USAP-DC

{"dp_type": "Dataset", "free_text": "ANDRILL"}

[{"awards": "0838842 Passchier, Sandra", "bounds_geometry": ["POINT(167.0833 -77.8889)"], "date_created": "Mon, 14 Jun 2021 00:00:00 GMT", "description": "This dataset contains measurements of particle-size distributions on four intervals of diamicitites from ANDRILL Site AND-2A. Carbonate, and organic matter were removed through addition of 10mL aliquots of 30% H2O2 and 2mL aliquots of 10% HCl to ~50-100mL suspension on a hot plate. Dispersion was through heating with sodium pyrophosphate. Samples were measured on a Malvern Mastersizer 2000 with a Hydro 2000MU (A) accessory, using a Refractive index of 1.544 (Quartz) and an absorption coefficient of 0.9. Results are in (vol. %) per size class, with diameter range equivalent to the diameter of spheres with the same volume as measured particles.", "east": 167.0833, "geometry": ["POINT(167.0833 -77.8889)"], "keywords": "Antarctica; Mcmurdo Sound; Miocene; Particle Size; Pleistocene; Pliocene", "locations": "Mcmurdo Sound; Antarctica", "north": -77.8889, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Passchier, Sandra; Hansen, Melissa A.", "project_titles": "Determining Middle Miocene through Pliocene Changes in Paleo Ice-flow and Basal Ice Conditions in East Antarctica through Sedimentological Analyses of Core Samples", "projects": [{"proj_uid": "p0000147", "repository": "USAP-DC", "title": "Determining Middle Miocene through Pliocene Changes in Paleo Ice-flow and Basal Ice Conditions in East Antarctica through Sedimentological Analyses of Core Samples"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -77.8889, "title": "Particle-size measurements for diamictites AND-2A sediment core, McMurdo Sound", "uid": "601452", "west": 167.0833}, {"awards": "0342484 Harwood, David", "bounds_geometry": ["POINT(167 -78)"], "date_created": "Mon, 14 Jun 2021 00:00:00 GMT", "description": "This dataset contains measurements of particle-size distributions on sediment from ANDRILL Site AND-2A. Carbonate, and organic matter were removed through addition of 10mL aliquots of 30% H2O2 and 2mL aliquots of 10% HCl to ~50-100mL suspension on a hot plate. Dispersion was through heating with sodium pyrophosphate. Samples were measured on a Malvern Mastersizer 2000 with a Hydro 2000MU (A) accessory, using a Refractive index of 1.544 (Quartz) and an absorption coefficient of 0.9. Results are in (vol. %) per size class, with diameter range equivalent to the diameter of spheres with the same volume as measured particles.", "east": 167.0, "geometry": ["POINT(167 -78)"], "keywords": "Andrill; Antarctica; Continental Shelf; Diamict; Mcmurdo Sound; Miocene; Paleoclimate; Particle Size", "locations": "Mcmurdo Sound; Antarctica", "north": -78.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Passchier, Sandra; Candice, Falk", "project_titles": "Collaborative Research: ANDRILL - - Investigating Antarcticas Role in Cenozoic Global Environmental Change", "projects": [{"proj_uid": "p0010297", "repository": "USAP-DC", "title": "Collaborative Research: ANDRILL - - Investigating Antarcticas Role in Cenozoic Global Environmental Change"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -78.0, "title": "Particle-size measurements at 3-m intervals for AND-2A sediment core, McMurdo Sound", "uid": "601451", "west": 167.0}, {"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))"], "date_created": "Sun, 24 Nov 2019 00:00:00 GMT", "description": "Interpretation of major post-middle Miocene seismic reflections in the Ross Sea are provided in i) ASCII files containing Line, Trace, X, Y, and TWTT (two-way travel) picks and ii) netcdf grid files of structure and isochore maps in two-way travel time and depth or thickness. Data are in the Antarctic Polar Stereographic projection.", "east": -145.0, "geometry": ["POINT(-175 -75)"], "keywords": "Andrill; Antarctica; Marine Geoscience; Ross Sea; Seismic Interpretation; Seismic Reflection; Stratigraphy; Subsidence; Victoria Land Basin", "locations": "Ross Sea; Victoria Land Basin; Antarctica", "north": -70.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Harry, Dennis L.", "project_titles": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History", "projects": [{"proj_uid": "p0000467", "repository": "USAP-DC", "title": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -80.0, "title": "Ross Sea post-middle Miocene seismic interpretation", "uid": "601227", "west": 155.0}, {"awards": "1443420 Dodd, Justin", "bounds_geometry": ["POINT(167.083333 -77.888889)"], "date_created": "Sun, 27 Oct 2019 00:00:00 GMT", "description": "The Andrill-1B (AND-1B) sediment core from under the Ross Ice Shelf in McMurdo Sound, Antarctica, recovered a mid to late Pliocene (~4.68 to 3.44 Ma) age diatomite unit with d18Odiatom values that range from +32.6 to +37.6 \u2030 (n=50 ", "east": 167.083333, "geometry": ["POINT(167.083333 -77.888889)"], "keywords": "And-1B; Andrill; Antarctica; Chemistry:sediment; Chemistry:Sediment; Delta 18O; Diatom; Mass Spectrometer; Oxygen Isotope; Paleoclimate; Pliocene; Sediment; Wais Project; West Antarctic Ice Sheet", "locations": "West Antarctic Ice Sheet; Antarctica", "north": -77.888889, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Dodd, Justin; Abbott, Tirzah", "project_titles": "Diatom and Oxygen Isotope Evidence of Pliocene Antarctic Ice Sheet Dynamics and Ross Sea Paleoceanography", "projects": [{"proj_uid": "p0010042", "repository": "USAP-DC", "title": "Diatom and Oxygen Isotope Evidence of Pliocene Antarctic Ice Sheet Dynamics and Ross Sea Paleoceanography"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -77.888889, "title": "Diatom Oxygen Isotope Evidence of Pliocene (~4.68 to 3.44 Ma) Antarctic Ice Sheet Dynamics and Ross Sea Paleoceanography", "uid": "601220", "west": 167.083333}, {"awards": "1141978 Foreman, Christine", "bounds_geometry": ["POINT(161.667 -77.117)"], "date_created": "Tue, 19 Dec 2017 00:00:00 GMT", "description": "Metadata presented include Fourier transform ion cyclotron resonance mass spectrometry characterization of carbon source material molecular composition for three isolated lyophilized OM samples: Cotton Glacier Supraglacial stream, IHSS Pony Lake, and IHSS Suwannee River", "east": 161.667, "geometry": ["POINT(161.667 -77.117)"], "keywords": "Antarctica; Biota; Chemistry:fluid; Chemistry:Fluid; Fluorescence Spectroscopy; Mass Spectrometry", "locations": "Antarctica", "north": -77.117, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "D\u0027Andrilli, Juliana; Foreman, Christine", "project_titles": "Multidimensional \"omics\" characterization of microbial metabolism and dissolved organic matter in Antarctica", "projects": [{"proj_uid": "p0000408", "repository": "USAP-DC", "title": "Multidimensional \"omics\" characterization of microbial metabolism and dissolved organic matter in Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.117, "title": "FT-ICR MS Metadata", "uid": "601077", "west": 161.667}, {"awards": "0839075 Priscu, John", "bounds_geometry": ["POINT(-112.08648 -79.46763)"], "date_created": "Mon, 06 Mar 2017 00:00:00 GMT", "description": "This data set include depth (WDC06A-7 dating) and fluorescence intensity measurements for five fluorophore regions (A, C, M, B, and T) commonly found in natural organic matter. Data from 1300-1700m, 1700-2100m, and 2100-2700m correspond to the early Holocene, deglaciation period, and the Last Glacial Maximum.", "east": -112.08648, "geometry": ["POINT(-112.08648 -79.46763)"], "keywords": "Antarctica; Fluorescence Spectroscopy; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Physical Properties; WAIS Divide; WAIS Divide Ice Core", "locations": "WAIS Divide; Antarctica", "north": -79.46763, "nsf_funding_programs": null, "persons": "Priscu, John; D\u0027Andrilli, Juliana", "project_titles": "Collaborative Research: Integrated High Resolution Chemical and Biological Measurements on the Deep WAIS Divide Core", "projects": [{"proj_uid": "p0000273", "repository": "USAP-DC", "title": "Collaborative Research: Integrated High Resolution Chemical and Biological Measurements on the Deep WAIS Divide Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.46763, "title": "Fluorescence spectroscopy data from the West Antarctic Ice Sheet (WAIS) Divide ice core, WDC06A", "uid": "601006", "west": -112.08648}, {"awards": "1043554 Willenbring, Jane", "bounds_geometry": ["POINT(161.5 -77.5)"], "date_created": "Wed, 09 Nov 2016 00:00:00 GMT", "description": "The PIs propose to address the question of whether ice surface melting zones developed at high elevations during warm climatic phases in the Transantarctic Mountains. Evidence from sediment cores drilled by the ANDRILL program indicates that open water in the Ross Sea could have been a source of warmth during Pliocene and Pleistocene. The question is whether marine warmth penetrated inland to the ice sheet margins. The glacial record may be ill suited to answer this question, as cold-based glaciers may respond too slowly to register brief warmth. Questions also surround possible orbital controls on regional climate and ice sheet margins. Northern Hemisphere insolation at obliquity and precession timescales is thought to control Antarctic climate through oceanic or atmospheric connections, but new thinking suggests that the duration of Southern Hemisphere summer may be more important. The PIs propose to use high elevation alluvial deposits in the Transantarctic Mountains as a proxy for inland warmth. These relatively young fans, channels, and debris flow levees stand out as visible evidence for the presence of melt water in an otherwise ancient, frozen landscape. Based on initial analyses of an alluvial fan in the Olympus Range, these deposits are sensitive recorders of rare melt events that occur at orbital timescales. For their study they will 1) map alluvial deposits using aerial photography, satellite imagery and GPS assisted field surveys to establish water sources and to quantify parameters effecting melt water production, 2) date stratigraphic sequences within these deposits using OSL, cosmogenic nuclide, and interbedded volcanic ash chronologies, 3) use paired nuclide analyses to estimate exposure and burial times, and rates of deposition and erosion, and 4) use micro and regional scale climate modeling to estimate paleoenvironmental conditions associated with melt events.\nThis study will produce a record of inland melting from sites adjacent to ice sheet margins to help determine controls on regional climate along margins of the East Antarctic Ice Sheet to aid ice sheet and sea level modeling studies. The proposal will support several graduate and undergraduates. A PhD student will be supported on existing funding. The PIs will work with multiple K-12 schools to conduct interviews and webcasts from Antarctica and they will make follow up visits to classrooms after the field season is complete.", "east": 161.5, "geometry": ["POINT(161.5 -77.5)"], "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Cosmogenic Radionuclides; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Isotope; Sample/collection Description; Sample/Collection Description; Transantarctic Mountains", "locations": "Transantarctic Mountains; Antarctica", "north": -77.5, "nsf_funding_programs": null, "persons": "Willenbring, Jane", "project_titles": "Collaborative Research: Activation of high-elