to changes in ocean conditions. Specifically, the project will examine energetic trade-offs between key developmental processes in the context of environmental change. While the project focuses on Antarctic species, the research is highly translatable to stress tolerance mechanisms of fishes along the coast of North America, many of which are also experiencing changes in multiple environmental factors. Research in the Antarctic allows scientists to identify unifying themes or generalities in physiology that extend beyond the waters of the Southern Ocean and therefore have broad implications for understanding what is limiting the performance of fishes globally. BROADER IMPACTS \u2013To build environmental stewardship and awareness, we must increase science literacy in the broader community. This project does this through three main objectives. First is to increase the diversity of students involved in environmental science research. Student diversity, in turn, gives the scientific community a broader perspective for addressing critical challenges in environmental biology. This project provides resources to support three PhD students, one postdoctoral scholar and two undergraduate students and promotes the diversity of young scientists and the advancement of groups traditionally underrepresented in environmental biology. Todgham will broaden the outreach effort by developing exhibits on environmental change impacts on polar regions for large public events, an opportunity to engage K-12 students, government officials in Sacramento and local and statewide communities. Lastly, through a collaboration with PolarTREC and teacher Denise Hardoy, lesson plans have been developed to teach K-12 students about experimental design, polar environments and sensitivity of Antarctic species to climate change.", "east": 170.0, "geometry": "POINT(166 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "FISH; AMD; FIELD INVESTIGATION; USA/NSF; McMurdo Sound; AMD/US; USAP-DC", "locations": "McMurdo Sound", "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Todgham, Anne", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": -78.0, "title": "Interacting Stressors: Metabolic Capacity to Acclimate under Ocean Warming and CO2- Acidification in Early Developmental Stages of Antarctic Fishes", "uid": "p0010241", "west": 162.0}, {"awards": "1927709 Friedlaender, Ari; 1947453 Hunt, Kathleen; 1927742 Fleming, Alyson", "bounds_geometry": "POLYGON((150 -60,153 -60,156 -60,159 -60,162 -60,165 -60,168 -60,171 -60,174 -60,177 -60,180 -60,180 -61.5,180 -63,180 -64.5,180 -66,180 -67.5,180 -69,180 -70.5,180 -72,180 -73.5,180 -75,177 -75,174 -75,171 -75,168 -75,165 -75,162 -75,159 -75,156 -75,153 -75,150 -75,150 -73.5,150 -72,150 -70.5,150 -69,150 -67.5,150 -66,150 -64.5,150 -63,150 -61.5,150 -60))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 10 Aug 2021 00:00:00 GMT", "description": "An archive of baleen plates from 800 Antarctic blue and fin whales harvested between 1946 and 1948 was recently rediscovered in the Smithsonian\u2019s National Museum of Natural History. As baleen grows, it incorporates compounds from the whale\u2019s diet and surroundings, recording continuous biological and oceanographic information across multiple years. The baleen record forms an ideal experimental platform for studying bottom-up, top-down and anthropogenic impacts on blue and fin whales. Such insights are likely impossible to obtain through any other means as blue and fin whales now number ~1 and 4% of their pre-whaling abundances. The baleen archive includes years with strong climate and temperature anomalies allowing the influence of climate variability on predators and the ecosystems that support them to be examined. Additionally, the impact of whaling on whale stress levels will be investigated by comparing years of intensive whaling with the non-whaling years of WWII, both of which are captured in the time series. We will use 1) bulk stable isotopes to examine the trophic dynamics of Antarctic blue and fin whales, 2) compound-specific stable isotope analysis (CSIA-AA) to characterize the biogeochemistry of the base of the Antarctic food web and 3) hormone analyses to examine the population biology of these species. These investigations will fill major gaps in our understanding of the largest krill predators, their response to disturbance and environmental change, and the impact that commercial whaling has had on the structure and function of the Antarctic marine ecosystem.", "east": 180.0, "geometry": "POINT(165 -67.5)", "instruments": null, "is_usap_dc": true, "keywords": "AMD/US; ECOSYSTEM FUNCTIONS; PELAGIC; Southern Ocean; USAP-DC; MAMMALS; USA/NSF; LABORATORY; AMD", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Fleming, Alyson; Friedlaender, Ari; McCarthy, Matthew; Hunt, Kathleen", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -75.0, "title": "Collaborative Research: A New Baseline for Antarctic Blue and Fin Whales", "uid": "p0010240", "west": 150.0}, {"awards": "1744871 Robinson, Rebecca", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Sediment chemistry of ODP Site 1098", "datasets": [{"dataset_uid": "601541", "doi": "10.15784/601541", "keywords": "Antarctica; Antarctic Peninsula; Cryosphere", "people": "Dove, Isabel", "repository": "USAP-DC", "science_program": null, "title": "Sediment chemistry of ODP Site 1098", "url": "https://www.usap-dc.org/view/dataset/601541"}], "date_created": "Wed, 28 Jul 2021 00:00:00 GMT", "description": "The chemical composition of diatom fossils in the Southern Ocean provides information about the environmental history of Antarctica, including sea ice extent, biological production, and ocean nutrient distribution. The sea ice zone is an important habitat for a group of diatoms, largely from the genus Chaetoceros, that have a unique life cycle stage under environmental stress, when they produce a structure called a resting spore. Resting spores are meant to reseed the surface ocean when conditions are more favorable. The production of these heavy resting spores tends to remove significant amounts of carbon and silicon, essential nutrients, out of the surface ocean. As a result, this group has the potential to remove carbon from the surface ocean and can impact the sedimentary record scientists use to reconstruct environmental change. \r\n\r\nThis project explores the role of resting spores and nutrients in the sedimentary record using the nitrogen isotopic signature of these fossils and how those measurements are used to estimate carbon cycle changes. Measurements of nitrogen stable isotopes of nitrate, biomass, and diatom-bound nitrogen and silicon-to-nitrogen ratios of individual species grown in the laboratory are used to quantify how resting spores record nutrient drawdown in the water column and to what degree their signature is biased toward low nutrient conditions. Laboratory incubations were conducted with surface sediment containing Chaetoceros spp.. The emergence of vegetative cells and subsequent formation of resting spores is manipulated with the addition of nutrients, primarily nitrate. The resulting samples, both of vegetative cells and resting spores were measured for diatom-bound d15N. Resting spore d15N values are consistently lower than the vegetative d15N \r\n from the same incubations. The incubation results will be used to quantify nutrient drawdown in sea ice environments during two contrasting intervals in earth history, the last ice age and the warm Pliocene. The project provided training and research opportunities for undergraduate and graduate students. Research efforts in Antarctic earth sciences are disseminated through an interactive display at the home institution and during university sponsored events.\r\n\r\nThis work addresses uncertainties in how Chaetoceros resting spores record surface nutrient conditions in their nitrogen stable isotopic composition, the relative impact of their specific signal with respect to the full sedimentary assemblage, and their potential to bias or enhance environmental reconstructions in the sea ice zone. \r\n", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; Antarctica; ISOTOPES; AMD/US; MARINE SEDIMENTS; NITROGEN; LABORATORY; AMD; USA/NSF", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Robinson, Rebecca", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "The nitrogen isotopic composition of diatom resting spores in Southern Ocean sediments: A source of bias and/or paleoenvironmental information?", "uid": "p0010234", "west": -180.0}, {"awards": "1947040 Postlethwait, John", "bounds_geometry": "POLYGON((-65.3 -63.3,-65 -63.3,-64.7 -63.3,-64.4 -63.3,-64.1 -63.3,-63.8 -63.3,-63.5 -63.3,-63.2 -63.3,-62.9 -63.3,-62.6 -63.3,-62.3 -63.3,-62.3 -63.47,-62.3 -63.64,-62.3 -63.81,-62.3 -63.98,-62.3 -64.15,-62.3 -64.32,-62.3 -64.49,-62.3 -64.66,-62.3 -64.83,-62.3 -65,-62.6 -65,-62.9 -65,-63.2 -65,-63.5 -65,-63.8 -65,-64.1 -65,-64.4 -65,-64.7 -65,-65 -65,-65.3 -65,-65.3 -64.83,-65.3 -64.66,-65.3 -64.49,-65.3 -64.32,-65.3 -64.15,-65.3 -63.98,-65.3 -63.81,-65.3 -63.64,-65.3 -63.47,-65.3 -63.3))", "dataset_titles": "18 SSU rDNA type sequences for Notoxcellia coronata (nov. sp.); 18 SSU rDNA type sequences for Notoxcellia picta (nov. sp.); Fish pictures and skin pathology of X-cell infection in Trematomus scotti.; Histopathology of X-cell xenomas in Trematomus scotti and Nototheniops larseni.; In situ hybridization of X-cell and host fish 18S SSU rRNA in alternate sections of tumor xenomas.; Metagenomic analysis of apparently healthy and tumor samples using Kaiju software ; microMRI analyses of Trematomus scotti Tsco_18_08 with X-cell xenomas; Morphological and pathological data of Trematomus scotti specimens captured on May 30th, 2018 in Andvord Bay.; Phylogenetic Analysis of Notoxcellia species.; Raw Illumina sequencing reads from skin tumors and visually healthy skins from Trematomus scotti and Nototheniops larseni; Temperature profiles at five fishing locations on the West Antarctic Peninsula during austral fall 2018.; Trematomus scotti with X-cell xenomas", "datasets": [{"dataset_uid": "200262", "doi": "", "keywords": null, "people": null, "repository": "MorphoSource", "science_program": null, "title": "Trematomus scotti with X-cell xenomas", "url": "https://www.morphosource.org/projects/000405843?locale=en"}, {"dataset_uid": "601494", "doi": "10.15784/601494", "keywords": "Andvord Bay; Antarctica; Cryosphere; Fish", "people": "Postlethwait, John; Le Francois, Nathalie; Lauridsen, Henrik; Desvignes, Thomas", "repository": "USAP-DC", "science_program": null, "title": "Morphological and pathological data of Trematomus scotti specimens captured on May 30th, 2018 in Andvord Bay.", "url": "https://www.usap-dc.org/view/dataset/601494"}, {"dataset_uid": "601495", "doi": "10.15784/601495", "keywords": "Antarctica; Antarctic Peninsula; Cryosphere", "people": "Desvignes, Thomas", "repository": "USAP-DC", "science_program": null, "title": "Temperature profiles at five fishing locations on the West Antarctic Peninsula during austral fall 2018.", "url": "https://www.usap-dc.org/view/dataset/601495"}, {"dataset_uid": "601496", "doi": "10.15784/601496", "keywords": "Andvord Bay; Antarctica; Cryosphere; Fish", "people": "Postlethwait, John; Desvignes, Thomas; Lauridsen, Henrik", "repository": "USAP-DC", "science_program": null, "title": "Fish pictures and skin pathology of X-cell infection in Trematomus scotti.", "url": "https://www.usap-dc.org/view/dataset/601496"}, {"dataset_uid": "601501", "doi": "10.15784/601501", "keywords": "Alveolata; Antarctica; Antarctic Peninsula; Biology; Biosphere; Cryosphere; Notoxcellia coronata; Notoxcellia picta; Oceans; Perkinsozoa; Xcellidae", "people": "Varsani, Arvind; Desvignes, Thomas; Postlethwait, John", "repository": "USAP-DC", "science_program": null, "title": "Phylogenetic Analysis of Notoxcellia species.", "url": "https://www.usap-dc.org/view/dataset/601501"}, {"dataset_uid": "200276", "doi": "", "keywords": null, "people": null, "repository": "GenBank", "science_program": null, "title": "18 SSU rDNA type sequences for Notoxcellia picta (nov. sp.)", "url": "https://www.ncbi.nlm.nih.gov/nuccore/OL630145"}, {"dataset_uid": "200277", "doi": "", "keywords": null, "people": null, "repository": "NCBI SRA", "science_program": null, "title": "Raw Illumina sequencing reads from skin tumors and visually healthy skins from Trematomus scotti and Nototheniops larseni", "url": "https://www.ncbi.nlm.nih.gov/bioproject/?term=PRJNA789574"}, {"dataset_uid": "601536", "doi": "10.15784/601536", "keywords": "Alveolata; Antarctica; Antarctic Peninsula; Cryosphere; Notoxcellia coronata; Notoxcellia picta; Perkinsozoa; Xcellidae", "people": "Desvignes, Thomas; Postlethwait, John; Murray, Katrina N. ; Kent, Michael L. ", "repository": "USAP-DC", "science_program": null, "title": "Histopathology of X-cell xenomas in Trematomus scotti and Nototheniops larseni.", "url": "https://www.usap-dc.org/view/dataset/601536"}, {"dataset_uid": "601537", "doi": "10.15784/601537", "keywords": "Alveolata; Antarctica; Antarctic Peninsula; Cryosphere; Notoxcellia coronata; Notoxcellia picta; Perkinsozoa; Xcellidae", "people": "Desvignes, Thomas; Postlethwait, John; Varsani, Arvind; Kraberger, Simona ; Fontenele, Rafaela S. ", "repository": "USAP-DC", "science_program": null, "title": "Metagenomic analysis of apparently healthy and tumor samples using Kaiju software ", "url": "https://www.usap-dc.org/view/dataset/601537"}, {"dataset_uid": "601538", "doi": "10.15784/601538", "keywords": "Alveolata; Antarctica; Antarctic Peninsula; Cryosphere; Notoxcellia coronata; Notoxcellia picta; Perkinsozoa; Xcellidae", "people": "Postlethwait, John; Lauridsen, Henrik; Desvignes, Thomas", "repository": "USAP-DC", "science_program": null, "title": "microMRI analyses of Trematomus scotti Tsco_18_08 with X-cell xenomas", "url": "https://www.usap-dc.org/view/dataset/601538"}, {"dataset_uid": "601539", "doi": "10.15784/601539", "keywords": "Alveolata; Antarctica; Antarctic Peninsula; Cryosphere; Notoxcellia coronata; Notoxcellia picta; Perkinsozoa; Xcellidae", "people": "Desvignes, Thomas; Postlethwait, John", "repository": "USAP-DC", "science_program": null, "title": "In situ hybridization of X-cell and host fish 18S SSU rRNA in alternate sections of tumor xenomas.", "url": "https://www.usap-dc.org/view/dataset/601539"}, {"dataset_uid": "200275", "doi": "", "keywords": null, "people": null, "repository": "GenBank", "science_program": null, "title": "18 SSU rDNA type sequences for Notoxcellia coronata (nov. sp.)", "url": "https://www.ncbi.nlm.nih.gov/nuccore/OL630144"}], "date_created": "Thu, 01 Jul 2021 00:00:00 GMT", "description": "Overview:\r\nAntarctic biota face increasing stressors from warming oceans. A key question is: What will be the effect of warming waters on Antarctic biota? A gap in our knowledge is the identify of early harbingers of new stressors. In our recent field season, we unexpectedly discovered pink, wart-like neoplasms in Antarctic notothenioid fish, including Trematomus scotti (crowned notothen) and Nototheniops larseni (painted notothen). Neoplasms affected about 30% of T. scotti collected in Andvord Bay on the West Antarctic Peninsula and covered 10 to 30% of the bodies of affected individuals, usually in one contiguous patch. We collected samples from affected and apparently unaffected controls. We could not find evidence of any similar outbreak. Our overall goal is to learn the biological origins of this neoplasm and how it affects cellular function and organismal physiology. \r\nIntellectual Merit:\r\nAim 1: Pathogenic agents. Aim 1a: To test the hypothesis that a virus causes the neoplasm. Methods involve isolating and sequencing viral nucleic acids from neoplasms and from unaffected skin and comparing sequences to known viruses. Aim 1b: To test the hypothesis that neoplasms are hosts to parasites not present in healthy skin. Methods include tissue sections and DNA sequencing to find evidence of parasitic organisms. Significance: achieving Aim 1 will narrow down possible etiological agents. An untested possibility is that environmental contaminants cause the condition; exploring that hypothesis would require further sampling outside the limits of an EAGER proposal.\r\nAim 2: Cell-level pathology. Aim 2a: To test the hypothesis that the histopathology of the neoplasms is similar to other known skin neoplasias; alternatively, it might be a previously unknown type of neoplasia. Methods involve the examination of histological sections to identify pathology-specific characters. Aim 2b: To find effects of neoplasms on cell function. Methods involve performing whole-genome transcriptomics of affected and normal skin by RNA-seq and aligning reads to a T. scotti reference genome. Significance: achieving Aim 2 will define the cell biology and gene-expression phenotypes of the neoplasia, thus suggesting mechanisms that cause it.\r\n[Note: NSF deleted funds specifically to achieve the Aim 3, which nevertheless appears here to represent the original proposal.] Aim 3: Organismal pathology. Aim 3a: To test the hypothesis that the neoplasm has adverse effects on growth and physiology. Methods are to perform morphometrics in fish with neoplasms compared to age-matched controls from otolith studies. Aim 3b: To test the hypothesis that the neoplasia affects reproductive traits. Methods compare reproductive effort in affected and unaffected individuals. Significance: if the neoplasia has little consequences on growth and reproduction, our worry about its spread will be lessened, but if it is harmful, then Antarctic ecology, which largely depends on notothenioid fish, might be in danger.\r\nAchieving Aims 1-3 will advance knowledge by identifying the causes of a neoplasia outbreak in Antarctic fish. Work is potentially transformative because it might represent an early sign of Antarctic fish responses to the stress of global climate change. Proposed work would be the first to investigate a neoplasia outbreak in Antarctic fish. We will assess the project\u2019s success by whether we identify a causative agent and its effects on physiology.\r\nBroader Impacts:\r\nAim 4: Publicizing the neoplasia. We aim to raise awareness of the outbreak and publicize its distinct diagnostic features, including assays to detect it, by contributing to groups that track Antarctic ecosystems. \r\nAim 5: Inclusion. We will involve underrepresented groups in scientific research with authentic research experiences.\r\nAchieving Aims 4 and 5 will benefit society because they will disseminate to scientific and lay communities a potential early-warning system for the effects of an apparently new neoplasia affecting, at least locally, a large proportion of a fish population. Dissemination will stir research to determine whether this neoplasia outbreak is an isolated event or is becoming a general phenomenon, and thus a concern for Antarctic ecosystems. Proposed research will enhance research infrastructure by providing tools to identify the neoplasia. Finally, the project will broaden access to research careers by exposing underserved high school students and undergraduates to an exciting live research project.\r\n", "east": -62.3, "geometry": "POINT(-63.8 -64.15)", "instruments": null, "is_usap_dc": true, "keywords": "PROTISTS; BENTHIC; FISH; Dallmann Bay; USAP-DC; Andvord Bay; NSF/USA; AMD/US; AMD; FIELD INVESTIGATION", "locations": "Andvord Bay; Dallmann Bay", "north": -63.3, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Postlethwait, John; Varsani, Arvind; Desvignes, Thomas", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "MorphoSource", "repositories": "GenBank; Other; USAP-DC", "science_programs": null, "south": -65.0, "title": "EAGER: Origin and Physiological Consequences of a Neoplasm Outbreak in Antarctic Fish ", "uid": "p0010221", "west": -65.3}, {"awards": "2032473 Kurbatov, Andrei; 2032463 Talghader, Joseph", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 30 Jun 2021 00:00:00 GMT", "description": "Overview\u003c/br\u003e\nIt is proposed that laser cutting technology can be used to rapidly extract high quality ice samples from borehole walls. The technology applies to both existing boreholes and newly drilled ones, even enabling scientists to obtain samples using non\u2010coring mechanical drills. Since the instrumentation is highly portable, a field team of three persons might take no longer than a few days in the field to extract ice, and samples from a critical time period could be extracted from multiple locations in a single field season.\n\nThis pilot program will investigate and validate the technology of laser sampling. It is beneficial to use fiber optics to convey light in borehole instrumentation rather than attempting to package a complete laser system for travel down a borehole, so the cutting laser and wavelength (1.07Pm) are chosen with such engineering in mind. The primary scientific goals of the program are to: 1) determine optimum cutting conditions in terms of laser power and operating conditions, 2) quantifying the effects of residual meltwater that remain in the cut slot after a cut so that re-cutting needs can be predicted or mitigated, 3) designing and testing mechanical structures to retract samples from blocks of ice once cut, and 4) analyzing the composition and crystal structure of ice near a cut slot to determine the impacted volume (if any) of ice and temperatures where scientific readings might be affected by the sampling process.\n\u003c/br\u003e\u003c/br\u003e\nIntellectual Merits\u003c/br\u003e\nThe collection of deep ice from the Polar Ice Sheets involves large amounts of time, effort, and expense. Often, the most important information is held in very small volumes of core, and while replicate coring can supplement this core, there is often a need to retrieve additional ice samples based on recent scientific findings or borehole logging at a site. In addition, there is currently no easy method of extracting ice from boreholes drilled by non\u2010coring mechanical drills, which are often much faster, lighter, and less expensive to operate. There are numerous specific projects that could immediately benefit from laser sampling including sampling ice overlaying buried impact craters and bolides, filling critical gaps in the chemical record in damaged core sections from Siple Dome, obtaining oldest ice cores from brittle sections near the surface of the Allan Hills blue ice area, where coring drills apply stresses that may fracture the ice, and replacing core whose value has degraded due to time and depressurization. This program builds on a prior engineering advances in optical fiber\u2010based logging technology, developed previously for Siple Dome borehole logging.\n\u003c/br\u003e\u003c/br\u003e\nBroader Impact\u003c/br\u003e\nLaser sampling would advance numerous fields interfaced with glaciology and ice core studies. These include climate and paleoenvironmental science, volcanology, and human history where large volumes of ice are crucial to extract ultra\u2010high resolution records of natural and anthropogenic emissions. Potentially the principle of laser sampling could be used to directly sample and study ice on other planets or their satellites.\nThis program encompasses a broad base of theoretical, experimental, and design work, which makes it ideal for training postdoctoral scientists, graduate students, and advanced undergraduates. The program will include a research opportunity for one or more middle school teachers through a Research Experience for Teachers program with one of the local school districts of the Twin Cities area. The teacher(s) will assist the investigators in the analysis of scattered laser light in glacier ice, and will set up a small experiment at various visible wavelengths to measure scattering constants. These experiments have been chosen because they can easily translate into classroom demonstrations and hands\u2010on activities using eye-safe visible- light LED sources and large samples of artificial ice. The teacher(s) will also produce a lesson plan on basic optics, glacial ice, or polar science as a deliverable.\nThis proposal does not involve field work.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Ice Core; FIELD INVESTIGATION; USA/NSF; AMD; Laser Cutting; AMD/US; SULFATE; OXYGEN COMPOUNDS; USAP-DC; LABORATORY; Sulfate", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Instrumentation and Facilities; Antarctic Instrumentation and Facilities", "paleo_time": null, "persons": "Talghader, Joseph; Kurbatov, Andrei V.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Laser Cutting Technology for Borehole Sampling", "uid": "p0010218", "west": -180.0}, {"awards": "1851022 Fudge, Tyler; 1851094 Baker, Ian", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 28 Jun 2021 00:00:00 GMT", "description": "An accurate constitutive relationship for ice is fundamental to ice-flow models and ice-core interpretations. While Glen\u2019s flow law describes well the overall deformation of ice when subjected to stress, many details remain poorly constrained. In particular, the effect of impurities on the strain rate both directly and through the development of ice fabric is not well understood. Variations in impurity concentrations are associated with variations in deformation rates as observed in both Greenland and Antarctica. The impact of uncertainties on the deformation of ice is most acutely observed in the interpretation of ice cores where the inference of past accumulation rate depends on the cumulative vertical thinning. Thus, many ice-core climate reconstructions, such as the gas-age ice-age difference, surface temperature histories, and aerosol fluxes, are also affected. Given the complexities of the possible impacts of sulfuric acid on the flow of ice and the interaction between these impacts, it seems almost impossible to examine an ice core and understand the impacts of impurities on the microstructural evolution and creep behavior. Our research seeks to understand the effects of sulfuric acid at concentrations applicable to polar ice sheets and relate these results to the flow of polar ice both through experiments and through modeling. Our results have shown that the presence of sulfuric acid in the grain boundaries of polar ice increases its strength in shear, while sulfuric acid in the whole matrix of polar ice reduces its strength. We have also found that sulfuric acid causes an initial increase in average grain sizes and then a subsequent decrease, a trend that differs from the continuous increase in average grain sizes observed in freshwater ice. We are also determining the role of stress state, i.e. simple compression versus shear, on the microstructural evolution and how sulfuric acid impacts this.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "AMD; USA/NSF; USAP-DC; Polycrystalline Ice; EPICA Dome C; LABORATORY; Ice Core; AMD/US; SNOW/ICE", "locations": "EPICA Dome C", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Science and Technology", "paleo_time": null, "persons": "Baker, Ian; Fudge, T. J.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: The Impact of Impurities and Stress State on Polycrystalline Ice Deformation", "uid": "p0010211", "west": null}, {"awards": "1850988 Teets, Nicholas", "bounds_geometry": "POLYGON((-64.366767 -62.68104,-63.9917036 -62.68104,-63.6166402 -62.68104,-63.2415768 -62.68104,-62.8665134 -62.68104,-62.49145 -62.68104,-62.1163866 -62.68104,-61.7413232 -62.68104,-61.3662598 -62.68104,-60.9911964 -62.68104,-60.616133 -62.68104,-60.616133 -62.9537037,-60.616133 -63.2263674,-60.616133 -63.4990311,-60.616133 -63.7716948,-60.616133 -64.0443585,-60.616133 -64.3170222,-60.616133 -64.5896859,-60.616133 -64.8623496,-60.616133 -65.1350133,-60.616133 -65.407677,-60.9911964 -65.407677,-61.3662598 -65.407677,-61.7413232 -65.407677,-62.1163866 -65.407677,-62.49145 -65.407677,-62.8665134 -65.407677,-63.2415768 -65.407677,-63.6166402 -65.407677,-63.9917036 -65.407677,-64.366767 -65.407677,-64.366767 -65.1350133,-64.366767 -64.8623496,-64.366767 -64.5896859,-64.366767 -64.3170222,-64.366767 -64.0443585,-64.366767 -63.7716948,-64.366767 -63.4990311,-64.366767 -63.2263674,-64.366767 -62.9537037,-64.366767 -62.68104))", "dataset_titles": "LMG2002 Expedtition Data", "datasets": [{"dataset_uid": "200222", "doi": "10.7284/908802", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "LMG2002 Expedtition Data", "url": "https://www.rvdata.us/search/cruise/LMG2002"}], "date_created": "Fri, 25 Jun 2021 00:00:00 GMT", "description": "The cold, dry terrestrial environments of Antarctica are inhospitable for insects, and only three midge species make Antarctica home. Of these, Belgica antarctica is the only species found exclusively in Antarctica, and it has been a resident of Antarctica since the continent split from South America ~30 million years ago. Thus, this species is an excellent system to model the biological history of Antarctica throughout its repeated glaciation events and shifts in climate. This insect is also a classic example of extreme adaptation, and much previous work has focused on identifying the genetic and physiological mechanisms that allow this species to survive where no other insect is capable. However, it has been difficult to pinpoint the unique evolutionary adaptations that are required to survive in Antarctica due to a lack of information from closely related Antarctic and sub-Antarctic species. This project will compare adaptations, genome sequences, and population characteristics of four midge species that span an environmental gradient from sub-Antarctic to Antarctic habitats. In addition to B. antarctica, these species include two species that are strictly sub-Antarctic and a third that is native to the sub-Antarctic but has invaded parts of Antarctica. The researchers, comprised of scientists from the US, UK, Chile, and France, will sample insects from across their geographic range and measure their ability to tolerate environmental stressors (i.e., cold and desiccation), quantify molecular responses to stress, and compare the makeup of the genome and patterns of genetic diversity. This research will contribute to a greater understanding of adaptation to extremes, to an understanding of biodiversity on the planet and to understanding and predicting changes accompanying environmental change. The project will train two graduate students and two postdoctoral researchers, and a K-12 educator will be a member of the field team and will assist with fieldwork and facilitate outreach with schools in the US. The project includes partnership activities with several STEM education organizations to deliver educational content to K-12 and secondary students. This is a project that is jointly funded by the National Science Foundation\u0027s Directorate of Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Each Agency funds the proportion of the budget and the investigators associated with its own country. UK participation in this project includes deploying scientists as part of the field team, supporting field and sampling logistics at remote Antarctic sites, and genome sequencing, annotation, and analyses.\r\n\r\nThis project focuses on the key physiological adaptations and molecular processes that allow a select few insect species to survive in Antarctica. The focal species are all wingless with limited dispersal capacity, suggesting there is also significant potential to locally adapt to variable environmental conditions across the range of these species. The central hypothesis is that similar molecular mechanisms drive both population-level adaptation to local environmental conditions and macroevolutionary changes across species living in different environments. The specific aims of the project are to 1) Characterize conserved and species-specific adaptations to extreme environments through comparative physiology and transcriptomics, 2) Compare the genome sequences of these species to identify genetic signatures of extreme adaption, and 3) Investigate patterns of diversification and local adaptation across each species? range using population genomics. The project establishes an international collaboration of researchers from the US, UK, Chile, and France with shared interests and complementary expertise in the biology, genomics, and conservation of Antarctic arthropods. The Broader Impacts of the project include training students and partnering with the Living Arts and Science Center to design and implement educational content for K-12 students.\r\n\r\nThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -60.616133, "geometry": "POINT(-62.49145 -64.0443585)", "instruments": null, "is_usap_dc": true, "keywords": "R/V LMG; Antarctic Peninsula; Livingston Island; AMD/US; Antarctica; USA/NSF; ARTHROPODS; USAP-DC; AMD; Anvers Island", "locations": "Antarctica; Antarctic Peninsula; Anvers Island; Livingston Island", "north": -62.68104, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Teets, Nicholas; Michel, Andrew", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "Other", "science_programs": null, "south": -65.407677, "title": "NSFGEO-NERC: Mechanisms of Adaptation to Terrestrial Antarctica through Comparative Physiology and Genomics of Antarctic and sub-Antarctic Insects", "uid": "p0010203", "west": -64.366767}, {"awards": "1643120 Iverson, Neal", "bounds_geometry": null, "dataset_titles": "Ice permeameter experimental parameters and results; Softening of temperate ice by interstitial water", "datasets": [{"dataset_uid": "601460", "doi": "10.15784/601460", "keywords": "Antarctica; Cryosphere; Glaciers/Ice Sheet; Glaciology; Ice Streams; lab experiment; Rheology; Snow/Ice; Water Content", "people": "Iverson, Neal", "repository": "USAP-DC", "science_program": null, "title": "Softening of temperate ice by interstitial water", "url": "https://www.usap-dc.org/view/dataset/601460"}, {"dataset_uid": "601515", "doi": "10.15784/601515", "keywords": "Antarctica; Cryosphere; Glacier Flow; Glacier Hydrology; Glaciological Instruments And Methods; Glaciology; Ice Physics; Ice Streams; Snow/Ice", "people": "Iverson, Neal; Fowler, Jacob", "repository": "USAP-DC", "science_program": null, "title": "Ice permeameter experimental parameters and results", "url": "https://www.usap-dc.org/view/dataset/601515"}], "date_created": "Wed, 23 Jun 2021 00:00:00 GMT", "description": "This award supports a project to study the effect of liquid, intercrystalline water on the flow resistance of ice and the mobility of this water within ice. Water plays a central role in the flow of ice streams. It lubricates their bases and softens their margins, where flow speeds abruptly transition from rapid to slow. Within ice stream margins some ice is \"temperate,\u201d meaning that it is at its pressure-melting temperature with relatively thick water films at grain boundaries that significantly soften the ice. The amount of water in ice depends sensitively on its permeability, values of which are too poorly known to estimate the water contents of ice-stream shear margins or associated ice viscosities.\n \n\nThis award stems from the NSF/GEO-UK NERC lead agency opportunity (NSF 14-118) and is a collaboration between Iowa State University and Oxford University in the United Kingdom. The experimental part of the project is executed at Iowa State University and is the focus herein because it has been supported by NSF. Two sets of experiments are conducted. In one set, a large ring-shear device is used to shear ice in confined compression and at its melting temperature to study the sensitivity of ice viscosity to water content. Ice is sheared at stresses and strain rates comparable to those of ice-stream margins, and water content is varied through twice the range explored in the only previous set of experiments that investigated ice softening by water. The second set of experiments required the design, fabrication, and testing of a laboratory ice permeameter that allows the permeability of temperate ice to be measured. Experiments are conducted to study the dependence of ice permeability on ice grain size and water content--the two dependencies required to model grain-scale water flow through temperate ice.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "GLACIER MOTION/ICE SHEET MOTION; USA/NSF; AMD; Iowa State University; AMD/US; USAP-DC; LABORATORY; Magmatic Volatiles", "locations": "Iowa State University", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Iverson, Neal; Zoet, Lucas", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "NSFGEO-NERC: Collaborative Research: Two-Phase Dynamics of Temperate Ice", "uid": "p0010197", "west": null}, {"awards": "1848887 McClintock, James", "bounds_geometry": "POINT(-64.0527 -64.77423)", "dataset_titles": null, "datasets": null, "date_created": "Mon, 21 Jun 2021 00:00:00 GMT", "description": "Undersea forests of seaweeds dominate the shallow waters of the central and northern coast of the western Antarctic Peninsula and provide critical structural habitat and carbon resources (food) for a host of marine organisms. Most of the seaweeds are chemically defended against herbivores yet support very high densities of herbivorous shrimp-like grazers (crustaceans, primarily amphipods) which greatly benefit their hosts by consuming filamentous and microscopic algae that otherwise overgrow the seaweeds. The amphipods benefit from the association with the chemically defended seaweeds by gaining an associational refuge from fish predation. The project builds on recent work that has demonstrated that several species of amphipods that are key members of crustacean assemblages associated with the seaweeds suffer significant mortality when chronically exposed to increased seawater acidity (reduced pH) and elevated temperatures representative of near-future oceans. By simulating these environmental conditions in the laboratory at Palmer Station, Antarctica, the investigators will test the overall hypothesis that ocean acidification will play a significant role in structuring crustacean assemblages associated with seaweeds. Broader impacts include expanding fundamental knowledge of the impacts of global climate change by focusing on a geographic region of the earth uniquely susceptible to climate change. This project will also further the NSF goals of training new generations of scientists and of making scientific discoveries available to the general public. This includes training graduate students and early career scientists with an emphasis on diversity, presentations to K-12 groups and the general public, and a variety of social media-based outreach programs.\r\n\r\nThe project will compare population and assemblage-wide impacts of natural (ambient) and carbon dioxide enriched seawater on assemblages of seaweed-associated crustacean grazers. Based on prior results, it is likely that some species will be relative \"winners\" and some will be relative \"losers\" under the changed conditions. The project will then aim to carry out measurements of growth, calcification, mineralogy, the incidence of molts, and biochemical and energetic body composition for two key amphipod \"winners\" and two key amphipod \"losers\". These measurements will allow an assessment of what factors drive species-specific enhanced or diminished performance under conditions of ocean acidification and sea surface warming. The project will expand on what little is known about prospective impacts of changing conditions on benthic marine Crustacea, in Antarctica, a taxonomic group that faces the additional physiological stressor of molting. The project is likely to provide additional insight on the indirect regulation of the seaweeds that comprise Antarctic undersea forests that provide key architectural components of the coastal marine ecosystem.", "east": -64.0527, "geometry": "POINT(-64.0527 -64.77423)", "instruments": null, "is_usap_dc": true, "keywords": "AMD/US; COASTAL; USA/NSF; BENTHIC; USAP-DC; Palmer Station; ANIMALS/INVERTEBRATES; AMD; FIELD INVESTIGATION; MACROALGAE (SEAWEEDS)", "locations": "Palmer Station", "north": -64.77423, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Amsler, Charles; McClintock, James", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": -64.77423, "title": "Assemblage-wide effects of ocean acidification and ocean warming on ecologically important macroalgal-associated crustaceans in Antarctica", "uid": "p0010193", "west": -64.0527}, {"awards": "1245871 McCarthy, Christine", "bounds_geometry": null, "dataset_titles": "Dataset for Tidal modulation of ice streams: Effect of periodic sliding velocity on ice friction and healing; Rate-state friction parameters for ice-on-rock oscillation experiments; RSFitOSC", "datasets": [{"dataset_uid": "200237", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "RSFitOSC", "url": "https://github.com/rmskarbek/RSFitOSC"}, {"dataset_uid": "601467", "doi": "10.15784/601467", "keywords": "Antarctica; Cryosphere", "people": "McCarthy, Christine M.; Skarbek, Rob; Savage, Heather", "repository": "USAP-DC", "science_program": null, "title": "Rate-state friction parameters for ice-on-rock oscillation experiments", "url": "https://www.usap-dc.org/view/dataset/601467"}, {"dataset_uid": "601497", "doi": "10.15784/601497", "keywords": "Antarctica; Cryosphere", "people": "Skarbek, Rob; McCarthy, Christine M.; Savage, Heather", "repository": "USAP-DC", "science_program": null, "title": "Dataset for Tidal modulation of ice streams: Effect of periodic sliding velocity on ice friction and healing", "url": "https://www.usap-dc.org/view/dataset/601497"}], "date_created": "Fri, 04 Jun 2021 00:00:00 GMT", "description": "This award supports a project to conduct laboratory experiments with a new, custom-fabricated cryo-friction apparatus to explore ice deformation oscillatory stresses like those experienced by tidewater glaciers in nature. The experimental design will explore the dynamic frictional properties of periodically loaded ice sliding on rock. Although the frictional strength of ice has been studied in the past these studies have all focused on constant rates of loading and sliding. The results of this work will advance understanding of ice stream dynamics by improving constraints on key material and frictional properties and allowing physics-based predictions of the amplitude and phase of glacier strain due to tidally induced stress variations. The intellectual merit of this work is that it will result in a better understanding of dynamic rheological parameters and will provide better predictive tools for dynamic glacier flow. The proposed experiments will provide dynamic material properties of ice and rock deformation at realistic frequencies experienced by Antarctic glaciers. The PIs will measure the full spectrum of material response from elastic to anelastic to viscous. The study will provide better constraints to improve predictive capability for glacier and ice-stream response to external forcing. The broader impacts of the work include providing estimates of material properties that can be used to broaden our understanding of glacier flow and that will ultimately be used for models of sea level rise and ice sheet stability. The ability to predict sea level in the near future is contingent on understanding of the processes responsible for flow of Antarctic ice streams and glaciers. Modulation of glacier flow by ocean tides represents a natural experiment that can be used to improve knowledge of ice and bed properties, and of the way in which these properties depend on time-varying forcings. Presently, the influence of tidal forcing on glacier movement is poorly understood, and knowledge of ice properties under tidal loading conditions is limited. The study will generate results of interest beyond polar science by examining phenomena that are of interest to seismology, glaciology and general materials science. The project will provide valuable research and laboratory experience for two undergraduate interns and will provide experience for the PI (currently a postdoc) in leading a scientific project. The three PIs are early career scientists. This proposal does not require fieldwork in the Antarctic.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; USA/NSF; Ice Deformation; AMD; AMD/US; LABORATORY; BASAL SHEAR STRESS", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "McCarthy, Christine M.; Savage, Heather", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "GitHub", "repositories": "Other; USAP-DC", "science_programs": null, "south": null, "title": "Laboratory Study of Ice Deformation under Tidal Loading Conditions with Application to Antarctic Glaciers", "uid": "p0010186", "west": null}, {"awards": "1935438 McCarthy, Christine", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 03 Jun 2021 00:00:00 GMT", "description": "The ice sheets of Antarctica and Greenland are losing mass and contributing to accelerating global sea-level rise. Satellite altimetry provides precise measurement of ice-sheet volume change, but computing ice-sheet mass change the quantity relevant for estimating the ice sheets sea-level contribution requires knowing the density of the ice sheet. The density near the ice-sheet surface also affects age estimates of air bubbles recovered in ice cores, which are a key source of information on past climate changes. Ice-sheet density is primarily controlled by the rate at which firn (snow that has persisted for a year or more on ice sheets) compacts into ice, but there is currently no widely accepted theory of how this compaction occurs. The goal of this project is thus to advance understanding of how firn densifies. The team will conduct laboratory experiments and analyze ice-penetrating radar and ice-core data from Antarctica. A key desired outcome of the project is a new model of firn densification that can be used to improve satellite-based altimetry measurements of present-day ice-sheet change and reconstructions of past climate changes from ice cores.\r\n\r\nThis project will combine laboratory experiments, numerical modeling, and geophysical techniques to determine the rheology of firn as it compacts to form ice. The team will use two methods to measure firn compaction: (1) lab-based experiments and (2) analysis of ice-core and radar data. For the lab-based work, the team will conduct a suite of compaction experiments on synthetic firn samples under uni-axial strain and constant temperature and axial stress. They will also measure the grain-size evolution. By running a large number of experiments (\u003e 25), the team will constrain key parameters that determine how firn compaction rate depends on density, temperature, grain size, and axial stress. The experiments will be conducted in a table-top apparatus at temperatures as low as -40 degrees C and axial stresses up to 4 MPa. For the field-data-based component, the team will analyze ice-core and ice-penetrating radar data to produce the first coincident set of radar-derived firn compaction rates, borehole temperatures, firn densities, and firn grain sizes. Results from lab and field data will be tied together using a numerical firn compaction model. This model is formulated using conservation of mass, momentum, and energy, along with an explicit description of firn rheology and grain-size evolution. Constraints on firn rheology will be incorporated into this model and the team will use it to examine fundamental questions about how changes in the climate affect firn density. This is a crucial unknown that contributes significant measurement uncertainty in estimates of past and present climate change.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "AMD; LABORATORY; USA/NSF; COMPUTERS; AMD/US; USAP-DC; FIRN; Antarctic Ice Sheet", "locations": "Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Arctic Natural Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "McCarthy, Christine M.; Kingslake, Jonathan", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "Understanding Firn Rheology Through Laboratory Compaction Experiments and Radar Data", "uid": "p0010185", "west": null}, {"awards": "1543286 Walter, Jacob; 1543399 Peng, Zhigang; 1745135 Walter, Jacob", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 19 May 2021 00:00:00 GMT", "description": "The continent of Antarctica has approximately the same surface area as the continental United States, though we know significantly less about its underlying geology and seismic activity. Multinational investments in geophysical infrastructure over the last few decades, especially broadband seismometers operating for several years, are allowing us to observe many interesting natural phenomena, including iceberg calving, ice stream slip, and tectonic earthquakes. To specifically leverage those past investments, we will analyze past and current data to gain a better understanding of Antarctic seismicity. Our recent research revealed that certain large earthquakes occurring elsewhere in the world triggered ice movement near various stations throughout Antarctica. We plan to conduct an exhaustive search of the terabytes of available data, using cutting-edge computational techniques, to uncover additional evidence for ice crevassing, ice stream slip, and earth movement during earthquakes. One specific focus of our research will include investigating whether some of these phenomena may be triggered by external influences, including passing surface waves from distant earthquakes, ocean tides, or seasonal melt. We plan to produce a catalog of the identified activity and share it publicly, so the public and researchers can easily access it. To reach a broader audience, we will present talks to high school classes, including Advanced Placement classes, in the Austin, Texas and Atlanta, Georgia metropolitan areas with emphasis on general aspects of seismic hazard, climate variability, and the geographies of Antarctica. This project will provide research opportunities for undergraduates, training for graduate students, and support for an early-career scientist.\r\n\r\nIn recent years, a new generation of geodetic and seismic instrumentation has been deployed as permanent stations throughout Antarctica (POLENET), in addition to stations deployed for shorter duration (less than 3 years) experiments (e.g. AGAP/TAMSEIS). These efforts are providing critical infrastructure needed to address fundamental questions about both crustal-scale tectonic structures and ice sheets, and their interactions. We plan to conduct a systematic detection of tectonic and icequake activities in Antarctica, focusing primarily on background seismicity, remotely-triggered seismicity, and glacier slip events. Our proposed tasks include: (1) Identification of seismicity throughout the Antarctic continent for both tectonic and ice sources. (2) An exhaustive search for additional triggered events in Antarctica during the last ~15 years of global significant earthquakes. (3) Determination of triggered source mechanisms and whether those triggered events also occur at other times, by analyzing years of data using a matched-filter analysis (where the triggered local event is used to detect similar events). (4) Further analysis of GPS measurements over a ~5.5 year period from Whillans Ice Plain, which suggests that triggering of stick-slip events occurred after the largest earthquakes. An improved knowledge of how the Antarctic ice sheet responds to external perturbations such as dynamic stresses from large distant earthquakes and recent ice unloading could lead to a better understanding of ice failure and related dynamic processes. By leveraging the vast logistical investment to install seismometers in Antarctica over the last decade, our project will build an exhaustive catalog of tectonic earthquakes, icequakes, calving events, and any other detectable near-surface seismic phenomena.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; USAP-DC; Antarctica; GLACIERS/ICE SHEETS; USA/NSF; SEISMOLOGICAL STATIONS; TECTONICS; AMD/US", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Walter, Jacob; Peng, Zhigang", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e SEISMOLOGICAL STATIONS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Triggering of Antarctic Icequakes, Slip Events, and other Tectonic Phenomena by Distant Earthquakes", "uid": "p0010182", "west": -180.0}, {"awards": "1246416 Stephen, Ralph; 1246151 Bromirski, Peter", "bounds_geometry": "POLYGON((-180 -77,-179.5 -77,-179 -77,-178.5 -77,-178 -77,-177.5 -77,-177 -77,-176.5 -77,-176 -77,-175.5 -77,-175 -77,-175 -77.4,-175 -77.8,-175 -78.2,-175 -78.6,-175 -79,-175 -79.4,-175 -79.8,-175 -80.2,-175 -80.6,-175 -81,-175.5 -81,-176 -81,-176.5 -81,-177 -81,-177.5 -81,-178 -81,-178.5 -81,-179 -81,-179.5 -81,180 -81,179 -81,178 -81,177 -81,176 -81,175 -81,174 -81,173 -81,172 -81,171 -81,170 -81,170 -80.6,170 -80.2,170 -79.8,170 -79.4,170 -79,170 -78.6,170 -78.2,170 -77.8,170 -77.4,170 -77,171 -77,172 -77,173 -77,174 -77,175 -77,176 -77,177 -77,178 -77,179 -77,-180 -77))", "dataset_titles": "Collaborative Research: Dynamic Response of the Ross Ice Shelf to Wave-Induced Vibrations and Collaborative Research: Mantle Structure and Dynamics of the Ross Sea from a Passive Seismic Deployment on the Ross Ice Shelf. International Federation of Digital Seismograph Networks. ; Dynamic Response of the Ross Ice Shelf to Wave-induced Vibrations 2015/2016, UNAVCO, Inc., GPS/GNSS Observations Dataset", "datasets": [{"dataset_uid": "200207", "doi": "10.7914/SN/XH_2014", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Collaborative Research: Dynamic Response of the Ross Ice Shelf to Wave-Induced Vibrations and Collaborative Research: Mantle Structure and Dynamics of the Ross Sea from a Passive Seismic Deployment on the Ross Ice Shelf. International Federation of Digital Seismograph Networks. ", "url": "http://www.fdsn.org/networks/detail/XH_2014/"}, {"dataset_uid": "200209", "doi": "10.7283/58E3-GA46", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Dynamic Response of the Ross Ice Shelf to Wave-induced Vibrations 2015/2016, UNAVCO, Inc., GPS/GNSS Observations Dataset", "url": "https://doi.org/10.7283/58E3-GA46"}], "date_created": "Thu, 15 Apr 2021 00:00:00 GMT", "description": "This award supports a project intended to discover, through field observations and numerical simulations, how ocean wave-induced vibrations on ice shelves in general, and the Ross Ice Shelf (RIS), in particular, can be used (1) to infer spatial and temporal variability of ice shelf mechanical properties, (2) to infer bulk elastic properties from signal propagation characteristics, and (3) to determine whether the RIS response to infragravity (IG) wave forcing observed distant from the front propagates as stress waves from the front or is \"locally\" generated by IG wave energy penetrating the RIS cavity. The intellectual merit of the work is that ocean gravity waves are dynamic elements of the global ocean environment, affected by ocean warming and changes in ocean and atmospheric circulation patterns. Their evolution may thus drive changes in ice-shelf stability by both mechanical interactions, and potentially increased basal melting, which in turn feed back on sea level rise. Gravity wave-induced signal propagation across ice shelves depends on ice shelf and sub-shelf water cavity geometry (e.g. structure, thickness, crevasse density and orientation), as well as ice shelf physical properties. Emphasis will be placed on observation and modeling of the RIS response to IG wave forcing at periods from 75 to 300 s. Because IG waves are not appreciably damped by sea ice, seasonal monitoring will give insights into the year-round RIS response to this oceanographic forcing. The 3-year project will involve a 24-month period of continuous data collection spanning two annual cycles on the RIS. RIS ice-front array coverage overlaps with a synergistic Ross Sea Mantle Structure (RSMS) study, giving an expanded array beneficial for IG wave localization. The ice-shelf deployment will consist of sixteen stations equipped with broadband seismometers and barometers. Three seismic stations near the RIS front will provide reference response/forcing functions, and measure the variability of the response across the front. A linear seismic array orthogonal to the front will consist of three stations in-line with three RSMS stations. Passive seismic array monitoring will be used to determine the spatial and temporal distribution of ocean wave-induced signal sources along the front of the RIS and estimate ice shelf structure, with the high-density array used to monitor and localize fracture (icequake) activity. The broader impacts include providing baseline measurements to enable detection of ice-shelf changes over coming decades which will help scientists and policy-makers respond to the socio-environmental challenges of climate change and sea-level rise. A postdoctoral scholar in interdisciplinary Earth science will be involved throughout the course of the research. Students at Cuyamaca Community College, San Diego County, will develop and manage a web site for the project to be used as a teaching tool for earth science and oceanography classes, with development of an associated web site on waves for middle school students.\n\r\nUnderstanding and being able to anticipate changes in the glaciological regime of the Ross Ice Shelf (RIS) and West Antarctic Ice Sheet (WAIS) are key to improving sea level rise projections due to ongoing ice mass loss in West Antarctica. The fate of the WAIS is a first-order climate change and global societal issue for this century and beyond that affects coastal communities and coastal infrastructure globally. \r\n\r\nIce shelf--ocean interactions include impacts from tsunami, ocean swell (10-30s period), and very long period ocean waves that impact ice shelves and produce vibrations that induce a variety of seismic signals detected by seismometers buried in the ice shelf surface layer, called firn. To study the wave-induced vibrations in the RIS, an extensive seismic array was deployed from Nov. 2014 to Nov. 2016. This unique seismometer array deployment on an ice shelf made continuous observations of the response of the RIS to ocean wave impacts from ocean swell and very long period waves. An extensive description of the project motivation and background (including photos and videos of the deployment operations), and list of published studies of analyses of the seismic data collected by this project, are available at the project website https://iceshelfvibes.ucsd.edu. \r\n\r\nTwo types of seismic signals detected by the seismic array are most prevalent: flexural gravity waves (plate waves) and icequakes (signals analogous to those from earthquakes but from fracturing of the ice). \r\nLong period ocean waves flex the ice shelf at the same period as the ocean waves, with wave energy at periods greater than ocean swell more efficient at coupling energy into flexing the ice shelf. Termed flexural gravity waves or plate waves (Chen et al., 2018), their wave-induced vibrations can reach 100\u2019s of km from the ice edge where they are excited, with long period wave energy propagating in the water layer below the shelf coupled with the ice shelf flexure. Flexural gravity waves at very long periods (\u003e 300 s period), such as from tsunami impacts (Bromirski et al., 2017), can readily reach grounding zones and may play a role in long-term grounding zone evolution. \r\nSwell-induced icequake activity was found to be most prevalent at the shelf front during the austral summer (January \u2013 March) when seasonal sea ice is absent and the associated damping of swell by sea ice is minimal (Chen et al., 2019). \r\n\r\nIn addition to the seismic array, a 14 station GPS (global positioning system) array was installed during seismic data retrieval and station servicing operations in October-November 2015. The GPS stations, co-located with seismic stations, extended from the shelf front southward to about 415 km at interior station RS18. Due to logistical constraints associated with battery weight during installation, only one station (at DR10) operated year-round. The GPS data collected give a detailed record of changes in iceflow velocity that are in close agreement with the increasing velocity estimates approaching the shelf front from satellite observations. Importantly, the year-round data at DR10 show an unprecedented seasonal cycle of changes in iceflow velocity, with a speed-up in northward (seaward) ice flow during Jan.-May and then a velocity decrease from June-Sep. (returning to the long-term mean flow velocity). This annual ice flow velocity change cycle has been attributed in part to seasonal changes in ice shelf mass (thinning, reducing buttressing) due to melting at the RIS basal (bottom) surface from intrusion of warmer ocean water (Klein et al., 2020). ", "east": 170.0, "geometry": "POINT(177.5 -79)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "USAP-DC; AMD; USA/NSF; AMD/US; IRIS; FIELD INVESTIGATION; GLACIER MOTION/ICE SHEET MOTION; Ross Ice Shelf", "locations": "Ross Ice Shelf", "north": -77.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Bromirski, Peter; Gerstoft, Peter; Stephen, Ralph", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "IRIS", "repositories": "IRIS; UNAVCO", "science_programs": null, "south": -81.0, "title": "Collaborative Research: Dynamic Response of the Ross Ice Shelf to Wave-induced Vibrations", "uid": "p0010169", "west": -175.0}, {"awards": "1842021 Campbell, Seth", "bounds_geometry": "POLYGON((-168 -82,-162.3 -82,-156.6 -82,-150.9 -82,-145.2 -82,-139.5 -82,-133.8 -82,-128.1 -82,-122.4 -82,-116.7 -82,-111 -82,-111 -82.5,-111 -83,-111 -83.5,-111 -84,-111 -84.5,-111 -85,-111 -85.5,-111 -86,-111 -86.5,-111 -87,-116.7 -87,-122.4 -87,-128.1 -87,-133.8 -87,-139.5 -87,-145.2 -87,-150.9 -87,-156.6 -87,-162.3 -87,-168 -87,-168 -86.5,-168 -86,-168 -85.5,-168 -85,-168 -84.5,-168 -84,-168 -83.5,-168 -83,-168 -82.5,-168 -82))", "dataset_titles": "2017 GPR Observations of the Whillans and Mercer Ice Streams; Whillans and Mercer Shear Margin Ice Flow simulation in ISSM", "datasets": [{"dataset_uid": "601404", "doi": "10.15784/601404", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Sheet Flow Model; Ice Shelf Dynamics; Mercer Ice Stream; Model Data; Snow/Ice; Whillans Ice Stream", "people": "Kaluzienski, Lynn", "repository": "USAP-DC", "science_program": null, "title": "Whillans and Mercer Shear Margin Ice Flow simulation in ISSM", "url": "https://www.usap-dc.org/view/dataset/601404"}, {"dataset_uid": "601403", "doi": "10.15784/601403", "keywords": "Antarctica; Crevasses; Cryosphere; Glaciology; GPR; GPS; Ice Sheet Flow Model; Ice Shelf Dynamics; Snow/Ice; Whillans Ice Stream", "people": "Kaluzienski, Lynn", "repository": "USAP-DC", "science_program": null, "title": "2017 GPR Observations of the Whillans and Mercer Ice Streams", "url": "https://www.usap-dc.org/view/dataset/601403"}], "date_created": "Mon, 14 Dec 2020 00:00:00 GMT", "description": "The Siple Coast in West Antarctica has undergone significant glacier changes over the last millenium. Several ice streams--rapidly moving streams of ice bordered by slow-moving ice--exist in this region that feeds into the Ross Ice Shelf. A long-term slowdown of Whillans Ice Stream appears to be occurring, and this is affecting the zone between the Whillans and Mercer Ice Streams. However, the consistency of this slowdown and resulting changes to the shear margin between the two ice streams are unknown. Shear zone stability represents a potentially critical control on mass balance of ice sheets, especially in regions of fast ice flow where basal shear stress is minimal. This project is therefore focused on understanding the spatial and temporal change of ice flow kinematics, shear margin structure, and shear margin location between Whillans and Mercer Ice Streams. A collateral benefit of and driver for this as a RAPID project is to test a method for assessing where crevassing will develop in this zone of steep velocity gradients. Such a method may benefit not only near-term field-project planning in the 2018-19 field season, but also planning for future fieldwork and traverses.\u003cbr/\u003e\u003cbr/\u003eThe team will use velocity estimates derived from available remote sensing datasets to determine transient velocity patterns and shifts in the shear-zone location over the last 20 years. This velocity time series will be incorporated into a large-scale ice-sheet model to estimate ice-sheet susceptibility to changing boundary conditions over the next century based on likely regional ice-flux scenarios. This approach is an extension of recent work conducted by the team that shows promise for predicting areas of changing high strain rates indicative of an active glacier shear margin. The ultimate objectives are to characterize the flow field of merging ice streams over time and investigate lateral boundary migration. This will provide a better understanding of shear-margin control on ice-shelf and up-glacier stability.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -111.0, "geometry": "POINT(-139.5 -84.5)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "FIELD SURVEYS; USA/NSF; Whillans Ice Stream; GLACIER MOTION/ICE SHEET MOTION; USAP-DC; AMD/US; MODELS; AMD", "locations": "Whillans Ice Stream", "north": -82.0, "nsf_funding_programs": "Antarctic Glaciology; Polar Special Initiatives", "paleo_time": null, "persons": "Campbell, Seth; Koons, Peter", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e MODELS \u003e MODELS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.0, "title": "RAPID Proposal: Constraining kinematics of the Whillans/Mercer Ice Stream Confluence", "uid": "p0010145", "west": -168.0}, {"awards": "1141411 Baker, Ian", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Laboratory Experiments with H2SO4-Doped Ice; The Effects of Soluble Impurities on the Flow and Fabric of Polycrystalline Ice", "datasets": [{"dataset_uid": "601081", "doi": "10.15784/601081", "keywords": null, "people": "Hammonds, Kevin", "repository": "USAP-DC", "science_program": null, "title": "Laboratory Experiments with H2SO4-Doped Ice", "url": "https://www.usap-dc.org/view/dataset/601081"}, {"dataset_uid": "600380", "doi": "10.15784/600380", "keywords": "Antarctica; Cryosphere; Glaciers/Ice Sheet; Glaciology; Ice; Physical Properties; Snow", "people": "Baker, Ian", "repository": "USAP-DC", "science_program": null, "title": "The Effects of Soluble Impurities on the Flow and Fabric of Polycrystalline Ice", "url": "https://www.usap-dc.org/view/dataset/600380"}], "date_created": "Fri, 09 Oct 2020 00:00:00 GMT", "description": "This award supports a project to undertake a systematic examination of the effects of soluble impurities, particularly sulfuric acid, on the creep of polycrystalline ice as function of temperature, strain rate and impurity concentration. The working hypothesis is that soluble impurities will increase the flow rate of polycrystalline ice compared to high-purity ice, that this effect will be temperature dependent and that the impurities by affecting the re-crystallization and grain growth will change the fabric of the ice. Both H2SO4-doped and high-purity poly-crystalline ice will be produced by freezing sheets of ice, breaking them up, sieving the ice particles and then sintering them in a mold into fine-grained cylindrical specimens with at least ten grains across their diameter. The resulting microstructures (dislocation structure, grain size and shape, grain boundary character and micro-structural location of the acid) will be characterized using a variety of techniques including: optical microscopy, scanning electron microscopy, including secondary electron imaging, electron backscattered patterns, energy dispersive X-ray spectroscopy, electron channeling contrast imaging, and X-ray topography. The creep of both the H2SO4-doped and the high-purity polycrystalline ice will be undertaken at a range of temperatures and stresses. The ice?s response to the creep deformation (grain boundary sliding, dislocation motion, re-crystallization, grain boundary migration, impurity redistribution) will be studied using a combination of methods. The creep behavior will be modeled and related to the microstructure. Of particular interest is how impurities affect the activation energy for creep. The intellectual merit of the work is that it will lead to a better understanding of glacier ice and will enable glaciologists to model the influence of impurities on the flow and fabric development in polycrystalline ice. The broader impacts of the project include the knowledge that will be gained of the effects of impurities on the flow of ice which will allow paleoclimatologists to better interpret ice core data and will allow scientists developing predictive models to better address the flow of ice sheets under various climate change scenarios. The project will also lead to the education and training of a Ph.D. student, several undergraduates and some high school students. Results from the research will be published in refereed journals. Several undergraduates, typically two per year, will also perform the work. Dartmouth aggressively courts minority students at all degree levels, and we will seek women or minority group undergraduates for this project. The undergraduates will be supported by Dartmouth?s nationally-honored Women In Science Project or by REU funding. The undergraduates? research will integrate closely with the Ph.D. student?s studies. Hanover High School students will also be involved in the project and develop an educational kit to introduce students to the properties of ice. Results from the research will be published in refereed journals and presented at conferences.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; LABORATORY; AMD/US; Antarctica; USAP-DC; SNOW/ICE; AMD", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Baker, Ian", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "The Effects of Soluble Impurities on the Flow and Fabric of Polycrystalline Ice", "uid": "p0010133", "west": -180.0}, {"awards": "1542885 Dunham, Eric", "bounds_geometry": null, "dataset_titles": "Earthquake Sequence Dynamics at the Interface Between an Elastic Layer and Underlying Half-Space in Antiplane Shear", "datasets": [{"dataset_uid": "601320", "doi": "10.15784/601320", "keywords": "Antarctica; Computer Model; Cryosphere; Glaciology; Model Data; Shear Stress; Solid Earth; Whillans Ice Stream", "people": "Abrahams, Lauren", "repository": "USAP-DC", "science_program": null, "title": "Earthquake Sequence Dynamics at the Interface Between an Elastic Layer and Underlying Half-Space in Antiplane Shear", "url": "https://www.usap-dc.org/view/dataset/601320"}], "date_created": "Fri, 09 Oct 2020 00:00:00 GMT", "description": "This project investigates a rapidly moving section of the West Antarctic Ice Sheet known as the Whillans Ice Stream. Ice streams and outlet glaciers are the major pathways for ice discharge from ice sheets into the ocean. Consequently, understanding ice stream dynamics, specifically the processes controlling the frictional resistance of ice sliding on sediments at its base, is essential for predictive modeling of how Earth\u0027s ice sheets will respond to a changing climate. Rather than flowing smoothly, Whillans Ice Stream advances in stick-slip cycles: brief periods of rapid sliding, equivalent to magnitude 7 earthquakes, alternating with much longer periods of repose. The PIs will perform simulations of these stick-slip cycles using computer codes originally developed for modeling tectonic earthquakes. By matching observed ice motions, the PIs will constrain the range of frictional processes acting at the base of the ice stream. An additional focus of the project is on brittle fracture processes in ice, expressed through seismic waves radiated by faulting and/or crevassing episodes that accompany the large-scale sliding events. An understanding of ice fracture provides a basis for assessing the susceptibility of ice shelves to rifting and catastrophic disintegration. Project results will be incorporated into outreach activities (from elementary school to community college events) as well as a polar science class for the California State Summer School for Mathematics and Science (COSMOS) program for high school students.\u003cbr/\u003e\u003cbr/\u003eSimulations of the stick-slip cycle will employ 3D dynamic rupture models that simultaneously solve for the seismic wavefield and rupture process, consistent with elastodynamic material response and friction laws on the ice stream bed. Stresses and frictional properties will be varied to achieve consistency with surface GPS and broadband seismic data as well as borehole seismograms from the WISSARD project. The results will be interpreted using laboratory till friction experiments, which link velocity-weakening/strengthening behavior to temperature and water content, and to related experiments quantifying basal drag from ice flow over rough beds. The source mechanism of seismicity accompanying the slip events (shear faulting versus crevassing) will be determined using 3D waveform modeling in conjunction with mechanical models of the seismic source processes. This proposal does not require fieldwork in the Antarctic.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOGRAPHS", "is_usap_dc": true, "keywords": "SEISMIC PROFILE; GROUND-BASED OBSERVATIONS; USA/NSF; USAP-DC; AMD; AMD/US; Antarctica", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Dunham, Eric", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Characterizing Brittle Failure and Fracture Propagation in Fast Ice Sliding with Dynamic Rupture Models based on Whillans Ice Stream Seismic/Geodetic Data", "uid": "p0010138", "west": null}, {"awards": "1543328 Van Mooy, Benjamin", "bounds_geometry": null, "dataset_titles": "Lipidomics of Antarctic waters. (TBD)", "datasets": [{"dataset_uid": "200149", "doi": "TBD", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Lipidomics of Antarctic waters. (TBD)", "url": "https://www.bco-dmo.org/data"}], "date_created": "Fri, 19 Jun 2020 00:00:00 GMT", "description": "The depletion of stratospheric ozone over Antarctica leads to abnormally high levels of ultraviolet radiation (UVR) from the sun reaching the surface of the ocean. This phenomenon is predicted to continue for the next half century, despite bans on ozone-destroying pollutants. Phytoplankton in the near surface ocean are subjected to variable amounts of UVR and contain a lot of lipids (fats). Because phytoplankton are at the base of the food chain their lipids makes their way into the Antarctic marine ecosystem\u0027s food web. The molecular structures of phytoplankton lipids are easily altered by UVR. When this happens, their lipids can be transformed from healthy molecules into potentially harmful molecules(oxylipins) known to be disruptive to reproductive and developmental processes. This project will use state-of-the-art molecular methods to answer questions about extent to which UVR damages lipid molecules in phytoplankton, and how these resultant molecules might effect the food chain in the ocean near Antarctica. \u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eLipid peroxidation is often invoked as consequence of increased exposure of phytoplankton to UVR-produced reactive oxygen species (ROS), but the literature is practically silent on peroxidized lipids and their byproducts (i.e. oxylipins) in the ocean. In waters of the West Antarctic Peninsula (WAP), spring-time blooms of diatoms contribute significantly to overall marine primary production. Oxylipins from diatoms can be highly bioactive; their impact on zooplankton grazers, bacteria, and other phytoplankton has been the subject of intense study. However, almost all of this work has focused on the production of oxylipins via enzymatic pathways, not by pathways involving UVR and/or ROS. Furthermore, rigorous experimental work on the effects of oxylipins has been confined almost exclusively to pure cultures and artificial communities. Thus, the true potential of these molecules to disrupt carbon cycling is very poorly-constrained, and is entirely unknown in the waters of the WAP. Armed with new highly-sensitive, state-of-the-art analytical techniques based on high-mass-resolution mass spectrometry, the principal investigator and his research group have begun to uncover an exquisite diversity of oxylipins in natural WAP planktonic communities. These techniques will be applied to understand the connections between UVR, ROS, oxylipins, and carbon cycling. The project will answer the question of how UVR, via ROS, affects oxylipin production by diatoms in WAP surface waters in controlled experiments conducted at a field station. With the answer to this question in hand, the project will also seek to answer how this phenomenon impacts the flow of carbon, particularly the export of organic carbon from the system, during a research cruise. The level of UVR-induced stresses experienced by oxylipin-rich planktonic communities in the WAP is unique, making Antarctica the only location for answering these fundamental questions. Major activities will include laboratory experiments with artificial membranes and diatom cultures, as well field experiments with phytoplankton, zooplankton, and bacteria in WAP waters.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Oxylipins; USAP-DC; Palmer Station; West Antarctic Shelf; NOT APPLICABLE; AQUATIC SCIENCES; Phytoplankton ; UV Radiation", "locations": "West Antarctic Shelf; Palmer Station", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Van Mooy, Benjamin", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "BCO-DMO", "repositories": "BCO-DMO", "science_programs": null, "south": null, "title": "Production and Fate of Oxylipins in Waters of the Western Antarctic Peninsula: Linkages Between UV Radiation, Lipid Peroxidation, and Carbon Cycling", "uid": "p0010109", "west": null}, {"awards": "1142035 Obbard, Rachel; 1142167 Pettit, Erin", "bounds_geometry": "POLYGON((-112.3 -79.2,-112.2 -79.2,-112.1 -79.2,-112 -79.2,-111.9 -79.2,-111.8 -79.2,-111.7 -79.2,-111.6 -79.2,-111.5 -79.2,-111.4 -79.2,-111.3 -79.2,-111.3 -79.23,-111.3 -79.26,-111.3 -79.29,-111.3 -79.32,-111.3 -79.35,-111.3 -79.38,-111.3 -79.41,-111.3 -79.44,-111.3 -79.47,-111.3 -79.5,-111.4 -79.5,-111.5 -79.5,-111.6 -79.5,-111.7 -79.5,-111.8 -79.5,-111.9 -79.5,-112 -79.5,-112.1 -79.5,-112.2 -79.5,-112.3 -79.5,-112.3 -79.47,-112.3 -79.44,-112.3 -79.41,-112.3 -79.38,-112.3 -79.35,-112.3 -79.32,-112.3 -79.29,-112.3 -79.26,-112.3 -79.23,-112.3 -79.2))", "dataset_titles": "ApRES Firn Density Study; ApRES Vertical Strain Study; GPS Horizontal Strain Network; South Pole (SPICEcore) Borehole Deformation; WAIS Divide Borehole Deformation", "datasets": [{"dataset_uid": "601315", "doi": "10.15784/601315", "keywords": "Acoustic Televiewer; Anisotropy; Antarctica; Borehole Logging; Cryosphere; Deformation; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Flow; Snow/Ice; South Pole; SPICEcore", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole (SPICEcore) Borehole Deformation", "url": "https://www.usap-dc.org/view/dataset/601315"}, {"dataset_uid": "200141", "doi": "", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "GPS Horizontal Strain Network", "url": ""}, {"dataset_uid": "601323", "doi": "10.15784/601323", "keywords": "Antarctica; Cryosphere; Glaciers/Ice Sheet; Glaciology; Ice Penetrating Radar; Ice Strain; Phase Sensitive Radar; Radar; Snow/Ice; WAIS divide", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "ApRES Vertical Strain Study", "url": "https://www.usap-dc.org/view/dataset/601323"}, {"dataset_uid": "601322", "doi": "10.15784/601322", "keywords": "Antarctica; Cryosphere; Firn; Firn Density; Glaciology; Ice Penetrating Radar; Phase Sensitive Radar; Radar; Snow/Ice; WAIS divide", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "ApRES Firn Density Study", "url": "https://www.usap-dc.org/view/dataset/601322"}, {"dataset_uid": "601314", "doi": "10.15784/601314", "keywords": "Acoustic Televiewer; Anisotropy; Antarctica; Borehole Logging; Cryosphere; Deformation; Glaciers/Ice Sheet; Glaciology; Ice Flow; WAIS divide; WAIS Divide Ice Core", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Borehole Deformation", "url": "https://www.usap-dc.org/view/dataset/601314"}], "date_created": "Fri, 15 May 2020 00:00:00 GMT", "description": "This award supports a project to develop a better understanding of the relation between ice microstructure, impurities, and ice flow and their connection to climate history for the West Antarctic Ice Sheet (WAIS) ice core site. This work builds on several ongoing studies at Siple Dome in West Antarctica and Dome C in East Antarctica. It is well known that the microstructure of ice evolves with depth and time in an ice sheet. This evolution of microstructure depends on the ice flow field, temperature, and impurity content. The ice flow field, in turn, depends on microstructure, leading to feedbacks that create layered variation in microstructure that relates to climate and flow history. The research proposed here focuses on developing a better understanding of: 1) how ice microstructure evolves with time and stress in an ice sheet and how that relates to impurity content, temperature, and strain rate; 2) how variations in ice microstructure and impurity content affect ice flow patterns near ice divides (on both small (1cm to 1m) and large (1m to 100km) scales); and 3) in what ways is the spatial variability of ice microstructure and its effect on ice flow important for interpretation of climate history in the WAIS Divide ice core. The study will integrate existing ice core and borehole data with a detailed study of ice microstructure using Electron Backscatter Diffraction (EBSD) techniques and measurements of borehole deformation through time using Acoustic Televiewers. This will be the first study to combine these two novel techniques for studying the relation between microstructure and deformation and it will build on other data being collected as part of other WAIS Divide borehole logging projects (e.g. sonic velocity, optical dust logging, temperature and other measurements on the ice core including fabric measurements from thin section analyses as well as studies of ice chemistry and stable isotopes. The intellectual merit of the work is that it will improve interpretation of ice core data (especially information on past accumulation) and overall understanding of ice flow. The broader impacts are that the work will ultimately contribute to a better interpretation of ice core records for both paleoclimate studies and for ice flow history, both of which connect to the broader questions of the role of ice in the climate system. The work will also advance the careers of two early-career female scientists, including one with a hearing impairment disability. This project will support a PhD student at the UAF and provide research and field experience for two or three undergraduates at Dartmouth. The PIs plan to include a teacher on their field team and collaborate with UAF\u0027s \"From STEM to STEAM\" toward enhancing the connection between art and science.", "east": -111.3, "geometry": "POINT(-111.8 -79.35)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR", "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; ICE CORE RECORDS; USAP-DC; GLACIER MOTION/ICE SHEET MOTION; FIELD INVESTIGATION; Radar; WAIS divide", "locations": "WAIS divide", "north": -79.2, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Pettit, Erin; Obbard, Rachel", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "UNAVCO; USAP-DC", "science_programs": "WAIS Divide Ice Core; SPICEcore", "south": -79.5, "title": "Collaborative Research: VeLveT Ice - eVoLution of Fabric and Texture in Ice at WAIS Divide, West Antarctica", "uid": "p0010098", "west": -112.3}, {"awards": "9615281 Luyendyk, Bruce; 9615282 Siddoway, Christine", "bounds_geometry": "POLYGON((-170 -76,-166.5 -76,-163 -76,-159.5 -76,-156 -76,-152.5 -76,-149 -76,-145.5 -76,-142 -76,-138.5 -76,-135 -76,-135 -76.8,-135 -77.6,-135 -78.4,-135 -79.2,-135 -80,-135 -80.8,-135 -81.6,-135 -82.4,-135 -83.2,-135 -84,-138.5 -84,-142 -84,-145.5 -84,-149 -84,-152.5 -84,-156 -84,-159.5 -84,-163 -84,-166.5 -84,-170 -84,-170 -83.2,-170 -82.4,-170 -81.6,-170 -80.8,-170 -80,-170 -79.2,-170 -78.4,-170 -77.6,-170 -76.8,-170 -76))", "dataset_titles": "SOAR-WMB Airborne gravity data", "datasets": [{"dataset_uid": "601294", "doi": "10.15784/601294", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Cryosphere; Free Air Gravity; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Marie Byrd Land; Potential Field; Ross Sea; Solid Earth", "people": "Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-WMB Airborne gravity data", "url": "https://www.usap-dc.org/view/dataset/601294"}], "date_created": "Fri, 24 Apr 2020 00:00:00 GMT", "description": "This award supports a collaborative project that combines air and ground geological-geophysical investigations to understand the tectonic and geological development of the boundary between the Ross Sea Rift and the Marie Byrd Land (MBL) volcanic province. The project will determine the Cenozoic tectonic history of the region and whether Neogene structures that localized outlet glacier flow developed within the context of Cenozoic rifting on the eastern Ross Embayment margin, or within the volcanic province in MBL. The geological structure at the boundary between the Ross Embayment and western MBL may be a result of: 1) Cenozoic extension on the eastern shoulder of the Ross Sea rift; 2) uplift and crustal extension related to Neogene mantle plume activity in western MBL; or a combination of the two. Faulting and volcanism, mountain uplift, and glacier downcutting appear to now be active in western MBL, where generally East-to-West-flowing outlet glaciers incise Paleozoic and Mesozoic bedrock, and deglaciated summits indicate a previous North-South glacial flow direction. This study requires data collection using SOAR (Support Office for Aerogeophysical Research, a facility supported by Office of Polar Programs which utilizes high precision differential GPS to support a laser altimeter, ice-penetrating radar, a towed proton magnetometer, and a Bell BGM-3 gravimeter). This survey requires data for 37,000 square kilometers using 5.3 kilometer line spacing with 15.6 kilometer tie lines, and 86,000 square kilometers using a grid of 10.6 by 10.6 kilometer spacing. Data will be acquired over several key features in the region including, among other, the eastern edge of the Ross Sea rift, over ice stream OEO, the transition from the Edward VII Peninsula plateau to the Ford Ranges, the continuation to the east of a gravity high known from previous reconnaissance mapping over the Fosdick Metamorphic Complex, an d the extent of the high-amplitude magnetic anomalies (volcanic centers?) detected southeast of the northern Ford Ranges by other investigators. SOAR products will include glaciology data useful for studying driving stresses, glacial flow and mass balance in the West Antarctic Ice Sheet (WAIS). The ground program is centered on the southern Ford Ranges. Geologic field mapping will focus on small scale brittle structures for regional kinematic interpretation, on glaciated surfaces and deposits, and on datable volcanic rocks for geochronologic control. The relative significance of fault and joint sets, the timing relationships between them, and the probable context of their formation will also be determined. Exposure ages will be determined for erosion surfaces and moraines. Interpretation of potential field data will be aided by on ground sampling for magnetic properties and density as well as ground based gravity measurements. Oriented samples will be taken for paleomagnetic studies. Combined airborne and ground investigations will obtain basic data for describing the geology and structure at the eastern boundary of the Ross Embayment both in outcrop and ice covered areas, and may be used to distinguish between Ross Sea rift- related structural activity from uplift and faulting on the perimeter of the MBL dome and volcanic province. Outcrop geology and structure will be extrapolated with the aerogeophysical data to infer the geology that resides beneath the WAIS. The new knowledge of Neogene tectonics in western MBL will contribute to a comprehensive model for the Cenozoic Ross rift and to understanding of the extent of plume activity in MBL. Both are important for determining the influence of Neogene tectonics on the ice streams and WAIS.", "east": -135.0, "geometry": "POINT(-152.5 -80)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e LGS", "is_usap_dc": true, "keywords": "GRAVITY; USAP-DC; TECTONICS; Ross Sea; Marie Byrd Land", "locations": "Ross Sea; Marie Byrd Land", "north": -76.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Luyendyk, Bruce P.; Siddoway, Christine", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -84.0, "title": "Air-Ground Study of Tectonics at the Boundary Between the Eastern Ross Embayment and Western Marie Byrd Land, Antarctica: Basement Geology and Structure", "uid": "p0010096", "west": -170.0}, {"awards": "1444167 Detrich, H. William", "bounds_geometry": "POLYGON((-70 -58,-68.5 -58,-67 -58,-65.5 -58,-64 -58,-62.5 -58,-61 -58,-59.5 -58,-58 -58,-56.5 -58,-55 -58,-55 -59.8,-55 -61.6,-55 -63.4,-55 -65.2,-55 -67,-55 -68.8,-55 -70.6,-55 -72.4,-55 -74.2,-55 -76,-56.5 -76,-58 -76,-59.5 -76,-61 -76,-62.5 -76,-64 -76,-65.5 -76,-67 -76,-68.5 -76,-70 -76,-70 -74.2,-70 -72.4,-70 -70.6,-70 -68.8,-70 -67,-70 -65.2,-70 -63.4,-70 -61.6,-70 -59.8,-70 -58))", "dataset_titles": "Assembled Contig Dat for Daane et al. (2019); E-MTAB-6759: RNA-seq across tissues in four Notothenioid species (Antarctic icefish); Expedition Data of LMG1603; Expedition Data of LMG1604; Expedition Data of LMG1605; Expedition Data of LMG1803; Expedition Data of LMG1804; Expedition Data of LMG1805; Full raw data set, computer code, and evolutionary trajectories for all species in Damsgaard et al. (2019); Histology-, CT-, ultrasound-, and MRI-scans (~2 TB) for Damsgaard et al. (2019); PRJNA420419: Genome and Transcriptome Data for Kim et al. (2019) Blackfin Icefish Genome; PRJNA531677: Sequencing Data for Daane et al. (2019); S-BSST132: Assembled Transcriptomes for Berthelot et al. (2018); SRP047484 RAD-tag Sequences of Genetically Mapped Notothenia coriiceps embryos; SRP118539: RAD-tag Sequences of Genetically Mapped Chaenocephalus aceratus Embryos; Transposable element sequences and genome sizes, refs 142597 to MF142757", "datasets": [{"dataset_uid": "200249", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of LMG1803", "url": "https://www.rvdata.us/search/cruise/LMG1803"}, {"dataset_uid": "200104", "doi": "", "keywords": null, "people": null, "repository": "eLife", "science_program": null, "title": "Histology-, CT-, ultrasound-, and MRI-scans (~2 TB) for Damsgaard et al. (2019)", "url": "https://retinaevolution.bios.au.dk/eLife%20documentation/README.txt"}, {"dataset_uid": "200096", "doi": "", "keywords": null, "people": null, "repository": "NCBI Sequence Read Archive", "science_program": null, "title": "SRP047484 RAD-tag Sequences of Genetically Mapped Notothenia coriiceps embryos", "url": "https://www.ncbi.nlm.nih.gov/sra/?term=SRP047484"}, {"dataset_uid": "200098", "doi": "", "keywords": null, "people": null, "repository": "NCBI BioProject ", "science_program": null, "title": "PRJNA531677: Sequencing Data for Daane et al. (2019)", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA531677"}, {"dataset_uid": "200251", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of LMG1804", "url": "https://www.rvdata.us/search/cruise/LMG1804"}, {"dataset_uid": "200095", "doi": "", "keywords": null, "people": null, "repository": "BioStudies", "science_program": null, "title": "S-BSST132: Assembled Transcriptomes for Berthelot et al. (2018)", "url": "https://www.ebi.ac.uk/biostudies/studies/S-BSST132"}, {"dataset_uid": "200250", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of LMG1603", "url": "https://www.rvdata.us/search/cruise/LMG1603"}, {"dataset_uid": "200254", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of LMG1805", "url": "https://www.rvdata.us/search/cruise/LMG1805"}, {"dataset_uid": "200253", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of LMG1605", "url": "https://www.rvdata.us/search/cruise/LMG1605"}, {"dataset_uid": "200252", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of LMG1604", "url": "https://www.rvdata.us/search/cruise/LMG1604"}, {"dataset_uid": "200099", "doi": "10.5281/zenodo.2628936", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Assembled Contig Dat for Daane et al. (2019)", "url": "https://zenodo.org/record/2628936#.Xegqj3dFw2w"}, {"dataset_uid": "200094", "doi": "", "keywords": null, "people": null, "repository": "ArrayExpress", "science_program": null, "title": "E-MTAB-6759: RNA-seq across tissues in four Notothenioid species (Antarctic icefish)", "url": "https://www.ebi.ac.uk/arrayexpress/experiments/E-MTAB-6759/"}, {"dataset_uid": "200093", "doi": "", "keywords": null, "people": null, "repository": "NCBI Sequence Read Archive", "science_program": null, "title": "SRP118539: RAD-tag Sequences of Genetically Mapped Chaenocephalus aceratus Embryos", "url": "https://www.ncbi.nlm.nih.gov/sra/SRP118539 "}, {"dataset_uid": "200102", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Transposable element sequences and genome sizes, refs 142597 to MF142757", "url": "https://www.ncbi.nlm.nih.gov/nuccore?LinkName=pubmed_nuccore\u0026from_uid=29739320"}, {"dataset_uid": "200103", "doi": "", "keywords": null, "people": null, "repository": "Github", "science_program": null, "title": "Full raw data set, computer code, and evolutionary trajectories for all species in Damsgaard et al. (2019)", "url": "https://github.com/elifesciences-publications/Retinaevolution"}, {"dataset_uid": "200092", "doi": "", "keywords": null, "people": null, "repository": "NCBI BioProject", "science_program": null, "title": "PRJNA420419: Genome and Transcriptome Data for Kim et al. (2019) Blackfin Icefish Genome", "url": "https://www.ncbi.nlm.nih.gov/bioproject/?term=prjna420419"}], "date_created": "Wed, 04 Dec 2019 00:00:00 GMT", "description": "Antarctic fish and their early developmental stages are an important component of the food web that sustains life in the cold Southern Ocean (SO) that surrounds Antarctica. They feed on smaller organisms and in turn are eaten by larger animals, including seals and killer whales. Little is known about how rising ocean temperatures will impact the development of Antarctic fish embryos and their growth after hatching. This project will address this gap by assessing the effects of elevated temperatures on embryo viability, on the rate of embryo development, and on the gene \"toolkits\" that respond to temperature stress. One of the two species to be studied does not produce red blood cells, a defect that may make its embryos particularly vulnerable to heat. The outcomes of this research will provide the public and policymakers with \"real world\" data that are necessary to inform decisions and design strategies to cope with changes in the Earth\u0027s climate, particularly with respect to protecting life in the SO. The project will also further the NSF goals of training new generations of scientists, including providing scientific training for undergraduate and graduate students, and of making scientific discoveries available to the general public. This includes the unique educational opportunity for undergraduates to participate in research in Antarctica and engaging the public in several ways, including the development of professionally-produced educational videos with bi-lingual \r\nclosed captioning. \r\nSince the onset of cooling of the SO about 40 million years ago, evolution of Antarctic marine organisms has been driven by the development of cold temperatures. Because body temperatures of Antarctic fishes fall in a narrow range determined by their habitat (-1.9 to +2.0 C), they are particularly attractive models for understanding how organismal physiology and biochemistry have been shaped to maintain life in a cooling environment. Yet these fishes are now threatened by rapid warming of the SO. The long-term objective of this project is to understand the capacities of Antarctic fishes to acclimatize and/or adapt to oceanic warming through analysis of their underlying genetic \"toolkits.\" This objective will be accomplished through three Specific Aims: 1) assessing the effects of elevated temperatures on gene expression during development of embryos; 2) examining the effects of elevated temperatures on embryonic morphology and on the temporal and spatial patterns of gene expression; and 3) evaluating the evolutionary mechanisms that have led to the loss of the red blood cell genetic program by the white-blooded fishes. Aims 1 and 2 will be investigated by acclimating experimental embryos of both red-blooded and white-blooded fish to elevated temperatures. Differential gene expression will be examined through the use of high throughput RNA sequencing. The temporal and spatial patterns of gene expression in the context of embryonic morphology (Aim 2) will be determined by microscopic analysis of embryos \"stained\" with (hybridized to) differentially expressed gene probes revealed by Aim 1; other key developmental marker genes will also be used. The genetic lesions resulting from loss of red blood cells by the white-blooded fishes (Aim 3) will be examined by comparing genes and genomes in the two fish groups.", "east": -55.0, "geometry": "POINT(-62.5 -67)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; South Shetland Islands; USAP-DC; Polar; COASTAL", "locations": "Polar; South Shetland Islands", "north": -58.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Detrich, H. William", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "R2R", "repositories": "Other", "science_programs": null, "south": -76.0, "title": "Antarctic Notothenioid Fishes: Sentinel Taxa for Southern Ocean Warming", "uid": "p0010073", "west": -70.0}, {"awards": "1341393 Denlinger, David; 1341385 Lee, Richard", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Alaskozetes antarcticus Raw sequence reads; Belgica antarctica Integrated Genome and Transcriptome Project; Data from: Rapid cold hardening protects against sublethal freezing injury in an Antarctic insect", "datasets": [{"dataset_uid": "200054", "doi": " https://doi.org/10.5061/dryad.29p7ng2", "keywords": null, "people": null, "repository": "Dryad Digital Repository", "science_program": null, "title": "Data from: Rapid cold hardening protects against sublethal freezing injury in an Antarctic insect", "url": "https://datadryad.org/resource/doi:10.5061/dryad.29p7ng2"}, {"dataset_uid": "200053", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Belgica antarctica Integrated Genome and Transcriptome Project", "url": "https://www.ncbi.nlm.nih.gov/bioproject/175916"}, {"dataset_uid": "200052", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Alaskozetes antarcticus Raw sequence reads", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA428758"}], "date_created": "Mon, 12 Aug 2019 00:00:00 GMT", "description": "Polar regions are deserts that are not only cold but also lack access to free water. Antarctic insects have unique survival mechanisms including the ability to tolerate freezing and extensive dehydration, surviving the loss of 70% of their body water. How this is done is of interest not only for understanding seasonal adaptations of insects and how they respond to climate change, but the molecular and physiological mechanisms employed may offer valuable insights into more general mechanisms that might be exploited for cryopreservation and long-term storage of human tissues and organs for transplantation and other medical applications. The investigators will study the proteins that are responsible for removing water from the body, cell level consequences of this, and how the responsible genes vary between populations. The project will also further the NSF goals of making scientific discoveries available to the general public and of training new generations of scientists. Each year a K-12 teacher will be a member of the field team and assist with fieldwork and outreach to school children and their teachers. Educational outreach efforts include presentations at local schools and national teacher meetings, providing lesson plans and podcasts on a website, and continuing to publish articles related to this research in education journals. In addition, undergraduate and graduate students will receive extensive training in all aspects of the research project with extended experiences that include publication of scientific papers and presentations at national meetings.\u003cbr/\u003e\u003cbr/\u003eThis project focuses on deciphering the physiological and molecular mechanisms that enable the Antarctic midge Belgica antarctica to survive environmental stress and the loss of most of its body water in the desiccating polar environment. This extremophile is an ideal system for investigating mechanisms of stress tolerance and local geographic adaptations and its genome has recently been sequenced. This project has three focal areas: 1) Evaluating the role of aquaporins (water channel proteins) in the rapid removal of water from the body by studying expression of their genes during dehydration; 2) Investigating the mechanism of metabolic depression and the role of autophagy (controlled breakdown of cellular components) as a mediator of stress tolerance by studying expression of the genes responsible for autophagy during the dehydration process; and 3) Evaluating the population structure, gene flow, and adaptive variation in physiological traits associated with stress tolerance using a genetic approach that takes advantage of the genomic sequence available for this species coupled with physiological and environmental data from the sampled populations and their habitats.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "Antarctica; USAP-DC; ARTHROPODS; NOT APPLICABLE", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Denlinger, David; Lee, Richard", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "Dryad Digital Repository", "repositories": "Other", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Winter Survival Mechanisms and Adaptive Genetic Variation in an Antarctic Insect", "uid": "p0010048", "west": -180.0}, {"awards": "1744645 Young, Jodi", "bounds_geometry": "POLYGON((-64.4 -64.2,-64.38 -64.2,-64.36 -64.2,-64.34 -64.2,-64.32 -64.2,-64.3 -64.2,-64.28 -64.2,-64.26 -64.2,-64.24 -64.2,-64.22 -64.2,-64.2 -64.2,-64.2 -64.26,-64.2 -64.32,-64.2 -64.38,-64.2 -64.44,-64.2 -64.5,-64.2 -64.56,-64.2 -64.62,-64.2 -64.68,-64.2 -64.74,-64.2 -64.8,-64.22 -64.8,-64.24 -64.8,-64.26 -64.8,-64.28 -64.8,-64.3 -64.8,-64.32 -64.8,-64.34 -64.8,-64.36 -64.8,-64.38 -64.8,-64.4 -64.8,-64.4 -64.74,-64.4 -64.68,-64.4 -64.62,-64.4 -64.56,-64.4 -64.5,-64.4 -64.44,-64.4 -64.38,-64.4 -64.32,-64.4 -64.26,-64.4 -64.2))", "dataset_titles": "Sea-ice diatom compatible solute shifts", "datasets": [{"dataset_uid": "200322", "doi": "10.21228/M84386", "keywords": null, "people": null, "repository": "Metabolomics workbench", "science_program": null, "title": "Sea-ice diatom compatible solute shifts", "url": "https://www.metabolomicsworkbench.org/data/DRCCMetadata.php?Mode=Study\u0026StudyID=ST001393"}], "date_created": "Tue, 23 Jul 2019 00:00:00 GMT", "description": "Rapid changes in the extent and thickness of sea ice during the austral spring subject microorganisms within or attached to the ice to large fluctuations in temperature, salinity, light and nutrients. This project aims to identify cellular responses in sea-ice algae to increasing temperature and decreasing salinity during the spring melt along the western Antarctic Peninsula and to determine how associated changes at the cellular level can potentially affect dynamic, biologically driven processes. Understanding how sea-ice algae cope with, and are adapted to, their environment will not only help predict how polar ecosystems may change as the extent and thickness of sea ice change, but will also provide a better understanding of the widespread success of photosynthetic life on Earth. The scientific context and resulting advances from the research will be communicated to the general public through outreach activities that includes work with Science Communication Fellows and the popular Polar Science Weekend at the Pacific Science Center in Seattle, Washington. The project will provide student training to college students as well as provide for educational experiences for K-12 school children. \u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eThere is currently a poor understanding of feedback relationships that exist between the rapidly changing environment in the western Antarctic Peninsula region and sea-ice algal production. The large shifts in temperature and salinity that algae experience during the spring melt affect critical cellular processes, including rates of enzyme-catalyzed reactions involved in photosynthesis and respiration, and the production of stress-protective compounds. These changes in cellular processes are poorly constrained but can be large and may have impacts on local ecosystem productivity and biogeochemical cycles. In particular, this study will focus on the thermal sensitivity of enzymes and the cycling of compatible solutes and exopolymers used for halo- and cryo-protection, and how they influence primary production and the biogeochemical cycling of carbon and nitrogen. Approaches will include field sampling during spring melt, incubation experiments of natural sea-ice communities under variable temperature and salinity conditions, and controlled manipulation of sea-ice algal species in laboratory culture. Employment of a range of techniques, from fast repetition rate fluorometry and gross and net photosynthetic measurements to metabolomics and enzyme kinetics, will tease apart the mechanistic effects of temperature and salinity on cell metabolism and primary production with the goal of quantifying how these changes will impact biogeochemical processes along the western Antarctic Peninsula.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -64.2, "geometry": "POINT(-64.3 -64.5)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; SHIPS; DIATOMS; Antarctic Peninsula", "locations": "Antarctic Peninsula", "north": -64.2, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Young, Jodi; Deming, Jody", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "Metabolomics workbench", "repositories": "Other", "science_programs": null, "south": -64.8, "title": "Spring Blooms of Sea Ice Algae Along the Western Antarctic Peninsula: Effects of Warming and Freshening on Cell Physiology and Biogeochemical Cycles.", "uid": "p0010039", "west": -64.4}, {"awards": "1247510 Detrich, H. William", "bounds_geometry": null, "dataset_titles": "E-MTAB-6759: RNA-seq across tissues in four Notothenioid species (Antarctic icefish); Expedition Data; Expedition data of LMG1003; Expedition data of LMG1004; PRJNA420419: Chaenocephalus aceratus Genome sequencing; PRJNA66471: Notothenia coriiceps Genome Sequencing Notothenia coriiceps isolate:Sejong01 (black rockcod); S-BSST 132: Assembled Transcriptomes for Berthelot et al. (2018); SRA091269: Notothenia coriiceps RNA Raw Sequence Reads; SRP047484: RAD-tag Sequences of Genetically Mapped Notothenia coriiceps Embryos ; SRP118539: RAD-tag Sequences of Genetically Mapped Chaenocephalus aceratus Embryos", "datasets": [{"dataset_uid": "001508", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0807"}, {"dataset_uid": "200093", "doi": "", "keywords": null, "people": null, "repository": "NCBI Sequence Read Archive", "science_program": null, "title": "SRP118539: RAD-tag Sequences of Genetically Mapped Chaenocephalus aceratus Embryos", "url": "https://www.ncbi.nlm.nih.gov/sra/SRP118539 "}, {"dataset_uid": "002684", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1003", "url": "https://www.rvdata.us/search/cruise/LMG1003"}, {"dataset_uid": "001509", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0806"}, {"dataset_uid": "200026", "doi": "", "keywords": null, "people": null, "repository": "NCBI Sequence Read Archive", "science_program": null, "title": "SRA091269: Notothenia coriiceps RNA Raw Sequence Reads", "url": "https://www.ncbi.nlm.nih.gov/sra/?term=SRA091269"}, {"dataset_uid": "200146", "doi": "", "keywords": null, "people": null, "repository": "NCBI Sequence Read Archive", "science_program": null, "title": "SRP047484: RAD-tag Sequences of Genetically Mapped Notothenia coriiceps Embryos ", "url": "https://www.ncbi.nlm.nih.gov/sra/?term=SRP047484"}, {"dataset_uid": "200145", "doi": "", "keywords": null, "people": null, "repository": "BioStudies", "science_program": null, "title": "S-BSST 132: Assembled Transcriptomes for Berthelot et al. (2018)", "url": "https://www.ebi.ac.uk/biostudies/studies/S-BSST132"}, {"dataset_uid": "200144", "doi": "", "keywords": null, "people": null, "repository": "Array Express", "science_program": null, "title": "E-MTAB-6759: RNA-seq across tissues in four Notothenioid species (Antarctic icefish)", "url": "https://www.ebi.ac.uk/arrayexpress/experiments/E-MTAB-6759/"}, {"dataset_uid": "200143", "doi": "", "keywords": null, "people": null, "repository": "NCBI BioProject", "science_program": null, "title": "PRJNA420419: Chaenocephalus aceratus Genome sequencing", "url": "https://www.ncbi.nlm.nih.gov/bioproject/420419"}, {"dataset_uid": "200142", "doi": "", "keywords": null, "people": null, "repository": "NCBI BioProject", "science_program": null, "title": "PRJNA66471: Notothenia coriiceps Genome Sequencing Notothenia coriiceps isolate:Sejong01 (black rockcod)", "url": "https://www.ncbi.nlm.nih.gov/bioproject/66471"}, {"dataset_uid": "002685", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1004", "url": "https://www.rvdata.us/search/cruise/LMG1004"}], "date_created": "Mon, 08 Apr 2019 00:00:00 GMT", "description": "Since the advent of Antarctic continental glaciation, the opening of the Drake Passage between South America and the Antarctic Peninsula, and the onset of cooling of the Southern Ocean ~40-25 million years ago, evolution of the Antarctic marine biota has been driven by the development of extreme cold temperatures. As circum-Antarctic coastal temperatures declined during this period from ~20\u00b0C to the modern -1.9 to +2.0\u00b0C (reached ~8-10 million years ago), the psychrophilic (cold-loving) ectotherms of the Southern Ocean evolved compensatory molecular, cellular, and physiological traits that enabled them to maintain normal metabolic function at cold temperatures. Today, these organisms are threatened by rapid warming of the Southern Ocean over periods measured in centuries (as much as 5\u00b0C/100 yr), a timeframe so short that re-adaptation and/or acclimatization to the \"new warm\" may not be possible. Thus, the long-term goals of this research project are: 1) to understand the biochemical and physiological capacities of the embryos of Antarctic notothenioid fish to resist or compensate for rapid oceanic warming; and 2) to assess the genetic toolkit available to support the acclimatization and adaptation of Antarctic notothenioid embryos to their warming habitat. The specific aims of this work are: 1) to determine the capacity of the chaperonin complex of notothenioid fishes to assist protein folding at temperatures between -4 and +20\u00b0C; and 2) to evaluate the genetic responses of notothenioid embryos, measured as global differential gene transcription, to temperature challenge, with -1.9\u00b0C as the \"normal\" control and +4 and +10\u00b0C as high temperature insults.\r\nThe physiology of embryonic development of marine stenotherms under future climate change scenarios is an important but understudied problem. This project will provide valuable insights into the capacity of Antarctic fish embryos to acclimatize and adapt to plausible climate change scenarios by examining multiple levels of biological organization, from the biochemical to the organismal. The results should also be broadly applicable to understanding the impact of global warming on marine biota worldwide. The research will also introduce graduate and undergraduate students to state-of-the-art biochemical, cellular, and molecular-biological research relevant to ecological and environmental issues of the Antarctic marine ecosystem.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SAMPLERS \u003e TRAWLS/NETS \u003e BOTTOM TRAWL", "is_usap_dc": false, "keywords": "AQUATIC SCIENCES; R/V LMG; USAP-DC; Southern Ocean", "locations": "Southern Ocean", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Detrich, H. William", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "Other", "science_programs": null, "south": null, "title": "Protein Folding and Embryogenesis in Antarctic Fishes: A Comparative Approach to Environmental Stress", "uid": "p0010024", "west": null}, {"awards": "1245766 Waller, Rhian", "bounds_geometry": "POINT(-63.0796667 -61.5157)", "dataset_titles": "Expedition Data; Log Sheets of coral samples for LMG1509", "datasets": [{"dataset_uid": "601160", "doi": "10.15784/601160", "keywords": "Antarctica; Antarctic Peninsula; Biology; Biosphere; Corals; Cryosphere; CTD; LMG1509; Oceans; Otter Trawl; R/V Laurence M. Gould; Sample/Collection Description; Sample Location; Southern Ocean", "people": "Waller, Rhian", "repository": "USAP-DC", "science_program": null, "title": "Log Sheets of coral samples for LMG1509", "url": "https://www.usap-dc.org/view/dataset/601160"}, {"dataset_uid": "001378", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG1509"}], "date_created": "Thu, 07 Mar 2019 00:00:00 GMT", "description": "The Western Antarctic Peninsula is experiencing climate change at one of the fastest rates of anywhere around the globe. Accelerated climate change is likely to affect the many benthic marine invertebrates that live within narrow temperature windows along the Antarctic Continental Shelf in presently unidentified ways. At present however, there are few data on the physiological consequences of climate change on the sensitive larval stages of cold-water corals, and none on species living in thermal extremes such as polar waters. This project will collect the larvae of the non-seasonal, brooding scleractinian Flabellum impensum to be used in a month-long climate change experiment at Palmer Station. Multidisciplinary techniques will be used to examine larval development and cellular stress using a combination of electron microscopy, flow cytometry, and Inductively Coupled Plasma Mass Spectometry. Data from this project will form the first systematic study of the larval stages of polar cold-water corals, and how these stages are affected by temperature stress at the cellular and developmental level. \u003cbr/\u003e\u003cbr/\u003eCold-water corals have been shown to be important ecosystem engineers, providing habitat for thousands of associated species, including many that are of commercial importance. Understanding how the larvae of these corals react to warming trends seen today in our oceans will allow researchers to predict future changes in important benthic communities around the globe. Associated education and outreach include: 1) Increasing student participation in polar research by involving postdoctoral and undergraduate students in the field and research program; ii) promotion of K-12 teaching and learning programs by providing information via a research website, Twitter, and in-school talks in the local area; iii) making the data collected available to the wider research community via peer reviewed published literature and iv) reaching a larger public audience through such venues as interviews in the popular media, You Tube and other popular media outlets, and local talks to the general public.", "east": -63.0796667, "geometry": "POINT(-63.0796667 -61.5157)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SAMPLERS \u003e TRAWLS/NETS \u003e OTTER TRAWL", "is_usap_dc": true, "keywords": "ANIMALS/INVERTEBRATES; R/V LMG; Southern Ocean; USAP-DC; AQUATIC SCIENCES; WATER TEMPERATURE", "locations": "Southern Ocean", "north": -61.5157, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Waller, Rhian; Jay, Lunden", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "USAP-DC", "repositories": "Other; USAP-DC", "science_programs": null, "south": -61.5157, "title": "Cold Corals in Hot Water - Investigating the Physiological Responses of Antarctic Coral Larvae to Climate change Stress", "uid": "p0010017", "west": -63.0796667}, {"awards": "1341476 Moran, Amy", "bounds_geometry": "POINT(166.666 -77.84999)", "dataset_titles": "Cuticle morphology and oxygen gradients of Antarctic sea spiders; Physiological and biochemical measurements on Pycnogonida from McMurdo Sound; Physiological, biomechanical, and locomotory data on Antarctic sea spiders fouled and unfouled with epibionts; Size scaling of oxygen physiology and metabolic rate of Antarctic sea spiders", "datasets": [{"dataset_uid": "601145", "doi": "10.15784/601145", "keywords": "Antarctica; Benthos; Biology; Biosphere; Body Size; Cryosphere; Cuticle; McMurdo Sound; Microelectrodes; Microscope; Microscopy; Oxygen; Pore; Respiration; Sea Spider; Southern Ocean", "people": "Woods, H. Arthur; Arthur Woods, H.", "repository": "USAP-DC", "science_program": null, "title": "Cuticle morphology and oxygen gradients of Antarctic sea spiders", "url": "https://www.usap-dc.org/view/dataset/601145"}, {"dataset_uid": "601150", "doi": "10.15784/601150", "keywords": "Antarctica; Biology; Biosphere; Body Size; Cryosphere; Cuticle; Metabolic Rate; Oxygen; Polar Gigantism; Respiration; Size Limits; Southern Ocean; Temperature", "people": "Shishido, Caitlin; Woods, H. Arthur; Lane, Steven J.; Moran, Amy", "repository": "USAP-DC", "science_program": null, "title": "Size scaling of oxygen physiology and metabolic rate of Antarctic sea spiders", "url": "https://www.usap-dc.org/view/dataset/601150"}, {"dataset_uid": "601149", "doi": "10.15784/601149", "keywords": "Antarctica; Barnacles; Biology; Biosphere; Cryosphere; Cuticle; Epibionts; Fouling; Grooming; Locomotion; Oxygen; Respiration; Respiration", "people": "Woods, H. Arthur; Moran, Amy; Lane, Steven J.; Tobalske, Bret; Shishido, Caitlin", "repository": "USAP-DC", "science_program": null, "title": "Physiological, biomechanical, and locomotory data on Antarctic sea spiders fouled and unfouled with epibionts", "url": "https://www.usap-dc.org/view/dataset/601149"}, {"dataset_uid": "601142", "doi": "10.15784/601142", "keywords": "Antarctica; Biology; Biomechanics; Biosphere; Cold Adaptation; Cryosphere; McMurdo Sound; metabolism; Oceans; Oxygen; Pycnogonida; Southern Ocean", "people": "Tobalske, Bret; Woods, H. Arthur; Moran, Amy", "repository": "USAP-DC", "science_program": null, "title": "Physiological and biochemical measurements on Pycnogonida from McMurdo Sound", "url": "https://www.usap-dc.org/view/dataset/601142"}], "date_created": "Mon, 10 Dec 2018 00:00:00 GMT", "description": "Beginning with the earliest expeditions to the poles, scientists have noted that many polar taxa grow to unusually large body sizes, a phenomenon now known as \u0027polar gigantism.\u0027 Although scientists have been interested in polar giants for many years, many questions still remain about the biology of this significant form of polar diversity. This award from the Antarctic Organisms and Ecosystems program within the Polar Sciences Division at the National Science Foundation will investigate the respiratory and biomechanical mechanisms underlying polar gigantism in Antarctic pycnogonids (commonly known as sea spiders). The project will use a series of manipulative experiments to investigate the effects of temperature and oxygen availability on respiratory capacity and biomechanical strength, and will compare Antarctic sea spiders to related species from temperate and tropical regions. The research will provide insight into the ability of polar giants to withstand the warming polar ocean temperatures associated with climate change.\u003cbr/\u003e\u003cbr/\u003eThe prevailing hypothesis to explain the evolution of gigantism invokes shifts in respiratory relationships in extremely cold ocean waters: in the cold, oxygen is more plentiful while at the same time metabolic rates are very low. Together these effects alleviate constraints on oxygen supply that restrict organisms living in warmer waters. Respiratory capacity must evolve in the context of adaptive tradeoffs, so for organisms including pycnogonids there must be tradeoffs between respiratory capacity and resistance to biomechanical stresses. The investigators will test a novel hypothesis that respiratory challenges are not associated with particular body sizes, and will answer the following questions: What are the dynamics of oxygen transport and consumption in Antarctic pycnogonids; how do structural features related to oxygen diffusion trade off with requirements for body support and locomotion; how does body size influence vulnerability to environmental hypoxia and to temperature-oxygen interactions; and does the cold-driven high oxygen availability in the Antarctic raise the limit on body size by reducing trade-offs between diffusivity and structural integrity? The research will explore the effects of increased ocean temperatures upon organisms that have different body sizes. In addition, it will provide training for graduate and undergraduate students affiliated with universities in EPSCOR states.", "east": 166.666, "geometry": "POINT(166.666 -77.84999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -77.84999, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Moran, Amy; Woods, H. Arthur", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.84999, "title": "Collaborative Research: Body Size, Oxygen, and Vulnerability to Climate Change in Antarctic Pycnogonida", "uid": "p0000007", "west": 166.666}, {"awards": "1144176 Lyons, W. Berry; 1144177 Pettit, Erin; 1144192 Tulaczyk, Slawek; 1727387 Mikucki, Jill", "bounds_geometry": "POLYGON((161.8 -77.7,161.88 -77.7,161.96 -77.7,162.04000000000002 -77.7,162.12 -77.7,162.2 -77.7,162.28 -77.7,162.36 -77.7,162.44 -77.7,162.51999999999998 -77.7,162.6 -77.7,162.6 -77.70700000000001,162.6 -77.714,162.6 -77.721,162.6 -77.728,162.6 -77.735,162.6 -77.742,162.6 -77.749,162.6 -77.756,162.6 -77.76299999999999,162.6 -77.77,162.51999999999998 -77.77,162.44 -77.77,162.36 -77.77,162.28 -77.77,162.2 -77.77,162.12 -77.77,162.04000000000002 -77.77,161.96 -77.77,161.88 -77.77,161.8 -77.77,161.8 -77.76299999999999,161.8 -77.756,161.8 -77.749,161.8 -77.742,161.8 -77.735,161.8 -77.728,161.8 -77.721,161.8 -77.714,161.8 -77.70700000000001,161.8 -77.7))", "dataset_titles": "Ablation Stake Data from of Taylor Glacier near Blood Falls; Antarctica Support 2014/2015 - C-528 Blood Falls GPS/GNSS Observations Dataset; Blood Falls, McMurdo Dry Va. International Federation of Digital Seismograph Networks. Dataset/Seismic Network; FLIR thermal imaging data near Blood Falls, Taylor Glacier; Ground Penetrating Radar Data near Blood Falls, Taylor Glacier; Ice Temperature in Shallow Boreholes Near Blood Falls at the Terminus of Taylor Glacier, McMurdo Dry Valleys, Antarctica; NCBI short read archive -Metagenomic survey of Antarctic Groundwater; Terrestrial Radar Interferometry near Blood Falls, Taylor Glacier; The Geochemistry of englacial brine from Taylor Glacier, Antarctica; Time Lapse imagery of the Blood Falls feature, Antarctica ; Vaisala Integrated Met Station near Blood Falls, Taylor Glacier", "datasets": [{"dataset_uid": "601168", "doi": "10.15784/601168", "keywords": "Antarctica; Atmosphere; Basal Crevassing; Cryosphere; Glacier Hydrology; Glaciers/Ice Sheet; Glaciology; Meteorology; Taylor Glacier; Temperature; Weather Station Data; Wind Speed", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": null, "title": "Vaisala Integrated Met Station near Blood Falls, Taylor Glacier", "url": "https://www.usap-dc.org/view/dataset/601168"}, {"dataset_uid": "601179", "doi": "10.15784/601179", "keywords": "Antarctica; Chemistry:Ice; Cryosphere; Geochemistry; Glaciers/Ice Sheet; Glaciology; Subglacial Brine", "people": "Lyons, W. Berry; Gardner, Christopher B.", "repository": "USAP-DC", "science_program": null, "title": "The Geochemistry of englacial brine from Taylor Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601179"}, {"dataset_uid": "601166", "doi": "10.15784/601166", "keywords": "Antarctica; Basal Crevassing; Cryosphere; Glacier Hydrology; Glaciers/Ice Sheet; Glaciology; GPR; Ground Penetrating Radar; Radar; Snow/Ice; Taylor Glacier", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": null, "title": "Terrestrial Radar Interferometry near Blood Falls, Taylor Glacier", "url": "https://www.usap-dc.org/view/dataset/601166"}, {"dataset_uid": "601167", "doi": "10.15784/601167", "keywords": "Antarctica; Basal Crevassing; Cryosphere; Glacier Hydrology; Glaciers/Ice Sheet; Glaciology; Photographs; Photo/Video; Snow/Ice; Taylor Glacier; Time Laps Images", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": null, "title": "Time Lapse imagery of the Blood Falls feature, Antarctica ", "url": "https://www.usap-dc.org/view/dataset/601167"}, {"dataset_uid": "200029", "doi": "10.7914/SN/YW_2013", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Blood Falls, McMurdo Dry Va. International Federation of Digital Seismograph Networks. Dataset/Seismic Network", "url": "http://www.fdsn.org/networks/detail/YW_2013/"}, {"dataset_uid": "601139", "doi": "10.15784/601139", "keywords": "Antarctica; Borehole; Borehole Logging; Cryosphere; Glaciers/Ice Sheet; Glaciology; Ice Temperature; Snow/Ice; Temperature; Temperature Profiles", "people": "Tulaczyk, Slawek", "repository": "USAP-DC", "science_program": null, "title": "Ice Temperature in Shallow Boreholes Near Blood Falls at the Terminus of Taylor Glacier, McMurdo Dry Valleys, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601139"}, {"dataset_uid": "200028", "doi": "10.7283/FCEN-8050", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica Support 2014/2015 - C-528 Blood Falls GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/fcen-8050"}, {"dataset_uid": "601165", "doi": "10.15784/601165", "keywords": "Antarctica; Basal Crevassing; Cryosphere; Glacier Hydrology; Glaciers/Ice Sheet; Glaciology; GPR; Ground Penetrating Radar; Radar; Snow/Ice; Taylor Glacier", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": null, "title": "Ground Penetrating Radar Data near Blood Falls, Taylor Glacier", "url": "https://www.usap-dc.org/view/dataset/601165"}, {"dataset_uid": "601164", "doi": "10.15784/601164", "keywords": "Antarctica; Basal Crevassing; Cryosphere; Glacier Hydrology; Glaciers/Ice Sheet; Glaciology; Snow/Ice", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": null, "title": "Ablation Stake Data from of Taylor Glacier near Blood Falls", "url": "https://www.usap-dc.org/view/dataset/601164"}, {"dataset_uid": "601169", "doi": "10.15784/601169", "keywords": "Antarctica; Basal Crevassing; Cryosphere; Glacier Hydrology; Glaciers/Ice Sheet; Glaciology; Infrared Imagery; Photo/Video; Taylor Glacier; Thermal Camera; Time Laps Images", "people": "Pettit, Erin", "repository": "USAP-DC", "science_program": null, "title": "FLIR thermal imaging data near Blood Falls, Taylor Glacier", "url": "https://www.usap-dc.org/view/dataset/601169"}, {"dataset_uid": "200074", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "NCBI short read archive -Metagenomic survey of Antarctic Groundwater", "url": "https://www.ncbi.nlm.nih.gov/sra/?term=SRR6667787"}], "date_created": "Wed, 28 Nov 2018 00:00:00 GMT", "description": "Recent discoveries of widespread liquid water and microbial ecosystems below the Antarctic ice sheets have generated considerable interest in studying Antarctic subglacial environments. Understanding subglacial hydrology, the persistence of life in extended isolation and the evolution and stability of subglacial habitats requires an integrated, interdisciplinary approach. The collaborative project, Minimally Invasive Direct Glacial Exploration (MIDGE) of the Biogeochemistry, Hydrology and Glaciology of Blood Falls, McMurdo Dry Valleys will integrate geophysical measurements, molecular microbial ecology and geochemical analyses to explore a unique Antarctic subglacial system known as Blood Falls. Blood Falls is a hypersaline, subglacial brine that supports an active microbial community. The subglacial brine is released from a crevasse at the surface of the Taylor Glacier providing an accessible portal into an Antarctic subglacial ecosystem. Recent geochemical and molecular analyses support a marine source for the salts and microorganisms in Blood Falls. The last time marine waters inundated this part of the McMurdo Dry Valleys was during the Late Tertiary, which suggests the brine is ancient. Still, no direct samples have been collected from the subglacial source to Blood Falls and little is known about the origin of this brine or the amount of time it has been sealed below Taylor Glacier. Radar profiles collected near Blood Falls delineate a possible fault in the subglacial substrate that may help explain the localized and episodic nature of brine release. However it remains unclear what triggers the episodic release of brine exclusively at the Blood Falls crevasse or the extent to which the brine is altered as it makes its way to the surface. \u003cbr/\u003e\u003cbr/\u003eThe MIDGE project aims to determine the mechanism of brine release at Blood Falls, evaluate changes in the geochemistry and the microbial community within the englacial conduit and assess if Blood Falls waters have a distinct impact on the thermal and stress state of Taylor Glacier, one of the most studied polar glaciers in Antarctica. The geophysical study of the glaciological structure and mechanism of brine release will use GPR, GPS, and a small passive seismic network. Together with international collaborators, the \u0027Ice Mole\u0027 team from FH Aachen University of Applied Sciences, Germany (funded by the German Aerospace Center, DLR), MIDGE will develop and deploy innovative, minimally invasive technologies for clean access and brine sample retrieval from deep within the Blood Falls drainage system. These technologies will allow for the collection of samples of the brine away from the surface (up to tens of meters) for geochemical analyses and microbial structure-function experiments. There is concern over the contamination of pristine subglacial environments from chemical and biological materials inherent in the drilling process; and MIDGE will provide data on the efficacy of thermoelectric probes for clean access and retrieval of representative subglacial samples. Antarctic subglacial environments provide an excellent opportunity for researching survivability and adaptability of microbial life and are potential terrestrial analogues for life habitats on icy planetary bodies. The MIDGE project offers a portable, versatile, clean alternative to hot water and mechanical drilling and will enable the exploration of subglacial hydrology and ecosystem function while making significant progress towards developing technologies for minimally invasive and clean sampling of icy systems.", "east": 162.6, "geometry": "POINT(162.2 -77.735)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; BACTERIA/ARCHAEA; USAP-DC", "locations": null, "north": -77.7, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Instrumentation and Support; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Tulaczyk, Slawek; Pettit, Erin; Lyons, W. Berry; Mikucki, Jill", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "IRIS; Other; UNAVCO; USAP-DC", "science_programs": null, "south": -77.77, "title": "Collaborative Research: MIDGE: Minimally Invasive Direct Glacial Exploration of Biogeochemistry, Hydrology and Glaciology of Blood Falls, McMurdo Dry Valleys", "uid": "p0000002", "west": 161.8}, {"awards": "1245915 Ray, Laura", "bounds_geometry": null, "dataset_titles": "Ground Penetrating Radar Grid Survey of the McMurdo Shear Zone", "datasets": [{"dataset_uid": "601102", "doi": "10.15784/601102", "keywords": "Antarctica; Cryosphere; Firn; Folds; Geology/Geophysics - Other; Glaciers/Ice Sheet; Glaciology; GPR; Snow/Ice", "people": "Lever, Jim; Arcone, Steven; Ray, Laura; Walker, Ben; Kaluzienski, Lynn; Koons, Peter", "repository": "USAP-DC", "science_program": null, "title": "Ground Penetrating Radar Grid Survey of the McMurdo Shear Zone", "url": "https://www.usap-dc.org/view/dataset/601102"}], "date_created": "Thu, 27 Sep 2018 00:00:00 GMT", "description": "This award supports an integrated field observation, remote sensing and numerical modeling study of the McMurdo Shear Zone (SZ). The SZ is a 5-10 km wide strip of heavily crevassed ice that separates the McMurdo and Ross ice shelves, and is an important region of lateral support for the Ross Ice Shelf. Previous radar and remote sensing studies reveal an enigmatic picture of the SZ in which crevasses detected at depth have no apparent surface expression, and have orientations which are possibly inconsistent with the observed flow field. In the proposed work, we seek to test the hypothesis that the SZ is a zone of chaotic Lagrangian mixing with (intersecting) buried crevasses which leads to rheological instability, potentially allowing large scale velocity discontinuities. The work will involve detailed field-based observations of crevasse distributions and structure using ground-penetrating radar, and GPS and remote sensing observations of the flow and stress field in the SZ. Because of the hazardous nature of the SZ, the radar surveys will be conducted largely with the aid of a lightweight robotic vehicle. Observations will be used to develop a finite element model of ice shelf shear margin behavior. The intellectual merit of this project is an increased understanding of ice shelf shear margin dynamics. Shear margins play a key role in ice shelf stability, and ice shelves in turn modulate the flux of ice from the ice sheet across the grounding line to the ocean. Insights from this project will improve large-scale models being developed to predict ice sheet evolution and future rates of sea level rise, which are topics of enormous societal concern. The broader impacts of the project include an improved basis for US Antarctic Program logistics planning as well as numerous opportunities to engage K-12 students in scientific discovery. Intensified crevassing in the shear zone between the Ross and McMurdo ice shelves would preclude surface crossing by heavy traverse vehicles which would lead to increased costs of delivering fuel to South Pole and a concomitant loss of flight time provided by heavy-lift aircraft for science missions on the continent. Our multidisciplinary research combining glaciology, numerical modeling, and robotics engineering is an engaging way to show how robotics can assist scientists in collecting hazardous field measurements. Our outreach activities will leverage Dartmouth\u0027s current NSF GK-12 program, build on faculty-educator relationships established during University of Maine\u0027s recent GK-12 program, and incorporate project results into University of Maine\u0027s IDEAS initiative, which integrates computational modeling with the existing science curriculum at the middle school level. This award has field work in Antarctica.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Ray, Laura", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Flow and Fracture Dynamics in an Ice Shelf Lateral Margin: Observations and Modeling of the McMurdo Shear Zone", "uid": "p0000701", "west": null}, {"awards": "1443126 MacAyeal, Douglas", "bounds_geometry": "POLYGON((166.1631 -77.9007,166.19736 -77.9007,166.23162 -77.9007,166.26588 -77.9007,166.30014 -77.9007,166.3344 -77.9007,166.36866 -77.9007,166.40292 -77.9007,166.43718 -77.9007,166.47144 -77.9007,166.5057 -77.9007,166.5057 -77.90423,166.5057 -77.90776,166.5057 -77.91129,166.5057 -77.91482,166.5057 -77.91835,166.5057 -77.92188,166.5057 -77.92541,166.5057 -77.92894,166.5057 -77.93247,166.5057 -77.936,166.47144 -77.936,166.43718 -77.936,166.40292 -77.936,166.36866 -77.936,166.3344 -77.936,166.30014 -77.936,166.26588 -77.936,166.23162 -77.936,166.19736 -77.936,166.1631 -77.936,166.1631 -77.93247,166.1631 -77.92894,166.1631 -77.92541,166.1631 -77.92188,166.1631 -77.91835,166.1631 -77.91482,166.1631 -77.91129,166.1631 -77.90776,166.1631 -77.90423,166.1631 -77.9007))", "dataset_titles": "McMurdo Ice Shelf AWS data; McMurdo Ice Shelf GPS survey of vertical motion; Supraglacial Lake Depths on McMurdo Ice Shelf, Antarctica; Time-lapse video of McMurdo Ice Shelf surface melting and hydrology", "datasets": [{"dataset_uid": "601116", "doi": "10.15784/601116", "keywords": "Antarctica; Cryosphere; Glaciers/Ice Sheet; Glaciology; Ice Shelf; Snow/Ice; subglacial and supraglacial water depth; supraglacial lake; Supraglacial Meltwater; water depth", "people": "Banwell, Alison; MacAyeal, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Supraglacial Lake Depths on McMurdo Ice Shelf, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601116"}, {"dataset_uid": "601106", "doi": "10.15784/601106", "keywords": "Antarctica; Cryosphere; Glaciers/Ice Sheet; Glaciology; Hydrology; Ice Shelf; Snow/Ice; Surface Hydrology; Surface Mass Balance; Weather Station Data", "people": "MacAyeal, Douglas; Banwell, Alison", "repository": "USAP-DC", "science_program": null, "title": "McMurdo Ice Shelf AWS data", "url": "https://www.usap-dc.org/view/dataset/601106"}, {"dataset_uid": "601113", "doi": "10.15784/601113", "keywords": "Antarctica; Cryosphere; Glaciers/Ice Sheet; Glaciology; Ice Shelf; Photo/Video; Supraglacial Meltwater", "people": "Banwell, Alison; MacAyeal, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Time-lapse video of McMurdo Ice Shelf surface melting and hydrology", "url": "https://www.usap-dc.org/view/dataset/601113"}, {"dataset_uid": "601107", "doi": "10.15784/601107", "keywords": "Antarctica; Cryosphere; Glaciers/Ice Sheet; Glaciology; GPS; Ice Flow Velocity; Ice Shelf; ice-shelf flexure; Snow/Ice; Surface Melt", "people": "MacAyeal, Douglas; Banwell, Alison", "repository": "USAP-DC", "science_program": null, "title": "McMurdo Ice Shelf GPS survey of vertical motion", "url": "https://www.usap-dc.org/view/dataset/601107"}], "date_created": "Tue, 24 Jul 2018 00:00:00 GMT", "description": "Meltwater lakes that sit on top of Antarctica\u0027s floating ice shelves have likely contributed to the dramatic changes seen in Antarctica\u0027s glacial ice cover over the past two decades. In 2002, the 1,600-square-kilometer Larsen B Ice Shelf located on the Eastern side of the Antarctic Peninsula, for example, broke into thousands of small icebergs, which subsequently floated away as a result of the formation of more than 2,000 meltwater lakes on its surface over the prior decade. Our research project addresses the reasons why surface lakes form on Antarctic ice shelves and how these surface lakes subsequently contribute to the forces that may contribute to ice-shelf breakup like that of the Larsen B. Our project focuses primarily on making precise global positioning system (GPS) measurements of ice-shelf bending in response to the filling and draining of a surface lake on the McMurdo Ice Shelf. The observed vertical displacements (on the order of tens of centimeters) in response to lake filling will be used to calibrate and test computer simulation models that predict the response of ice shelves to surface lakes more generally and in a variety of future climate conditions. Our project will make hourly measurements of both vertical ice-shelf movements (using GPS surveying instruments) and of temperature and sunlight conditions (that drive melting) around a surface lake located close to the McMurdo Station airfield. Following this initial data-gathering effort, computer simulations and other more theoretical analysis will be undertaken to determine the suitability of the chosen McMurdo Ice Shelf surface lake as a field-laboratory for continued study. Ultimately, the research will contribute to understanding of the glaciological processes that link climate change to rising sea level. A successful outcome of the research will allow glaciologists to better assess the processes that promote or erode the influence Antarctic ice shelves have in controlling the transfer of ice from the interior of Antarctica into the ocean. The project will undertake two outreach activities: (1) web-posting of a field-activity journal and (2) establishing an open-access glaciological teaching and outreach web-sharing site for the International Glaciological Society.\u003cbr/\u003e\u003cbr/\u003eThe proposed project seeks to experimentally verify a theory of ice-shelf instability proposed to explain the explosive break-up of Larsen B Ice Shelf in 2002. This theory holds that the filling and draining of supraglacial lakes on floating ice shelves induces sufficient flexure stress within the ice to (a) induce upward/downward propagating fractures originating at the base/surface of the ice shelf that (b) dissect the ice shelf into fragments that tend to have widths less than about half the ice thickness. The significance of narrow widths is that they promote capsize of the ice-shelf fragments during the break-up process. This capsize releases large amounts of gravitational potential energy (comparable to thousands of kilotons of TNT for the Larsen B Ice Shelf) thereby promoting explosiveness of the Larsen B event. The observational motivation for experimentally verifying the surface-lake mechanism for ice-shelf breakup is based on the fact that \u003e2,000 surface lakes developed on the Larsen B Ice Shelf in the decade prior to its break up, and that these lakes were observed (via satellite imagery) to drain in a coordinated fashion during the day prior to the initiation of the break up.\u003cbr/\u003e\u003cbr/\u003eThe field-observation component of the project will focus on a supraglacial lake on the McMurdo Ice Shelf where there is persistent summer season surface melting. The lake will be studied during a single provisional field season to determine whether grooming of surrounding surface streams and shorelines with heavy construction equipment will allow surface water to be manually encouraged to fill the lake. If successfully encouraged to develop, the McMurdo Ice Shelf surface lake will allow measurements of key ice-shelf flexure and stress variables needed to develop the theory of ice-shelf surface lakes without having to access the much more logistically demanding surface lakes of ice-shelves located elsewhere in Antarctica. Data to be gathered during the 6-week provisional field season include: energy- and water-balance parameters determining how the surface lake grows and fills, and various global positioning system measurements of the vertical bending of the ice sheet in response to the changing meltwater load contained within the surface lake. These data will be used to (1) constrain a computer model of viscoelastic flexure and possible fracture of the ice shelf in response to the increasing load of meltwater in the lake, and (2) determine whether continued study of the incipient surface-meltwater lake features on the McMurdo Ice Shelf provides a promising avenue for constraining the more-general behavior of surface meltwater lakes on other ice shelves located in warmer parts of Antarctica. Computer models constrained by the observational data obtained from the field project will inform energy- and water-balance models of ice shelves in general, and allow more accurate forecasts of changing ice-shelf conditions surrounding the inland ice of Antarctica. The project will create the first-ever ground-based observations useful for spawning the development of models capable of predicting viscoelastic and fracture behavior of ice shelves in response to supraglacial lake evolution, including slow changes due to energy balance effects, as well as fast changes due to filling and draining.", "east": 166.5057, "geometry": "POINT(166.3344 -77.91835)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS", "is_usap_dc": true, "keywords": "AWOS; USAP-DC", "locations": null, "north": -77.9007, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "MacAyeal, Douglas", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e AWOS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.936, "title": "Impact of Supraglacial Lakes on Ice-Shelf Stability", "uid": "p0000138", "west": 166.1631}, {"awards": "1246045 Waddington, Edwin", "bounds_geometry": "POLYGON((-180 -70,-144 -70,-108 -70,-72 -70,-36 -70,0 -70,36 -70,72 -70,108 -70,144 -70,180 -70,180 -72,180 -74,180 -76,180 -78,180 -80,180 -82,180 -84,180 -86,180 -88,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -88,-180 -86,-180 -84,-180 -82,-180 -80,-180 -78,-180 -76,-180 -74,-180 -72,-180 -70))", "dataset_titles": "Code for inference of fabric from sonic velocity and thin-section measurements.; Code for models involving stochastic treatment of ice fabric", "datasets": [{"dataset_uid": "000244", "doi": "", "keywords": null, "people": null, "repository": "Github", "science_program": null, "title": "Code for models involving stochastic treatment of ice fabric", "url": "https://github.com/mjhay/stochastic_fabric"}, {"dataset_uid": "000243", "doi": "", "keywords": null, "people": null, "repository": "Github", "science_program": null, "title": "Code for inference of fabric from sonic velocity and thin-section measurements.", "url": "https://github.com/mjhay/neem_sonic_model"}], "date_created": "Mon, 02 Apr 2018 00:00:00 GMT", "description": "Waddington/1246045 \u003cbr/\u003e\u003cbr/\u003eThis award supports a project to investigate the onset and growth of folds and other disturbances seen in the stratigraphic layers of polar ice sheets. The intellectual merit of the work is that it will lead to a better understanding of the grain-scale processes that control the development of these stratigraphic features in the ice and will help answer questions such as what processes can initiate such disturbances. Snow is deposited on polar ice sheets in layers that are generally flat, with thicknesses that vary slowly along the layers. However, ice cores and ice-penetrating radar show that in some cases, after conversion to ice, and following lengthy burial, the layers can become folded, develop pinch-and-swell structures (boudinage), and be sheared by ice flow, at scales ranging from centimeters to hundreds of meters. The processes causing these disturbances are still poorly understood. Disturbances appear to develop first at the ice-crystal scale, then cascade up to larger scales with continuing ice flow and strain. Crystal-scale processes causing distortions of cm-scale layers will be modeled using Elle, a microstructure-modeling package, and constrained by fabric thin-sections and grain-elongation measurements from the West Antarctic Ice Sheet divide ice-core. A full-stress continuum anisotropic ice-flow model coupled to an ice-fabric evolution model will be used to study bulk flow of anisotropic ice, to understand evolution and growth of flow disturbances on the meter and larger scale. Results from this study will assist in future ice-core site selection, and interpretation of stratigraphy in ice cores and radar, and will provide improved descriptions of rheology and stratigraphy for ice-sheet flow models.The broader impacts are that it will bring greater understanding to ice dynamics responsible for stratigraphic disturbance. This information is valuable to constrain depth-age relationships in ice cores for paleoclimate study. This will allow researchers to put current climate change in a more accurate context. This project will provide three years of support for a graduate student as well as support and research experience for an undergraduate research assistant; this will contribute to development of talent needed to address important future questions in glaciology and climate change. The research will be communicated to the public through outreach events and results from the study will be disseminated through public and professional meetings as well as journal publications. The project does not require field work in Antarctica.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -70.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Waddington, Edwin D.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "Github", "repositories": "Other", "science_programs": null, "south": -90.0, "title": "Anisotropic Ice and Stratigraphic Disturbances", "uid": "p0000073", "west": -180.0}, {"awards": "1543380 Shadwick, Elizabeth", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of LMG1704", "datasets": [{"dataset_uid": "002732", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1704", "url": "https://www.rvdata.us/search/cruise/LMG1704"}, {"dataset_uid": "001364", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG1704"}], "date_created": "Fri, 29 Dec 2017 00:00:00 GMT", "description": "Interest in the reduced alkalinity of high latitude waters under conditions of enhanced CO2 uptake from the atmosphere have been the impetus of numerous recent studies of bio-stressors in the polar marine environment. The project seeks to improve our understanding of the variance of coastal Southern Ocean carbonate species (CO2 system), its diurnal and inter-annual variability, by acquiring autonomous, high frequency observations from an Antarctic coastal mooring(s). \u003cbr/\u003e\u003cbr/\u003eA moored observing system co-located within the existing Palmer LTER array will measure pH, CO2 partial pressure, temperature, salinity and dissolved oxygen with 3-hour frequency in this region of the West Antarctic Peninsula continental shelf. Such observations will help estimate the dominant physical and biological controls on the seasonal variations in the CO2 system in coastal Antarctic waters, including the sign, seasonality and the flux of the net annual air-sea exchange of carbon dioxide. The Palmer LTER site is experiencing rapid ecological change in the West Antarctic Peninsula, a region that is warming at rates faster than any other region of coastal Antarctica.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e XBT; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS", "is_usap_dc": false, "keywords": "R/V LMG; LMG1704", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Shadwick, Elizabeth; Shadwick, Elizabeth", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "Other", "science_programs": null, "south": null, "title": "Resolving CO2 System Seasonality in the West Antarctic Peninsula with Autonomous Observations", "uid": "p0000875", "west": null}, {"awards": "1565576 Pettit, Erin", "bounds_geometry": "POLYGON((-62.2 -65.5,-62.12 -65.5,-62.04 -65.5,-61.96 -65.5,-61.88 -65.5,-61.8 -65.5,-61.72 -65.5,-61.64 -65.5,-61.56 -65.5,-61.48 -65.5,-61.4 -65.5,-61.4 -65.53,-61.4 -65.56,-61.4 -65.59,-61.4 -65.62,-61.4 -65.65,-61.4 -65.68,-61.4 -65.71,-61.4 -65.74,-61.4 -65.77,-61.4 -65.8,-61.48 -65.8,-61.56 -65.8,-61.64 -65.8,-61.72 -65.8,-61.8 -65.8,-61.88 -65.8,-61.96 -65.8,-62.04 -65.8,-62.12 -65.8,-62.2 -65.8,-62.2 -65.77,-62.2 -65.74,-62.2 -65.71,-62.2 -65.68,-62.2 -65.65,-62.2 -65.62,-62.2 -65.59,-62.2 -65.56,-62.2 -65.53,-62.2 -65.5))", "dataset_titles": "Scar Inlet Terrestrial Radar Interferometry; Weather data from LARISSA / SCAR Inlet Rapid AMIGOS and cGPS stations", "datasets": [{"dataset_uid": "601078", "doi": "10.15784/601078", "keywords": "Antarctica; Antarctic Peninsula; Bathymetry/Topography; Cryosphere; Glaciers/Ice Sheet; Glaciology; Navigation; Radar; Radar Interferometer", "people": "Truffer, Martin", "repository": "USAP-DC", "science_program": null, "title": "Scar Inlet Terrestrial Radar Interferometry", "url": "https://www.usap-dc.org/view/dataset/601078"}, {"dataset_uid": "601084", "doi": "10.15784/601084", "keywords": "Antarctica; Antarctic Peninsula; Atmosphere; Automated Weather Station (AWS); Cryosphere; Flask Glacier; Foehn Winds; Glaciers/Ice Sheet; LARISSA; Larsen B Ice Shelf; Meteorology; Scar Inlet; WeatherStation; Wind Speed", "people": "Scambos, Ted", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Weather data from LARISSA / SCAR Inlet Rapid AMIGOS and cGPS stations", "url": "https://www.usap-dc.org/view/dataset/601084"}], "date_created": "Wed, 20 Dec 2017 00:00:00 GMT", "description": "This award supports a Rapid Response Research (RAPID) project to observe the current weakened state of the Scar Inlet Ice Shelf, and potentially capture data during its anticipated disintegration. The Scar Inlet Ice Shelf (SIIS) is the southern remnant of the former Larsen B Ice Shelf, which disintegrated in March of 2002. Since then, the SIIS has weakened significantly but has not yet broken up. Cooler conditions than those seen prior to 2006 have reduced the chance of a disintegration in recent years, although a single warm season is likely to be enough to trigger such an event. The predicted \"Super El Nino\" for this austral summer may have significant effects on Antarctica\u0027s weather, potentially leading to a break-up or disintegration this year. Given the very weak state of the SIIS, it is urgent that we act now to better understand the processes involved in shelf disintegration or break-up of ice shelves. The goal of this work is to collect several key data sets, publish initial observations and preliminary conclusions, and then make the complete data record available to all scientists.\u003cbr/\u003e\u003cbr/\u003eExtreme changes in the stress conditions on the SIIS resulted from both the loss of the Larsen B ice plate and the continued inflow of ice from three large glaciers (Flask, Leppard, and Starbuck). The SIIS now has a number of large rifts and it is expected to break up or disintegrate in the very near future. Past research has made use of satellite data and weather instruments, establishing many of the current ideas regarding ice shelf break-ups and ice shelf weakening. Additional ground-based data to be collected under this study will test a number of hypotheses regarding pre-disintegration characteristics, triggering mechanisms, fracturing processes, runaway feedback effects, and stabilizing mechanisms. The project will collect extensive multi-instrument field observations of the SIIS and possibly capture a major disintegration event. In collaboration with the British Antarctic Survey, a team of 4 people will be deployed via Twin Otter for up to 4 weeks to a site with a broad view of the shelf and will install several temporary observing instruments there. The study derives its intellectual merit from the role of the Antarctic Peninsula as a microcosm of how other parts of Antarctica might evolve and de-glaciate in the next few centuries. The broader impacts include an opportunity to educate the public about the anticipated collapse of this remnant ice shelf and its relationship to future changes in Antarctica. The potential for wide media coverage (through a connection with the National Geographic) will underscore the critical changes scientists are observing in the crysophere driven by climate change. This proposal requires field work in Antarctica.", "east": -61.4, "geometry": "POINT(-61.8 -65.65)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-1565576; Not provided", "locations": null, "north": -65.5, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Glaciology", "paleo_time": null, "persons": "Pettit, Erin", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "LARISSA", "south": -65.8, "title": "RAPID: Observing the Disintegration of the Scar Inlet Ice Shelf", "uid": "p0000274", "west": -62.2}, {"awards": "1341712 Hallet, Bernard", "bounds_geometry": "POLYGON((160.9 -76.7,161.08 -76.7,161.26 -76.7,161.44 -76.7,161.62 -76.7,161.8 -76.7,161.98 -76.7,162.16 -76.7,162.34 -76.7,162.52 -76.7,162.7 -76.7,162.7 -76.79,162.7 -76.88,162.7 -76.97,162.7 -77.06,162.7 -77.15,162.7 -77.24,162.7 -77.33,162.7 -77.42,162.7 -77.51,162.7 -77.6,162.52 -77.6,162.34 -77.6,162.16 -77.6,161.98 -77.6,161.8 -77.6,161.62 -77.6,161.44 -77.6,161.26 -77.6,161.08 -77.6,160.9 -77.6,160.9 -77.51,160.9 -77.42,160.9 -77.33,160.9 -77.24,160.9 -77.15,160.9 -77.06,160.9 -76.97,160.9 -76.88,160.9 -76.79,160.9 -76.7))", "dataset_titles": "Long-term rock abrasion study in the Dry Valleys", "datasets": [{"dataset_uid": "601060", "doi": "10.15784/601060", "keywords": "Antarctica; Cryosphere; Dry Valleys; Geology/Geophysics - Other; Rocks", "people": "Sletten, Ronald S.; Hallet, Bernard; Malin, Michael", "repository": "USAP-DC", "science_program": null, "title": "Long-term rock abrasion study in the Dry Valleys", "url": "https://www.usap-dc.org/view/dataset/601060"}], "date_created": "Fri, 13 Oct 2017 00:00:00 GMT", "description": "Many of the natural processes that modify the landscape inhabited by humans occur over very long timescales, making them difficult to observe. Exceptions include rare catastrophic events such as earthquakes, volcanic eruptions, and floods that occur on short timescales. Many significant processes that affect the land and landscape that we inhabit operate on time scales imperceptible to humans. One of these processes is wind transport of sand, with related impacts to exposed rock surfaces and man-made objects, including buildings, windshields, solar panels and wind-farm turbine blades. The goal of this project is to gain an understanding of wind erosion processes over long timescales, in the Antarctic Dry Valleys, a cold desert environment where there were no competing processes (such as rain and vegetation) that might mask the effects. The main objective is recovery of rock samples that were deployed in 1983/1984 at 11 locations in the Antarctic Dry Valleys, along with measurements on the rock samples and characterization of the sites. In the late 1980s and early 1990s some of these samples were returned and indicated more time was needed to accumulate information about the timescales and impacts of the wind erosion processes. This project will allow collection of the remaining samples from this experiment after 30 to 31 years of exposure. The field work will be carried out during the 2014/15 Austral summer. The results will allow direct measurement of the abrasion rate and hence the volumes and timescales of sand transport; this will conclude the longest direct examination of such processes ever conducted. Appropriate scaling of the results may be applied to buildings, vegetation (crops), and other aspects of human presence in sandy and windy locations, in order to better determine the impact of these processes and possible mitigation of the impacts. The project is a collaborative effort between a small business, Malin Space Science Systems (MSSS), and the University of Washington (UW). MSSS will highlight this Antarctic research on its web site, by developing thematic presentations describing our research and providing a broad range of visual materials. The public will be engaged through daily updates on a website and through links to material prepared for viewing in Google Earth. UW students will be involved in the laboratory work and in the interpretation of the results.\u003cbr\u003eTechnical Description of Project:\u003cbr\u003eThe goal of this project is to study the role of wind abrasion by entrained particles in the evolution of the McMurdo Dry Valleys in the Transantarctic Mountains. During the 1983 to 1984 field seasons, over 5000 rock targets were installed at five heights facing the 4 cardinal directions at 10 locations (with an additional site containing fewer targets) to study rates of physical weathering due primarily to eolian abrasion. In addition, rock cubes and cylinders were deployed at each site to examine effects of chemical weathering. The initial examination of samples returned after 1, 5, and 10 years of exposure, showed average contemporary abrasion rates consistent with those determined by cosmogenic isotope studies, but further stress that \"average\" should not be interpreted as meaning \"uniform.\" The samples will be characterized using mass measurements wtih 0.01 mg precision balances, digital microphotography to compare the evolution of their surface features and textures, SEM imaging to examine the micro textures of abraded rock surfaces, and optical microscopy of thin sections of a few samples to examine the consequences of particle impacts extending below the abraded surfaces. As much as 60-80% of the abrasion measured in samples from 1984-1994 appears to have occurred during a few brief hours in 1984. This is consistent with theoretical models that suggest abrasion scales as the 5th power of wind velocity. The field work will allow return of multiple samples after three decades of exposure, which will provide a statistical sampling (beyond what is acquired by studying a single sample), and will yield the mass loss data in light of complementary environmental and sand kinetic energy flux data from other sources (e.g. LTER meteorology stations). This study promises to improve insights into one of the principal active geomorphic process in the Dry Valleys, an important cold desert environment, and the solid empirical database will provide general constraints on eolian abrasion under natural conditions.", "east": 162.7, "geometry": "POINT(161.8 -77.15)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -76.7, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Hallet, Bernard; Sletten, Ronald S.", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.6, "title": "Collaborative Proposal: Decades-long Experiment on Wind-Driven Rock Abrasion in the Ice-Free Valleys, Antarctica", "uid": "p0000074", "west": 160.9}, {"awards": "1043576 Crockett, Elizabeth; 1043781 O\u0027Brien, Kristin", "bounds_geometry": "POLYGON((-64.45 -63.467,-64.2633 -63.467,-64.0766 -63.467,-63.8899 -63.467,-63.7032 -63.467,-63.5165 -63.467,-63.3298 -63.467,-63.1431 -63.467,-62.9564 -63.467,-62.7697 -63.467,-62.583 -63.467,-62.583 -63.5653,-62.583 -63.6636,-62.583 -63.7619,-62.583 -63.8602,-62.583 -63.9585,-62.583 -64.0568,-62.583 -64.1551,-62.583 -64.2534,-62.583 -64.3517,-62.583 -64.45,-62.7697 -64.45,-62.9564 -64.45,-63.1431 -64.45,-63.3298 -64.45,-63.5165 -64.45,-63.7032 -64.45,-63.8899 -64.45,-64.0766 -64.45,-64.2633 -64.45,-64.45 -64.45,-64.45 -64.3517,-64.45 -64.2534,-64.45 -64.1551,-64.45 -64.0568,-64.45 -63.9585,-64.45 -63.8602,-64.45 -63.7619,-64.45 -63.6636,-64.45 -63.5653,-64.45 -63.467))", "dataset_titles": "Electronic fishing logs; Expedition data of LMG1104; Redox Balance in Antarctic Notothenioid Fishes", "datasets": [{"dataset_uid": "002687", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1104", "url": "https://www.rvdata.us/search/cruise/LMG1104"}, {"dataset_uid": "600390", "doi": "10.15784/600390", "keywords": "Antarctica; Biology; Southern Ocean", "people": "Crockett, Elizabeth", "repository": "USAP-DC", "science_program": null, "title": "Electronic fishing logs", "url": "https://www.usap-dc.org/view/dataset/600390"}, {"dataset_uid": "600382", "doi": "10.15784/600382", "keywords": "Antarctica; Antarctic Peninsula; Biology; Biosphere; Fish; Sample/Collection Description; Southern Ocean", "people": "O\u0027Brien, Kristin", "repository": "USAP-DC", "science_program": null, "title": "Redox Balance in Antarctic Notothenioid Fishes", "url": "https://www.usap-dc.org/view/dataset/600382"}], "date_created": "Tue, 06 Dec 2016 00:00:00 GMT", "description": "Antarctic channichthyid icefishes are stunning examples of the unique physiological traits that can arise during evolution in a constantly cold environment. Icefishes are the only vertebrates that as adults, lack the circulating oxygen-binding protein hemoglobin (Hb); several species within this family also lack the intracellular oxygen-binding protein myoglobin (Mb) in their heart ventricle. The loss of Hb and Mb has resulted in striking modifications in the cardiovascular system to ensure adequate tissue oxygenation, some of which are energetically costly. Recent indicate there may be at least one benefit to not expressing these heme-centered proteins - oxidized proteins and lipids are higher in red-blooded notothenioids compared to icefishes. The research will address the hypothesis that the loss of Hb and Mb reduces oxidative stress in icefishes compared to red-blooded notothenioid fishes, resulting in a lower rate of protein turnover and energetic cost savings. Specifically, the project will (1) Characterize levels of oxidative stress in red- and white-blooded notothenioid fishes, (2) Determine if red- and white-blooded notothenioids differ in their regulation of iron, (3) Determine if lower levels of oxidized proteins in icefishes result in lower rates of protein turnover and energetic cost savings, and (4) Determine if oxygen-binding proteins promote oxidative stress in-vivo and in-vitro.\u003cbr/\u003e\u003cbr/\u003eThe results will contribute to the understanding of iron-catalyzed oxidative stress, which is associated with the progression of Alzheimer\u0027s, Parkinson\u0027s and cardiovascular diseases. Moreover, the research will increase understanding of factors related to iron metabolism and oxidative stress in notothenioid fishes that may have played key roles in the success of channichthyid icefishes. The broader impacts include development of a website will enable teachers and students to learn more about the fascinating biology of Antarctic icefishes, as well as the impacts of global climate change and commercial fishing activities on Antarctic fishes. Additionally, Alaska Native high school and undergraduate students will be involved in research at the University of Alaska, Fairbanks.", "east": -62.583, "geometry": "POINT(-63.5165 -63.9585)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "R/V LMG; Not provided", "locations": null, "north": -63.467, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Crockett, Elizabeth; O\u0027Brien, Kristin", "platforms": "Not provided; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "Other; USAP-DC", "science_programs": null, "south": -64.45, "title": "Collaborative research: Redox Balance in Antarctic Notothenioid fishes: Do Icefishes have an Advantage?", "uid": "p0000320", "west": -64.45}, {"awards": "1246202 Hofmann, Gretchen", "bounds_geometry": "POLYGON((163.317388 -77.3354,163.6520742 -77.3354,163.9867604 -77.3354,164.3214466 -77.3354,164.6561328 -77.3354,164.990819 -77.3354,165.3255052 -77.3354,165.6601914 -77.3354,165.9948776 -77.3354,166.3295638 -77.3354,166.66425 -77.3354,166.66425 -77.386975,166.66425 -77.43855,166.66425 -77.490125,166.66425 -77.5417,166.66425 -77.593275,166.66425 -77.64485,166.66425 -77.696425,166.66425 -77.748,166.66425 -77.799575,166.66425 -77.85115,166.3295638 -77.85115,165.9948776 -77.85115,165.6601914 -77.85115,165.3255052 -77.85115,164.990819 -77.85115,164.6561328 -77.85115,164.3214466 -77.85115,163.9867604 -77.85115,163.6520742 -77.85115,163.317388 -77.85115,163.317388 -77.799575,163.317388 -77.748,163.317388 -77.696425,163.317388 -77.64485,163.317388 -77.593275,163.317388 -77.5417,163.317388 -77.490125,163.317388 -77.43855,163.317388 -77.386975,163.317388 -77.3354))", "dataset_titles": "mRNA sequencing - RNAseq; Nearshore pH, temperature, (salinity, depth) at mooring sites in McMurdo Sound, Antarctica, Overwinter 2011-2016; pH temp sal measurement data", "datasets": [{"dataset_uid": "601141", "doi": "10.15784/601141", "keywords": "Antarctica; Cryosphere; McMurdo Sound; McMurdo Station; Mooring; mooring data; Oceans; ocean temperature; PH; Physical Oceanography; Ross Sea; Sea Surface Temperature; seawater measurements; Southern Ocean; Temperature", "people": "Hoshijima, Umihiko; Hofmann, Gretchen; Kapsenberg, Lydia", "repository": "USAP-DC", "science_program": null, "title": "Nearshore pH, temperature, (salinity, depth) at mooring sites in McMurdo Sound, Antarctica, Overwinter 2011-2016", "url": "https://www.usap-dc.org/view/dataset/601141"}, {"dataset_uid": "000181", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "mRNA sequencing - RNAseq", "url": "http://www.bco-dmo.org/dataset/639502"}, {"dataset_uid": "002576", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "pH temp sal measurement data", "url": "https://www.bco-dmo.org/dataset/639502"}], "date_created": "Tue, 13 Sep 2016 00:00:00 GMT", "description": "The research supported in this project will examine the effects of environmental change on a key Antarctic marine invertebrate, a pelagic mollusk, the pteropod, Limacina helicina antarctica. There are two main activities in this project: (1) to deploy oceanographic equipment ? in this case, autonomously recording pH sensors called SeaFETs and other devices that record temperature and salinity, and (2) to use these environmental data in the laboratory at McMurdo Station to study the response of the marine invertebrates to future changes in water quality that is expected in the next few decades. Notably, changes in oceanic pH (aka ocean acidification) and ocean warming are projected to be particularly threatening to calcifying marine organisms in cold-water, high latitude seas, making tolerance data on these organisms a critical research need in Antarctic marine ecosystems. \u003cbr/\u003e\u003cbr/\u003eThese Antarctic shelled-animals are especially vulnerable to dissolution stress from ocean acidification because they currently inhabit seawater that is barely at the saturation level to support biogenic calcification. Indeed, these polar animals are considered to be the \u0027first responders\u0027 to chemical changes in the surface oceans. Thus, this project will lead to information about the adaptive capacity of L. helcina antarctica. From an ecological perspective this is important because this animal is a critical part of the Antarctic food chain in coastal waters and changes in its abundance will impact other species. Finally, the research conducted in this project will serve as a training and educational opportunity for undergraduate and graduate students as well as postdoctoral scholars.", "east": 166.66425, "geometry": "POINT(164.990819 -77.593275)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.3354, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Hofmann, Gretchen", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "BCO-DMO; USAP-DC", "science_programs": null, "south": -77.85115, "title": "Ocean Acidification Seascape: Linking Natural Variability and Anthropogenic changes in pH and Temperature to Performance in Calcifying Antarctic Marine Invertebrates", "uid": "p0000390", "west": 163.317388}, {"awards": "0944358 Dugger, Katie; 0944141 Ballard, Grant; 0944411 Ainley, David", "bounds_geometry": "POLYGON((165.9 -76.9,166.25 -76.9,166.6 -76.9,166.95 -76.9,167.3 -76.9,167.65 -76.9,168 -76.9,168.35 -76.9,168.7 -76.9,169.05 -76.9,169.4 -76.9,169.4 -76.97,169.4 -77.04,169.4 -77.11,169.4 -77.18,169.4 -77.25,169.4 -77.32,169.4 -77.39,169.4 -77.46,169.4 -77.53,169.4 -77.6,169.05 -77.6,168.7 -77.6,168.35 -77.6,168 -77.6,167.65 -77.6,167.3 -77.6,166.95 -77.6,166.6 -77.6,166.25 -77.6,165.9 -77.6,165.9 -77.53,165.9 -77.46,165.9 -77.39,165.9 -77.32,165.9 -77.25,165.9 -77.18,165.9 -77.11,165.9 -77.04,165.9 -76.97,165.9 -76.9))", "dataset_titles": "Adelie penguin banding data 1994-2009; Adelie penguin chick counts 1997-2009; Adelie penguin chick measurements 1996 - 2009; Adelie penguin diet data 1996 - 2009; Adelie penguin dive data 1999-2009; Adelie penguin Geolocation Sensor data 2003-2007; Adelie penguin resighting data 1997-2009; Adelie penguin resighting data 1997-2021 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science; Adelie penguin satellite position data 2000-2009; Adelie penguin weighbridge data 1994-2009; Daily weather observations 1996-2009; Leopard Seal counts 1997-2009; PRBO/California Avian Data Center (CADC)", "datasets": [{"dataset_uid": "600013", "doi": "", "keywords": null, "people": "Ballard, Grant", "repository": "USAP-DC", "science_program": null, "title": "Adelie penguin dive data 1999-2009", "url": "https://www.usap-dc.org/view/dataset/600013"}, {"dataset_uid": "600011", "doi": "", "keywords": null, "people": "Ballard, Grant", "repository": "USAP-DC", "science_program": null, "title": "Adelie penguin resighting data 1997-2009", "url": "https://www.usap-dc.org/view/dataset/600011"}, {"dataset_uid": "600010", "doi": "", "keywords": "Biosphere; Oceans", "people": "Ballard, Grant", "repository": "USAP-DC", "science_program": null, "title": "Leopard Seal counts 1997-2009", "url": "https://www.usap-dc.org/view/dataset/600010"}, {"dataset_uid": "600009", "doi": "", "keywords": null, "people": "Ballard, Grant", "repository": "USAP-DC", "science_program": null, "title": "Adelie penguin Geolocation Sensor data 2003-2007", "url": "https://www.usap-dc.org/view/dataset/600009"}, {"dataset_uid": "600014", "doi": "", "keywords": null, "people": "Ballard, Grant", "repository": "USAP-DC", "science_program": null, "title": "Adelie penguin weighbridge data 1994-2009", "url": "https://www.usap-dc.org/view/dataset/600014"}, {"dataset_uid": "000154", "doi": "", "keywords": null, "people": null, "repository": "CADC", "science_program": null, "title": "PRBO/California Avian Data Center (CADC)", "url": "http://data.prbo.org/apps/penguinscience/"}, {"dataset_uid": "600015", "doi": "", "keywords": null, "people": "Ballard, Grant", "repository": "USAP-DC", "science_program": null, "title": "Daily weather observations 1996-2009", "url": "https://www.usap-dc.org/view/dataset/600015"}, {"dataset_uid": "600012", "doi": "", "keywords": null, "people": "Ballard, Grant", "repository": "USAP-DC", "science_program": null, "title": "Adelie penguin satellite position data 2000-2009", "url": "https://www.usap-dc.org/view/dataset/600012"}, {"dataset_uid": "600007", "doi": "", "keywords": "Biosphere", "people": "Ballard, Grant", "repository": "USAP-DC", "science_program": null, "title": "Adelie penguin chick counts 1997-2009", "url": "https://www.usap-dc.org/view/dataset/600007"}, {"dataset_uid": "600006", "doi": "", "keywords": null, "people": "Ballard, Grant", "repository": "USAP-DC", "science_program": null, "title": "Adelie penguin chick measurements 1996 - 2009", "url": "https://www.usap-dc.org/view/dataset/600006"}, {"dataset_uid": "600005", "doi": "", "keywords": null, "people": "Ballard, Grant", "repository": "USAP-DC", "science_program": null, "title": "Adelie penguin banding data 1994-2009", "url": "https://www.usap-dc.org/view/dataset/600005"}, {"dataset_uid": "600008", "doi": "", "keywords": null, "people": "Ballard, Grant", "repository": "USAP-DC", "science_program": null, "title": "Adelie penguin diet data 1996 - 2009", "url": "https://www.usap-dc.org/view/dataset/600008"}, {"dataset_uid": "601444", "doi": "10.15784/601444", "keywords": "Adelie Penguin; Antarctica; Biosphere; Cryosphere; Demography; Mark-Recapture; Monitoring; Penguin; Ross Island", "people": "Ballard, Grant", "repository": "USAP-DC", "science_program": null, "title": "Adelie penguin resighting data 1997-2021 from the California Avian Data Center hosted by Point Reyes Bird Observatory Conservation Science", "url": "https://www.usap-dc.org/view/dataset/601444"}], "date_created": "Sun, 13 Dec 2015 00:00:00 GMT", "description": "While changes in populations typically are tracked to gauge the impact of climate or habitat change, the process involves the response of individuals as each copes with an altered environment. In a study of Adelie penguins that spans 13 breeding seasons, results indicate that only 20% of individuals within a colony successfully raise offspring, and that they do so because of their exemplary foraging proficiency. Moreover, foraging appears to require more effort at the largest colony, where intraspecific competition is higher than at small colonies, and also requires more proficiency during periods of environmental stress. When conditions are particularly daunting, emigration dramatically increases, countering the long-standing assumption that Ad\u00e9lie penguins are highly philopatric. The research project will 1) determine the effect of age, experience and physiology on individual foraging efficiency; 2) determine the effect of age, experience, and individual quality on breeding success and survival in varying environmental and competitive conditions at the colony level; and 3) develop a comprehensive model for the Ross-Beaufort Island metapopulation dynamics. Broader impacts include training of interns, continuation of public outreach through the highly successful project website penguinscience.com, development of classroom materials and other standards-based instructional resources.", "east": 169.4, "geometry": "POINT(167.65 -77.25)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -76.9, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Ainley, David; Dugger, Katie; Ballard, Grant", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "Other; USAP-DC", "science_programs": null, "south": -77.6, "title": "COLLABORATIVE: Adelie Penguin Response to Climate Change at the Individual, Colony and Metapopulation Levels", "uid": "p0000318", "west": 165.9}, {"awards": "0944557 Marsh, Adam", "bounds_geometry": "POINT(166 78)", "dataset_titles": "Environmental Genomics of an Antarctic Polychaete #SRP040946", "datasets": [{"dataset_uid": "000223", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Environmental Genomics of an Antarctic Polychaete #SRP040946", "url": "https://www.ncbi.nlm.nih.gov/sra/?term=SRP040946"}], "date_created": "Tue, 13 Jan 2015 00:00:00 GMT", "description": "Genome-enabled biology provides a foundation for understanding the genetic basis of organism-environment interactions. . The research project links gene expression, genome methylation, and metabolic rates to assess the mechanisms of environmental adaptation (temperature) across multiple generations in a polar, and closely related temperate, polychaete. By comparing these two species, the research will assess how a polar environment shapes responses to environmental stress. This work will produce: 1) a database of full transcriptome (gene specific) profiling data for the polar polychaete cultured at two temperatures; 2) the contribution of genome methylation to the suppression of gene transcription activities; 3) the linkage between shifts in mRNA pools and total cellular activities (as ATP consumption via respiration); 4) an assessment of the inheritance of patterns of gene expression and metabolic activities across three generations; and 5) a simple demographic model of the polar polychaete population dynamics under normal and \u0027global-warming\u0027 temperature scenarios. Broader impacts include two outreach activities. The first is a mentoring program, where African-American undergraduate students spend 1.5 years working on a research project with a UD faculty member (2 summers plus their senior academic year). The second is a children\u0027s display activity at UD?s School of Marine Science \"Coast Day\".", "east": 166.0, "geometry": "POINT(166 -78)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -78.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Marsh, Adam G.", "platforms": "Not provided", "repo": "NCBI GenBank", "repositories": "Other", "science_programs": null, "south": -78.0, "title": "Environmental Genomics in an Antarctic polychaete", "uid": "p0000355", "west": 166.0}, {"awards": "1040945 Place, Sean; 1040957 Sarmiento, Jorge; 1447291 Place, Sean", "bounds_geometry": "POLYGON((-180 90,-144 90,-108 90,-72 90,-36 90,0 90,36 90,72 90,108 90,144 90,180 90,180 72,180 54,180 36,180 18,180 0,180 -18,180 -36,180 -54,180 -72,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -72,-180 -54,-180 -36,-180 -18,-180 0,-180 18,-180 36,-180 54,-180 72,-180 90))", "dataset_titles": "Does the strength of the carbonate pump change with ocean stratification and acidification and how? Project data; NCBI GenBank RNA sequences, Pagothenia borchgrevinki; NCBI GenBank RNA sequences, Trematomus bernacchii; NCBI GenBank RNA sequences, Trematomus newnesi; NCBI links to BioProjects of total RNA isolated from Trematomus bernacchii gill tissues acclimated to elevated temperature and pCO2, July 2015", "datasets": [{"dataset_uid": "000184", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "NCBI GenBank RNA sequences, Trematomus bernacchii", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA289753"}, {"dataset_uid": "000219", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Does the strength of the carbonate pump change with ocean stratification and acidification and how? Project data", "url": "http://www.bco-dmo.org/project/521216"}, {"dataset_uid": "000166", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "NCBI links to BioProjects of total RNA isolated from Trematomus bernacchii gill tissues acclimated to elevated temperature and pCO2, July 2015", "url": "http://www.bco-dmo.org/dataset/665853"}, {"dataset_uid": "000185", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "NCBI GenBank RNA sequences, Pagothenia borchgrevinki", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA294774"}, {"dataset_uid": "000163", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "NCBI GenBank RNA sequences, Trematomus bernacchii", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA289753"}, {"dataset_uid": "000164", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "NCBI GenBank RNA sequences, Pagothenia borchgrevinki", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA294774"}, {"dataset_uid": "000165", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "NCBI GenBank RNA sequences, Trematomus newnesi", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA294787"}, {"dataset_uid": "000186", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "NCBI GenBank RNA sequences, Trematomus newnesi", "url": "https://www.ncbi.nlm.nih.gov/bioproject/PRJNA294787"}], "date_created": "Mon, 12 Jan 2015 00:00:00 GMT", "description": "The proposed research will investigate the interacting and potentially synergistic influence of two oceanographic features - ocean acidification and the projected rise in mean sea surface temperature - on the performance of Notothenioids, the dominant fish of the Antarctic marine ecosystem. Understanding the joint effects of acidification and temperature rise on these fish is a vital component of predicting the resilience of coastal marine ecosystems. Notothenioids have repeatedly displayed a narrow window of physiological tolerances when subjected to abiotic stresses. Given that evolutionary adaptation may have led to finely-tuned traits with narrow physiological limits in these organisms, this system provides a unique opportunity to examine physiological trade-offs associated with acclimation to the multi-stressor environment expected from future atmospheric CO2 projections. Understanding these trade-offs will provide valuable insight into the capacity species have for responses to climate change via phenotypic plasticity. As an extension to functional measurements, this study will use evolutionary approaches to map variation in physiological responses onto the phylogeny of these fishes and the genetic diversity within species. These approaches offer insight into the historical constraints and future potential for evolutionary optimization. The research will significantly expand the genomic resources available to polar researchers and will support the training of graduate students and a post doc at an EPSCoR institution. Research outcomes will be incorporated into classroom curriculum.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": 90.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Integrated System Science; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Place, Sean; Sarmiento, Jorge; Dudycha, Jeffry; Kwon, Eun-Young", "platforms": "Not provided", "repo": "NCBI GenBank", "repositories": "BCO-DMO; Other", "science_programs": null, "south": -90.0, "title": "Ocean Acidification Category 1: Identifying Adaptive Responses of Polar Fishes in a Vulnerable Ecosystem", "uid": "p0000006", "west": -180.0}, {"awards": "0944201 Hofmann, Gretchen", "bounds_geometry": "POLYGON((-180 -68,-177 -68,-174 -68,-171 -68,-168 -68,-165 -68,-162 -68,-159 -68,-156 -68,-153 -68,-150 -68,-150 -69,-150 -70,-150 -71,-150 -72,-150 -73,-150 -74,-150 -75,-150 -76,-150 -77,-150 -78,-153 -78,-156 -78,-159 -78,-162 -78,-165 -78,-168 -78,-171 -78,-174 -78,-177 -78,180 -78,178 -78,176 -78,174 -78,172 -78,170 -78,168 -78,166 -78,164 -78,162 -78,160 -78,160 -77,160 -76,160 -75,160 -74,160 -73,160 -72,160 -71,160 -70,160 -69,160 -68,162 -68,164 -68,166 -68,168 -68,170 -68,172 -68,174 -68,176 -68,178 -68,-180 -68))", "dataset_titles": "Effect of Ocean Acidification on Early Life History Stages of the Antarctic Sea Urchins Sterechinus Neumayeri", "datasets": [{"dataset_uid": "600112", "doi": "10.15784/600112", "keywords": "Antarctica; Biosphere; Oceans; Southern Ocean", "people": "Hofmann, Gretchen", "repository": "USAP-DC", "science_program": null, "title": "Effect of Ocean Acidification on Early Life History Stages of the Antarctic Sea Urchins Sterechinus Neumayeri", "url": "https://www.usap-dc.org/view/dataset/600112"}], "date_created": "Tue, 23 Dec 2014 00:00:00 GMT", "description": "Abstract\u003cbr/\u003e\u003cbr/\u003eThe research examine the effects of ocean acidification on embryos and larvae of a contemporary calcifier in the coastal waters of Antarctica, the sea urchin Sterechinus neumayeri. The effect of future ocean acidification is projected to be particularly threatening to calcifying marine organisms in coldwater, high latitude seas, making tolerance data on these organisms a critical research need in Antarctic marine ecosystems. Due to a high magnesium (Mg) content of their calcitic hard parts, echinoderms are especially vulnerable to dissolution stress from ocean acidification because they currently inhabit seawater that is barely at the saturation level to support biogenic calcification. Thus, cold-water, high latitude species with a high Mg-content in their hard parts are considered to be the \u0027first responders\u0027 to chemical changes in the surface oceans. Studies in this proposal will use several metrics to examine the physiological plasticity of contemporary urchin embryos and larvae to CO2-acidified seawater, to mimic the scenarios defined by IPCC models and by analyses of future acidification predicted for the Southern Ocean. The research also will investigats the biological consequences of synergistic interactions of two converging climate change-related stressors - CO2- driven ocean acidification and ocean warming. Specifically the research will (1) assess the effect of CO2-acidified seawater on the development of early embryos and larvae, (2) using morphometrics, examine changes in the larval endoskeleton in response to development under the high-CO2 conditions of ocean acidification, (3) using a DNA microarray, profile changes in gene expression for genes involved in biomineralization and other important physiological processes, and (4) measure costs and physiological consequences of development under conditions of ocean acidification. The proposal will support the training of undergraduates, graduate students and a postdoctoral fellow. The PI also will collaborate with the UC Santa Barbara Gevirtz Graduate School of Education to link the biological effects of ocean acidification to the chemical changes expected for the Southern Ocean using the \u0027Science on a Sphere\u0027 technology. This display will be housed in an education and public outreach center, the Outreach Center for Teaching Ocean Science (OCTOS), a new state-of-the-art facility under construction at UC Santa Barbara.", "east": -150.0, "geometry": "POINT(-175 -73)", "instruments": null, "is_usap_dc": true, "keywords": "MOORINGS", "locations": null, "north": -68.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Hofmann, Gretchen", "platforms": "WATER-BASED PLATFORMS \u003e BUOYS \u003e MOORED \u003e MOORINGS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Effect of Ocean Acidification on Early Life History Stages of the Antarctic Sea Urchins Sterechinus Neumayeri", "uid": "p0000352", "west": 160.0}, {"awards": "0837559 Lee, Richard", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Belgica antarctica isolate:Palmer_Station_2011 Genome sequencing and assembly", "datasets": [{"dataset_uid": "000147", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Belgica antarctica isolate:Palmer_Station_2011 Genome sequencing and assembly", "url": "http://www.ncbi.nlm.nih.gov/bioproject/PRJNA172148"}], "date_created": "Thu, 16 Oct 2014 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).\u003cbr/\u003e\u003cbr/\u003ePolar terrestrial environments are often described as deserts, where water availability is a critical factor limiting the distribution of terrestrial organisms. In such environments, tolerance of low moisture conditions is likely as important as cold resistance. Winter survival for many polar organisms depends on a coordinated transition from feeding, growth and reproduction during short summers, to an energy-conserving dormancy coupled with enhanced resistance to environmental extremes during long, severe winters. The midge Belgica antarctica provides an excellent model system for investigating mechanisms of stress (cold and low moisture) tolerance, and the role of extreme photoperiodic changes in coordinating seasonal adaptations. The proposed research will use gene and protein level approaches to investigate the seasonal roles of dehydration and photoperiodic cues in preparing a polar insect for winter survival. The research will investigate (1) the role of aquaporins, dehydrins, and cryoprotective dehydration in seasonal survival, and (2) the role of photoperiodism in preparing for winter. Broader impacts involve engagement of K-12 educators and students, including hands-on, in-the-field research experiences for teachers, presentations at local schools, development of lesson plans and podcasts, and publication of articles in education journals. The principal investigators also will engage graduate students, undergraduates, and post-docs in the project.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Lee, Richard", "platforms": "Not provided", "repo": "NCBI GenBank", "repositories": "Other", "science_programs": null, "south": -90.0, "title": "Collaborative Proposal: Roles for Dehydration and Photoperiodism in Preparing an Antarctic Insect for the Polar Night", "uid": "p0000669", "west": -180.0}, {"awards": "1043700 Harry, Dennis", "bounds_geometry": "POLYGON((-180 -70,-176.5 -70,-173 -70,-169.5 -70,-166 -70,-162.5 -70,-159 -70,-155.5 -70,-152 -70,-148.5 -70,-145 -70,-145 -71,-145 -72,-145 -73,-145 -74,-145 -75,-145 -76,-145 -77,-145 -78,-145 -79,-145 -80,-148.5 -80,-152 -80,-155.5 -80,-159 -80,-162.5 -80,-166 -80,-169.5 -80,-173 -80,-176.5 -80,180 -80,177.5 -80,175 -80,172.5 -80,170 -80,167.5 -80,165 -80,162.5 -80,160 -80,157.5 -80,155 -80,155 -79,155 -78,155 -77,155 -76,155 -75,155 -74,155 -73,155 -72,155 -71,155 -70,157.5 -70,160 -70,162.5 -70,165 -70,167.5 -70,170 -70,172.5 -70,175 -70,177.5 -70,-180 -70))", "dataset_titles": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History; Ross Sea post-middle Miocene seismic interpretation", "datasets": [{"dataset_uid": "601227", "doi": "10.15784/601227", "keywords": "ANDRILL; Antarctica; Cryosphere; Marine Geoscience; Ross Sea; Seismic Interpretation; Seismic Reflection; Stratigraphy; Subsidence; Victoria Land Basin", "people": "Harry, Dennis L.", "repository": "USAP-DC", "science_program": "ANDRILL", "title": "Ross Sea post-middle Miocene seismic interpretation", "url": "https://www.usap-dc.org/view/dataset/601227"}, {"dataset_uid": "600128", "doi": "10.15784/600128", "keywords": "ANDRILL; Antarctica; Continental Rift; Cryosphere; Geology/Geophysics - Other; Lithosphere; Model; Ross Sea; Solid Earth; Tectonic; Transantarctic Mountains", "people": "Harry, Dennis L.", "repository": "USAP-DC", "science_program": "ANDRILL", "title": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History", "url": "https://www.usap-dc.org/view/dataset/600128"}], "date_created": "Sun, 31 Aug 2014 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eThis research will place the subsidence history of the southern Victoria Land Basin into a quantitative geodynamic context and will assess the influence of flexure associated with late Neogene volcanic loading of the crust by the Erebus Volcanic Group. This will be done by extending geodynamic models of extension in the West Antarctic Rift System to include extensional hiatuses hypothesized to have occurred during the Late Paleogene and Miocene, and by developing a new geodynamic model of volcanic loading and associated lithosphere flexure. Finite element and finite difference modeling methods will be used. In the first phase of the project, a series of extensional geodynamic models will be developed to examine the effect that proposed extensional hiatuses have on the style of extension, with emphasis placed on developing a process based understanding of the change in rift style from diffuse during the Late Cretaceous to more focused during the Cenozoic. The models will test the hypotheses that extensional hiatuses led to the change in rifting style, and will place constraints on the timing and duration of the hiatuses. The second phase of the project will use the thermal and rheological properties of the previous models to constrain the flexural rigidity of the lithosphere in order to model the flexural response to volcanic loading to test the hypotheses that flexural subsidence contributed to cyclic changes between grounded and floating ice at the ANDRILL AND-1A site, complicating interpretations of the climatic record from this core, and that flexure contributes to the stress orientation at the AND-2B site, which is inconsistent with the expected regional extensional stress orientation.\u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eThe project will train an undergraduate student and an M.S. student. Outreach activities include a planned series of talks at regional high schools, junior colleges, and 4-year colleges that have geology programs.", "east": -145.0, "geometry": "POINT(-175 -75)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; Antarctica; MARINE GEOPHYSICS; NOT APPLICABLE", "locations": "Antarctica", "north": -70.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Harry, Dennis L.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -80.0, "title": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History", "uid": "p0000467", "west": 155.0}, {"awards": "1043265 Deming, Jody", "bounds_geometry": "POLYGON((162.1397 -77.14085,162.828507 -77.14085,163.517314 -77.14085,164.206121 -77.14085,164.894928 -77.14085,165.583735 -77.14085,166.272542 -77.14085,166.961349 -77.14085,167.650156 -77.14085,168.338963 -77.14085,169.02777 -77.14085,169.02777 -77.200745,169.02777 -77.26064,169.02777 -77.320535,169.02777 -77.38043,169.02777 -77.440325,169.02777 -77.50022,169.02777 -77.560115,169.02777 -77.62001,169.02777 -77.679905,169.02777 -77.7398,168.338963 -77.7398,167.650156 -77.7398,166.961349 -77.7398,166.272542 -77.7398,165.583735 -77.7398,164.894928 -77.7398,164.206121 -77.7398,163.517314 -77.7398,162.828507 -77.7398,162.1397 -77.7398,162.1397 -77.679905,162.1397 -77.62001,162.1397 -77.560115,162.1397 -77.50022,162.1397 -77.440325,162.1397 -77.38043,162.1397 -77.320535,162.1397 -77.26064,162.1397 -77.200745,162.1397 -77.14085))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 31 Jul 2014 00:00:00 GMT", "description": "The relatively pristine Antarctic continent with its extensive maritime zone represents a unique location on the planet to investigate the long distance aerial transport and deposition of marine microorganisms. The vast extent of new sea ice that forms each winter around the continent results in large numbers of frost flowers, delicate ice-crystal structures of high salt content that form on the surface of the ice and are readily dispersed by wind. The proposed research builds on earlier work in the Arctic and tests the new hypothesis that wind-borne frost flowers provide an effective mechanism for the transport of marine bacteria over long distances, one that can be uniquely sourced and tracked by the frost flower salt signature in the Antarctic realm. A highly resolved genomic snapshot of the microbial community will be acquired at each stage in the transport path, which will track decreasing fractions of the marine microbial community as it freezes into sea ice, incorporates into frost flowers, converts to aerosols, and ultimately deposits within continental snowpack. En route from sea ice to snowpack, marine bacteria will be exposed to an array of environmental stresses, including high salinity, low temperatures, UV light and potential desiccation. A parallel proteomic analysis will enable an evaluation of the microbial response to these extreme conditions and potential survival mechanisms that allow persistence or eventual colonization of deposition sites across Antarctica. \u003cbr/\u003e\u003cbr/\u003eCurrent understanding of microbes in the Antarctic atmosphere is based on a limited number of microscopic and culture-based assays and a single report of low-resolution 16S RNA gene sequence analysis. The research will broadly impact understanding of atmospheric microbiology, from source to deposition, and various issues of microbial survival, colonization, endemism, and diversity under extreme conditions. In addition to venues that reach the scientific community, the research team will develop a permanent multi-media and artifact-based exhibit on Antarctic Microbial Transport that will be showcased at Seattle\u0027s Pacific Science Center (PSC), which educates nearly a million visitors annually.", "east": 169.02777, "geometry": "POINT(165.583735 -77.440325)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.14085, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Deming, Jody", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -77.7398, "title": "High Resolution Genomic and Proteomic Analyses of a Microbial Transport Mechanism from Antarctic Marine Waters to Permanent Snowpack", "uid": "p0000356", "west": 162.1397}, {"awards": "0934534 Sergienko, Olga", "bounds_geometry": "POLYGON((-106 -70,-105.4 -70,-104.8 -70,-104.2 -70,-103.6 -70,-103 -70,-102.4 -70,-101.8 -70,-101.2 -70,-100.6 -70,-100 -70,-100 -70.6,-100 -71.2,-100 -71.8,-100 -72.4,-100 -73,-100 -73.6,-100 -74.2,-100 -74.8,-100 -75.4,-100 -76,-100.6 -76,-101.2 -76,-101.8 -76,-102.4 -76,-103 -76,-103.6 -76,-104.2 -76,-104.8 -76,-105.4 -76,-106 -76,-106 -75.4,-106 -74.8,-106 -74.2,-106 -73.6,-106 -73,-106 -72.4,-106 -71.8,-106 -71.2,-106 -70.6,-106 -70))", "dataset_titles": "Inverted Basal Shear Stress of Antarctic and Greenland Ice Streams and Glaciers", "datasets": [{"dataset_uid": "609626", "doi": "10.7265/N5XS5SBW", "keywords": "Antarctica; Arctic; Bindschadler Ice Stream; Cryosphere; Glaciers/Ice Sheet; Glaciology; Greenland; Lambert Ice Stream; MacAyeal Ice Stream; Pine Island Glacier; Thwaites Glacier", "people": "Sergienko, Olga", "repository": "USAP-DC", "science_program": null, "title": "Inverted Basal Shear Stress of Antarctic and Greenland Ice Streams and Glaciers", "url": "https://www.usap-dc.org/view/dataset/609626"}], "date_created": "Thu, 06 Feb 2014 00:00:00 GMT", "description": "Funds are provided to enable applications of powerful mathematical concepts and computational tools for rigorous sensitivity analysis, pseudo-spectra and generalized stability theory, and advanced state estimation in the context of large-scale ice sheet modeling. At the center of the proposal is the generation and application of adjoint model (ADM) and tangent linear model (TLM) components of the new Community Ice Sheet Model (CISM). The goal will be achieved through rigorous use of automatic differentiation (AD) to ensure synchronicity between the ongoing model development and improvement in terms of better representation of higher-order stress terms (which account for crucial fast flow regimes) of the nonlinear forward model (NLM) code and the derivative codes. The adjoint enables extremely efficient computation of gradients of scalar-valued functions in very high-dimensional control spaces. A hierarchy of applications is envisioned: (1) sensitivity calculations in support of the Intergovernmental Panel on Climate Change (IPCC) in order to determine to which control variables the polar ice sheet volumes are most sensitive; based on adjoint sensitivity maps, to establish quantitative estimates of ice sheet volume changes for relevant forcing scenarios; and to assess how sensitivities change when including higher-order stress terms; (2) coupling of the ADM and TLM to calculate pseudo-spectra or singular vectors (SV?s) of relevant ice sheet norms; SV?s provide perturbation patterns which lead to non-normal growth, optimally amplifying norm kernels over finite times; among the many applications of SV?s are optimal initialization of ensembles to assess uncertainties; SV?s are calculated through matrix-free iterative solution of a generalized eigenvalue problem via Lanczos or Arnoldi implicit restart algorithms; (3) a long-term goal is the development of an ice sheet state estimation system based on the adjoint or Lagrange Multiplier Method (LMM) in order to synthesize, in a formal manner, the increasing number and heterogeneous types of observations with a three-dimensional, state-of-the-art ice sheet model; an important requirement is that the adjoint incorporate new schemes that are being developed for CISM to capture crucial, but as yet unrepresented physical processes.", "east": -100.0, "geometry": "POINT(-103 -73)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e VISUAL OBSERVATIONS", "is_usap_dc": true, "keywords": "Not provided; AGDC-project; AGDC; inverse model; GROUND-BASED OBSERVATIONS; Basal Shear Stress", "locations": null, "north": -70.0, "nsf_funding_programs": "Arctic Natural Sciences", "paleo_time": null, "persons": "Sergienko, Olga", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.0, "title": "COLLABORATIVE RESEARCH: Enabling ice sheet sensitivity and stability analysis with a large-scale higher-order ice sheet model\u0027s adjoint to support sea level change assessment", "uid": "p0000048", "west": -106.0}, {"awards": "0944248 MacAyeal, Douglas", "bounds_geometry": "POLYGON((-63.72 -63.73,-62.893 -63.73,-62.066 -63.73,-61.239 -63.73,-60.412 -63.73,-59.585 -63.73,-58.758 -63.73,-57.931 -63.73,-57.104 -63.73,-56.277 -63.73,-55.45 -63.73,-55.45 -64.0876,-55.45 -64.4452,-55.45 -64.8028,-55.45 -65.1604,-55.45 -65.518,-55.45 -65.8756,-55.45 -66.2332,-55.45 -66.5908,-55.45 -66.9484,-55.45 -67.306,-56.277 -67.306,-57.104 -67.306,-57.931 -67.306,-58.758 -67.306,-59.585 -67.306,-60.412 -67.306,-61.239 -67.306,-62.066 -67.306,-62.893 -67.306,-63.72 -67.306,-63.72 -66.9484,-63.72 -66.5908,-63.72 -66.2332,-63.72 -65.8756,-63.72 -65.518,-63.72 -65.1604,-63.72 -64.8028,-63.72 -64.4452,-63.72 -64.0876,-63.72 -63.73))", "dataset_titles": "Go to the NSIDC and search for the data.; Standing Water Depth on Larsen B Ice Shelf", "datasets": [{"dataset_uid": "001996", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Go to the NSIDC and search for the data.", "url": "http://nsidc.org"}, {"dataset_uid": "609584", "doi": "10.7265/N500002K", "keywords": "Antarctica; Antarctic Peninsula; Cryosphere; Glaciers/Ice Sheet; Glaciology; Ice Shelf; Larsen B Ice Shelf; Sample/Collection Description; Supraglacial Meltwater", "people": "MacAyeal, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Standing Water Depth on Larsen B Ice Shelf", "url": "https://www.usap-dc.org/view/dataset/609584"}], "date_created": "Sat, 21 Dec 2013 00:00:00 GMT", "description": "MacAyeal/0944248\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to develop a better understanding of the processes and conditions that trigger ice shelf instability and explosive disintegration. A significant product of the proposed research will be the establishment of parameterizations of micro- and meso-scale ice-shelf surface processes needed in large scale ice-sheet models designed to predict future sea level rise. The proposed research represents a 3-year effort to conduct numerical model studies of 6 aspects of surface-water evolution on Antarctic ice shelves. These 6 model-study areas include energy balance models of melting ice-shelf surfaces, with treatment of surface ponds and water-filled crevasses, distributed, Darcian water flow modeling to simulate initial firn melting, brine infiltration, pond drainage and crevasse filling, ice-shelf surface topography evolution modeling by phase change (surface melting and freezing), surface-runoff driven erosion and seepage flows, mass loading and flexure effects of ice-shelf and iceberg surfaces; feedbacks between surface-water loads and flexure stresses; possible seiche phenomena of the surface water, ice and underlying ocean that constitute a mechanism for, inducing surface crevassing., surface pond and crevasse convection, and basal crevasse thermohaline convection (as a phenomena related to area 5 above). The broader impacts of the proposed work bears on the socio-environmental concerns of climate change and sea-level rise, and will contribute to the important goal of advising public policy. The project will form the basis of a dissertation project of a graduate student whose training will contribute to the scientific workforce of the nation and the PI and graduate student will additionally participate in a summer science-enrichment program for high-school teachers organized by colleagues at the University of Chicago.", "east": -55.45, "geometry": "POINT(-59.585 -65.518)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e ETM+; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e PHOTOMETERS \u003e SPECTROPHOTOMETERS", "is_usap_dc": true, "keywords": "melt ponds; standing water depth; Breakup of Larsen B Ice Shelf; ice shelf stability; LANDSAT-7; supraglacial lake", "locations": null, "north": -63.73, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "MacAyeal, Douglas", "platforms": "SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e LANDSAT \u003e LANDSAT-7", "repo": "NSIDC", "repositories": "NSIDC; USAP-DC", "science_programs": null, "south": -67.306, "title": "Model Studies of Surface Water Behavior on Ice Shelves", "uid": "p0000052", "west": -63.72}, {"awards": "0944743 Buckley, Bradley", "bounds_geometry": "POINT(166.66667 -77.83333)", "dataset_titles": "The Cellular Stress Response in Cold-adapted Organisms: Building Novel Mechanistic Links between Heat Stress, Cell Cycle Arrest and Apoptosis in Antarctic Fishes.", "datasets": [{"dataset_uid": "600118", "doi": "10.15784/600118", "keywords": "Biology; Biosphere; Southern Ocean", "people": "Buckley, Bradley", "repository": "USAP-DC", "science_program": null, "title": "The Cellular Stress Response in Cold-adapted Organisms: Building Novel Mechanistic Links between Heat Stress, Cell Cycle Arrest and Apoptosis in Antarctic Fishes.", "url": "https://www.usap-dc.org/view/dataset/600118"}], "date_created": "Thu, 19 Dec 2013 00:00:00 GMT", "description": "The research will investigate a novel mechanism by which cold-adapted fishes of the Southern Ocean sense and respond to elevated temperatures. It is hypothesized that sub-lethal heat stress may induce cell cycle arrest and/or programmed cell death through apoptosis. The study will use genome-enabled technologies to examine the environmental control over gene expression in Antarctic species and will build direct mechanistic links between the expression of a specific signaling pathway gene and heat-induced changes in cells. Prior results support the hypothesis that heat stress results in cell cycle arrest and, in some cases, programmed cell death in Antarctic fishes. If so, this represents a novel, modified version of the well-conserved cellular stress response found in essentially all other species and suggests that warming ocean temperatures may have profound cellular and physiological impacts on these extremely stenothermal species. The P.I. conducts outreach activities with the Oregon Museum of Science and Industry, will be involved in developing a science curriculum for the Native American Youth and Family Center (NAYA) Early College Academy in Portland, and supports the educational and professional development of both undergraduate and graduate students at Portland State University.", "east": 166.66667, "geometry": "POINT(166.66667 -77.83333)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.83333, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Buckley, Bradley", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.83333, "title": "The Cellular Stress Response in Cold-adapted Organisms: Building Novel Mechanistic Links between Heat Stress, Cell Cycle Arrest and Apoptosis in Antarctic Fishes.", "uid": "p0000493", "west": 166.66667}, {"awards": "0838811 Sergienko, Olga", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,180 -90,180 -90,180 -90,180 -90,180 -90,180 -90,180 -90,180 -90,180 -90,180 -90,180 -90,180 -87,180 -84,180 -81,180 -78,180 -75,180 -72,180 -69,180 -66,180 -63,180 -60,180 -60,180 -60,180 -60,180 -60,180 -60,180 -60,180 -60,180 -60,180 -60,-180 -60))", "dataset_titles": "Interaction of Ice Stream Flow with Heterogeneous Beds", "datasets": [{"dataset_uid": "609583", "doi": "10.7265/N53R0QS6", "keywords": "Antarctica; Cryosphere; Glaciers/Ice Sheet; Glaciology; Ice Sheet Model; Ice Thickness; Ice Velocity", "people": "Sergienko, Olga", "repository": "USAP-DC", "science_program": null, "title": "Interaction of Ice Stream Flow with Heterogeneous Beds", "url": "https://www.usap-dc.org/view/dataset/609583"}], "date_created": "Tue, 27 Aug 2013 00:00:00 GMT", "description": "Sergienko/0838811 \u003cbr/\u003e\u003cbr/\u003eThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to conduct a modeling study of the ice stream ? sub-glacial water system. A suite of numerical models of various dimensionality and complexity will be constructed in a sequential, hierarchical fashion to formulate and test hypotheses regarding how sub-glacial lakes form under ice streams, determine the effect of sub-glacial lakes on ice-stream flow and mass balance, and to determine feedback effects whereby the ice stream ? sub-glacial water system can elicit both stable and unstable responses to environmental perturbations. This research will address one of the only observationally verified fast-time-scale processes apparent within the Antarctic Ice Stream system. The intellectual merit of the project is that understanding the origins and consequences of near-grounding-line sub-glacial lakes is a priority in glaciological research designed to predict short-term variations in Antarctica?s near-term future mass balance. The broader impacts of the proposed work are that it will contribute to better understanding of a system that has important societal relevance through contribution to sea level rise. Participation of a graduate student in the project will provide the student?s training and education in application of the numerical modeling in geosciences.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "subglacial and supraglacial water depth; direct numerical simulation; Bed and Surface elevation deviatoric stresses; AGDC-project; Not provided; Ice Streams", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Sergienko, Olga; Hulbe, Christina", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Model Investigation of Ice Stream/Subglacial Lake Systems", "uid": "p0000045", "west": 180.0}, {"awards": "0636584 Creyts, Timothy", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 07 Aug 2012 00:00:00 GMT", "description": "Studinger/0636584\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to estimate the salinity of subglacial Lake Vostok, Lake Concordia and the 90 deg.E lake using existing airborne ice-penetrating radar and laser altimeter data. These lakes have been selected because of the availability of modern aerogeophysical data and because they are large enough for the floating ice to be unaffected by boundary stresses near the grounding lines. The proposed approach is based on the assumption that the ice sheet above large subglacial lakes is in hydrostatic equilibrium and the density and subsequently salinity of the lake\u0027s water can be estimated from the (linear) relationship between ice surface elevation and ice thickness of the floating ice. The goal of the proposed work is to estimate the salinity of Lake Vostok and determine spatial changes and to compare the salinity estimates of 3 large subglacial lakes in East Antarctica. The intellectual merits of the project are that this work will contribute to the knowledge of the physical and chemical processes operating within subglacial lake environments. Due to the inaccessibility of subglacial lakes numerical modeling of the water circulation is currently the only way forward to develop a conceptual understanding of the circulation and melting and freezing regimes in subglacial lakes. Numerical experiments show that the salinity of the lake\u0027s water is a crucial input parameter for the 3-D fluid dynamic models. Improved numerical models will contribute to our knowledge of water circulation in subglacial lakes, its effects on water and heat budgets, stratification, melting and freezing, and the conditions that support life in such extreme environments. The broader impacts of the project are that subglacial lakes have captured the interest of many people, scientists and laymen. The national and international press frequently reports about the research of the Principal Investigator. His Lake Vostok illustrations have been used in math and earth science text books. Lake Vostok will be used for education and outreach in the Earth2Class project. Earth2Class is a highly successful science/math/technology learning resource for K-12 students, teachers, and administrators in the New York metropolitan area. Earth2Class is created through collaboration by research scientists at the Lamont- Doherty Earth Observatory; curriculum and educational technology specialists from Teachers College, Columbia University; and classroom teachers in the New York metropolitan area.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e LIDAR/LASER SOUNDERS \u003e LASERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e ALTIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e RADAR ALTIMETERS", "is_usap_dc": false, "keywords": "aerogeophysical; hydrostatic; subglacial; circulation; FIELD SURVEYS; numerical modeling; Salinity; Not provided; LABORATORY", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Creyts, Timothy; Studinger, Michael S.", "platforms": "Not provided; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "Estimating the Salinity of Subglacial Lakes From Existing Aerogeophysical Data", "uid": "p0000704", "west": null}, {"awards": "0758274 Parizek, Byron; 0636724 Blankenship, Donald", "bounds_geometry": "POLYGON((-110.058 -74.0548,-109.57993 -74.0548,-109.10186 -74.0548,-108.62379 -74.0548,-108.14572 -74.0548,-107.66765 -74.0548,-107.18958 -74.0548,-106.71151 -74.0548,-106.23344 -74.0548,-105.75537 -74.0548,-105.2773 -74.0548,-105.2773 -74.31383,-105.2773 -74.57286,-105.2773 -74.83189,-105.2773 -75.09092,-105.2773 -75.34995,-105.2773 -75.60898,-105.2773 -75.86801,-105.2773 -76.12704,-105.2773 -76.38607,-105.2773 -76.6451,-105.75537 -76.6451,-106.23344 -76.6451,-106.71151 -76.6451,-107.18958 -76.6451,-107.66765 -76.6451,-108.14572 -76.6451,-108.62379 -76.6451,-109.10186 -76.6451,-109.57993 -76.6451,-110.058 -76.6451,-110.058 -76.38607,-110.058 -76.12704,-110.058 -75.86801,-110.058 -75.60898,-110.058 -75.34995,-110.058 -75.09092,-110.058 -74.83189,-110.058 -74.57286,-110.058 -74.31383,-110.058 -74.0548))", "dataset_titles": "Access to data; AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment; AGASEA Ice Thickness Profile Data from the Amundsen Sea Embayment, Antarctica; Airborne Laser Altimetry of the Thwaites Glacier Catchment, West Antarctica; ICECAP Basal Interface Specularity Content Profiles: IPY and OIB; Subglacial water flow paths under Thwaites Glacier, West Antarctica; Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "datasets": [{"dataset_uid": "000248", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Access to data", "url": "http://nsidc.org/data/netcdf/tools.html"}, {"dataset_uid": "601371", "doi": "10.15784/601371", "keywords": "Antarctica; Cryosphere; East Antarctica; ICECAP; Ice Penetrating Radar; Radar Echo Sounder; Radar Echo Sounding; Subglacial Hydrology", "people": "van Ommen, Tas; Greenbaum, Jamin; Schroeder, Dustin; Siegert, Martin; Blankenship, Donald D.; Roberts, Jason; Young, Duncan A.", "repository": "USAP-DC", "science_program": null, "title": "ICECAP Basal Interface Specularity Content Profiles: IPY and OIB", "url": "https://www.usap-dc.org/view/dataset/601371"}, {"dataset_uid": "609334", "doi": "10.7265/N5HD7SK8", "keywords": "AGASEA; Airborne Altimetry; Antarctica; Bathymetry/Topography; Cryosphere; Glaciers/Ice Sheet; Glaciology; Thwaites Glacier", "people": "Morse, David L.; Kempf, Scott D.; Young, Duncan A.; Blankenship, Donald D.; Holt, John W.", "repository": "USAP-DC", "science_program": null, "title": "Airborne Laser Altimetry of the Thwaites Glacier Catchment, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609334"}, {"dataset_uid": "609619", "doi": "10.7265/N58913TN", "keywords": "Amundsen Sea; Antarctica; Cryosphere; Glaciers/Ice Sheet; Glaciology; Ice Sheet Model; Thwaites Glacier", "people": "Dupont, Todd K.; Parizek, Byron R.; Blankenship, Donald D.; Holt, John W.", "repository": "USAP-DC", "science_program": null, "title": "Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "url": "https://www.usap-dc.org/view/dataset/609619"}, {"dataset_uid": "601673", "doi": null, "keywords": "AntArchitecture; Antarctica; Cryosphere; Ice Penetrating Radar; Isochron; layers; Radar; Radioglaciology; Thwaites Glacier", "people": "Blankenship, Donald D.; Muldoon, Gail R.; Young, Duncan A.; Jackson, Charles", "repository": "USAP-DC", "science_program": null, "title": "AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment", "url": "https://www.usap-dc.org/view/dataset/601673"}, {"dataset_uid": "609517", "doi": "10.7265/N5W95730", "keywords": "AGASEA; Airborne Radar; Amundsen Sea Embayment; Antarctica; Bathymetry/Topography; Cryosphere; Glaciers/Ice Sheet; Glaciology; Ice Thickness", "people": "Kempf, Scott D.; Blankenship, Donald D.; Young, Duncan A.; Holt, John W.", "repository": "USAP-DC", "science_program": null, "title": "AGASEA Ice Thickness Profile Data from the Amundsen Sea Embayment, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609517"}, {"dataset_uid": "609518", "doi": "10.7265/N5RJ4GC8", "keywords": "AGASEA; Airborne Radar; Antarctica; Bathymetry/Topography; Cryosphere; Flow Paths; Glaciers/Ice Sheet; Glaciology; Thwaites Glacier", "people": "Blankenship, Donald D.; Carter, Sasha P.; Young, Duncan A.", "repository": "USAP-DC", "science_program": null, "title": "Subglacial water flow paths under Thwaites Glacier, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609518"}, {"dataset_uid": "002536", "doi": "", "keywords": null, "people": null, "repository": "NASA", "science_program": null, "title": "Access to data", "url": "http://www.giss.nasa.gov/tools/panoply/"}], "date_created": "Tue, 15 May 2012 00:00:00 GMT", "description": "This award supports a three-year study to isolate essential physical processes affecting Thwaites Glacier (TG) in the Amundsen Sea Embayment (ASE) of West Antarctica using a suite of existing numerical models in conjunction with existing and International Polar Year (IPY)-proposed data sets. Four different models will be utilized to explore the effects of embayment geometry, ice-shelf buttressing, basal-stress distribution, surface mass balance, surface climate, and inland dynamic perturbations on the present and future dynamics of TG. This particular collection of models is ideally suited for the broad nature of this investigation, as they incorporate efficient and complementary simplifications of the stress field (shallow-ice and shelf-stream), system geometry (1-d and 2-d plan-view and flowline; depth-integrated and depth-dependent), and mass-momentum energy coupling (mechanical and thermo-mechanical). The models will be constrained and validated by data sets (including regional maps of ice thickness, surface elevation, basal topography, ice surface velocity, and potential fields) and geophysical data analyses (including increasing the spatial resolution of surface elevations, improving regional estimates of geothermal flux, and characterizing the sub-glacial interface of grounded ice as well as the grounding-zone transition between grounded and floating ice). The intellectual merit of the research focuses on several of the NSF Glaciology program\u0027s emphases, including: ice dynamics, numerical modeling, and remote sensing of ice sheets. In addition, the research directly addresses the following specific NSF objectives: \"investigation of the physics of fast glacier flow with emphasis on processes at glacier beds\"; \"investigation of ice-shelf stability\"; and \"identification and quantification of the feedback between ice dynamics and climate change\". The broader impacts of this research effort will help answer societally relevant questions of future ice sheet stability and sea-level change. The research also will aid in the early career development of two young investigators and will contribute to the education of both graduate and undergraduate students directly involved in the research, and results will be incorporated into courses and informal presentations.", "east": -105.2773, "geometry": "POINT(-107.66765 -75.34995)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e ALTIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e RADIO \u003e INS", "is_usap_dc": true, "keywords": "Ice Dynamics; glaciers; Grounding Zone; Ice Sheet Thickness; Model Input Data; Ice Sheet Elevation; diagnostic; Ice Stream; West Antarctic; Airborne Laser Altimeters; prognostic; basal-stress distribution; FIELD INVESTIGATION; basal rheology; Surface Elevation; Airborne geophysical survey of the Amundsen Sea Embayment; basal topography; subglacial; ice-shelf buttressing; ice surface velocity; Thwaites Glacier; surface climate; bed elevations; Antarctica (AGASEA); model results; Airborne Laser Altimetry; Hydrology; FIELD SURVEYS; Antarctic Ice Sheet; Glacier; numerical modeling; glacier dynamics; DHC-6; West Antarctic Ice Sheet; Ice Sheet; embayment geometry; Amundsen Sea Embayment; Glacier Surface; Airborne Radar Sounding; Digital Elevation Model; Antarctica; Altimetry; LABORATORY", "locations": "Antarctica; Thwaites Glacier; West Antarctic Ice Sheet; Antarctic Ice Sheet; Amundsen Sea Embayment", "north": -74.0548, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Carter, Sasha P.; Dupont, Todd K.; Holt, John W.; Morse, David L.; Parizek, Byron R.; Young, Duncan A.; Kempf, Scott D.; Blankenship, Donald D.", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "NSIDC", "repositories": "NASA; NSIDC; USAP-DC", "science_programs": null, "south": -76.6451, "title": "Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "uid": "p0000174", "west": -110.058}, {"awards": "0814241 Dupont, Todd", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 21 Mar 2012 00:00:00 GMT", "description": "This award supports a three-year modeling effort to understand the dynamics surrounding ice-air surface slope reversals on ice streams and ice shelves, with implications for the creation and stability of subglacial lakes. Local reversal of the ice-air surface slope may lead, through a reversal of the hydraulic gradient, to the trapping of basal and surface water, producing subglacial and supraglacial lakes, respectively. In the case of subglacial lakes, once such a sizable reservoir of pressurized water is created the potential exists for drainage, in the form of large outburst floods or as smaller, but sustained, periods of increased subglacial water flow. The research seeks to extend some initial work that has been done to include time-dependence and a wider array of parameters and geometries. The methods will involve the use of a suite of models, all of which will include longitudinal deviatoric and basal-shear stresses, with some also taking account of lateral drag and internal vertical shear. The intellectual merit of the proposed activity includes an improved understanding of the processes and parameters involved in the formation of surface-slope reversals in ice-stream/ice-shelf systems, as well as insight into the stability of subglacial lakes formed as a consequence of slope reversals. The broader impacts resulting from this activity include the provision of tools to study the dynamics of ice-stream/ice-shelf systems, an improved understanding of the physics behind outburst floods, and insights into the coupling of ice streams with their subglacial water systems. The research will support the studies of a beginning postdoctoral researcher. Results of the research will be incorporated into courses and public outreach serving anywhere from hundreds to thousands of people per year.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "LABORATORY", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Alley, Richard; Dupont, Todd K.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "Modeling the Dynamics of Surface-slope Reversals and their Role in the Formation and Stability of Subglacial Lakes", "uid": "p0000665", "west": null}, {"awards": "0632325 Seals, Cheryl; 0632346 Tulaczyk, Slawek; 0632161 Johnson, Jesse; 0632168 Hulbe, Christina", "bounds_geometry": "POLYGON((-180 -50.05,-144 -50.05,-108 -50.05,-72 -50.05,-36 -50.05,0 -50.05,36 -50.05,72 -50.05,108 -50.05,144 -50.05,180 -50.05,180 -54.045,180 -58.04,180 -62.035,180 -66.03,180 -70.025,180 -74.02,180 -78.015,180 -82.01,180 -86.005,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -86.005,-180 -82.01,-180 -78.015,-180 -74.02,-180 -70.025,-180 -66.03,-180 -62.035,-180 -58.04,-180 -54.045,-180 -50.05))", "dataset_titles": "Singular Value Decomposition Analysis of Ice Sheet Model Output Fields; Wiki containing the data and provenance.", "datasets": [{"dataset_uid": "609396", "doi": "10.7265/N5K64G1S", "keywords": "Antarctica; Community Ice Sheet Model; Cryosphere; Glaciers/Ice Sheet; Glaciology", "people": "Daescu, Dacian N.; Hulbe, Christina", "repository": "USAP-DC", "science_program": null, "title": "Singular Value Decomposition Analysis of Ice Sheet Model Output Fields", "url": "https://www.usap-dc.org/view/dataset/609396"}, {"dataset_uid": "001499", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Wiki containing the data and provenance.", "url": "http://websrv.cs.umt.edu/isis/index.php/Present_Day_Antarctica"}], "date_created": "Fri, 02 Jul 2010 00:00:00 GMT", "description": "Johnson/0632161\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to create a \"Community Ice Sheet Model (CISM)\". The intellectual merit of the proposed activity is that the development of such a model will aid in advancing the science of ice sheet modeling. The model will be developed with the goal of assuring that CISM is accurate, robust, well documented, intuitive, and computationally efficient. The development process will stress principles of software design. Two complementary efforts will occur. One will involve novel predictive modeling experiments on the Amundsen Sea Embayment region of Antarctica with the goal of understanding how interactions between basal processes and ice sheet dynamics can result in abrupt reconfigurations of ice-sheets, and how those reconfigurations impact other Earth systems. New modeling physics are to include the higher order stress terms that allow proper resolution of ice stream and shelf features, and the associated numerical methods that allow higher and lower order physics to be coexist in a single model. The broader impacts of the proposed activity involve education and public outreach. The model will be elevated to a high standard in terms of user interface and design, which will allow for the production of inquiry based, polar and climate science curriculum for K-12 education. The development of a CISM itself would represent a sea change in the way that glaciological research is conducted, eliminating numerous barriers to progress in polar research such as duplicated efforts, lack of transparency in publication, lack of a cryospheric model for others to link to and reference, and a common starting point from which to begin investigation. As the appropriate interfaces are developed, a curriculum to utilize CISM in education will be developed. Students participating in this grant will be required to be involved in public outreach through various mechanisms including local and state science fairs. The model will also serve as a basis for educating \"a new generation\" of climate scientists. This project is relevant to the International Polar Year (IPY) as the research team is multi-institutional and multi-disciplinary, will bring new groups and new specialties into the realm of polar research and is part of a larger group of proposals whose research focuses on research in the Amundsen Sea Embayment Plan region of Antarctica. The project is international in scope and the nature of software development is quite international, with firm commitments from the United Kingdom and Belgium to collaborate. In addition there will be an international external advisory board that will be used to guide development, and serve as a link to other IPY activities.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Numerical models; MODELS; Modeling; Basal Temperature; Amundsen Sea Embayment; International Polar Year; Antarctic Ice Sheet; Derived Basal Temperature Evolution; Environmental Modeling; IPY; Ice Sheet; Antarctica; Community Ice Sheet Model; Model; Not provided; Ice Dynamic; Ice Sheet Model; LABORATORY; EISMINT", "locations": "Antarctic Ice Sheet; Antarctica; Amundsen Sea Embayment", "north": -50.05, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Hulbe, Christina; Seals, Cheryl; Johnson, Jesse; Daescu, Dacian N.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; OTHER \u003e MODELS \u003e MODELS; Not provided", "repo": "USAP-DC", "repositories": "Other; USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: IPY, The Next Generation: A Community Ice Sheet Model for Scientists and Educators With Demonstration Experiments in Amundsen Sea Embayment Region", "uid": "p0000756", "west": -180.0}, {"awards": "9910093 Powell, Thomas", "bounds_geometry": null, "dataset_titles": "Expedition data of NBP0104", "datasets": [{"dataset_uid": "002584", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0104", "url": "https://www.rvdata.us/search/cruise/NBP0104"}, {"dataset_uid": "002657", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0104", "url": "https://www.rvdata.us/search/cruise/NBP0104"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This project is a contribution to a coordinated attempt to understand the interactions of biological and physical dynamics by developing relationships among the evolution of the antarctic winter ice and snow cover, biological habitat variability, and the seasonal progression of marine ecological processes. The work will be carried out in the context of the Southern Ocean Experiment of the Global Ocean Ecosystem Dynamics Study (Globec), a large, multi-investigator study of the winter survival strategy of krill under the antarctic sea ice in the vicinity of Marguerite Bay on the western side of the Antarctic Peninsula.\u003cbr/\u003e\u003cbr/\u003eThe objective of this project is to make a quantitative assessment of the small scale temperature and salinity structure of the oceanic surface layer in order to study the effect of stratification and turbulence on the biochemical and biological processes under the winter sea ice.\u003cbr/\u003e\u003cbr/\u003eThe water masses on the continental shelf off Marguerite Bay consist of inflowing Upper Circumpolar Deep Water, which is relatively warm, salty, oxygen-poor, and nutrient-rich. In winter atmospheric processes cool and freshen this water, and recharge it with oxygen to produce Antarctic Surface Water which is diffused seaward, and supports both a sea ice cover and a productive krill-based food web. The modification processes work through mixing associated with shear instabilities of the internal wave field, double diffusion of salt and heat, and mixing driven by surface stress and convection. These processes will be quantified with two microstructure profilers, capable of resolving the small but crucial vertical variations that drive these processes.\u003cbr/\u003e***", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Powell, Thomas", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "Other", "science_programs": null, "south": null, "title": "Collaborative Research: WinDSSOcK: Winter Distribution and Success of Southern Ocean Krill", "uid": "p0000804", "west": null}, {"awards": "0126279 Lawver, Lawrence; 0125624 Wilson, Terry", "bounds_geometry": "POLYGON((163.69456 -75.04911,164.525266 -75.04911,165.355972 -75.04911,166.186678 -75.04911,167.017384 -75.04911,167.84809 -75.04911,168.678796 -75.04911,169.509502 -75.04911,170.340208 -75.04911,171.170914 -75.04911,172.00162 -75.04911,172.00162 -75.3293,172.00162 -75.60949,172.00162 -75.88968,172.00162 -76.16987,172.00162 -76.45006,172.00162 -76.73025,172.00162 -77.01044,172.00162 -77.29063,172.00162 -77.57082,172.00162 -77.85101,171.170914 -77.85101,170.340208 -77.85101,169.509502 -77.85101,168.678796 -77.85101,167.84809 -77.85101,167.017384 -77.85101,166.186678 -77.85101,165.355972 -77.85101,164.525266 -77.85101,163.69456 -77.85101,163.69456 -77.57082,163.69456 -77.29063,163.69456 -77.01044,163.69456 -76.73025,163.69456 -76.45006,163.69456 -76.16987,163.69456 -75.88968,163.69456 -75.60949,163.69456 -75.3293,163.69456 -75.04911))", "dataset_titles": "Expedition Data; NBP0401 data", "datasets": [{"dataset_uid": "001664", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0401"}, {"dataset_uid": "000106", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP0401 data", "url": "https://www.rvdata.us/search/cruise/NBP0401"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a study to investigate the tectonic development of the southwestern Ross Sea region. Displacements between East and West Antarctica have long been proposed based on global plate circuits, apparent hot spot motions, interpretations of seafloor magnetic anomalies, paleomagnetism, and on geologic grounds. Such motions require plate boundaries crossing Antarctica, yet these boundaries have never been explicitly defined. This project will attempt to delineate the late Cenozoic - active boundary between East and West Antarctica along the Terror Rift in the western Ross Sea, where young structures have been identified, continuity between active extension and intracontinental structures can be established, and where accessibility via ship will allow new key data sets to be acquired. We will use multi-source marine and airborne geophysical data to map the fault patterns and volcanic structure along the eastern margin of the Terror Rift. The orientations of volcanic fissures and seamount alignments on the seafloor will be mapped using multibeam bathymetry. The volcanic alignments will show the regional extension or shear directions across the Terror Rift and the orientations of associated crustal stresses. Swath bathymetry and single channel seismic data will be used to document neotectonic fault patterns and the eastern limit of recent faulting. Delineation of neotectonic fault patterns will demonstrate whether the eastern margin of the Terror Rift forms a continuous boundary and whether the rift itself can be linked with postulated strike-slip faults in the northwestern Ross Sea. Seafloor findings from this project will be combined with fault kinematic and stress field determinations from the surrounding volcanic islands and the Transantarctic Mountains. The integrated results will test the propositions that the eastern boundary of the Terror Rift forms the limit of the major, late Cenozoic -active structures through the Ross Sea and that Terror Rift kinematics involve dextral transtension linked to the right-lateral strike-slip faulting to the north. These results will help constrain the kinematic and dynamic links between the West Antarctic rift system and Southern Ocean structures and any related motions between East and West Antarctica. In the first year, a collaborative structural analysis of existing multichannel and single channel seismic profiles and aeromagnetic data over the Terror Rift will be conducted. The location of volcanic vents or fissures and any fault scarps on the sea floor will be identified and a preliminary interpretation of the age and kinematics of deformation in the Terror Rift will be produced. Late in the second year, a one-month cruise on RVIB N.B. Palmer will carry out multibeam bathymetric and sidescan sonar mapping of selected portions of the seafloor of Terror Rift. Gravity, magnetics, seismic reflection and Bathy2000 3.5 kHz sub-bottom profile data will also be collected across the rift. In the third year, we will use these multisource data to map the orientations and forms of volcanic bodies and the extent and geometry of neotectonic faulting associated with the Terror Rift. The project will: 1) complete a map of neotectonic faults and volcanic structures in the Terror Rift; 2) interpret the structural pattern to derive the motions and stresses associated with development of the rift; 3) compare Terror Rift structures with faults and lineaments mapped in the Transantarctic Mountains to improve age constraints on the structures; and 4) integrate the late Cenozoic structural interpretations from the western Ross Sea with Southern Ocean plate boundary kinematics.", "east": 172.00162, "geometry": "POINT(167.84809 -76.45006)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": true, "keywords": "R/V NBP", "locations": null, "north": -75.04911, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Wilson, Terry", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "Other", "science_programs": null, "south": -77.85101, "title": "Collaborative Research: Neotectonic Structure of Terror Rift, Western Ross Sea", "uid": "p0000111", "west": 163.69456}, {"awards": "9980379 Baker, Ian", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 15 Feb 2010 00:00:00 GMT", "description": "This award is for support for three years of funding to study the effects of impurities on the flow of poly-\u003cbr/\u003ecrystalline ice. It has been known for thirty years that both hydrofluoric acid (HF) and hydrochloric acid (HCl) dramatically decrease the strength of ice and recent work by the author\u0027s group has shown that sulfuric acid (H2SO4) produces a similar reduction in strength. However, these data are for single crystals at strain rates and stresses that far exceed those found in glaciers and ice sheets, and often at concentrations that far exceed those in natural ice. Therefore, it is not known how impurities found in nature affect the flow of polycrystalline ice at slow strain rates. In this research, the effects of nitric acid and sulfuric acid (which are naturally occurring impurities in ice) on the microstructure (dislocation structure, grain boundary structure and location of the acids) and creep of polycrystalline ice (at a range of temperatures and stresses) will be determined. The ice\u0027s response to creep deformation will be studied using a combination of x-ray topography, optical microscopy and scanning electron microscopy. X-ray microanalysis in an environmental scanning electron microscope will be used to study the location of impurities. The structure and creep behavior of the acid-doped ice will be compared with those of both high-purity laboratory-grown ice and ice from Byrd Station, Antarctica. The end-result of this project will be to elucidate the effects of naturally-occurring acid impurities on the mechanical properties of polycrystalline ice under conditions relevant to the deformation of glaciers and ice sheets, including and understanding of how impurities affect the underlying deformation mechanisms.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e PARTICLE DETECTORS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e SCANNING ELECTRON MICROSCOPES", "is_usap_dc": true, "keywords": "Ice Core Data; Ice Core; Microstructure; Ice Sheet; Ice Core Chemistry; ice cores; Antarctic Ice Sheet; LABORATORY", "locations": "Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Baker, Ian; Obbard, Rachel", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "The Effects of Impurities on the Flow of Polycrystalline Ice", "uid": "p0000015", "west": null}, {"awards": "0538195 Marone, Chris", "bounds_geometry": "POLYGON((-147.75896 -61.77943,-147.758362 -61.77943,-147.757764 -61.77943,-147.757166 -61.77943,-147.756568 -61.77943,-147.75597 -61.77943,-147.755372 -61.77943,-147.754774 -61.77943,-147.754176 -61.77943,-147.753578 -61.77943,-147.75298 -61.77943,-147.75298 -61.779665,-147.75298 -61.7799,-147.75298 -61.780135,-147.75298 -61.78037,-147.75298 -61.780605,-147.75298 -61.78084,-147.75298 -61.781075,-147.75298 -61.78131,-147.75298 -61.781545,-147.75298 -61.78178,-147.753578 -61.78178,-147.754176 -61.78178,-147.754774 -61.78178,-147.755372 -61.78178,-147.75597 -61.78178,-147.756568 -61.78178,-147.757166 -61.78178,-147.757764 -61.78178,-147.758362 -61.78178,-147.75896 -61.78178,-147.75896 -61.781545,-147.75896 -61.78131,-147.75896 -61.781075,-147.75896 -61.78084,-147.75896 -61.780605,-147.75896 -61.78037,-147.75896 -61.780135,-147.75896 -61.7799,-147.75896 -61.779665,-147.75896 -61.77943))", "dataset_titles": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "datasets": [{"dataset_uid": "609460", "doi": "10.7265/N5WH2MX7", "keywords": "Cryosphere; Geology/Geophysics - Other; Glaciers/Ice Sheet; Shear Stress; Solid Earth; Strain", "people": "Marone, Chris; Anandakrishnan, Sridhar", "repository": "USAP-DC", "science_program": null, "title": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "url": "https://www.usap-dc.org/view/dataset/609460"}, {"dataset_uid": "600054", "doi": "10.15784/600054", "keywords": "Antarctica; Cryosphere; Glacial Till; Glaciers/Ice Sheet; lab experiment; Marine Sediments; Physical Properties; Solid Earth", "people": "Marone, Chris; Anandakrishnan, Sridhar", "repository": "USAP-DC", "science_program": null, "title": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "url": "https://www.usap-dc.org/view/dataset/600054"}], "date_created": "Thu, 18 Jun 2009 00:00:00 GMT", "description": "0538195\u003cbr/\u003eMarone\u003cbr/\u003eThis award supports a project to conduct laboratory experiments and numerical modeling to determine the constitutive properties of subglacial till under dynamic stressing and to test the hypothesis that granular properties of till are sufficient, when coupled elastically to a large ice stream, to reproduce the field observations of triggered slip and subglacial seismicity. Testing will be carried out in a servo-controlled biaxial shear device under controlled temperature and stress conditions, which will allow both sliding and microstructural processes to be studied in detail. The main focus of the work will be on laboratory measurements. In addition, we will construct continuum models to evaluate whether our results can predict complex ice sheet motions and observed characteristics of subglacial seismicity. In terms of broader impacts, the proposed work will encourage interactions between the rock-mechanics and glaciology communities and will bring together members of different scientific backgrounds and vocabularies, but similar problems and data. The project will train undergraduate and graduate students at Penn State University and the scientists involved plan to give presentations to grade school classes, scout groups, and at community open houses. Results will be presented at professional meetings and will be published in a timely manner. The work will result in a better understanding of glacial motion and the physics of earthquake slip, which is essential for understanding ice sheet dynamics and earthquake hazard.", "east": -147.75298, "geometry": "POINT(-147.75597 -61.780605)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE TRANSDUCERS", "is_usap_dc": true, "keywords": "Laboratory investigations; Laboratory investigation; LABORATORY; Subglacial Observations; subglacial", "locations": null, "north": -61.77943, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Marone, Chris; Anandakrishnan, Sridhar", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -61.78178, "title": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "uid": "p0000554", "west": -147.75896}, {"awards": "0440636 Fahnestock, Mark; 0440670 Hulbe, Christina", "bounds_geometry": "POLYGON((-180 -70,-175 -70,-170 -70,-165 -70,-160 -70,-155 -70,-150 -70,-145 -70,-140 -70,-135 -70,-130 -70,-130 -71.6,-130 -73.2,-130 -74.8,-130 -76.4,-130 -78,-130 -79.6,-130 -81.2,-130 -82.8,-130 -84.4,-130 -86,-135 -86,-140 -86,-145 -86,-150 -86,-155 -86,-160 -86,-165 -86,-170 -86,-175 -86,180 -86,180 -86,180 -86,180 -86,180 -86,180 -86,180 -86,180 -86,180 -86,180 -86,180 -86,180 -84.4,180 -82.8,180 -81.2,180 -79.6,180 -78,180 -76.4,180 -74.8,180 -73.2,180 -71.6,180 -70,180 -70,180 -70,180 -70,180 -70,180 -70,180 -70,180 -70,180 -70,180 -70,-180 -70))", "dataset_titles": "MOA-derived Structural Feature Map of the Ronne Ice Shelf; MOA-derived Structural Feature Map of the Ross Ice Shelf; Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams", "datasets": [{"dataset_uid": "601432", "doi": "10.15784/601432", "keywords": "Antarctica; Cryosphere", "people": "Forbes, Martin; Hulbe, Christina; Ledoux, Christine", "repository": "USAP-DC", "science_program": null, "title": "MOA-derived Structural Feature Map of the Ross Ice Shelf", "url": "https://www.usap-dc.org/view/dataset/601432"}, {"dataset_uid": "609497", "doi": "10.7265/N5PR7SXR", "keywords": "Antarctica; Cryosphere; Glaciers/Ice Sheet; Glaciology; MOA; MODIS; Ronne Ice Shelf", "people": "Hulbe, Christina; Ledoux, Christine", "repository": "USAP-DC", "science_program": null, "title": "MOA-derived Structural Feature Map of the Ronne Ice Shelf", "url": "https://www.usap-dc.org/view/dataset/609497"}, {"dataset_uid": "600024", "doi": "", "keywords": null, "people": "Fahnestock, Mark", "repository": "USAP-DC", "science_program": null, "title": "Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams", "url": "https://www.usap-dc.org/view/dataset/600024"}], "date_created": "Thu, 25 Sep 2008 00:00:00 GMT", "description": "This award supports a three year project to develop the tools required to interpret complex patterns of flow features on the Ross Ice Shelf, which record the discharge history the ice streams flowing east off of the West Antarctic Ice Sheet. This work builds on previous research that used flow features visible in satellite image mosaics and numerical models of ice shelf flow to detect changes in grounding zone dynamics and redirection of ice stream outlets over hundreds of years. Recently observed changes on Whillans Ice Stream fit within this framework. The pattern of redirection is driven by the influence of rapid downstream thinning on the basal thermal gradient in the ice and associated \"sticky spot\" (ice rise) formation. In pursuing this work, the investigators recognized other records of discharge variation on the shelf that can be used to build a more complete history and understanding of ice-stream discharge variability. The intellectual merit of the proposed work lies in the fact that these records, including fracture patterns and spatial variation in ice thickness, when understood in the proper context, will yield quantitative information about the timing and dynamics of ice stream slowdowns, grounding line retreat, and the relative history of discharge between the ice streams. New tools will help further constrain this history. The laser altimeter on NASA\u0027s IceSAT has improved our knowledge of the surface elevation of Antarctic ice. IceSAT surface elevations provide a high-resolution map of ice-shelf thickness that, along with provenance maps from ice-shelf image mosaics, will be used to estimate the volumes of ice involved in past ice-stream discharge events (slowdowns, redirections, and so on). This project will develop new numerical models for fracture propagation; these will allow past variations in ice-shelf stress state to be investigated. Together, the dynamic and volume-flux histories will provide a powerful set of observations for understanding past variations in ice stream discharge and the underlying physical processes. The broader impacts of this project center on how it contributes to the ability to estimate West Antarctic contributions to global sea level rise and to answer outstanding questions about the causes of millennial and longer-scale evolution of ice streams. This work will provide a history of the most complex record of ice discharge known. In addition to the incorporation of this research into graduate student advising and normal teaching duties, the investigators are involved in other avenues of civic engagement and education. Outreach to high school students and the community at large is promoted on an annual basis by the investigators at both institutions. New outreach projects at Portland State University are developed with the assistance of researchers with expertise in student learning and achievement in science and mathematics. The collaborative research team includes two glaciologists with experience in the pairing of high resolution satellite imagery and a variety of ice-flow models and a geologist whose focus is the mechanics of rock deformation.", "east": -130.0, "geometry": "POINT(-155 -78)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e MODIS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e MODIS", "is_usap_dc": true, "keywords": "West Antarctica; FIELD INVESTIGATION; Fracture Patterns; Ross Ice Shelf; Ice Streams; SATELLITES; West Antarctic Ice Sheet; Ice Motion; Grounding Line; Whillans Ice Stream; satellite image mosaics; Not provided; Antarctica; fracture propagation; Whillans Ice Streams; ice stream outlets; ice stream motion; Ice Thickness; ICESat; ice rise; Numerical models; TERRA; flow features; Ice Sheet; Kamb Ice Stream; Antarctic Ice Sheet; LABORATORY; Kamb Ice Streams; Grounding Line Migration; basal thermal gradient; ICESAT; ice-stream discharge", "locations": "Kamb Ice Stream; Whillans Ice Stream; Antarctica; Ross Ice Shelf; West Antarctic Ice Sheet; Antarctic Ice Sheet; West Antarctica", "north": -70.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Hulbe, Christina; Ledoux, Christine; Fahnestock, Mark", "platforms": "Not provided; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e ICE, CLOUD AND LAND ELEVATION SATELLITE (ICESAT) \u003e ICESAT; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e TERRA; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -86.0, "title": "Collaborative Research: Using Fracture Patterns and Ice Thickness to Study the History and Dynamics of Grounding Line Migration and Shutdown of Kamb and Whillans Ice Streams", "uid": "p0000096", "west": 180.0}, {"awards": "0337656 Lee, Richard", "bounds_geometry": "POLYGON((-64.1 -64.75,-64.085 -64.75,-64.07 -64.75,-64.055 -64.75,-64.04 -64.75,-64.025 -64.75,-64.01 -64.75,-63.995 -64.75,-63.98 -64.75,-63.965 -64.75,-63.95 -64.75,-63.95 -64.757,-63.95 -64.764,-63.95 -64.771,-63.95 -64.778,-63.95 -64.785,-63.95 -64.792,-63.95 -64.799,-63.95 -64.806,-63.95 -64.813,-63.95 -64.82,-63.965 -64.82,-63.98 -64.82,-63.995 -64.82,-64.01 -64.82,-64.025 -64.82,-64.04 -64.82,-64.055 -64.82,-64.07 -64.82,-64.085 -64.82,-64.1 -64.82,-64.1 -64.813,-64.1 -64.806,-64.1 -64.799,-64.1 -64.792,-64.1 -64.785,-64.1 -64.778,-64.1 -64.771,-64.1 -64.764,-64.1 -64.757,-64.1 -64.75))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 06 Jun 2008 00:00:00 GMT", "description": "Polar terrestrial environments are often described as deserts, where water availability is recognized as one of the most important limits on the distribution of terrestrial organisms. In addition, prolonged low winter temperatures threaten survival, and summer temperatures challenge organisms with extensive diel variations and rapid transitions from freezing to desiccating conditions. Global warming has further impacted the extreme thermal and hydric conditions experienced by Antarctic terrestrial plant and arthropod communities, especially as a result of glacial retreat along the Antarctic Peninsula. This research will focus on thermal and hydric adaptations in the terrestrial midge, Belgica antarctica, the largest and most southerly holometabolous insect living in this challenging and changing environment. \u003cbr/\u003eOverwintering midge larvae encased in the frozen substrate must endure desert-like conditions for more than 300 days since free water is biologically unavailable as ice. During the summer, larvae may be immersed in melt water or outwash from penguin colonies and seal wallows, in addition to saltwater splash. Alternatively, the larvae may be subjected to extended periods of desiccation as their microhabitats dry out. Due to their small size, relative immobility and the patchiness of suitable microhabitats, larvae may thus be subjected to stresses that include desiccation, hypo- or hyperosmotic conditions, high salinity exposure, and anoxia for extended periods. Research efforts will focus in three areas relevant to the stress tolerance mechanisms operating in these midges:(1) obtaining a detailed characterization of microclimatic conditions experienced by B. antarctica, especially those related to thermal and hydric diversity, both seasonally and among microhabitat types in the vicinity of Palmer Station, Antarctica; (2) examining the effects of extreme fluctuations in water availability and effects on physiological and molecular responses - to determine if midge larvae utilize the mechanism of cryoprotective dehydration for winter survival, and if genes encoding heat shock proteins and other genes are upregulated in larval responses to dehydration and rehydration; (3) investigating the dietary transmission of cryoprotectants from plant to insect host, which will test the hypothesis that midge larvae acquire increased resistance to desiccation and temperature stress by acquiring cryoprotectants from their host plants. \u003cbr/\u003eThis project will provide outreach to both elementary and secondary educators and their students. The team will include a teacher who will benefit professionally by full participation in the research, and will also assist in providing outreach to other teachers and their students. From Palmer Station, the field team will communicate daily research progress by e-mail supplemented with digital pictures with teachers and their elementary students to stimulate interest in an Antarctic biology and scientific research. These efforts will be supplemented with presentations at local schools and national teacher meetings, and by publishing hands-on, inquiry-based articles related to cryobiology and polar biology in education journals. Furthermore, the principal investigators will maintain major commitments to training graduate students and postdoctoral scholars, as well as undergraduate students by providing extended research experience that includes publication of scientific papers and presentations at national meetings.", "east": -63.95, "geometry": "POINT(-64.025 -64.785)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -64.75, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Denlinger, David; Lee, Richard", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -64.82, "title": "Physiological and Molecular Mechanisms of Stress Tolerance in a Polar Insect", "uid": "p0000742", "west": -64.1}, {"awards": "0229292 Cressie, Noel", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 28 Feb 2007 00:00:00 GMT", "description": "Ice streams are believed to play a major role in determining the response of their parent ice sheet to climate change, and in determining global sea level by serving as regulators on the fresh water stored in the ice sheets. Ice streams are characterized by rapid, laterally confined flow which makes them uniquely identifiable within the body of the more slowly and more homogeneously flowing ice sheet. But while these characteristics enable the identification of ice streams, the processes which control ice-stream motion and evolution, and differences among ice streams in the polar regions, are only partially understood. Understanding the relative importance of lateral and basal drags, as well as the role of gradients in longitudinal stress, is essential for developing models for future evolution of the polar ice\u003cbr/\u003esheets. In this project, physical statistical models will be used to explore the processes that control ice-stream flow, and to compare these processes between seemingly different ice-stream systems. In particular, Whillans Ice Stream draining into the Ross Ice Shelf, will be compared with Recovery and RAMP glaciers draining into the Ronne-Filchner Ice Shelf, and the Northeast Ice Stream in Greenland. Geophysical models lie at the core of the approach, but are embellished by modeling various components of variability statistically. One important component comes from the uncertainty in observations on basal elevation, surface elevation, and surface velocity. In this project new observational data collected using remote-sensing techniques will be used. The various components, some of which are spatial, are combined hierarchically using Bayesian statistical methodology. All these components will be combined mathematically into a physical statistical model that yields the posterior distribution for basal, longitudinal, and lateral stress fields, and velocity fields, conditional on the data. Inference based on this distribution will be carried out via Markov chain Monte Carlo techniques, to obtain estimates of these unknown fields along with uncertainty measures associated with them.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Surface Elevation; Stress Field; Basal Elevation; DHC-6", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Cressie, Noel; Jezek, Kenneth; Berliner, L.", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6", "repositories": null, "science_programs": null, "south": null, "title": "Dynamics of Ice Streams: A Physical Statistical Approach", "uid": "p0000711", "west": null}, {"awards": "0126149 Liu, Hongxing", "bounds_geometry": null, "dataset_titles": "Access to Antarctic coastline coverage and reference documents; Access to Antarctic snow zone coverage and reference documents; Access to boundary file and reference documents; Access to ice velocity data and reference documents; Access to snow melt extent image files and reference documents", "datasets": [{"dataset_uid": "001351", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Access to Antarctic coastline coverage and reference documents", "url": "http://geog.tamu.edu/~liu/research/download.htm"}, {"dataset_uid": "001350", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Access to boundary file and reference documents", "url": "http://geog.tamu.edu/~liu/research/download.htm"}, {"dataset_uid": "001640", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Access to snow melt extent image files and reference documents", "url": "http://geog.tamu.edu/~liu/research/download.htm"}, {"dataset_uid": "001779", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Access to ice velocity data and reference documents", "url": "http://geog.tamu.edu/~liu/research/download.htm"}, {"dataset_uid": "001352", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Access to Antarctic snow zone coverage and reference documents", "url": "http://geog.tamu.edu/~liu/research/download.htm"}], "date_created": "Tue, 15 Aug 2006 00:00:00 GMT", "description": "This award supports a project to characterize the morphology, ice motion velocity and mass balance of Lambert Glacier, Antarctica using state-of-the-art remote sensing and GIS techniques. Lambert Glacier is the largest ice stream in the world. Because of its size, it plays a fundamental role in the study of glacial dynamics and mass budget in response to present and future climate changes. Along with the bedrock topography and ice thickness data derived from airborne radio echo soundings and snow accumulation data compiled from ground-based measurements, the dynamic behavior and mass balance of the Lambert glacial basin in a Geographic Information Systems (GIS) environment will be examined. Specific objectives are to: (1) Extract two-dimensional ice velocity field over the entire Lambert glacial basin using speckle matching and differential interferometric SAR (InSAR) techniques, and produce a full coverage of radar coherence map over the drainage basin. With the ice velocity data, calculate the strain rate field from the initiation areas of the ice stream onto the Amery Ice Shelf; (2) Derive high-resolution digital elevation model (DEM) over the Lambert glacial drainage basin using SAR stereo, differential interferometric SAR, and GLAS laser altimetry techniques. Based on the DEM, extract ice divides and ice flow directions, delineate the snow catchment basin, and calculate the balance deformation velocity and the basal shear stress; (3) Interpolate traverse ice thickness data collected by Australian and Russian airborne radio echo sounding surveys into a regular grid, and derive a regular grid of bedrock topography in combination with the DEM; (4) Integrate newly derived ice velocity and ice thickness data as well as snow accumulation rate data compiled from previous ground-based measurements into a geographic information system (GIS), and calculate the mass flux through the ice stream at the grounding lines and net mass balance throughout the drainage basin. With these new measurements and calculations derived from advanced remote sensing techniques, we will be able to improve our understanding of dynamic behavior and current mass balance status of the Lambert glacial basin, gain an insight on the relationship between ice mass change and the variation in regional and global climate at decadal scale, and provide an evaluation on the issue of whether the Lambert glacier basin is subject to surging in the context of future climate change.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e SMMR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e SSM/I; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e IFSAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e SAR", "is_usap_dc": false, "keywords": "DEM; Not provided; RADARSAT-1", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Liu, Hongxing; Jezek, Kenneth", "platforms": "SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e RADARSAT \u003e RADARSAT-1; OTHER \u003e MODELS \u003e DEM; Not provided", "repo": "PI website", "repositories": "Other", "science_programs": null, "south": null, "title": "High-Resolution Modeling of Surface Topography, Ice Motion, and Mass Balance in the Lambert Glacial Basin using Radar Remote Sensing and GIS Techniques", "uid": "p0000204", "west": null}, {"awards": "0086997 Truffer, Martin", "bounds_geometry": null, "dataset_titles": "Margin Migration Rates and Dynamics: Siple Coast Ice Streams", "datasets": [{"dataset_uid": "609263", "doi": "10.7265/N50K26HH", "keywords": "Antarctica; Cryosphere; Glaciers/Ice Sheet; Glaciology; Siple Coast", "people": "Echelmeyer, Keith A.; Truffer, Martin", "repository": "USAP-DC", "science_program": null, "title": "Margin Migration Rates and Dynamics: Siple Coast Ice Streams", "url": "https://www.usap-dc.org/view/dataset/609263"}], "date_created": "Thu, 17 Mar 2005 00:00:00 GMT", "description": "0086997\u003cbr/\u003eTruffer\u003cbr/\u003e\u003cbr/\u003eThis award supports a two year project to investigate the dynamics of the marginal zone of the Siple Coast ice streams using existing velocity and temperature profiles. The flow and stress fields will be modeled using finite element methods and a thermo-mechanical model will be used to investigate the coupling of the flow and temperature fields. Direct comparison of these models with the observed velocity profiles will lead to estimates of the structure of the margins and the softening of the marginal ice. The distribution of basal and marginal shear stress will be investigated, leading to an estimate of the relative roles of the bed and the margins in the overall force balance of the ice streams.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e SURVEYING TOOLS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e THEODOLITE", "is_usap_dc": true, "keywords": "Ice Motion; USAP-DC; NSIDC; GROUND-BASED OBSERVATIONS; AGDC; Ice Velocity; Siple Dome; Ice Stream", "locations": "Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Truffer, Martin; Echelmeyer, Keith A.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Margin Migration Rates and Margin Dynamics of the Siple Coast Ice Streams", "uid": "p0000144", "west": null}, {"awards": "0135989 Wilen, Larry", "bounds_geometry": null, "dataset_titles": "Ice Fabric Characteristics: Siple Dome, A Core", "datasets": [{"dataset_uid": "609255", "doi": "10.7265/N54B2Z7V", "keywords": "Antarctica; Cryosphere; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Siple Dome; Siple Dome Ice Core", "people": "Wilen, Larry", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Ice Fabric Characteristics: Siple Dome, A Core", "url": "https://www.usap-dc.org/view/dataset/609255"}], "date_created": "Wed, 02 Mar 2005 00:00:00 GMT", "description": "0135989\u003cbr/\u003eWilen\u003cbr/\u003e\u003cbr/\u003eThis is a collaborative proposal by Principal Investigators at the University of Washington and Ohio University. Detailed knowledge about the interactions between micro-structure of ice and its deformation is needed to assess the integrity of stratigraphic layering and the depth-age relationship in ice cores, which is essential for interpreting the paleoclimate record. The Principal Investigators will use micro-structure to study fabric, the orientation distribution of crystal c-axes, and texture, the size and shape of crystals. Numerical modeling of ice deformation is a useful tool in understanding these interactions. Accurate modeling of ice deformation is complicated by factors, such as the fabric, grain size, dynamic recrystallization, stress level, and precise knowledge of initial conditions. For example, ice fabric evolves as the ice is strained and the deformation depends on the fabric. This complicated feedback mechanism must be understood to correctly model ice deformation. In another example, the usual assumption is that the initial fabric is isotropic or random, but there are excellent examples of near-surface ice in the ice cores that are apparently not isotropic. One must know the initial fabric to calculate the deformation rate in ice sheets. Dr. Wilen will combine results of his new automatic fabric analyzer (AFA) with predictions of detailed ice deformation models (Dr. Thorsteinsson) to refine and better constrain such models. The AFA gives new information in thin sections because the precision and number of measured c-axis orientations are greatly improved. The Principal Investigators will analyze existing data and collect new data on fabric and texture from ice cores to address questions regarding near-surface fabric, deformation mechanisms, dynamic recrystallization, and potential sources of layer disturbances. The data will be used to constrain models of fabric evolution and recrystallization processes. With the more refined models, scientists can address different questions and important problems related to ice deformation and ice cores. For example, the recent agreement between the climate records from the Greenland Ice Core Project (GRIP) and Greenland Ice Sheet Project 2 (GISP2) ice cores of the upper-90%, and the disagreement in the lower-10% emphasizes the need to understand and predict the mechanisms and probable depths of disruption in these and future deep ice cores. Evidence suggests that the stratigraphic disturbances arise from the anisotropic nature of ice crystals at a variety of scales. To properly model the deformation of anisotropic ice, the influence of fabric on deformation must be well known.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "GROUND-BASED OBSERVATIONS; Siple Dome; ice fabric; Ice Core Data; Ice Core; USAP-DC", "locations": "Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Arctic Natural Sciences", "paleo_time": null, "persons": "Wilen, Larry", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Collaborative Research: Fabric and Texture Characteristics of Micro-Physical Processes in Ice", "uid": "p0000134", "west": null}]
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This proposal represents collaborative research to explore manganese (Mn) limitation in Antarctic diatoms by two early career investigators. Diatoms are central players in the Southern Ocean carbon cycle, where the micronutrient chemistry is fundamentally different from other oceans. The Southern Ocean is characterized by widespread low Mn, coupled with high zinc (Zn). High Zn levels are potentially toxic to diatoms as Zn can competitively inhibit Mn uptake and metabolism, compromising the ability of building critical cellular components, thus impacting the biological pump. Using culture experiments with a matrix of micronutrient treatments (Mn, Zn, Fe) and irradiances, and using physiological and transcriptomic approaches, along with biochemical principles, the Principal Investigators will address the central hypothesis (that diatoms from the Southern Ocean possess unique physiological mechanisms to adapt to low Mn/high Zn) by quantifying rates of uptake and transporter binding constants. The transcriptomics approach will help to identify candidate genes that may provide Antarctic diatoms physiological mechanisms in low Mn/high Zn environment. The project does not require fieldwork but instead would make use of culture experiments with 4 diatom species (3 Antarctic, and 1 temperate). The proposed approach will also enable the goal of developing biomarker(s) for assessing Mn stress or Zn toxicity and results from the physiological experiments will help parameterize models of micronutrient limitation in the Southern Ocean.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Mixotrophic microorganisms that are capable of both photosynthetic and heterotrophic forms of metabolism are key contributors to primary productivity and organic carbon remineralization in the Southern Ocean. However, uncertainties in their grazing behavior and physiology prevent an accurate understanding of microbial food web dynamics and biogeochemical cycling in the Antarctic ecosystem. Polar mixotrophs have evolved to withstand extreme seasonality, including variable light, sea ice, temperature, and micronutrient concentrations. In particular, the Southern Ocean appears to be the only region of the world’s ocean where the bioessential trace metals iron (Fe) and manganese (Mn) are low enough to inhibit photosynthetic growth. The molecular physiology of mixotrophs experiencing Fe and Mn growth limitation has not yet been examined, and we lack an understanding of how seasonal changes in the availability of these micronutrients influence mixotrophic growth dynamics. We aim to examine whether grazing affords mixotrophs an ecological advantage in the Fe and Mn-deficient Southern Ocean, and to characterize the shifts in metabolic processes that occur during transitions in micronutrient conditions. Culture studies will directly measure growth responses, grazing behavior, and changes in elemental stoichiometry in response to Fe and Mn limitation. Transcriptomic analyses will reveal the metabolic underpinnings of trophic behavior and micronutrient stress responses, with implications for key biogeochemical processes such as carbon fixation, remineralization, and nutrient cycling.
Anandakrishnan/1643961<br/><br/>This award supports a project to study conditions under the Rutford Ice Stream, a large glacier that flows from the interior of the West Antarctic Ice Sheet to the Filchner Ronne Ice Shelf and then on to the ocean. The speed and volume of ice delivered to the ocean by this and similar glaciers is central to the question of sea-level change in the coming decades: if the volume of ice carried by Rutford to the ocean increases, then it will contribute to a rise in sea level. Numerical models of glacier flow that are used to forecast future conditions must include a component that accounts for the sliding of the ice over its bed. The sliding process is poorly modeled because of lack of detailed information about the bottom of glaciers, leading to increased uncertainty in the ice-flow models. Data from this project will provide such information. <br/><br/>During this project, in collaboration with researchers at the British Antarctic Survey, a detailed survey of the properties of the bed of Rutford Ice Stream will be carried out. These surveys include using seismic instruments (which are sensitive to naturally occurring earthquakes within glaciers--called icequakes) to monitor the distribution of those icequakes at the bed. The locations, size, and timing of icequakes are controlled by the properties of the bed such as porosity, water pressure, and stress. As part of this project, a hole will be drilled to the bed of the glacier to monitor water pressures and to extract a sample of the basal material. By comparing the pressure variations with icequake production, the properties of the basal material over a large area can be better determined. Those results will aid in the application of numerical models by informing their description of the sliding process. This award requires field work in Antarctica.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
As plate tectonics pushed Antarctica into a polar position, by ~34 million years ago, the continent and its surrounding Southern Ocean (SO) became geographically and thermally isolated by the Antarctic Circumpolar Current. Terrestrial and marine glaciation followed, resulting in extinctions as well as the survival and radiation of unique flora and fauna. The notothenioid fish survived and arose from a common ancestral stock into tax with 120 species that dominates today's SO fish fauna. The Notothenioids evolved adaptive traits including novel antifreeze proteins for survival in extreme cold, but also suffered seemingly adverse trait loss including red blood cells in the icefish family, and the ability to mount cellular responses to mitigate heat stress ? otherwise ubiquitous across all life. This project aims to understand how the notothenoid genomes have changed and contributed to their evolution in the cold. The project will sequence, analyze and compare the genomes of two strategic pairs of notothenioid fishes representing both red-blooded and white-blooded species. Each pair will consist of one Antarctic species and one that has readapted to the temperate waters of S. America or New Zealand. The project will also compare the Antarctic species genomes to a genome of the closet non-Antarctic relative representing the temperate notothenioid ancestor. The work aims to uncover the mechanisms that enabled the adaptive evolution of this ecologically vital group of fish in the freezing Southern Ocean, and shed light on their adaptability to a warming world. The finished genomes will be made available to promote and advance Antarctic research and the project will host a symposium of Polar researchers to discuss the cutting edge developments regarding of genomic adaptations in the polar region.<br/>Despite subzero, icy conditions that are perilous to teleost fish, the fish fauna of the isolated Southern Ocean (SO) surrounding Antarctica is remarkably bountiful. A single teleost group - the notothenioid fishes - dominate the fauna, comprising over 120 species that arose from a common ancestor. When Antarctica became isolated and SO temperatures began to plunge in early Oligocene, the prior temperate fishes became extinct. The ancestor of Antarctic notothenioids overcame forbidding polar conditions and, absent niche competition, it diversified and filled the SO. How did notothenioids adapt to freezing environmental selection pressures and achieve such extraordinary success? And having specialized to life in chronic cold for 30 myr, can they evolve in pace with today's warming climate to stay viable? Past studies of Antarctic notothenioid evolutionary adaptation have discovered various remarkable traits including the key, life-saving antifreeze proteins. But life specialized to cold also led to paradoxical trait changes such as the loss of the otherwise universal heat shock response, and of the O2-transporting hemoglobin and red blood cells in the icefish family. A few species interestingly regained abilities to live in temperate waters following the escape of their ancestor out of the freezing SO. <br/>This proposed project is the first major effort to advance the field from single trait studies to understanding the full spectrum of genomic and genetic responses to climatic and environmental change during notothenioid evolution, and to evaluate their adaptability to continuing climate change. To this end, the project will sequence the genomes of four key species that embody genomic responses to different thermal selection regimes during notothenioids' evolutionary history, and by comparative analyses of genomic structure, architecture and content, deduce the responding changes. Specifically, the project will (i) obtain whole genome assemblies of the red-blooded T. borchgrevinki and the S. American icefish C. esox; (ii) using the finished genomes from (i) as template, obtain assemblies of the New Zealand notothenioid N. angustata, and the white-blooded icefish C. gunnari, representing a long (11 myr) and recent (1 myr) secondarily temperate evolutionary history respectively. Genes that are under selection in the temperate environment but not in the Antarctic environment can be inferred to be directly necessary for that environment and the reverse is also true for genes under selection in the Antarctic but not in the temperate environment. Further, genes important for survival in temperate waters will show parallel selection between N. angustata and C. esox despite the fact that the two fish left the Antarctic at far separated time points. Finally, gene families that expanded due to strong selection within the cold Antarctic should show a degradation of duplicates in the temperate environment. The project will test these hypotheses using a number of techniques to compare the content and form of genes, the structure of the chromosomes containing those genes, and through the identification of key characters, such as selfish genetic elements, introns, and structural variants.
The response of the Antarctic ice sheet to climate change is a central issue in projecting global sea-level rise. While much attention is focused on the ongoing rapid changes at the coastal margin of the West Antarctic Ice Sheet, obtaining records of past ice-sheet and climate change is the only way to constrain how an ice sheet changes over millennial timescales. Whether the West Antarctic Ice Sheet collapsed during the last interglacial period (~130,000 to 116,000 years ago), when temperatures were slightly warmer than today, remains a major unsolved problem in Antarctic glaciology. Hercules Dome is an ice divide located at the intersection of the East Antarctic and West Antarctic ice sheets. It is ideally situated to record the glaciological and climatic effects of changes in the West Antarctic Ice Sheet. This project will establish whether Hercules Dome experienced major changes in flow due to changes in the elevation of the two ice sheets. The project will also ascertain whether Hercules Domes is a suitable site from which to recover climate records from the last interglacial period. These records could be used to determine whether the West Antarctic Ice Sheet collapsed during that period. The project will support two early-career researchers and train students at the University of Washington. Results will be communicated through outreach programs in coordination the Ice Drilling Project Office, the University of Washington's annual Polar Science Weekend in Seattle, and art-science collaboration.<br/><br/>This project will develop a history of ice dynamics at the intersection of the East and West Antarctic ice sheets, and ascertain whether the site is suitable for a deep ice-coring operation. Ice divides provide a unique opportunity to assess the stability of past ice flow. The low deviatoric stresses and non-linearity of ice flow causes an arch (a "Raymond Bump") in the internal layers beneath a stable ice divide. This information can be used to determine the duration of steady ice flow. Due to the slow horizontal ice-flow velocities, ice divides also preserve old ice with internal layering that reflects past flow conditions caused by divide migration. Hercules Dome is an ice divide that is well positioned to retain information of past variations in the geometry of both the East and West Antarctic Ice Sheets. This dome is also the most promising location at which to recover an ice core that can be used to determine whether the West Antarctic Ice Sheet collapsed during the last interglacial period. Limited ice-penetrating radar data collected along a previous scientific surface traverse indicate well-preserved englacial stratigraphy and evidence suggestive of a Raymond Bump, but the previous survey was not sufficiently extensive to allow thorough characterization or determination of past changes in ice dynamics. This project will conduct a dedicated survey to map the englacial stratigraphy and subglacial topography as well as basal properties at Hercules Dome. The project will use ground-based ice-penetrating radar to 1) image internal layers and the ice-sheet basal interface, 2) accurately measure englacial attenuation, and 3) determine englacial vertical strain rates. The radar data will be combined with GPS observations for detailed topography and surface velocities and ice-flow modeling to constrain the basal characteristics and the history of past ice flow.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Part 1: Non-technical description:
With support from the Office of Polar Programs, this project will evaluate how an important part of the food web in the coastal ocean of Antarctica will respond to climate change. The focal study organism in the plankton is a shelled mollusk, the Antarctic pteropod, Limacina helicina antarctica, a Southern Ocean organism that this known to respond to climate driven changes in ocean acidification and ocean warming. Ocean acidification, the lowering of ocean pH via the absorption of atmospheric carbon dioxide in the surface of the ocean, is a change in the ocean that is expected to cross deleterious thresholds of pH within decades. This study will improve understanding of how pteropods will respond, which will provide insight into predicting the resilience of the Antarctic marine ecosystem during future changes, one of the planets last marine wildernesses. The project will use tools of molecular biology to examine specifically how gene expression is modulated in the pteropods, and further, how the changes and regulation of genes act to resist the stress of low pH and high temperature. In addition, this project supports the training of Ph.D. graduate students and advances the goal of inclusive excellence in STEM and in marine sciences, in particular. The students involved in this project are from groups traditionally under-represented in marine science including first-generation college students. Overall, the project contributes to the development of the U.S. work force and contributes to diversity and inclusive excellence in the geosciences.
Part 2: Technical description:
The overarching goal of this project is to investigate the molecular response of the Antarctic thecosome pteropod, Limacina helicina antarctica to ocean acidification (OA) and ocean warming. The project will investigate changes in the epigenome of juvenile L. h. antarctica, by assessing the dynamics of DNA methylation in response to three scenarios of environmental conditions that were simulated in laboratory mesocosm CO2 experiments: (1) present-day pCO2 conditions for summer and winter, (2) future ocean acidification expected within 10-15 years, and (3) a multiple stressor experiment to investigate synergistic interaction of OA and high temperature stress. Recent lab-based mesocosm experiment research showed significant changes in the dynamics of global DNA methylation in the pteropod genome, along with variation in gene expression in response to abiotic changes. Thus, it is clear that juvenile L. h. antarctica are capable of mounting a substantial epigenetic response to ocean acidification. However, it is not known how DNA methylation, as an epigenetic process, is modulating changes in the transcriptome. In order to address this gap in the epigenetic knowledge regarding pteropods, the project will use next-generation sequencing approaches (e.g., RNA sequencing and reduced representation bisulfite sequencing) to integrate changes in methylation status with changes in gene expression in juvenile pteropods. Overall, this investigation is an important step in exploring environmental transcriptomics and phenotypic plasticity of an ecologically important member of Southern Ocean macrozoooplankton in response to anthropogenic climate change.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Icebergs influence climate by controlling how freshwater from ice sheets is distributed into the ocean, where roughly half of ice sheet mass loss is attributed to iceberg calving in the current climate. The freshwater deposited by icebergs as they drift and melt can affect ocean circulation, sea-ice formation, and biological primary productivity. Furthermore, calving of icebergs from ice shelves, the floating extensions of ice sheets, can influence ice sheet evolution and sea-level rise by reducing the resistive stresses provided by ice shelves on the seaward flow of upstream grounded ice. The majority of mass calved from ice shelves occurs in the form of tabular icebergs, which are typically hundreds of meters thick and on the order of tens to hundreds of kilometers in length and width. Tabular calving occurs when full-thickness ice shelf fractures known as rifts propagate to the edges of the ice shelf. These calving events are infrequent, often with decades between events on an individual ice shelf. Changes in tabular calving behavior, i.e., the size and frequency of calving events, can strongly influence climate and ice sheet evolution. However, tabular calving behavior, and how it responds to changes in climate, is neither well understood nor accurately represented in climate models.
In this project, a tabular calving parameterization for climate models will be developed. The parameterization will be derived according to data generated from a series of realistic and idealized century-scale tabular calving simulations, which will be performed with a novel ice flow and damage framework that can be applied at the scale of individual ice sheet-ice shelf systems: the CD-MPM-SSA (Continuum Damage Material Point Method for Shelfy-Stream Approximation). During these simulations, the geometry of the ice shelf, mechanical/rheological properties of the ice, and climate forcings such as ocean temperature will be varied to determine the rifting and calving response. The calving parameterization derived from these experiments will be implemented in a Geophysical Fluid Dynamics Laboratory (GFDL) climate model, where it will be coupled with a bonded-particle iceberg model. Then, experiments will be run to study the feedback between changes in iceberg calving behavior and climate. Success of this project will improve our understanding and representation of the ice mass budget, ice sheet evolution, and ocean freshwater fluxes, and will improve projections of climate change and sea-level rise.
Predicting the response of ice sheets to changing climate and their contribution to sea level requires accurate representation in numerical models of basal conditions under the ice. There remain large data gaps for these basal boundary conditions under the East Antarctic Ice Sheet as well as in West Antarctica, including basal melt rates under ice shelves. This project developed and tested a prototype ground-based radar system to sound and image ice more than 4km thick, detect thin water films at the ice bed, and determine basal melt rates under ice shelves. The team worked with European partners (France, Italy, Germany) at Dome C to conduct deep-field Antarctic testing of the new radar.
The project built and tested an L-band radar system (1.2-1.4GHz) with peak transmit power of 2kW. In addition to sounding and imaging thick ice, detection goals included resolving thin water films (>0.5mm). Such a system targets glaciological problems including site selection for ice in the 1.5-million-year age range, basal stress boundary conditions under grounded ice, and melt rates under floating shelves. By demonstrating feasibility, the project aims to influence sensor selection for satellite missions.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The Weddell seal is a champion diver with high natural tolerance for low blood oxygen concentration (hypoxemia) and inadequate blood supply (ischemia). The processes unique to this species protects their tissues from inflammation and oxidative stress observed in other mammalian tissues exposed to such physiological conditions. This project aims to understand the signatures of the processes that protect seals from inflammation and oxidant stress, using molecular, cellular and metabolic tools. Repetitive short dives before long ones are hypothesized to precondition seal tissues and activate the protective processes. The new aspect of this work is the study of endothelial cells, which sense changes in oxygen and blood flow, providing a link between breath-holding and cellular function. The approach is one of laboratory experiments combined with 2-years of field work in an ice camp off McMurdo Station in Antarctica. The study is structured by three main objectives: 1) laboratory experiments with arterial endothelial cells exposed to changes in oxygen and flow to identify molecular pathways responsible for tolerance of hypoxia and ischemia using several physiological, biochemical and genomic tools including CRSPR/Cas9 knockout and knockdown approaches. 2) Metabolomic analyses of blood metabolites produced by seals during long dives. And 3) Metabolomic and genomic determinations of seal physiology during short dives hypothesized to pre-condition tolerance responses. In the field, blood samples will be taken after seals dive in an isolated ice hole and its diving performance recorded. It is expected that the blood will contain metabolites that can be related to molecular pathways identified in lab experiments.
Isotopic and sedimentary datasets reveal that volcanic activity typically increases during interglacial periods. However, the physical mechanisms through which changes in the surface loading affect volcanic magmatic plumbing systems remain unconstrained. Recently generated 40Ar/39Ar eruption ages indicate that 86% of the dated samples from Mt. Waesche, a late Quaternary volcano in Marie Byrd land, correlate with interglacial periods, suggesting this volcano uniquely responds to changes in the West Antarctic Ice Sheet. We propose to combine the petrology of Mount Waesche’s volcanic record, constraints on changing ice loads through time, and geodynamic modelling to: (1) Determine how pre-eruptive storage conditions change during glacial and interglacial periods using whole rock and mineral compositions of volcanic rocks; (2) Conduct geodynamic modeling to elucidate the relationship between lithospheric structure, temporal variations in ice sheet thickness, and subsequent changes in crustal stresses and magmatic transport and, therefore, the mechanism(s) by which deglaciation impacts magmatic plumbing systems; (3) Use the outcomes of objectives (1) and (2) to provide new constraints on the changes in ice sheet thickness through time that could plausibly trigger future volcanic and magmatic activity in West Antarctica. This collaborative approach will provide a novel methodology to determine prior magnitudes and rates of ice load changes within the Marie Byrd Land region of Antarctica. Lastly, estimates of WAIS elevation changes from this study will be compared to ongoing studies at Mount Waesche focused on constraining last interglacial ice sheet draw down using cosmogenic exposure ages obtained from shallow drilling. The scope of work also includes a partnership with Mentoring Kids Works to develop several Polar and Earth Science Educational Modules aimed at improving reading skills in third grade students in New Mexico. The proposed Polar and Earth Science program consists of modules that include readings of books introducing students to Earth and Polar science themes, paired with Earth and Polar Science activities, followed by simple experiments, where students make predictions and collect data. Information required to implement our Polar and Earth Science curriculum will be made available online.
This project fits within the second of three major themes identified by the National Academy of Science report “A Strategic Vision for NSF Investments in Antarctic and Southern Ocean Research”. How do Antarctic biota evolve and adapt to the changing environment? Decoding the genomic and transcriptomic bases of biological adaptation and response across Antarctic organisms and ecosystems. Central in this theme is the physiological capacity of animals to cope with changes in environmental conditions over their lifetime, which this research firmly addresses. In the Southern Ocean surrounding Antarctica there is an extraordinary diversity of marine life. Much of our understanding of the biology of these animals comes from studies of the adaptations of these animals to sub-zero ocean conditions. Antarctic marine organisms have evolved to survive in stable, cold ocean conditions and possess a limited capacity to respond to environmental change. Research to date on Antarctic fishes has focused on adult life stages with much less research on early life stages that likely prioritize growth and development and not physiological mechanisms of stress tolerance. This project addresses the mechanisms that early life stages (embryos, larvae and juveniles) of Antarctic fishes use to respond to changes in ocean conditions. Specifically, the project will examine energetic trade-offs between key developmental processes in the context of environmental change. While the project focuses on Antarctic species, the research is highly translatable to stress tolerance mechanisms of fishes along the coast of North America, many of which are also experiencing changes in multiple environmental factors. Research in the Antarctic allows scientists to identify unifying themes or generalities in physiology that extend beyond the waters of the Southern Ocean and therefore have broad implications for understanding what is limiting the performance of fishes globally. BROADER IMPACTS –To build environmental stewardship and awareness, we must increase science literacy in the broader community. This project does this through three main objectives. First is to increase the diversity of students involved in environmental science research. Student diversity, in turn, gives the scientific community a broader perspective for addressing critical challenges in environmental biology. This project provides resources to support three PhD students, one postdoctoral scholar and two undergraduate students and promotes the diversity of young scientists and the advancement of groups traditionally underrepresented in environmental biology. Todgham will broaden the outreach effort by developing exhibits on environmental change impacts on polar regions for large public events, an opportunity to engage K-12 students, government officials in Sacramento and local and statewide communities. Lastly, through a collaboration with PolarTREC and teacher Denise Hardoy, lesson plans have been developed to teach K-12 students about experimental design, polar environments and sensitivity of Antarctic species to climate change.
An archive of baleen plates from 800 Antarctic blue and fin whales harvested between 1946 and 1948 was recently rediscovered in the Smithsonian’s National Museum of Natural History. As baleen grows, it incorporates compounds from the whale’s diet and surroundings, recording continuous biological and oceanographic information across multiple years. The baleen record forms an ideal experimental platform for studying bottom-up, top-down and anthropogenic impacts on blue and fin whales. Such insights are likely impossible to obtain through any other means as blue and fin whales now number ~1 and 4% of their pre-whaling abundances. The baleen archive includes years with strong climate and temperature anomalies allowing the influence of climate variability on predators and the ecosystems that support them to be examined. Additionally, the impact of whaling on whale stress levels will be investigated by comparing years of intensive whaling with the non-whaling years of WWII, both of which are captured in the time series. We will use 1) bulk stable isotopes to examine the trophic dynamics of Antarctic blue and fin whales, 2) compound-specific stable isotope analysis (CSIA-AA) to characterize the biogeochemistry of the base of the Antarctic food web and 3) hormone analyses to examine the population biology of these species. These investigations will fill major gaps in our understanding of the largest krill predators, their response to disturbance and environmental change, and the impact that commercial whaling has had on the structure and function of the Antarctic marine ecosystem.
The chemical composition of diatom fossils in the Southern Ocean provides information about the environmental history of Antarctica, including sea ice extent, biological production, and ocean nutrient distribution. The sea ice zone is an important habitat for a group of diatoms, largely from the genus Chaetoceros, that have a unique life cycle stage under environmental stress, when they produce a structure called a resting spore. Resting spores are meant to reseed the surface ocean when conditions are more favorable. The production of these heavy resting spores tends to remove significant amounts of carbon and silicon, essential nutrients, out of the surface ocean. As a result, this group has the potential to remove carbon from the surface ocean and can impact the sedimentary record scientists use to reconstruct environmental change.
This project explores the role of resting spores and nutrients in the sedimentary record using the nitrogen isotopic signature of these fossils and how those measurements are used to estimate carbon cycle changes. Measurements of nitrogen stable isotopes of nitrate, biomass, and diatom-bound nitrogen and silicon-to-nitrogen ratios of individual species grown in the laboratory are used to quantify how resting spores record nutrient drawdown in the water column and to what degree their signature is biased toward low nutrient conditions. Laboratory incubations were conducted with surface sediment containing Chaetoceros spp.. The emergence of vegetative cells and subsequent formation of resting spores is manipulated with the addition of nutrients, primarily nitrate. The resulting samples, both of vegetative cells and resting spores were measured for diatom-bound d15N. Resting spore d15N values are consistently lower than the vegetative d15N
from the same incubations. The incubation results will be used to quantify nutrient drawdown in sea ice environments during two contrasting intervals in earth history, the last ice age and the warm Pliocene. The project provided training and research opportunities for undergraduate and graduate students. Research efforts in Antarctic earth sciences are disseminated through an interactive display at the home institution and during university sponsored events.
This work addresses uncertainties in how Chaetoceros resting spores record surface nutrient conditions in their nitrogen stable isotopic composition, the relative impact of their specific signal with respect to the full sedimentary assemblage, and their potential to bias or enhance environmental reconstructions in the sea ice zone.
Overview:
Antarctic biota face increasing stressors from warming oceans. A key question is: What will be the effect of warming waters on Antarctic biota? A gap in our knowledge is the identify of early harbingers of new stressors. In our recent field season, we unexpectedly discovered pink, wart-like neoplasms in Antarctic notothenioid fish, including Trematomus scotti (crowned notothen) and Nototheniops larseni (painted notothen). Neoplasms affected about 30% of T. scotti collected in Andvord Bay on the West Antarctic Peninsula and covered 10 to 30% of the bodies of affected individuals, usually in one contiguous patch. We collected samples from affected and apparently unaffected controls. We could not find evidence of any similar outbreak. Our overall goal is to learn the biological origins of this neoplasm and how it affects cellular function and organismal physiology.
Intellectual Merit:
Aim 1: Pathogenic agents. Aim 1a: To test the hypothesis that a virus causes the neoplasm. Methods involve isolating and sequencing viral nucleic acids from neoplasms and from unaffected skin and comparing sequences to known viruses. Aim 1b: To test the hypothesis that neoplasms are hosts to parasites not present in healthy skin. Methods include tissue sections and DNA sequencing to find evidence of parasitic organisms. Significance: achieving Aim 1 will narrow down possible etiological agents. An untested possibility is that environmental contaminants cause the condition; exploring that hypothesis would require further sampling outside the limits of an EAGER proposal.
Aim 2: Cell-level pathology. Aim 2a: To test the hypothesis that the histopathology of the neoplasms is similar to other known skin neoplasias; alternatively, it might be a previously unknown type of neoplasia. Methods involve the examination of histological sections to identify pathology-specific characters. Aim 2b: To find effects of neoplasms on cell function. Methods involve performing whole-genome transcriptomics of affected and normal skin by RNA-seq and aligning reads to a T. scotti reference genome. Significance: achieving Aim 2 will define the cell biology and gene-expression phenotypes of the neoplasia, thus suggesting mechanisms that cause it.
[Note: NSF deleted funds specifically to achieve the Aim 3, which nevertheless appears here to represent the original proposal.] Aim 3: Organismal pathology. Aim 3a: To test the hypothesis that the neoplasm has adverse effects on growth and physiology. Methods are to perform morphometrics in fish with neoplasms compared to age-matched controls from otolith studies. Aim 3b: To test the hypothesis that the neoplasia affects reproductive traits. Methods compare reproductive effort in affected and unaffected individuals. Significance: if the neoplasia has little consequences on growth and reproduction, our worry about its spread will be lessened, but if it is harmful, then Antarctic ecology, which largely depends on notothenioid fish, might be in danger.
Achieving Aims 1-3 will advance knowledge by identifying the causes of a neoplasia outbreak in Antarctic fish. Work is potentially transformative because it might represent an early sign of Antarctic fish responses to the stress of global climate change. Proposed work would be the first to investigate a neoplasia outbreak in Antarctic fish. We will assess the project’s success by whether we identify a causative agent and its effects on physiology.
Broader Impacts:
Aim 4: Publicizing the neoplasia. We aim to raise awareness of the outbreak and publicize its distinct diagnostic features, including assays to detect it, by contributing to groups that track Antarctic ecosystems.
Aim 5: Inclusion. We will involve underrepresented groups in scientific research with authentic research experiences.
Achieving Aims 4 and 5 will benefit society because they will disseminate to scientific and lay communities a potential early-warning system for the effects of an apparently new neoplasia affecting, at least locally, a large proportion of a fish population. Dissemination will stir research to determine whether this neoplasia outbreak is an isolated event or is becoming a general phenomenon, and thus a concern for Antarctic ecosystems. Proposed research will enhance research infrastructure by providing tools to identify the neoplasia. Finally, the project will broaden access to research careers by exposing underserved high school students and undergraduates to an exciting live research project.
Overview</br>
It is proposed that laser cutting technology can be used to rapidly extract high quality ice samples from borehole walls. The technology applies to both existing boreholes and newly drilled ones, even enabling scientists to obtain samples using non‐coring mechanical drills. Since the instrumentation is highly portable, a field team of three persons might take no longer than a few days in the field to extract ice, and samples from a critical time period could be extracted from multiple locations in a single field season.
This pilot program will investigate and validate the technology of laser sampling. It is beneficial to use fiber optics to convey light in borehole instrumentation rather than attempting to package a complete laser system for travel down a borehole, so the cutting laser and wavelength (1.07Pm) are chosen with such engineering in mind. The primary scientific goals of the program are to: 1) determine optimum cutting conditions in terms of laser power and operating conditions, 2) quantifying the effects of residual meltwater that remain in the cut slot after a cut so that re-cutting needs can be predicted or mitigated, 3) designing and testing mechanical structures to retract samples from blocks of ice once cut, and 4) analyzing the composition and crystal structure of ice near a cut slot to determine the impacted volume (if any) of ice and temperatures where scientific readings might be affected by the sampling process.
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Intellectual Merits</br>
The collection of deep ice from the Polar Ice Sheets involves large amounts of time, effort, and expense. Often, the most important information is held in very small volumes of core, and while replicate coring can supplement this core, there is often a need to retrieve additional ice samples based on recent scientific findings or borehole logging at a site. In addition, there is currently no easy method of extracting ice from boreholes drilled by non‐coring mechanical drills, which are often much faster, lighter, and less expensive to operate. There are numerous specific projects that could immediately benefit from laser sampling including sampling ice overlaying buried impact craters and bolides, filling critical gaps in the chemical record in damaged core sections from Siple Dome, obtaining oldest ice cores from brittle sections near the surface of the Allan Hills blue ice area, where coring drills apply stresses that may fracture the ice, and replacing core whose value has degraded due to time and depressurization. This program builds on a prior engineering advances in optical fiber‐based logging technology, developed previously for Siple Dome borehole logging.
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Broader Impact</br>
Laser sampling would advance numerous fields interfaced with glaciology and ice core studies. These include climate and paleoenvironmental science, volcanology, and human history where large volumes of ice are crucial to extract ultra‐high resolution records of natural and anthropogenic emissions. Potentially the principle of laser sampling could be used to directly sample and study ice on other planets or their satellites.
This program encompasses a broad base of theoretical, experimental, and design work, which makes it ideal for training postdoctoral scientists, graduate students, and advanced undergraduates. The program will include a research opportunity for one or more middle school teachers through a Research Experience for Teachers program with one of the local school districts of the Twin Cities area. The teacher(s) will assist the investigators in the analysis of scattered laser light in glacier ice, and will set up a small experiment at various visible wavelengths to measure scattering constants. These experiments have been chosen because they can easily translate into classroom demonstrations and hands‐on activities using eye-safe visible- light LED sources and large samples of artificial ice. The teacher(s) will also produce a lesson plan on basic optics, glacial ice, or polar science as a deliverable.
This proposal does not involve field work.
An accurate constitutive relationship for ice is fundamental to ice-flow models and ice-core interpretations. While Glen’s flow law describes well the overall deformation of ice when subjected to stress, many details remain poorly constrained. In particular, the effect of impurities on the strain rate both directly and through the development of ice fabric is not well understood. Variations in impurity concentrations are associated with variations in deformation rates as observed in both Greenland and Antarctica. The impact of uncertainties on the deformation of ice is most acutely observed in the interpretation of ice cores where the inference of past accumulation rate depends on the cumulative vertical thinning. Thus, many ice-core climate reconstructions, such as the gas-age ice-age difference, surface temperature histories, and aerosol fluxes, are also affected. Given the complexities of the possible impacts of sulfuric acid on the flow of ice and the interaction between these impacts, it seems almost impossible to examine an ice core and understand the impacts of impurities on the microstructural evolution and creep behavior. Our research seeks to understand the effects of sulfuric acid at concentrations applicable to polar ice sheets and relate these results to the flow of polar ice both through experiments and through modeling. Our results have shown that the presence of sulfuric acid in the grain boundaries of polar ice increases its strength in shear, while sulfuric acid in the whole matrix of polar ice reduces its strength. We have also found that sulfuric acid causes an initial increase in average grain sizes and then a subsequent decrease, a trend that differs from the continuous increase in average grain sizes observed in freshwater ice. We are also determining the role of stress state, i.e. simple compression versus shear, on the microstructural evolution and how sulfuric acid impacts this.
The cold, dry terrestrial environments of Antarctica are inhospitable for insects, and only three midge species make Antarctica home. Of these, Belgica antarctica is the only species found exclusively in Antarctica, and it has been a resident of Antarctica since the continent split from South America ~30 million years ago. Thus, this species is an excellent system to model the biological history of Antarctica throughout its repeated glaciation events and shifts in climate. This insect is also a classic example of extreme adaptation, and much previous work has focused on identifying the genetic and physiological mechanisms that allow this species to survive where no other insect is capable. However, it has been difficult to pinpoint the unique evolutionary adaptations that are required to survive in Antarctica due to a lack of information from closely related Antarctic and sub-Antarctic species. This project will compare adaptations, genome sequences, and population characteristics of four midge species that span an environmental gradient from sub-Antarctic to Antarctic habitats. In addition to B. antarctica, these species include two species that are strictly sub-Antarctic and a third that is native to the sub-Antarctic but has invaded parts of Antarctica. The researchers, comprised of scientists from the US, UK, Chile, and France, will sample insects from across their geographic range and measure their ability to tolerate environmental stressors (i.e., cold and desiccation), quantify molecular responses to stress, and compare the makeup of the genome and patterns of genetic diversity. This research will contribute to a greater understanding of adaptation to extremes, to an understanding of biodiversity on the planet and to understanding and predicting changes accompanying environmental change. The project will train two graduate students and two postdoctoral researchers, and a K-12 educator will be a member of the field team and will assist with fieldwork and facilitate outreach with schools in the US. The project includes partnership activities with several STEM education organizations to deliver educational content to K-12 and secondary students. This is a project that is jointly funded by the National Science Foundation's Directorate of Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Each Agency funds the proportion of the budget and the investigators associated with its own country. UK participation in this project includes deploying scientists as part of the field team, supporting field and sampling logistics at remote Antarctic sites, and genome sequencing, annotation, and analyses.
This project focuses on the key physiological adaptations and molecular processes that allow a select few insect species to survive in Antarctica. The focal species are all wingless with limited dispersal capacity, suggesting there is also significant potential to locally adapt to variable environmental conditions across the range of these species. The central hypothesis is that similar molecular mechanisms drive both population-level adaptation to local environmental conditions and macroevolutionary changes across species living in different environments. The specific aims of the project are to 1) Characterize conserved and species-specific adaptations to extreme environments through comparative physiology and transcriptomics, 2) Compare the genome sequences of these species to identify genetic signatures of extreme adaption, and 3) Investigate patterns of diversification and local adaptation across each species? range using population genomics. The project establishes an international collaboration of researchers from the US, UK, Chile, and France with shared interests and complementary expertise in the biology, genomics, and conservation of Antarctic arthropods. The Broader Impacts of the project include training students and partnering with the Living Arts and Science Center to design and implement educational content for K-12 students.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This award supports a project to study the effect of liquid, intercrystalline water on the flow resistance of ice and the mobility of this water within ice. Water plays a central role in the flow of ice streams. It lubricates their bases and softens their margins, where flow speeds abruptly transition from rapid to slow. Within ice stream margins some ice is "temperate,” meaning that it is at its pressure-melting temperature with relatively thick water films at grain boundaries that significantly soften the ice. The amount of water in ice depends sensitively on its permeability, values of which are too poorly known to estimate the water contents of ice-stream shear margins or associated ice viscosities.
This award stems from the NSF/GEO-UK NERC lead agency opportunity (NSF 14-118) and is a collaboration between Iowa State University and Oxford University in the United Kingdom. The experimental part of the project is executed at Iowa State University and is the focus herein because it has been supported by NSF. Two sets of experiments are conducted. In one set, a large ring-shear device is used to shear ice in confined compression and at its melting temperature to study the sensitivity of ice viscosity to water content. Ice is sheared at stresses and strain rates comparable to those of ice-stream margins, and water content is varied through twice the range explored in the only previous set of experiments that investigated ice softening by water. The second set of experiments required the design, fabrication, and testing of a laboratory ice permeameter that allows the permeability of temperate ice to be measured. Experiments are conducted to study the dependence of ice permeability on ice grain size and water content--the two dependencies required to model grain-scale water flow through temperate ice.
Undersea forests of seaweeds dominate the shallow waters of the central and northern coast of the western Antarctic Peninsula and provide critical structural habitat and carbon resources (food) for a host of marine organisms. Most of the seaweeds are chemically defended against herbivores yet support very high densities of herbivorous shrimp-like grazers (crustaceans, primarily amphipods) which greatly benefit their hosts by consuming filamentous and microscopic algae that otherwise overgrow the seaweeds. The amphipods benefit from the association with the chemically defended seaweeds by gaining an associational refuge from fish predation. The project builds on recent work that has demonstrated that several species of amphipods that are key members of crustacean assemblages associated with the seaweeds suffer significant mortality when chronically exposed to increased seawater acidity (reduced pH) and elevated temperatures representative of near-future oceans. By simulating these environmental conditions in the laboratory at Palmer Station, Antarctica, the investigators will test the overall hypothesis that ocean acidification will play a significant role in structuring crustacean assemblages associated with seaweeds. Broader impacts include expanding fundamental knowledge of the impacts of global climate change by focusing on a geographic region of the earth uniquely susceptible to climate change. This project will also further the NSF goals of training new generations of scientists and of making scientific discoveries available to the general public. This includes training graduate students and early career scientists with an emphasis on diversity, presentations to K-12 groups and the general public, and a variety of social media-based outreach programs.
The project will compare population and assemblage-wide impacts of natural (ambient) and carbon dioxide enriched seawater on assemblages of seaweed-associated crustacean grazers. Based on prior results, it is likely that some species will be relative "winners" and some will be relative "losers" under the changed conditions. The project will then aim to carry out measurements of growth, calcification, mineralogy, the incidence of molts, and biochemical and energetic body composition for two key amphipod "winners" and two key amphipod "losers". These measurements will allow an assessment of what factors drive species-specific enhanced or diminished performance under conditions of ocean acidification and sea surface warming. The project will expand on what little is known about prospective impacts of changing conditions on benthic marine Crustacea, in Antarctica, a taxonomic group that faces the additional physiological stressor of molting. The project is likely to provide additional insight on the indirect regulation of the seaweeds that comprise Antarctic undersea forests that provide key architectural components of the coastal marine ecosystem.
This award supports a project to conduct laboratory experiments with a new, custom-fabricated cryo-friction apparatus to explore ice deformation oscillatory stresses like those experienced by tidewater glaciers in nature. The experimental design will explore the dynamic frictional properties of periodically loaded ice sliding on rock. Although the frictional strength of ice has been studied in the past these studies have all focused on constant rates of loading and sliding. The results of this work will advance understanding of ice stream dynamics by improving constraints on key material and frictional properties and allowing physics-based predictions of the amplitude and phase of glacier strain due to tidally induced stress variations. The intellectual merit of this work is that it will result in a better understanding of dynamic rheological parameters and will provide better predictive tools for dynamic glacier flow. The proposed experiments will provide dynamic material properties of ice and rock deformation at realistic frequencies experienced by Antarctic glaciers. The PIs will measure the full spectrum of material response from elastic to anelastic to viscous. The study will provide better constraints to improve predictive capability for glacier and ice-stream response to external forcing. The broader impacts of the work include providing estimates of material properties that can be used to broaden our understanding of glacier flow and that will ultimately be used for models of sea level rise and ice sheet stability. The ability to predict sea level in the near future is contingent on understanding of the processes responsible for flow of Antarctic ice streams and glaciers. Modulation of glacier flow by ocean tides represents a natural experiment that can be used to improve knowledge of ice and bed properties, and of the way in which these properties depend on time-varying forcings. Presently, the influence of tidal forcing on glacier movement is poorly understood, and knowledge of ice properties under tidal loading conditions is limited. The study will generate results of interest beyond polar science by examining phenomena that are of interest to seismology, glaciology and general materials science. The project will provide valuable research and laboratory experience for two undergraduate interns and will provide experience for the PI (currently a postdoc) in leading a scientific project. The three PIs are early career scientists. This proposal does not require fieldwork in the Antarctic.
The ice sheets of Antarctica and Greenland are losing mass and contributing to accelerating global sea-level rise. Satellite altimetry provides precise measurement of ice-sheet volume change, but computing ice-sheet mass change the quantity relevant for estimating the ice sheets sea-level contribution requires knowing the density of the ice sheet. The density near the ice-sheet surface also affects age estimates of air bubbles recovered in ice cores, which are a key source of information on past climate changes. Ice-sheet density is primarily controlled by the rate at which firn (snow that has persisted for a year or more on ice sheets) compacts into ice, but there is currently no widely accepted theory of how this compaction occurs. The goal of this project is thus to advance understanding of how firn densifies. The team will conduct laboratory experiments and analyze ice-penetrating radar and ice-core data from Antarctica. A key desired outcome of the project is a new model of firn densification that can be used to improve satellite-based altimetry measurements of present-day ice-sheet change and reconstructions of past climate changes from ice cores.
This project will combine laboratory experiments, numerical modeling, and geophysical techniques to determine the rheology of firn as it compacts to form ice. The team will use two methods to measure firn compaction: (1) lab-based experiments and (2) analysis of ice-core and radar data. For the lab-based work, the team will conduct a suite of compaction experiments on synthetic firn samples under uni-axial strain and constant temperature and axial stress. They will also measure the grain-size evolution. By running a large number of experiments (> 25), the team will constrain key parameters that determine how firn compaction rate depends on density, temperature, grain size, and axial stress. The experiments will be conducted in a table-top apparatus at temperatures as low as -40 degrees C and axial stresses up to 4 MPa. For the field-data-based component, the team will analyze ice-core and ice-penetrating radar data to produce the first coincident set of radar-derived firn compaction rates, borehole temperatures, firn densities, and firn grain sizes. Results from lab and field data will be tied together using a numerical firn compaction model. This model is formulated using conservation of mass, momentum, and energy, along with an explicit description of firn rheology and grain-size evolution. Constraints on firn rheology will be incorporated into this model and the team will use it to examine fundamental questions about how changes in the climate affect firn density. This is a crucial unknown that contributes significant measurement uncertainty in estimates of past and present climate change.
The continent of Antarctica has approximately the same surface area as the continental United States, though we know significantly less about its underlying geology and seismic activity. Multinational investments in geophysical infrastructure over the last few decades, especially broadband seismometers operating for several years, are allowing us to observe many interesting natural phenomena, including iceberg calving, ice stream slip, and tectonic earthquakes. To specifically leverage those past investments, we will analyze past and current data to gain a better understanding of Antarctic seismicity. Our recent research revealed that certain large earthquakes occurring elsewhere in the world triggered ice movement near various stations throughout Antarctica. We plan to conduct an exhaustive search of the terabytes of available data, using cutting-edge computational techniques, to uncover additional evidence for ice crevassing, ice stream slip, and earth movement during earthquakes. One specific focus of our research will include investigating whether some of these phenomena may be triggered by external influences, including passing surface waves from distant earthquakes, ocean tides, or seasonal melt. We plan to produce a catalog of the identified activity and share it publicly, so the public and researchers can easily access it. To reach a broader audience, we will present talks to high school classes, including Advanced Placement classes, in the Austin, Texas and Atlanta, Georgia metropolitan areas with emphasis on general aspects of seismic hazard, climate variability, and the geographies of Antarctica. This project will provide research opportunities for undergraduates, training for graduate students, and support for an early-career scientist.
In recent years, a new generation of geodetic and seismic instrumentation has been deployed as permanent stations throughout Antarctica (POLENET), in addition to stations deployed for shorter duration (less than 3 years) experiments (e.g. AGAP/TAMSEIS). These efforts are providing critical infrastructure needed to address fundamental questions about both crustal-scale tectonic structures and ice sheets, and their interactions. We plan to conduct a systematic detection of tectonic and icequake activities in Antarctica, focusing primarily on background seismicity, remotely-triggered seismicity, and glacier slip events. Our proposed tasks include: (1) Identification of seismicity throughout the Antarctic continent for both tectonic and ice sources. (2) An exhaustive search for additional triggered events in Antarctica during the last ~15 years of global significant earthquakes. (3) Determination of triggered source mechanisms and whether those triggered events also occur at other times, by analyzing years of data using a matched-filter analysis (where the triggered local event is used to detect similar events). (4) Further analysis of GPS measurements over a ~5.5 year period from Whillans Ice Plain, which suggests that triggering of stick-slip events occurred after the largest earthquakes. An improved knowledge of how the Antarctic ice sheet responds to external perturbations such as dynamic stresses from large distant earthquakes and recent ice unloading could lead to a better understanding of ice failure and related dynamic processes. By leveraging the vast logistical investment to install seismometers in Antarctica over the last decade, our project will build an exhaustive catalog of tectonic earthquakes, icequakes, calving events, and any other detectable near-surface seismic phenomena.
This award supports a project intended to discover, through field observations and numerical simulations, how ocean wave-induced vibrations on ice shelves in general, and the Ross Ice Shelf (RIS), in particular, can be used (1) to infer spatial and temporal variability of ice shelf mechanical properties, (2) to infer bulk elastic properties from signal propagation characteristics, and (3) to determine whether the RIS response to infragravity (IG) wave forcing observed distant from the front propagates as stress waves from the front or is "locally" generated by IG wave energy penetrating the RIS cavity. The intellectual merit of the work is that ocean gravity waves are dynamic elements of the global ocean environment, affected by ocean warming and changes in ocean and atmospheric circulation patterns. Their evolution may thus drive changes in ice-shelf stability by both mechanical interactions, and potentially increased basal melting, which in turn feed back on sea level rise. Gravity wave-induced signal propagation across ice shelves depends on ice shelf and sub-shelf water cavity geometry (e.g. structure, thickness, crevasse density and orientation), as well as ice shelf physical properties. Emphasis will be placed on observation and modeling of the RIS response to IG wave forcing at periods from 75 to 300 s. Because IG waves are not appreciably damped by sea ice, seasonal monitoring will give insights into the year-round RIS response to this oceanographic forcing. The 3-year project will involve a 24-month period of continuous data collection spanning two annual cycles on the RIS. RIS ice-front array coverage overlaps with a synergistic Ross Sea Mantle Structure (RSMS) study, giving an expanded array beneficial for IG wave localization. The ice-shelf deployment will consist of sixteen stations equipped with broadband seismometers and barometers. Three seismic stations near the RIS front will provide reference response/forcing functions, and measure the variability of the response across the front. A linear seismic array orthogonal to the front will consist of three stations in-line with three RSMS stations. Passive seismic array monitoring will be used to determine the spatial and temporal distribution of ocean wave-induced signal sources along the front of the RIS and estimate ice shelf structure, with the high-density array used to monitor and localize fracture (icequake) activity. The broader impacts include providing baseline measurements to enable detection of ice-shelf changes over coming decades which will help scientists and policy-makers respond to the socio-environmental challenges of climate change and sea-level rise. A postdoctoral scholar in interdisciplinary Earth science will be involved throughout the course of the research. Students at Cuyamaca Community College, San Diego County, will develop and manage a web site for the project to be used as a teaching tool for earth science and oceanography classes, with development of an associated web site on waves for middle school students.
Understanding and being able to anticipate changes in the glaciological regime of the Ross Ice Shelf (RIS) and West Antarctic Ice Sheet (WAIS) are key to improving sea level rise projections due to ongoing ice mass loss in West Antarctica. The fate of the WAIS is a first-order climate change and global societal issue for this century and beyond that affects coastal communities and coastal infrastructure globally.
Ice shelf--ocean interactions include impacts from tsunami, ocean swell (10-30s period), and very long period ocean waves that impact ice shelves and produce vibrations that induce a variety of seismic signals detected by seismometers buried in the ice shelf surface layer, called firn. To study the wave-induced vibrations in the RIS, an extensive seismic array was deployed from Nov. 2014 to Nov. 2016. This unique seismometer array deployment on an ice shelf made continuous observations of the response of the RIS to ocean wave impacts from ocean swell and very long period waves. An extensive description of the project motivation and background (including photos and videos of the deployment operations), and list of published studies of analyses of the seismic data collected by this project, are available at the project website https://iceshelfvibes.ucsd.edu.
Two types of seismic signals detected by the seismic array are most prevalent: flexural gravity waves (plate waves) and icequakes (signals analogous to those from earthquakes but from fracturing of the ice).
Long period ocean waves flex the ice shelf at the same period as the ocean waves, with wave energy at periods greater than ocean swell more efficient at coupling energy into flexing the ice shelf. Termed flexural gravity waves or plate waves (Chen et al., 2018), their wave-induced vibrations can reach 100’s of km from the ice edge where they are excited, with long period wave energy propagating in the water layer below the shelf coupled with the ice shelf flexure. Flexural gravity waves at very long periods (> 300 s period), such as from tsunami impacts (Bromirski et al., 2017), can readily reach grounding zones and may play a role in long-term grounding zone evolution.
Swell-induced icequake activity was found to be most prevalent at the shelf front during the austral summer (January – March) when seasonal sea ice is absent and the associated damping of swell by sea ice is minimal (Chen et al., 2019).
In addition to the seismic array, a 14 station GPS (global positioning system) array was installed during seismic data retrieval and station servicing operations in October-November 2015. The GPS stations, co-located with seismic stations, extended from the shelf front southward to about 415 km at interior station RS18. Due to logistical constraints associated with battery weight during installation, only one station (at DR10) operated year-round. The GPS data collected give a detailed record of changes in iceflow velocity that are in close agreement with the increasing velocity estimates approaching the shelf front from satellite observations. Importantly, the year-round data at DR10 show an unprecedented seasonal cycle of changes in iceflow velocity, with a speed-up in northward (seaward) ice flow during Jan.-May and then a velocity decrease from June-Sep. (returning to the long-term mean flow velocity). This annual ice flow velocity change cycle has been attributed in part to seasonal changes in ice shelf mass (thinning, reducing buttressing) due to melting at the RIS basal (bottom) surface from intrusion of warmer ocean water (Klein et al., 2020).
The Siple Coast in West Antarctica has undergone significant glacier changes over the last millenium. Several ice streams--rapidly moving streams of ice bordered by slow-moving ice--exist in this region that feeds into the Ross Ice Shelf. A long-term slowdown of Whillans Ice Stream appears to be occurring, and this is affecting the zone between the Whillans and Mercer Ice Streams. However, the consistency of this slowdown and resulting changes to the shear margin between the two ice streams are unknown. Shear zone stability represents a potentially critical control on mass balance of ice sheets, especially in regions of fast ice flow where basal shear stress is minimal. This project is therefore focused on understanding the spatial and temporal change of ice flow kinematics, shear margin structure, and shear margin location between Whillans and Mercer Ice Streams. A collateral benefit of and driver for this as a RAPID project is to test a method for assessing where crevassing will develop in this zone of steep velocity gradients. Such a method may benefit not only near-term field-project planning in the 2018-19 field season, but also planning for future fieldwork and traverses.<br/><br/>The team will use velocity estimates derived from available remote sensing datasets to determine transient velocity patterns and shifts in the shear-zone location over the last 20 years. This velocity time series will be incorporated into a large-scale ice-sheet model to estimate ice-sheet susceptibility to changing boundary conditions over the next century based on likely regional ice-flux scenarios. This approach is an extension of recent work conducted by the team that shows promise for predicting areas of changing high strain rates indicative of an active glacier shear margin. The ultimate objectives are to characterize the flow field of merging ice streams over time and investigate lateral boundary migration. This will provide a better understanding of shear-margin control on ice-shelf and up-glacier stability.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This award supports a project to undertake a systematic examination of the effects of soluble impurities, particularly sulfuric acid, on the creep of polycrystalline ice as function of temperature, strain rate and impurity concentration. The working hypothesis is that soluble impurities will increase the flow rate of polycrystalline ice compared to high-purity ice, that this effect will be temperature dependent and that the impurities by affecting the re-crystallization and grain growth will change the fabric of the ice. Both H2SO4-doped and high-purity poly-crystalline ice will be produced by freezing sheets of ice, breaking them up, sieving the ice particles and then sintering them in a mold into fine-grained cylindrical specimens with at least ten grains across their diameter. The resulting microstructures (dislocation structure, grain size and shape, grain boundary character and micro-structural location of the acid) will be characterized using a variety of techniques including: optical microscopy, scanning electron microscopy, including secondary electron imaging, electron backscattered patterns, energy dispersive X-ray spectroscopy, electron channeling contrast imaging, and X-ray topography. The creep of both the H2SO4-doped and the high-purity polycrystalline ice will be undertaken at a range of temperatures and stresses. The ice?s response to the creep deformation (grain boundary sliding, dislocation motion, re-crystallization, grain boundary migration, impurity redistribution) will be studied using a combination of methods. The creep behavior will be modeled and related to the microstructure. Of particular interest is how impurities affect the activation energy for creep. The intellectual merit of the work is that it will lead to a better understanding of glacier ice and will enable glaciologists to model the influence of impurities on the flow and fabric development in polycrystalline ice. The broader impacts of the project include the knowledge that will be gained of the effects of impurities on the flow of ice which will allow paleoclimatologists to better interpret ice core data and will allow scientists developing predictive models to better address the flow of ice sheets under various climate change scenarios. The project will also lead to the education and training of a Ph.D. student, several undergraduates and some high school students. Results from the research will be published in refereed journals. Several undergraduates, typically two per year, will also perform the work. Dartmouth aggressively courts minority students at all degree levels, and we will seek women or minority group undergraduates for this project. The undergraduates will be supported by Dartmouth?s nationally-honored Women In Science Project or by REU funding. The undergraduates? research will integrate closely with the Ph.D. student?s studies. Hanover High School students will also be involved in the project and develop an educational kit to introduce students to the properties of ice. Results from the research will be published in refereed journals and presented at conferences.
This project investigates a rapidly moving section of the West Antarctic Ice Sheet known as the Whillans Ice Stream. Ice streams and outlet glaciers are the major pathways for ice discharge from ice sheets into the ocean. Consequently, understanding ice stream dynamics, specifically the processes controlling the frictional resistance of ice sliding on sediments at its base, is essential for predictive modeling of how Earth's ice sheets will respond to a changing climate. Rather than flowing smoothly, Whillans Ice Stream advances in stick-slip cycles: brief periods of rapid sliding, equivalent to magnitude 7 earthquakes, alternating with much longer periods of repose. The PIs will perform simulations of these stick-slip cycles using computer codes originally developed for modeling tectonic earthquakes. By matching observed ice motions, the PIs will constrain the range of frictional processes acting at the base of the ice stream. An additional focus of the project is on brittle fracture processes in ice, expressed through seismic waves radiated by faulting and/or crevassing episodes that accompany the large-scale sliding events. An understanding of ice fracture provides a basis for assessing the susceptibility of ice shelves to rifting and catastrophic disintegration. Project results will be incorporated into outreach activities (from elementary school to community college events) as well as a polar science class for the California State Summer School for Mathematics and Science (COSMOS) program for high school students.<br/><br/>Simulations of the stick-slip cycle will employ 3D dynamic rupture models that simultaneously solve for the seismic wavefield and rupture process, consistent with elastodynamic material response and friction laws on the ice stream bed. Stresses and frictional properties will be varied to achieve consistency with surface GPS and broadband seismic data as well as borehole seismograms from the WISSARD project. The results will be interpreted using laboratory till friction experiments, which link velocity-weakening/strengthening behavior to temperature and water content, and to related experiments quantifying basal drag from ice flow over rough beds. The source mechanism of seismicity accompanying the slip events (shear faulting versus crevassing) will be determined using 3D waveform modeling in conjunction with mechanical models of the seismic source processes. This proposal does not require fieldwork in the Antarctic.
The depletion of stratospheric ozone over Antarctica leads to abnormally high levels of ultraviolet radiation (UVR) from the sun reaching the surface of the ocean. This phenomenon is predicted to continue for the next half century, despite bans on ozone-destroying pollutants. Phytoplankton in the near surface ocean are subjected to variable amounts of UVR and contain a lot of lipids (fats). Because phytoplankton are at the base of the food chain their lipids makes their way into the Antarctic marine ecosystem's food web. The molecular structures of phytoplankton lipids are easily altered by UVR. When this happens, their lipids can be transformed from healthy molecules into potentially harmful molecules(oxylipins) known to be disruptive to reproductive and developmental processes. This project will use state-of-the-art molecular methods to answer questions about extent to which UVR damages lipid molecules in phytoplankton, and how these resultant molecules might effect the food chain in the ocean near Antarctica. <br/><br/><br/>Lipid peroxidation is often invoked as consequence of increased exposure of phytoplankton to UVR-produced reactive oxygen species (ROS), but the literature is practically silent on peroxidized lipids and their byproducts (i.e. oxylipins) in the ocean. In waters of the West Antarctic Peninsula (WAP), spring-time blooms of diatoms contribute significantly to overall marine primary production. Oxylipins from diatoms can be highly bioactive; their impact on zooplankton grazers, bacteria, and other phytoplankton has been the subject of intense study. However, almost all of this work has focused on the production of oxylipins via enzymatic pathways, not by pathways involving UVR and/or ROS. Furthermore, rigorous experimental work on the effects of oxylipins has been confined almost exclusively to pure cultures and artificial communities. Thus, the true potential of these molecules to disrupt carbon cycling is very poorly-constrained, and is entirely unknown in the waters of the WAP. Armed with new highly-sensitive, state-of-the-art analytical techniques based on high-mass-resolution mass spectrometry, the principal investigator and his research group have begun to uncover an exquisite diversity of oxylipins in natural WAP planktonic communities. These techniques will be applied to understand the connections between UVR, ROS, oxylipins, and carbon cycling. The project will answer the question of how UVR, via ROS, affects oxylipin production by diatoms in WAP surface waters in controlled experiments conducted at a field station. With the answer to this question in hand, the project will also seek to answer how this phenomenon impacts the flow of carbon, particularly the export of organic carbon from the system, during a research cruise. The level of UVR-induced stresses experienced by oxylipin-rich planktonic communities in the WAP is unique, making Antarctica the only location for answering these fundamental questions. Major activities will include laboratory experiments with artificial membranes and diatom cultures, as well field experiments with phytoplankton, zooplankton, and bacteria in WAP waters.
This award supports a project to develop a better understanding of the relation between ice microstructure, impurities, and ice flow and their connection to climate history for the West Antarctic Ice Sheet (WAIS) ice core site. This work builds on several ongoing studies at Siple Dome in West Antarctica and Dome C in East Antarctica. It is well known that the microstructure of ice evolves with depth and time in an ice sheet. This evolution of microstructure depends on the ice flow field, temperature, and impurity content. The ice flow field, in turn, depends on microstructure, leading to feedbacks that create layered variation in microstructure that relates to climate and flow history. The research proposed here focuses on developing a better understanding of: 1) how ice microstructure evolves with time and stress in an ice sheet and how that relates to impurity content, temperature, and strain rate; 2) how variations in ice microstructure and impurity content affect ice flow patterns near ice divides (on both small (1cm to 1m) and large (1m to 100km) scales); and 3) in what ways is the spatial variability of ice microstructure and its effect on ice flow important for interpretation of climate history in the WAIS Divide ice core. The study will integrate existing ice core and borehole data with a detailed study of ice microstructure using Electron Backscatter Diffraction (EBSD) techniques and measurements of borehole deformation through time using Acoustic Televiewers. This will be the first study to combine these two novel techniques for studying the relation between microstructure and deformation and it will build on other data being collected as part of other WAIS Divide borehole logging projects (e.g. sonic velocity, optical dust logging, temperature and other measurements on the ice core including fabric measurements from thin section analyses as well as studies of ice chemistry and stable isotopes. The intellectual merit of the work is that it will improve interpretation of ice core data (especially information on past accumulation) and overall understanding of ice flow. The broader impacts are that the work will ultimately contribute to a better interpretation of ice core records for both paleoclimate studies and for ice flow history, both of which connect to the broader questions of the role of ice in the climate system. The work will also advance the careers of two early-career female scientists, including one with a hearing impairment disability. This project will support a PhD student at the UAF and provide research and field experience for two or three undergraduates at Dartmouth. The PIs plan to include a teacher on their field team and collaborate with UAF's "From STEM to STEAM" toward enhancing the connection between art and science.
This award supports a collaborative project that combines air and ground geological-geophysical investigations to understand the tectonic and geological development of the boundary between the Ross Sea Rift and the Marie Byrd Land (MBL) volcanic province. The project will determine the Cenozoic tectonic history of the region and whether Neogene structures that localized outlet glacier flow developed within the context of Cenozoic rifting on the eastern Ross Embayment margin, or within the volcanic province in MBL. The geological structure at the boundary between the Ross Embayment and western MBL may be a result of: 1) Cenozoic extension on the eastern shoulder of the Ross Sea rift; 2) uplift and crustal extension related to Neogene mantle plume activity in western MBL; or a combination of the two. Faulting and volcanism, mountain uplift, and glacier downcutting appear to now be active in western MBL, where generally East-to-West-flowing outlet glaciers incise Paleozoic and Mesozoic bedrock, and deglaciated summits indicate a previous North-South glacial flow direction. This study requires data collection using SOAR (Support Office for Aerogeophysical Research, a facility supported by Office of Polar Programs which utilizes high precision differential GPS to support a laser altimeter, ice-penetrating radar, a towed proton magnetometer, and a Bell BGM-3 gravimeter). This survey requires data for 37,000 square kilometers using 5.3 kilometer line spacing with 15.6 kilometer tie lines, and 86,000 square kilometers using a grid of 10.6 by 10.6 kilometer spacing. Data will be acquired over several key features in the region including, among other, the eastern edge of the Ross Sea rift, over ice stream OEO, the transition from the Edward VII Peninsula plateau to the Ford Ranges, the continuation to the east of a gravity high known from previous reconnaissance mapping over the Fosdick Metamorphic Complex, an d the extent of the high-amplitude magnetic anomalies (volcanic centers?) detected southeast of the northern Ford Ranges by other investigators. SOAR products will include glaciology data useful for studying driving stresses, glacial flow and mass balance in the West Antarctic Ice Sheet (WAIS). The ground program is centered on the southern Ford Ranges. Geologic field mapping will focus on small scale brittle structures for regional kinematic interpretation, on glaciated surfaces and deposits, and on datable volcanic rocks for geochronologic control. The relative significance of fault and joint sets, the timing relationships between them, and the probable context of their formation will also be determined. Exposure ages will be determined for erosion surfaces and moraines. Interpretation of potential field data will be aided by on ground sampling for magnetic properties and density as well as ground based gravity measurements. Oriented samples will be taken for paleomagnetic studies. Combined airborne and ground investigations will obtain basic data for describing the geology and structure at the eastern boundary of the Ross Embayment both in outcrop and ice covered areas, and may be used to distinguish between Ross Sea rift- related structural activity from uplift and faulting on the perimeter of the MBL dome and volcanic province. Outcrop geology and structure will be extrapolated with the aerogeophysical data to infer the geology that resides beneath the WAIS. The new knowledge of Neogene tectonics in western MBL will contribute to a comprehensive model for the Cenozoic Ross rift and to understanding of the extent of plume activity in MBL. Both are important for determining the influence of Neogene tectonics on the ice streams and WAIS.
Antarctic fish and their early developmental stages are an important component of the food web that sustains life in the cold Southern Ocean (SO) that surrounds Antarctica. They feed on smaller organisms and in turn are eaten by larger animals, including seals and killer whales. Little is known about how rising ocean temperatures will impact the development of Antarctic fish embryos and their growth after hatching. This project will address this gap by assessing the effects of elevated temperatures on embryo viability, on the rate of embryo development, and on the gene "toolkits" that respond to temperature stress. One of the two species to be studied does not produce red blood cells, a defect that may make its embryos particularly vulnerable to heat. The outcomes of this research will provide the public and policymakers with "real world" data that are necessary to inform decisions and design strategies to cope with changes in the Earth's climate, particularly with respect to protecting life in the SO. The project will also further the NSF goals of training new generations of scientists, including providing scientific training for undergraduate and graduate students, and of making scientific discoveries available to the general public. This includes the unique educational opportunity for undergraduates to participate in research in Antarctica and engaging the public in several ways, including the development of professionally-produced educational videos with bi-lingual
closed captioning.
Since the onset of cooling of the SO about 40 million years ago, evolution of Antarctic marine organisms has been driven by the development of cold temperatures. Because body temperatures of Antarctic fishes fall in a narrow range determined by their habitat (-1.9 to +2.0 C), they are particularly attractive models for understanding how organismal physiology and biochemistry have been shaped to maintain life in a cooling environment. Yet these fishes are now threatened by rapid warming of the SO. The long-term objective of this project is to understand the capacities of Antarctic fishes to acclimatize and/or adapt to oceanic warming through analysis of their underlying genetic "toolkits." This objective will be accomplished through three Specific Aims: 1) assessing the effects of elevated temperatures on gene expression during development of embryos; 2) examining the effects of elevated temperatures on embryonic morphology and on the temporal and spatial patterns of gene expression; and 3) evaluating the evolutionary mechanisms that have led to the loss of the red blood cell genetic program by the white-blooded fishes. Aims 1 and 2 will be investigated by acclimating experimental embryos of both red-blooded and white-blooded fish to elevated temperatures. Differential gene expression will be examined through the use of high throughput RNA sequencing. The temporal and spatial patterns of gene expression in the context of embryonic morphology (Aim 2) will be determined by microscopic analysis of embryos "stained" with (hybridized to) differentially expressed gene probes revealed by Aim 1; other key developmental marker genes will also be used. The genetic lesions resulting from loss of red blood cells by the white-blooded fishes (Aim 3) will be examined by comparing genes and genomes in the two fish groups.
Polar regions are deserts that are not only cold but also lack access to free water. Antarctic insects have unique survival mechanisms including the ability to tolerate freezing and extensive dehydration, surviving the loss of 70% of their body water. How this is done is of interest not only for understanding seasonal adaptations of insects and how they respond to climate change, but the molecular and physiological mechanisms employed may offer valuable insights into more general mechanisms that might be exploited for cryopreservation and long-term storage of human tissues and organs for transplantation and other medical applications. The investigators will study the proteins that are responsible for removing water from the body, cell level consequences of this, and how the responsible genes vary between populations. The project will also further the NSF goals of making scientific discoveries available to the general public and of training new generations of scientists. Each year a K-12 teacher will be a member of the field team and assist with fieldwork and outreach to school children and their teachers. Educational outreach efforts include presentations at local schools and national teacher meetings, providing lesson plans and podcasts on a website, and continuing to publish articles related to this research in education journals. In addition, undergraduate and graduate students will receive extensive training in all aspects of the research project with extended experiences that include publication of scientific papers and presentations at national meetings.<br/><br/>This project focuses on deciphering the physiological and molecular mechanisms that enable the Antarctic midge Belgica antarctica to survive environmental stress and the loss of most of its body water in the desiccating polar environment. This extremophile is an ideal system for investigating mechanisms of stress tolerance and local geographic adaptations and its genome has recently been sequenced. This project has three focal areas: 1) Evaluating the role of aquaporins (water channel proteins) in the rapid removal of water from the body by studying expression of their genes during dehydration; 2) Investigating the mechanism of metabolic depression and the role of autophagy (controlled breakdown of cellular components) as a mediator of stress tolerance by studying expression of the genes responsible for autophagy during the dehydration process; and 3) Evaluating the population structure, gene flow, and adaptive variation in physiological traits associated with stress tolerance using a genetic approach that takes advantage of the genomic sequence available for this species coupled with physiological and environmental data from the sampled populations and their habitats.
Rapid changes in the extent and thickness of sea ice during the austral spring subject microorganisms within or attached to the ice to large fluctuations in temperature, salinity, light and nutrients. This project aims to identify cellular responses in sea-ice algae to increasing temperature and decreasing salinity during the spring melt along the western Antarctic Peninsula and to determine how associated changes at the cellular level can potentially affect dynamic, biologically driven processes. Understanding how sea-ice algae cope with, and are adapted to, their environment will not only help predict how polar ecosystems may change as the extent and thickness of sea ice change, but will also provide a better understanding of the widespread success of photosynthetic life on Earth. The scientific context and resulting advances from the research will be communicated to the general public through outreach activities that includes work with Science Communication Fellows and the popular Polar Science Weekend at the Pacific Science Center in Seattle, Washington. The project will provide student training to college students as well as provide for educational experiences for K-12 school children. <br/><br/><br/>There is currently a poor understanding of feedback relationships that exist between the rapidly changing environment in the western Antarctic Peninsula region and sea-ice algal production. The large shifts in temperature and salinity that algae experience during the spring melt affect critical cellular processes, including rates of enzyme-catalyzed reactions involved in photosynthesis and respiration, and the production of stress-protective compounds. These changes in cellular processes are poorly constrained but can be large and may have impacts on local ecosystem productivity and biogeochemical cycles. In particular, this study will focus on the thermal sensitivity of enzymes and the cycling of compatible solutes and exopolymers used for halo- and cryo-protection, and how they influence primary production and the biogeochemical cycling of carbon and nitrogen. Approaches will include field sampling during spring melt, incubation experiments of natural sea-ice communities under variable temperature and salinity conditions, and controlled manipulation of sea-ice algal species in laboratory culture. Employment of a range of techniques, from fast repetition rate fluorometry and gross and net photosynthetic measurements to metabolomics and enzyme kinetics, will tease apart the mechanistic effects of temperature and salinity on cell metabolism and primary production with the goal of quantifying how these changes will impact biogeochemical processes along the western Antarctic Peninsula.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Since the advent of Antarctic continental glaciation, the opening of the Drake Passage between South America and the Antarctic Peninsula, and the onset of cooling of the Southern Ocean ~40-25 million years ago, evolution of the Antarctic marine biota has been driven by the development of extreme cold temperatures. As circum-Antarctic coastal temperatures declined during this period from ~20°C to the modern -1.9 to +2.0°C (reached ~8-10 million years ago), the psychrophilic (cold-loving) ectotherms of the Southern Ocean evolved compensatory molecular, cellular, and physiological traits that enabled them to maintain normal metabolic function at cold temperatures. Today, these organisms are threatened by rapid warming of the Southern Ocean over periods measured in centuries (as much as 5°C/100 yr), a timeframe so short that re-adaptation and/or acclimatization to the "new warm" may not be possible. Thus, the long-term goals of this research project are: 1) to understand the biochemical and physiological capacities of the embryos of Antarctic notothenioid fish to resist or compensate for rapid oceanic warming; and 2) to assess the genetic toolkit available to support the acclimatization and adaptation of Antarctic notothenioid embryos to their warming habitat. The specific aims of this work are: 1) to determine the capacity of the chaperonin complex of notothenioid fishes to assist protein folding at temperatures between -4 and +20°C; and 2) to evaluate the genetic responses of notothenioid embryos, measured as global differential gene transcription, to temperature challenge, with -1.9°C as the "normal" control and +4 and +10°C as high temperature insults.
The physiology of embryonic development of marine stenotherms under future climate change scenarios is an important but understudied problem. This project will provide valuable insights into the capacity of Antarctic fish embryos to acclimatize and adapt to plausible climate change scenarios by examining multiple levels of biological organization, from the biochemical to the organismal. The results should also be broadly applicable to understanding the impact of global warming on marine biota worldwide. The research will also introduce graduate and undergraduate students to state-of-the-art biochemical, cellular, and molecular-biological research relevant to ecological and environmental issues of the Antarctic marine ecosystem.
The Western Antarctic Peninsula is experiencing climate change at one of the fastest rates of anywhere around the globe. Accelerated climate change is likely to affect the many benthic marine invertebrates that live within narrow temperature windows along the Antarctic Continental Shelf in presently unidentified ways. At present however, there are few data on the physiological consequences of climate change on the sensitive larval stages of cold-water corals, and none on species living in thermal extremes such as polar waters. This project will collect the larvae of the non-seasonal, brooding scleractinian Flabellum impensum to be used in a month-long climate change experiment at Palmer Station. Multidisciplinary techniques will be used to examine larval development and cellular stress using a combination of electron microscopy, flow cytometry, and Inductively Coupled Plasma Mass Spectometry. Data from this project will form the first systematic study of the larval stages of polar cold-water corals, and how these stages are affected by temperature stress at the cellular and developmental level. <br/><br/>Cold-water corals have been shown to be important ecosystem engineers, providing habitat for thousands of associated species, including many that are of commercial importance. Understanding how the larvae of these corals react to warming trends seen today in our oceans will allow researchers to predict future changes in important benthic communities around the globe. Associated education and outreach include: 1) Increasing student participation in polar research by involving postdoctoral and undergraduate students in the field and research program; ii) promotion of K-12 teaching and learning programs by providing information via a research website, Twitter, and in-school talks in the local area; iii) making the data collected available to the wider research community via peer reviewed published literature and iv) reaching a larger public audience through such venues as interviews in the popular media, You Tube and other popular media outlets, and local talks to the general public.
Beginning with the earliest expeditions to the poles, scientists have noted that many polar taxa grow to unusually large body sizes, a phenomenon now known as 'polar gigantism.' Although scientists have been interested in polar giants for many years, many questions still remain about the biology of this significant form of polar diversity. This award from the Antarctic Organisms and Ecosystems program within the Polar Sciences Division at the National Science Foundation will investigate the respiratory and biomechanical mechanisms underlying polar gigantism in Antarctic pycnogonids (commonly known as sea spiders). The project will use a series of manipulative experiments to investigate the effects of temperature and oxygen availability on respiratory capacity and biomechanical strength, and will compare Antarctic sea spiders to related species from temperate and tropical regions. The research will provide insight into the ability of polar giants to withstand the warming polar ocean temperatures associated with climate change.<br/><br/>The prevailing hypothesis to explain the evolution of gigantism invokes shifts in respiratory relationships in extremely cold ocean waters: in the cold, oxygen is more plentiful while at the same time metabolic rates are very low. Together these effects alleviate constraints on oxygen supply that restrict organisms living in warmer waters. Respiratory capacity must evolve in the context of adaptive tradeoffs, so for organisms including pycnogonids there must be tradeoffs between respiratory capacity and resistance to biomechanical stresses. The investigators will test a novel hypothesis that respiratory challenges are not associated with particular body sizes, and will answer the following questions: What are the dynamics of oxygen transport and consumption in Antarctic pycnogonids; how do structural features related to oxygen diffusion trade off with requirements for body support and locomotion; how does body size influence vulnerability to environmental hypoxia and to temperature-oxygen interactions; and does the cold-driven high oxygen availability in the Antarctic raise the limit on body size by reducing trade-offs between diffusivity and structural integrity? The research will explore the effects of increased ocean temperatures upon organisms that have different body sizes. In addition, it will provide training for graduate and undergraduate students affiliated with universities in EPSCOR states.
Recent discoveries of widespread liquid water and microbial ecosystems below the Antarctic ice sheets have generated considerable interest in studying Antarctic subglacial environments. Understanding subglacial hydrology, the persistence of life in extended isolation and the evolution and stability of subglacial habitats requires an integrated, interdisciplinary approach. The collaborative project, Minimally Invasive Direct Glacial Exploration (MIDGE) of the Biogeochemistry, Hydrology and Glaciology of Blood Falls, McMurdo Dry Valleys will integrate geophysical measurements, molecular microbial ecology and geochemical analyses to explore a unique Antarctic subglacial system known as Blood Falls. Blood Falls is a hypersaline, subglacial brine that supports an active microbial community. The subglacial brine is released from a crevasse at the surface of the Taylor Glacier providing an accessible portal into an Antarctic subglacial ecosystem. Recent geochemical and molecular analyses support a marine source for the salts and microorganisms in Blood Falls. The last time marine waters inundated this part of the McMurdo Dry Valleys was during the Late Tertiary, which suggests the brine is ancient. Still, no direct samples have been collected from the subglacial source to Blood Falls and little is known about the origin of this brine or the amount of time it has been sealed below Taylor Glacier. Radar profiles collected near Blood Falls delineate a possible fault in the subglacial substrate that may help explain the localized and episodic nature of brine release. However it remains unclear what triggers the episodic release of brine exclusively at the Blood Falls crevasse or the extent to which the brine is altered as it makes its way to the surface. <br/><br/>The MIDGE project aims to determine the mechanism of brine release at Blood Falls, evaluate changes in the geochemistry and the microbial community within the englacial conduit and assess if Blood Falls waters have a distinct impact on the thermal and stress state of Taylor Glacier, one of the most studied polar glaciers in Antarctica. The geophysical study of the glaciological structure and mechanism of brine release will use GPR, GPS, and a small passive seismic network. Together with international collaborators, the 'Ice Mole' team from FH Aachen University of Applied Sciences, Germany (funded by the German Aerospace Center, DLR), MIDGE will develop and deploy innovative, minimally invasive technologies for clean access and brine sample retrieval from deep within the Blood Falls drainage system. These technologies will allow for the collection of samples of the brine away from the surface (up to tens of meters) for geochemical analyses and microbial structure-function experiments. There is concern over the contamination of pristine subglacial environments from chemical and biological materials inherent in the drilling process; and MIDGE will provide data on the efficacy of thermoelectric probes for clean access and retrieval of representative subglacial samples. Antarctic subglacial environments provide an excellent opportunity for researching survivability and adaptability of microbial life and are potential terrestrial analogues for life habitats on icy planetary bodies. The MIDGE project offers a portable, versatile, clean alternative to hot water and mechanical drilling and will enable the exploration of subglacial hydrology and ecosystem function while making significant progress towards developing technologies for minimally invasive and clean sampling of icy systems.
This award supports an integrated field observation, remote sensing and numerical modeling study of the McMurdo Shear Zone (SZ). The SZ is a 5-10 km wide strip of heavily crevassed ice that separates the McMurdo and Ross ice shelves, and is an important region of lateral support for the Ross Ice Shelf. Previous radar and remote sensing studies reveal an enigmatic picture of the SZ in which crevasses detected at depth have no apparent surface expression, and have orientations which are possibly inconsistent with the observed flow field. In the proposed work, we seek to test the hypothesis that the SZ is a zone of chaotic Lagrangian mixing with (intersecting) buried crevasses which leads to rheological instability, potentially allowing large scale velocity discontinuities. The work will involve detailed field-based observations of crevasse distributions and structure using ground-penetrating radar, and GPS and remote sensing observations of the flow and stress field in the SZ. Because of the hazardous nature of the SZ, the radar surveys will be conducted largely with the aid of a lightweight robotic vehicle. Observations will be used to develop a finite element model of ice shelf shear margin behavior. The intellectual merit of this project is an increased understanding of ice shelf shear margin dynamics. Shear margins play a key role in ice shelf stability, and ice shelves in turn modulate the flux of ice from the ice sheet across the grounding line to the ocean. Insights from this project will improve large-scale models being developed to predict ice sheet evolution and future rates of sea level rise, which are topics of enormous societal concern. The broader impacts of the project include an improved basis for US Antarctic Program logistics planning as well as numerous opportunities to engage K-12 students in scientific discovery. Intensified crevassing in the shear zone between the Ross and McMurdo ice shelves would preclude surface crossing by heavy traverse vehicles which would lead to increased costs of delivering fuel to South Pole and a concomitant loss of flight time provided by heavy-lift aircraft for science missions on the continent. Our multidisciplinary research combining glaciology, numerical modeling, and robotics engineering is an engaging way to show how robotics can assist scientists in collecting hazardous field measurements. Our outreach activities will leverage Dartmouth's current NSF GK-12 program, build on faculty-educator relationships established during University of Maine's recent GK-12 program, and incorporate project results into University of Maine's IDEAS initiative, which integrates computational modeling with the existing science curriculum at the middle school level. This award has field work in Antarctica.
Meltwater lakes that sit on top of Antarctica's floating ice shelves have likely contributed to the dramatic changes seen in Antarctica's glacial ice cover over the past two decades. In 2002, the 1,600-square-kilometer Larsen B Ice Shelf located on the Eastern side of the Antarctic Peninsula, for example, broke into thousands of small icebergs, which subsequently floated away as a result of the formation of more than 2,000 meltwater lakes on its surface over the prior decade. Our research project addresses the reasons why surface lakes form on Antarctic ice shelves and how these surface lakes subsequently contribute to the forces that may contribute to ice-shelf breakup like that of the Larsen B. Our project focuses primarily on making precise global positioning system (GPS) measurements of ice-shelf bending in response to the filling and draining of a surface lake on the McMurdo Ice Shelf. The observed vertical displacements (on the order of tens of centimeters) in response to lake filling will be used to calibrate and test computer simulation models that predict the response of ice shelves to surface lakes more generally and in a variety of future climate conditions. Our project will make hourly measurements of both vertical ice-shelf movements (using GPS surveying instruments) and of temperature and sunlight conditions (that drive melting) around a surface lake located close to the McMurdo Station airfield. Following this initial data-gathering effort, computer simulations and other more theoretical analysis will be undertaken to determine the suitability of the chosen McMurdo Ice Shelf surface lake as a field-laboratory for continued study. Ultimately, the research will contribute to understanding of the glaciological processes that link climate change to rising sea level. A successful outcome of the research will allow glaciologists to better assess the processes that promote or erode the influence Antarctic ice shelves have in controlling the transfer of ice from the interior of Antarctica into the ocean. The project will undertake two outreach activities: (1) web-posting of a field-activity journal and (2) establishing an open-access glaciological teaching and outreach web-sharing site for the International Glaciological Society.<br/><br/>The proposed project seeks to experimentally verify a theory of ice-shelf instability proposed to explain the explosive break-up of Larsen B Ice Shelf in 2002. This theory holds that the filling and draining of supraglacial lakes on floating ice shelves induces sufficient flexure stress within the ice to (a) induce upward/downward propagating fractures originating at the base/surface of the ice shelf that (b) dissect the ice shelf into fragments that tend to have widths less than about half the ice thickness. The significance of narrow widths is that they promote capsize of the ice-shelf fragments during the break-up process. This capsize releases large amounts of gravitational potential energy (comparable to thousands of kilotons of TNT for the Larsen B Ice Shelf) thereby promoting explosiveness of the Larsen B event. The observational motivation for experimentally verifying the surface-lake mechanism for ice-shelf breakup is based on the fact that >2,000 surface lakes developed on the Larsen B Ice Shelf in the decade prior to its break up, and that these lakes were observed (via satellite imagery) to drain in a coordinated fashion during the day prior to the initiation of the break up.<br/><br/>The field-observation component of the project will focus on a supraglacial lake on the McMurdo Ice Shelf where there is persistent summer season surface melting. The lake will be studied during a single provisional field season to determine whether grooming of surrounding surface streams and shorelines with heavy construction equipment will allow surface water to be manually encouraged to fill the lake. If successfully encouraged to develop, the McMurdo Ice Shelf surface lake will allow measurements of key ice-shelf flexure and stress variables needed to develop the theory of ice-shelf surface lakes without having to access the much more logistically demanding surface lakes of ice-shelves located elsewhere in Antarctica. Data to be gathered during the 6-week provisional field season include: energy- and water-balance parameters determining how the surface lake grows and fills, and various global positioning system measurements of the vertical bending of the ice sheet in response to the changing meltwater load contained within the surface lake. These data will be used to (1) constrain a computer model of viscoelastic flexure and possible fracture of the ice shelf in response to the increasing load of meltwater in the lake, and (2) determine whether continued study of the incipient surface-meltwater lake features on the McMurdo Ice Shelf provides a promising avenue for constraining the more-general behavior of surface meltwater lakes on other ice shelves located in warmer parts of Antarctica. Computer models constrained by the observational data obtained from the field project will inform energy- and water-balance models of ice shelves in general, and allow more accurate forecasts of changing ice-shelf conditions surrounding the inland ice of Antarctica. The project will create the first-ever ground-based observations useful for spawning the development of models capable of predicting viscoelastic and fracture behavior of ice shelves in response to supraglacial lake evolution, including slow changes due to energy balance effects, as well as fast changes due to filling and draining.
Waddington/1246045 <br/><br/>This award supports a project to investigate the onset and growth of folds and other disturbances seen in the stratigraphic layers of polar ice sheets. The intellectual merit of the work is that it will lead to a better understanding of the grain-scale processes that control the development of these stratigraphic features in the ice and will help answer questions such as what processes can initiate such disturbances. Snow is deposited on polar ice sheets in layers that are generally flat, with thicknesses that vary slowly along the layers. However, ice cores and ice-penetrating radar show that in some cases, after conversion to ice, and following lengthy burial, the layers can become folded, develop pinch-and-swell structures (boudinage), and be sheared by ice flow, at scales ranging from centimeters to hundreds of meters. The processes causing these disturbances are still poorly understood. Disturbances appear to develop first at the ice-crystal scale, then cascade up to larger scales with continuing ice flow and strain. Crystal-scale processes causing distortions of cm-scale layers will be modeled using Elle, a microstructure-modeling package, and constrained by fabric thin-sections and grain-elongation measurements from the West Antarctic Ice Sheet divide ice-core. A full-stress continuum anisotropic ice-flow model coupled to an ice-fabric evolution model will be used to study bulk flow of anisotropic ice, to understand evolution and growth of flow disturbances on the meter and larger scale. Results from this study will assist in future ice-core site selection, and interpretation of stratigraphy in ice cores and radar, and will provide improved descriptions of rheology and stratigraphy for ice-sheet flow models.The broader impacts are that it will bring greater understanding to ice dynamics responsible for stratigraphic disturbance. This information is valuable to constrain depth-age relationships in ice cores for paleoclimate study. This will allow researchers to put current climate change in a more accurate context. This project will provide three years of support for a graduate student as well as support and research experience for an undergraduate research assistant; this will contribute to development of talent needed to address important future questions in glaciology and climate change. The research will be communicated to the public through outreach events and results from the study will be disseminated through public and professional meetings as well as journal publications. The project does not require field work in Antarctica.
Interest in the reduced alkalinity of high latitude waters under conditions of enhanced CO2 uptake from the atmosphere have been the impetus of numerous recent studies of bio-stressors in the polar marine environment. The project seeks to improve our understanding of the variance of coastal Southern Ocean carbonate species (CO2 system), its diurnal and inter-annual variability, by acquiring autonomous, high frequency observations from an Antarctic coastal mooring(s). <br/><br/>A moored observing system co-located within the existing Palmer LTER array will measure pH, CO2 partial pressure, temperature, salinity and dissolved oxygen with 3-hour frequency in this region of the West Antarctic Peninsula continental shelf. Such observations will help estimate the dominant physical and biological controls on the seasonal variations in the CO2 system in coastal Antarctic waters, including the sign, seasonality and the flux of the net annual air-sea exchange of carbon dioxide. The Palmer LTER site is experiencing rapid ecological change in the West Antarctic Peninsula, a region that is warming at rates faster than any other region of coastal Antarctica.
This award supports a Rapid Response Research (RAPID) project to observe the current weakened state of the Scar Inlet Ice Shelf, and potentially capture data during its anticipated disintegration. The Scar Inlet Ice Shelf (SIIS) is the southern remnant of the former Larsen B Ice Shelf, which disintegrated in March of 2002. Since then, the SIIS has weakened significantly but has not yet broken up. Cooler conditions than those seen prior to 2006 have reduced the chance of a disintegration in recent years, although a single warm season is likely to be enough to trigger such an event. The predicted "Super El Nino" for this austral summer may have significant effects on Antarctica's weather, potentially leading to a break-up or disintegration this year. Given the very weak state of the SIIS, it is urgent that we act now to better understand the processes involved in shelf disintegration or break-up of ice shelves. The goal of this work is to collect several key data sets, publish initial observations and preliminary conclusions, and then make the complete data record available to all scientists.<br/><br/>Extreme changes in the stress conditions on the SIIS resulted from both the loss of the Larsen B ice plate and the continued inflow of ice from three large glaciers (Flask, Leppard, and Starbuck). The SIIS now has a number of large rifts and it is expected to break up or disintegrate in the very near future. Past research has made use of satellite data and weather instruments, establishing many of the current ideas regarding ice shelf break-ups and ice shelf weakening. Additional ground-based data to be collected under this study will test a number of hypotheses regarding pre-disintegration characteristics, triggering mechanisms, fracturing processes, runaway feedback effects, and stabilizing mechanisms. The project will collect extensive multi-instrument field observations of the SIIS and possibly capture a major disintegration event. In collaboration with the British Antarctic Survey, a team of 4 people will be deployed via Twin Otter for up to 4 weeks to a site with a broad view of the shelf and will install several temporary observing instruments there. The study derives its intellectual merit from the role of the Antarctic Peninsula as a microcosm of how other parts of Antarctica might evolve and de-glaciate in the next few centuries. The broader impacts include an opportunity to educate the public about the anticipated collapse of this remnant ice shelf and its relationship to future changes in Antarctica. The potential for wide media coverage (through a connection with the National Geographic) will underscore the critical changes scientists are observing in the crysophere driven by climate change. This proposal requires field work in Antarctica.
Many of the natural processes that modify the landscape inhabited by humans occur over very long timescales, making them difficult to observe. Exceptions include rare catastrophic events such as earthquakes, volcanic eruptions, and floods that occur on short timescales. Many significant processes that affect the land and landscape that we inhabit operate on time scales imperceptible to humans. One of these processes is wind transport of sand, with related impacts to exposed rock surfaces and man-made objects, including buildings, windshields, solar panels and wind-farm turbine blades. The goal of this project is to gain an understanding of wind erosion processes over long timescales, in the Antarctic Dry Valleys, a cold desert environment where there were no competing processes (such as rain and vegetation) that might mask the effects. The main objective is recovery of rock samples that were deployed in 1983/1984 at 11 locations in the Antarctic Dry Valleys, along with measurements on the rock samples and characterization of the sites. In the late 1980s and early 1990s some of these samples were returned and indicated more time was needed to accumulate information about the timescales and impacts of the wind erosion processes. This project will allow collection of the remaining samples from this experiment after 30 to 31 years of exposure. The field work will be carried out during the 2014/15 Austral summer. The results will allow direct measurement of the abrasion rate and hence the volumes and timescales of sand transport; this will conclude the longest direct examination of such processes ever conducted. Appropriate scaling of the results may be applied to buildings, vegetation (crops), and other aspects of human presence in sandy and windy locations, in order to better determine the impact of these processes and possible mitigation of the impacts. The project is a collaborative effort between a small business, Malin Space Science Systems (MSSS), and the University of Washington (UW). MSSS will highlight this Antarctic research on its web site, by developing thematic presentations describing our research and providing a broad range of visual materials. The public will be engaged through daily updates on a website and through links to material prepared for viewing in Google Earth. UW students will be involved in the laboratory work and in the interpretation of the results.<br>Technical Description of Project:<br>The goal of this project is to study the role of wind abrasion by entrained particles in the evolution of the McMurdo Dry Valleys in the Transantarctic Mountains. During the 1983 to 1984 field seasons, over 5000 rock targets were installed at five heights facing the 4 cardinal directions at 10 locations (with an additional site containing fewer targets) to study rates of physical weathering due primarily to eolian abrasion. In addition, rock cubes and cylinders were deployed at each site to examine effects of chemical weathering. The initial examination of samples returned after 1, 5, and 10 years of exposure, showed average contemporary abrasion rates consistent with those determined by cosmogenic isotope studies, but further stress that "average" should not be interpreted as meaning "uniform." The samples will be characterized using mass measurements wtih 0.01 mg precision balances, digital microphotography to compare the evolution of their surface features and textures, SEM imaging to examine the micro textures of abraded rock surfaces, and optical microscopy of thin sections of a few samples to examine the consequences of particle impacts extending below the abraded surfaces. As much as 60-80% of the abrasion measured in samples from 1984-1994 appears to have occurred during a few brief hours in 1984. This is consistent with theoretical models that suggest abrasion scales as the 5th power of wind velocity. The field work will allow return of multiple samples after three decades of exposure, which will provide a statistical sampling (beyond what is acquired by studying a single sample), and will yield the mass loss data in light of complementary environmental and sand kinetic energy flux data from other sources (e.g. LTER meteorology stations). This study promises to improve insights into one of the principal active geomorphic process in the Dry Valleys, an important cold desert environment, and the solid empirical database will provide general constraints on eolian abrasion under natural conditions.
Antarctic channichthyid icefishes are stunning examples of the unique physiological traits that can arise during evolution in a constantly cold environment. Icefishes are the only vertebrates that as adults, lack the circulating oxygen-binding protein hemoglobin (Hb); several species within this family also lack the intracellular oxygen-binding protein myoglobin (Mb) in their heart ventricle. The loss of Hb and Mb has resulted in striking modifications in the cardiovascular system to ensure adequate tissue oxygenation, some of which are energetically costly. Recent indicate there may be at least one benefit to not expressing these heme-centered proteins - oxidized proteins and lipids are higher in red-blooded notothenioids compared to icefishes. The research will address the hypothesis that the loss of Hb and Mb reduces oxidative stress in icefishes compared to red-blooded notothenioid fishes, resulting in a lower rate of protein turnover and energetic cost savings. Specifically, the project will (1) Characterize levels of oxidative stress in red- and white-blooded notothenioid fishes, (2) Determine if red- and white-blooded notothenioids differ in their regulation of iron, (3) Determine if lower levels of oxidized proteins in icefishes result in lower rates of protein turnover and energetic cost savings, and (4) Determine if oxygen-binding proteins promote oxidative stress in-vivo and in-vitro.<br/><br/>The results will contribute to the understanding of iron-catalyzed oxidative stress, which is associated with the progression of Alzheimer's, Parkinson's and cardiovascular diseases. Moreover, the research will increase understanding of factors related to iron metabolism and oxidative stress in notothenioid fishes that may have played key roles in the success of channichthyid icefishes. The broader impacts include development of a website will enable teachers and students to learn more about the fascinating biology of Antarctic icefishes, as well as the impacts of global climate change and commercial fishing activities on Antarctic fishes. Additionally, Alaska Native high school and undergraduate students will be involved in research at the University of Alaska, Fairbanks.
The research supported in this project will examine the effects of environmental change on a key Antarctic marine invertebrate, a pelagic mollusk, the pteropod, Limacina helicina antarctica. There are two main activities in this project: (1) to deploy oceanographic equipment ? in this case, autonomously recording pH sensors called SeaFETs and other devices that record temperature and salinity, and (2) to use these environmental data in the laboratory at McMurdo Station to study the response of the marine invertebrates to future changes in water quality that is expected in the next few decades. Notably, changes in oceanic pH (aka ocean acidification) and ocean warming are projected to be particularly threatening to calcifying marine organisms in cold-water, high latitude seas, making tolerance data on these organisms a critical research need in Antarctic marine ecosystems. <br/><br/>These Antarctic shelled-animals are especially vulnerable to dissolution stress from ocean acidification because they currently inhabit seawater that is barely at the saturation level to support biogenic calcification. Indeed, these polar animals are considered to be the 'first responders' to chemical changes in the surface oceans. Thus, this project will lead to information about the adaptive capacity of L. helcina antarctica. From an ecological perspective this is important because this animal is a critical part of the Antarctic food chain in coastal waters and changes in its abundance will impact other species. Finally, the research conducted in this project will serve as a training and educational opportunity for undergraduate and graduate students as well as postdoctoral scholars.
While changes in populations typically are tracked to gauge the impact of climate or habitat change, the process involves the response of individuals as each copes with an altered environment. In a study of Adelie penguins that spans 13 breeding seasons, results indicate that only 20% of individuals within a colony successfully raise offspring, and that they do so because of their exemplary foraging proficiency. Moreover, foraging appears to require more effort at the largest colony, where intraspecific competition is higher than at small colonies, and also requires more proficiency during periods of environmental stress. When conditions are particularly daunting, emigration dramatically increases, countering the long-standing assumption that Adélie penguins are highly philopatric. The research project will 1) determine the effect of age, experience and physiology on individual foraging efficiency; 2) determine the effect of age, experience, and individual quality on breeding success and survival in varying environmental and competitive conditions at the colony level; and 3) develop a comprehensive model for the Ross-Beaufort Island metapopulation dynamics. Broader impacts include training of interns, continuation of public outreach through the highly successful project website penguinscience.com, development of classroom materials and other standards-based instructional resources.
Genome-enabled biology provides a foundation for understanding the genetic basis of organism-environment interactions. . The research project links gene expression, genome methylation, and metabolic rates to assess the mechanisms of environmental adaptation (temperature) across multiple generations in a polar, and closely related temperate, polychaete. By comparing these two species, the research will assess how a polar environment shapes responses to environmental stress. This work will produce: 1) a database of full transcriptome (gene specific) profiling data for the polar polychaete cultured at two temperatures; 2) the contribution of genome methylation to the suppression of gene transcription activities; 3) the linkage between shifts in mRNA pools and total cellular activities (as ATP consumption via respiration); 4) an assessment of the inheritance of patterns of gene expression and metabolic activities across three generations; and 5) a simple demographic model of the polar polychaete population dynamics under normal and 'global-warming' temperature scenarios. Broader impacts include two outreach activities. The first is a mentoring program, where African-American undergraduate students spend 1.5 years working on a research project with a UD faculty member (2 summers plus their senior academic year). The second is a children's display activity at UD?s School of Marine Science "Coast Day".
The proposed research will investigate the interacting and potentially synergistic influence of two oceanographic features - ocean acidification and the projected rise in mean sea surface temperature - on the performance of Notothenioids, the dominant fish of the Antarctic marine ecosystem. Understanding the joint effects of acidification and temperature rise on these fish is a vital component of predicting the resilience of coastal marine ecosystems. Notothenioids have repeatedly displayed a narrow window of physiological tolerances when subjected to abiotic stresses. Given that evolutionary adaptation may have led to finely-tuned traits with narrow physiological limits in these organisms, this system provides a unique opportunity to examine physiological trade-offs associated with acclimation to the multi-stressor environment expected from future atmospheric CO2 projections. Understanding these trade-offs will provide valuable insight into the capacity species have for responses to climate change via phenotypic plasticity. As an extension to functional measurements, this study will use evolutionary approaches to map variation in physiological responses onto the phylogeny of these fishes and the genetic diversity within species. These approaches offer insight into the historical constraints and future potential for evolutionary optimization. The research will significantly expand the genomic resources available to polar researchers and will support the training of graduate students and a post doc at an EPSCoR institution. Research outcomes will be incorporated into classroom curriculum.
Abstract<br/><br/>The research examine the effects of ocean acidification on embryos and larvae of a contemporary calcifier in the coastal waters of Antarctica, the sea urchin Sterechinus neumayeri. The effect of future ocean acidification is projected to be particularly threatening to calcifying marine organisms in coldwater, high latitude seas, making tolerance data on these organisms a critical research need in Antarctic marine ecosystems. Due to a high magnesium (Mg) content of their calcitic hard parts, echinoderms are especially vulnerable to dissolution stress from ocean acidification because they currently inhabit seawater that is barely at the saturation level to support biogenic calcification. Thus, cold-water, high latitude species with a high Mg-content in their hard parts are considered to be the 'first responders' to chemical changes in the surface oceans. Studies in this proposal will use several metrics to examine the physiological plasticity of contemporary urchin embryos and larvae to CO2-acidified seawater, to mimic the scenarios defined by IPCC models and by analyses of future acidification predicted for the Southern Ocean. The research also will investigats the biological consequences of synergistic interactions of two converging climate change-related stressors - CO2- driven ocean acidification and ocean warming. Specifically the research will (1) assess the effect of CO2-acidified seawater on the development of early embryos and larvae, (2) using morphometrics, examine changes in the larval endoskeleton in response to development under the high-CO2 conditions of ocean acidification, (3) using a DNA microarray, profile changes in gene expression for genes involved in biomineralization and other important physiological processes, and (4) measure costs and physiological consequences of development under conditions of ocean acidification. The proposal will support the training of undergraduates, graduate students and a postdoctoral fellow. The PI also will collaborate with the UC Santa Barbara Gevirtz Graduate School of Education to link the biological effects of ocean acidification to the chemical changes expected for the Southern Ocean using the 'Science on a Sphere' technology. This display will be housed in an education and public outreach center, the Outreach Center for Teaching Ocean Science (OCTOS), a new state-of-the-art facility under construction at UC Santa Barbara.
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).<br/><br/>Polar terrestrial environments are often described as deserts, where water availability is a critical factor limiting the distribution of terrestrial organisms. In such environments, tolerance of low moisture conditions is likely as important as cold resistance. Winter survival for many polar organisms depends on a coordinated transition from feeding, growth and reproduction during short summers, to an energy-conserving dormancy coupled with enhanced resistance to environmental extremes during long, severe winters. The midge Belgica antarctica provides an excellent model system for investigating mechanisms of stress (cold and low moisture) tolerance, and the role of extreme photoperiodic changes in coordinating seasonal adaptations. The proposed research will use gene and protein level approaches to investigate the seasonal roles of dehydration and photoperiodic cues in preparing a polar insect for winter survival. The research will investigate (1) the role of aquaporins, dehydrins, and cryoprotective dehydration in seasonal survival, and (2) the role of photoperiodism in preparing for winter. Broader impacts involve engagement of K-12 educators and students, including hands-on, in-the-field research experiences for teachers, presentations at local schools, development of lesson plans and podcasts, and publication of articles in education journals. The principal investigators also will engage graduate students, undergraduates, and post-docs in the project.
Intellectual Merit: <br/>This research will place the subsidence history of the southern Victoria Land Basin into a quantitative geodynamic context and will assess the influence of flexure associated with late Neogene volcanic loading of the crust by the Erebus Volcanic Group. This will be done by extending geodynamic models of extension in the West Antarctic Rift System to include extensional hiatuses hypothesized to have occurred during the Late Paleogene and Miocene, and by developing a new geodynamic model of volcanic loading and associated lithosphere flexure. Finite element and finite difference modeling methods will be used. In the first phase of the project, a series of extensional geodynamic models will be developed to examine the effect that proposed extensional hiatuses have on the style of extension, with emphasis placed on developing a process based understanding of the change in rift style from diffuse during the Late Cretaceous to more focused during the Cenozoic. The models will test the hypotheses that extensional hiatuses led to the change in rifting style, and will place constraints on the timing and duration of the hiatuses. The second phase of the project will use the thermal and rheological properties of the previous models to constrain the flexural rigidity of the lithosphere in order to model the flexural response to volcanic loading to test the hypotheses that flexural subsidence contributed to cyclic changes between grounded and floating ice at the ANDRILL AND-1A site, complicating interpretations of the climatic record from this core, and that flexure contributes to the stress orientation at the AND-2B site, which is inconsistent with the expected regional extensional stress orientation.<br/><br/>Broader impacts: <br/>The project will train an undergraduate student and an M.S. student. Outreach activities include a planned series of talks at regional high schools, junior colleges, and 4-year colleges that have geology programs.
The relatively pristine Antarctic continent with its extensive maritime zone represents a unique location on the planet to investigate the long distance aerial transport and deposition of marine microorganisms. The vast extent of new sea ice that forms each winter around the continent results in large numbers of frost flowers, delicate ice-crystal structures of high salt content that form on the surface of the ice and are readily dispersed by wind. The proposed research builds on earlier work in the Arctic and tests the new hypothesis that wind-borne frost flowers provide an effective mechanism for the transport of marine bacteria over long distances, one that can be uniquely sourced and tracked by the frost flower salt signature in the Antarctic realm. A highly resolved genomic snapshot of the microbial community will be acquired at each stage in the transport path, which will track decreasing fractions of the marine microbial community as it freezes into sea ice, incorporates into frost flowers, converts to aerosols, and ultimately deposits within continental snowpack. En route from sea ice to snowpack, marine bacteria will be exposed to an array of environmental stresses, including high salinity, low temperatures, UV light and potential desiccation. A parallel proteomic analysis will enable an evaluation of the microbial response to these extreme conditions and potential survival mechanisms that allow persistence or eventual colonization of deposition sites across Antarctica. <br/><br/>Current understanding of microbes in the Antarctic atmosphere is based on a limited number of microscopic and culture-based assays and a single report of low-resolution 16S RNA gene sequence analysis. The research will broadly impact understanding of atmospheric microbiology, from source to deposition, and various issues of microbial survival, colonization, endemism, and diversity under extreme conditions. In addition to venues that reach the scientific community, the research team will develop a permanent multi-media and artifact-based exhibit on Antarctic Microbial Transport that will be showcased at Seattle's Pacific Science Center (PSC), which educates nearly a million visitors annually.
Funds are provided to enable applications of powerful mathematical concepts and computational tools for rigorous sensitivity analysis, pseudo-spectra and generalized stability theory, and advanced state estimation in the context of large-scale ice sheet modeling. At the center of the proposal is the generation and application of adjoint model (ADM) and tangent linear model (TLM) components of the new Community Ice Sheet Model (CISM). The goal will be achieved through rigorous use of automatic differentiation (AD) to ensure synchronicity between the ongoing model development and improvement in terms of better representation of higher-order stress terms (which account for crucial fast flow regimes) of the nonlinear forward model (NLM) code and the derivative codes. The adjoint enables extremely efficient computation of gradients of scalar-valued functions in very high-dimensional control spaces. A hierarchy of applications is envisioned: (1) sensitivity calculations in support of the Intergovernmental Panel on Climate Change (IPCC) in order to determine to which control variables the polar ice sheet volumes are most sensitive; based on adjoint sensitivity maps, to establish quantitative estimates of ice sheet volume changes for relevant forcing scenarios; and to assess how sensitivities change when including higher-order stress terms; (2) coupling of the ADM and TLM to calculate pseudo-spectra or singular vectors (SV?s) of relevant ice sheet norms; SV?s provide perturbation patterns which lead to non-normal growth, optimally amplifying norm kernels over finite times; among the many applications of SV?s are optimal initialization of ensembles to assess uncertainties; SV?s are calculated through matrix-free iterative solution of a generalized eigenvalue problem via Lanczos or Arnoldi implicit restart algorithms; (3) a long-term goal is the development of an ice sheet state estimation system based on the adjoint or Lagrange Multiplier Method (LMM) in order to synthesize, in a formal manner, the increasing number and heterogeneous types of observations with a three-dimensional, state-of-the-art ice sheet model; an important requirement is that the adjoint incorporate new schemes that are being developed for CISM to capture crucial, but as yet unrepresented physical processes.
MacAyeal/0944248<br/><br/>This award supports a project to develop a better understanding of the processes and conditions that trigger ice shelf instability and explosive disintegration. A significant product of the proposed research will be the establishment of parameterizations of micro- and meso-scale ice-shelf surface processes needed in large scale ice-sheet models designed to predict future sea level rise. The proposed research represents a 3-year effort to conduct numerical model studies of 6 aspects of surface-water evolution on Antarctic ice shelves. These 6 model-study areas include energy balance models of melting ice-shelf surfaces, with treatment of surface ponds and water-filled crevasses, distributed, Darcian water flow modeling to simulate initial firn melting, brine infiltration, pond drainage and crevasse filling, ice-shelf surface topography evolution modeling by phase change (surface melting and freezing), surface-runoff driven erosion and seepage flows, mass loading and flexure effects of ice-shelf and iceberg surfaces; feedbacks between surface-water loads and flexure stresses; possible seiche phenomena of the surface water, ice and underlying ocean that constitute a mechanism for, inducing surface crevassing., surface pond and crevasse convection, and basal crevasse thermohaline convection (as a phenomena related to area 5 above). The broader impacts of the proposed work bears on the socio-environmental concerns of climate change and sea-level rise, and will contribute to the important goal of advising public policy. The project will form the basis of a dissertation project of a graduate student whose training will contribute to the scientific workforce of the nation and the PI and graduate student will additionally participate in a summer science-enrichment program for high-school teachers organized by colleagues at the University of Chicago.
The research will investigate a novel mechanism by which cold-adapted fishes of the Southern Ocean sense and respond to elevated temperatures. It is hypothesized that sub-lethal heat stress may induce cell cycle arrest and/or programmed cell death through apoptosis. The study will use genome-enabled technologies to examine the environmental control over gene expression in Antarctic species and will build direct mechanistic links between the expression of a specific signaling pathway gene and heat-induced changes in cells. Prior results support the hypothesis that heat stress results in cell cycle arrest and, in some cases, programmed cell death in Antarctic fishes. If so, this represents a novel, modified version of the well-conserved cellular stress response found in essentially all other species and suggests that warming ocean temperatures may have profound cellular and physiological impacts on these extremely stenothermal species. The P.I. conducts outreach activities with the Oregon Museum of Science and Industry, will be involved in developing a science curriculum for the Native American Youth and Family Center (NAYA) Early College Academy in Portland, and supports the educational and professional development of both undergraduate and graduate students at Portland State University.
Sergienko/0838811 <br/><br/>This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).<br/><br/>This award supports a project to conduct a modeling study of the ice stream ? sub-glacial water system. A suite of numerical models of various dimensionality and complexity will be constructed in a sequential, hierarchical fashion to formulate and test hypotheses regarding how sub-glacial lakes form under ice streams, determine the effect of sub-glacial lakes on ice-stream flow and mass balance, and to determine feedback effects whereby the ice stream ? sub-glacial water system can elicit both stable and unstable responses to environmental perturbations. This research will address one of the only observationally verified fast-time-scale processes apparent within the Antarctic Ice Stream system. The intellectual merit of the project is that understanding the origins and consequences of near-grounding-line sub-glacial lakes is a priority in glaciological research designed to predict short-term variations in Antarctica?s near-term future mass balance. The broader impacts of the proposed work are that it will contribute to better understanding of a system that has important societal relevance through contribution to sea level rise. Participation of a graduate student in the project will provide the student?s training and education in application of the numerical modeling in geosciences.
Studinger/0636584<br/><br/>This award supports a project to estimate the salinity of subglacial Lake Vostok, Lake Concordia and the 90 deg.E lake using existing airborne ice-penetrating radar and laser altimeter data. These lakes have been selected because of the availability of modern aerogeophysical data and because they are large enough for the floating ice to be unaffected by boundary stresses near the grounding lines. The proposed approach is based on the assumption that the ice sheet above large subglacial lakes is in hydrostatic equilibrium and the density and subsequently salinity of the lake's water can be estimated from the (linear) relationship between ice surface elevation and ice thickness of the floating ice. The goal of the proposed work is to estimate the salinity of Lake Vostok and determine spatial changes and to compare the salinity estimates of 3 large subglacial lakes in East Antarctica. The intellectual merits of the project are that this work will contribute to the knowledge of the physical and chemical processes operating within subglacial lake environments. Due to the inaccessibility of subglacial lakes numerical modeling of the water circulation is currently the only way forward to develop a conceptual understanding of the circulation and melting and freezing regimes in subglacial lakes. Numerical experiments show that the salinity of the lake's water is a crucial input parameter for the 3-D fluid dynamic models. Improved numerical models will contribute to our knowledge of water circulation in subglacial lakes, its effects on water and heat budgets, stratification, melting and freezing, and the conditions that support life in such extreme environments. The broader impacts of the project are that subglacial lakes have captured the interest of many people, scientists and laymen. The national and international press frequently reports about the research of the Principal Investigator. His Lake Vostok illustrations have been used in math and earth science text books. Lake Vostok will be used for education and outreach in the Earth2Class project. Earth2Class is a highly successful science/math/technology learning resource for K-12 students, teachers, and administrators in the New York metropolitan area. Earth2Class is created through collaboration by research scientists at the Lamont- Doherty Earth Observatory; curriculum and educational technology specialists from Teachers College, Columbia University; and classroom teachers in the New York metropolitan area.
This award supports a three-year study to isolate essential physical processes affecting Thwaites Glacier (TG) in the Amundsen Sea Embayment (ASE) of West Antarctica using a suite of existing numerical models in conjunction with existing and International Polar Year (IPY)-proposed data sets. Four different models will be utilized to explore the effects of embayment geometry, ice-shelf buttressing, basal-stress distribution, surface mass balance, surface climate, and inland dynamic perturbations on the present and future dynamics of TG. This particular collection of models is ideally suited for the broad nature of this investigation, as they incorporate efficient and complementary simplifications of the stress field (shallow-ice and shelf-stream), system geometry (1-d and 2-d plan-view and flowline; depth-integrated and depth-dependent), and mass-momentum energy coupling (mechanical and thermo-mechanical). The models will be constrained and validated by data sets (including regional maps of ice thickness, surface elevation, basal topography, ice surface velocity, and potential fields) and geophysical data analyses (including increasing the spatial resolution of surface elevations, improving regional estimates of geothermal flux, and characterizing the sub-glacial interface of grounded ice as well as the grounding-zone transition between grounded and floating ice). The intellectual merit of the research focuses on several of the NSF Glaciology program's emphases, including: ice dynamics, numerical modeling, and remote sensing of ice sheets. In addition, the research directly addresses the following specific NSF objectives: "investigation of the physics of fast glacier flow with emphasis on processes at glacier beds"; "investigation of ice-shelf stability"; and "identification and quantification of the feedback between ice dynamics and climate change". The broader impacts of this research effort will help answer societally relevant questions of future ice sheet stability and sea-level change. The research also will aid in the early career development of two young investigators and will contribute to the education of both graduate and undergraduate students directly involved in the research, and results will be incorporated into courses and informal presentations.
This award supports a three-year modeling effort to understand the dynamics surrounding ice-air surface slope reversals on ice streams and ice shelves, with implications for the creation and stability of subglacial lakes. Local reversal of the ice-air surface slope may lead, through a reversal of the hydraulic gradient, to the trapping of basal and surface water, producing subglacial and supraglacial lakes, respectively. In the case of subglacial lakes, once such a sizable reservoir of pressurized water is created the potential exists for drainage, in the form of large outburst floods or as smaller, but sustained, periods of increased subglacial water flow. The research seeks to extend some initial work that has been done to include time-dependence and a wider array of parameters and geometries. The methods will involve the use of a suite of models, all of which will include longitudinal deviatoric and basal-shear stresses, with some also taking account of lateral drag and internal vertical shear. The intellectual merit of the proposed activity includes an improved understanding of the processes and parameters involved in the formation of surface-slope reversals in ice-stream/ice-shelf systems, as well as insight into the stability of subglacial lakes formed as a consequence of slope reversals. The broader impacts resulting from this activity include the provision of tools to study the dynamics of ice-stream/ice-shelf systems, an improved understanding of the physics behind outburst floods, and insights into the coupling of ice streams with their subglacial water systems. The research will support the studies of a beginning postdoctoral researcher. Results of the research will be incorporated into courses and public outreach serving anywhere from hundreds to thousands of people per year.
Johnson/0632161<br/><br/>This award supports a project to create a "Community Ice Sheet Model (CISM)". The intellectual merit of the proposed activity is that the development of such a model will aid in advancing the science of ice sheet modeling. The model will be developed with the goal of assuring that CISM is accurate, robust, well documented, intuitive, and computationally efficient. The development process will stress principles of software design. Two complementary efforts will occur. One will involve novel predictive modeling experiments on the Amundsen Sea Embayment region of Antarctica with the goal of understanding how interactions between basal processes and ice sheet dynamics can result in abrupt reconfigurations of ice-sheets, and how those reconfigurations impact other Earth systems. New modeling physics are to include the higher order stress terms that allow proper resolution of ice stream and shelf features, and the associated numerical methods that allow higher and lower order physics to be coexist in a single model. The broader impacts of the proposed activity involve education and public outreach. The model will be elevated to a high standard in terms of user interface and design, which will allow for the production of inquiry based, polar and climate science curriculum for K-12 education. The development of a CISM itself would represent a sea change in the way that glaciological research is conducted, eliminating numerous barriers to progress in polar research such as duplicated efforts, lack of transparency in publication, lack of a cryospheric model for others to link to and reference, and a common starting point from which to begin investigation. As the appropriate interfaces are developed, a curriculum to utilize CISM in education will be developed. Students participating in this grant will be required to be involved in public outreach through various mechanisms including local and state science fairs. The model will also serve as a basis for educating "a new generation" of climate scientists. This project is relevant to the International Polar Year (IPY) as the research team is multi-institutional and multi-disciplinary, will bring new groups and new specialties into the realm of polar research and is part of a larger group of proposals whose research focuses on research in the Amundsen Sea Embayment Plan region of Antarctica. The project is international in scope and the nature of software development is quite international, with firm commitments from the United Kingdom and Belgium to collaborate. In addition there will be an international external advisory board that will be used to guide development, and serve as a link to other IPY activities.
This project is a contribution to a coordinated attempt to understand the interactions of biological and physical dynamics by developing relationships among the evolution of the antarctic winter ice and snow cover, biological habitat variability, and the seasonal progression of marine ecological processes. The work will be carried out in the context of the Southern Ocean Experiment of the Global Ocean Ecosystem Dynamics Study (Globec), a large, multi-investigator study of the winter survival strategy of krill under the antarctic sea ice in the vicinity of Marguerite Bay on the western side of the Antarctic Peninsula.<br/><br/>The objective of this project is to make a quantitative assessment of the small scale temperature and salinity structure of the oceanic surface layer in order to study the effect of stratification and turbulence on the biochemical and biological processes under the winter sea ice.<br/><br/>The water masses on the continental shelf off Marguerite Bay consist of inflowing Upper Circumpolar Deep Water, which is relatively warm, salty, oxygen-poor, and nutrient-rich. In winter atmospheric processes cool and freshen this water, and recharge it with oxygen to produce Antarctic Surface Water which is diffused seaward, and supports both a sea ice cover and a productive krill-based food web. The modification processes work through mixing associated with shear instabilities of the internal wave field, double diffusion of salt and heat, and mixing driven by surface stress and convection. These processes will be quantified with two microstructure profilers, capable of resolving the small but crucial vertical variations that drive these processes.<br/>***
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, provides funds for a study to investigate the tectonic development of the southwestern Ross Sea region. Displacements between East and West Antarctica have long been proposed based on global plate circuits, apparent hot spot motions, interpretations of seafloor magnetic anomalies, paleomagnetism, and on geologic grounds. Such motions require plate boundaries crossing Antarctica, yet these boundaries have never been explicitly defined. This project will attempt to delineate the late Cenozoic - active boundary between East and West Antarctica along the Terror Rift in the western Ross Sea, where young structures have been identified, continuity between active extension and intracontinental structures can be established, and where accessibility via ship will allow new key data sets to be acquired. We will use multi-source marine and airborne geophysical data to map the fault patterns and volcanic structure along the eastern margin of the Terror Rift. The orientations of volcanic fissures and seamount alignments on the seafloor will be mapped using multibeam bathymetry. The volcanic alignments will show the regional extension or shear directions across the Terror Rift and the orientations of associated crustal stresses. Swath bathymetry and single channel seismic data will be used to document neotectonic fault patterns and the eastern limit of recent faulting. Delineation of neotectonic fault patterns will demonstrate whether the eastern margin of the Terror Rift forms a continuous boundary and whether the rift itself can be linked with postulated strike-slip faults in the northwestern Ross Sea. Seafloor findings from this project will be combined with fault kinematic and stress field determinations from the surrounding volcanic islands and the Transantarctic Mountains. The integrated results will test the propositions that the eastern boundary of the Terror Rift forms the limit of the major, late Cenozoic -active structures through the Ross Sea and that Terror Rift kinematics involve dextral transtension linked to the right-lateral strike-slip faulting to the north. These results will help constrain the kinematic and dynamic links between the West Antarctic rift system and Southern Ocean structures and any related motions between East and West Antarctica. In the first year, a collaborative structural analysis of existing multichannel and single channel seismic profiles and aeromagnetic data over the Terror Rift will be conducted. The location of volcanic vents or fissures and any fault scarps on the sea floor will be identified and a preliminary interpretation of the age and kinematics of deformation in the Terror Rift will be produced. Late in the second year, a one-month cruise on RVIB N.B. Palmer will carry out multibeam bathymetric and sidescan sonar mapping of selected portions of the seafloor of Terror Rift. Gravity, magnetics, seismic reflection and Bathy2000 3.5 kHz sub-bottom profile data will also be collected across the rift. In the third year, we will use these multisource data to map the orientations and forms of volcanic bodies and the extent and geometry of neotectonic faulting associated with the Terror Rift. The project will: 1) complete a map of neotectonic faults and volcanic structures in the Terror Rift; 2) interpret the structural pattern to derive the motions and stresses associated with development of the rift; 3) compare Terror Rift structures with faults and lineaments mapped in the Transantarctic Mountains to improve age constraints on the structures; and 4) integrate the late Cenozoic structural interpretations from the western Ross Sea with Southern Ocean plate boundary kinematics.
This award is for support for three years of funding to study the effects of impurities on the flow of poly-<br/>crystalline ice. It has been known for thirty years that both hydrofluoric acid (HF) and hydrochloric acid (HCl) dramatically decrease the strength of ice and recent work by the author's group has shown that sulfuric acid (H2SO4) produces a similar reduction in strength. However, these data are for single crystals at strain rates and stresses that far exceed those found in glaciers and ice sheets, and often at concentrations that far exceed those in natural ice. Therefore, it is not known how impurities found in nature affect the flow of polycrystalline ice at slow strain rates. In this research, the effects of nitric acid and sulfuric acid (which are naturally occurring impurities in ice) on the microstructure (dislocation structure, grain boundary structure and location of the acids) and creep of polycrystalline ice (at a range of temperatures and stresses) will be determined. The ice's response to creep deformation will be studied using a combination of x-ray topography, optical microscopy and scanning electron microscopy. X-ray microanalysis in an environmental scanning electron microscope will be used to study the location of impurities. The structure and creep behavior of the acid-doped ice will be compared with those of both high-purity laboratory-grown ice and ice from Byrd Station, Antarctica. The end-result of this project will be to elucidate the effects of naturally-occurring acid impurities on the mechanical properties of polycrystalline ice under conditions relevant to the deformation of glaciers and ice sheets, including and understanding of how impurities affect the underlying deformation mechanisms.
0538195<br/>Marone<br/>This award supports a project to conduct laboratory experiments and numerical modeling to determine the constitutive properties of subglacial till under dynamic stressing and to test the hypothesis that granular properties of till are sufficient, when coupled elastically to a large ice stream, to reproduce the field observations of triggered slip and subglacial seismicity. Testing will be carried out in a servo-controlled biaxial shear device under controlled temperature and stress conditions, which will allow both sliding and microstructural processes to be studied in detail. The main focus of the work will be on laboratory measurements. In addition, we will construct continuum models to evaluate whether our results can predict complex ice sheet motions and observed characteristics of subglacial seismicity. In terms of broader impacts, the proposed work will encourage interactions between the rock-mechanics and glaciology communities and will bring together members of different scientific backgrounds and vocabularies, but similar problems and data. The project will train undergraduate and graduate students at Penn State University and the scientists involved plan to give presentations to grade school classes, scout groups, and at community open houses. Results will be presented at professional meetings and will be published in a timely manner. The work will result in a better understanding of glacial motion and the physics of earthquake slip, which is essential for understanding ice sheet dynamics and earthquake hazard.
This award supports a three year project to develop the tools required to interpret complex patterns of flow features on the Ross Ice Shelf, which record the discharge history the ice streams flowing east off of the West Antarctic Ice Sheet. This work builds on previous research that used flow features visible in satellite image mosaics and numerical models of ice shelf flow to detect changes in grounding zone dynamics and redirection of ice stream outlets over hundreds of years. Recently observed changes on Whillans Ice Stream fit within this framework. The pattern of redirection is driven by the influence of rapid downstream thinning on the basal thermal gradient in the ice and associated "sticky spot" (ice rise) formation. In pursuing this work, the investigators recognized other records of discharge variation on the shelf that can be used to build a more complete history and understanding of ice-stream discharge variability. The intellectual merit of the proposed work lies in the fact that these records, including fracture patterns and spatial variation in ice thickness, when understood in the proper context, will yield quantitative information about the timing and dynamics of ice stream slowdowns, grounding line retreat, and the relative history of discharge between the ice streams. New tools will help further constrain this history. The laser altimeter on NASA's IceSAT has improved our knowledge of the surface elevation of Antarctic ice. IceSAT surface elevations provide a high-resolution map of ice-shelf thickness that, along with provenance maps from ice-shelf image mosaics, will be used to estimate the volumes of ice involved in past ice-stream discharge events (slowdowns, redirections, and so on). This project will develop new numerical models for fracture propagation; these will allow past variations in ice-shelf stress state to be investigated. Together, the dynamic and volume-flux histories will provide a powerful set of observations for understanding past variations in ice stream discharge and the underlying physical processes. The broader impacts of this project center on how it contributes to the ability to estimate West Antarctic contributions to global sea level rise and to answer outstanding questions about the causes of millennial and longer-scale evolution of ice streams. This work will provide a history of the most complex record of ice discharge known. In addition to the incorporation of this research into graduate student advising and normal teaching duties, the investigators are involved in other avenues of civic engagement and education. Outreach to high school students and the community at large is promoted on an annual basis by the investigators at both institutions. New outreach projects at Portland State University are developed with the assistance of researchers with expertise in student learning and achievement in science and mathematics. The collaborative research team includes two glaciologists with experience in the pairing of high resolution satellite imagery and a variety of ice-flow models and a geologist whose focus is the mechanics of rock deformation.
Polar terrestrial environments are often described as deserts, where water availability is recognized as one of the most important limits on the distribution of terrestrial organisms. In addition, prolonged low winter temperatures threaten survival, and summer temperatures challenge organisms with extensive diel variations and rapid transitions from freezing to desiccating conditions. Global warming has further impacted the extreme thermal and hydric conditions experienced by Antarctic terrestrial plant and arthropod communities, especially as a result of glacial retreat along the Antarctic Peninsula. This research will focus on thermal and hydric adaptations in the terrestrial midge, Belgica antarctica, the largest and most southerly holometabolous insect living in this challenging and changing environment. <br/>Overwintering midge larvae encased in the frozen substrate must endure desert-like conditions for more than 300 days since free water is biologically unavailable as ice. During the summer, larvae may be immersed in melt water or outwash from penguin colonies and seal wallows, in addition to saltwater splash. Alternatively, the larvae may be subjected to extended periods of desiccation as their microhabitats dry out. Due to their small size, relative immobility and the patchiness of suitable microhabitats, larvae may thus be subjected to stresses that include desiccation, hypo- or hyperosmotic conditions, high salinity exposure, and anoxia for extended periods. Research efforts will focus in three areas relevant to the stress tolerance mechanisms operating in these midges:(1) obtaining a detailed characterization of microclimatic conditions experienced by B. antarctica, especially those related to thermal and hydric diversity, both seasonally and among microhabitat types in the vicinity of Palmer Station, Antarctica; (2) examining the effects of extreme fluctuations in water availability and effects on physiological and molecular responses - to determine if midge larvae utilize the mechanism of cryoprotective dehydration for winter survival, and if genes encoding heat shock proteins and other genes are upregulated in larval responses to dehydration and rehydration; (3) investigating the dietary transmission of cryoprotectants from plant to insect host, which will test the hypothesis that midge larvae acquire increased resistance to desiccation and temperature stress by acquiring cryoprotectants from their host plants. <br/>This project will provide outreach to both elementary and secondary educators and their students. The team will include a teacher who will benefit professionally by full participation in the research, and will also assist in providing outreach to other teachers and their students. From Palmer Station, the field team will communicate daily research progress by e-mail supplemented with digital pictures with teachers and their elementary students to stimulate interest in an Antarctic biology and scientific research. These efforts will be supplemented with presentations at local schools and national teacher meetings, and by publishing hands-on, inquiry-based articles related to cryobiology and polar biology in education journals. Furthermore, the principal investigators will maintain major commitments to training graduate students and postdoctoral scholars, as well as undergraduate students by providing extended research experience that includes publication of scientific papers and presentations at national meetings.
Ice streams are believed to play a major role in determining the response of their parent ice sheet to climate change, and in determining global sea level by serving as regulators on the fresh water stored in the ice sheets. Ice streams are characterized by rapid, laterally confined flow which makes them uniquely identifiable within the body of the more slowly and more homogeneously flowing ice sheet. But while these characteristics enable the identification of ice streams, the processes which control ice-stream motion and evolution, and differences among ice streams in the polar regions, are only partially understood. Understanding the relative importance of lateral and basal drags, as well as the role of gradients in longitudinal stress, is essential for developing models for future evolution of the polar ice<br/>sheets. In this project, physical statistical models will be used to explore the processes that control ice-stream flow, and to compare these processes between seemingly different ice-stream systems. In particular, Whillans Ice Stream draining into the Ross Ice Shelf, will be compared with Recovery and RAMP glaciers draining into the Ronne-Filchner Ice Shelf, and the Northeast Ice Stream in Greenland. Geophysical models lie at the core of the approach, but are embellished by modeling various components of variability statistically. One important component comes from the uncertainty in observations on basal elevation, surface elevation, and surface velocity. In this project new observational data collected using remote-sensing techniques will be used. The various components, some of which are spatial, are combined hierarchically using Bayesian statistical methodology. All these components will be combined mathematically into a physical statistical model that yields the posterior distribution for basal, longitudinal, and lateral stress fields, and velocity fields, conditional on the data. Inference based on this distribution will be carried out via Markov chain Monte Carlo techniques, to obtain estimates of these unknown fields along with uncertainty measures associated with them.
This award supports a project to characterize the morphology, ice motion velocity and mass balance of Lambert Glacier, Antarctica using state-of-the-art remote sensing and GIS techniques. Lambert Glacier is the largest ice stream in the world. Because of its size, it plays a fundamental role in the study of glacial dynamics and mass budget in response to present and future climate changes. Along with the bedrock topography and ice thickness data derived from airborne radio echo soundings and snow accumulation data compiled from ground-based measurements, the dynamic behavior and mass balance of the Lambert glacial basin in a Geographic Information Systems (GIS) environment will be examined. Specific objectives are to: (1) Extract two-dimensional ice velocity field over the entire Lambert glacial basin using speckle matching and differential interferometric SAR (InSAR) techniques, and produce a full coverage of radar coherence map over the drainage basin. With the ice velocity data, calculate the strain rate field from the initiation areas of the ice stream onto the Amery Ice Shelf; (2) Derive high-resolution digital elevation model (DEM) over the Lambert glacial drainage basin using SAR stereo, differential interferometric SAR, and GLAS laser altimetry techniques. Based on the DEM, extract ice divides and ice flow directions, delineate the snow catchment basin, and calculate the balance deformation velocity and the basal shear stress; (3) Interpolate traverse ice thickness data collected by Australian and Russian airborne radio echo sounding surveys into a regular grid, and derive a regular grid of bedrock topography in combination with the DEM; (4) Integrate newly derived ice velocity and ice thickness data as well as snow accumulation rate data compiled from previous ground-based measurements into a geographic information system (GIS), and calculate the mass flux through the ice stream at the grounding lines and net mass balance throughout the drainage basin. With these new measurements and calculations derived from advanced remote sensing techniques, we will be able to improve our understanding of dynamic behavior and current mass balance status of the Lambert glacial basin, gain an insight on the relationship between ice mass change and the variation in regional and global climate at decadal scale, and provide an evaluation on the issue of whether the Lambert glacier basin is subject to surging in the context of future climate change.
0086997<br/>Truffer<br/><br/>This award supports a two year project to investigate the dynamics of the marginal zone of the Siple Coast ice streams using existing velocity and temperature profiles. The flow and stress fields will be modeled using finite element methods and a thermo-mechanical model will be used to investigate the coupling of the flow and temperature fields. Direct comparison of these models with the observed velocity profiles will lead to estimates of the structure of the margins and the softening of the marginal ice. The distribution of basal and marginal shear stress will be investigated, leading to an estimate of the relative roles of the bed and the margins in the overall force balance of the ice streams.
0135989<br/>Wilen<br/><br/>This is a collaborative proposal by Principal Investigators at the University of Washington and Ohio University. Detailed knowledge about the interactions between micro-structure of ice and its deformation is needed to assess the integrity of stratigraphic layering and the depth-age relationship in ice cores, which is essential for interpreting the paleoclimate record. The Principal Investigators will use micro-structure to study fabric, the orientation distribution of crystal c-axes, and texture, the size and shape of crystals. Numerical modeling of ice deformation is a useful tool in understanding these interactions. Accurate modeling of ice deformation is complicated by factors, such as the fabric, grain size, dynamic recrystallization, stress level, and precise knowledge of initial conditions. For example, ice fabric evolves as the ice is strained and the deformation depends on the fabric. This complicated feedback mechanism must be understood to correctly model ice deformation. In another example, the usual assumption is that the initial fabric is isotropic or random, but there are excellent examples of near-surface ice in the ice cores that are apparently not isotropic. One must know the initial fabric to calculate the deformation rate in ice sheets. Dr. Wilen will combine results of his new automatic fabric analyzer (AFA) with predictions of detailed ice deformation models (Dr. Thorsteinsson) to refine and better constrain such models. The AFA gives new information in thin sections because the precision and number of measured c-axis orientations are greatly improved. The Principal Investigators will analyze existing data and collect new data on fabric and texture from ice cores to address questions regarding near-surface fabric, deformation mechanisms, dynamic recrystallization, and potential sources of layer disturbances. The data will be used to constrain models of fabric evolution and recrystallization processes. With the more refined models, scientists can address different questions and important problems related to ice deformation and ice cores. For example, the recent agreement between the climate records from the Greenland Ice Core Project (GRIP) and Greenland Ice Sheet Project 2 (GISP2) ice cores of the upper-90%, and the disagreement in the lower-10% emphasizes the need to understand and predict the mechanisms and probable depths of disruption in these and future deep ice cores. Evidence suggests that the stratigraphic disturbances arise from the anisotropic nature of ice crystals at a variety of scales. To properly model the deformation of anisotropic ice, the influence of fabric on deformation must be well known.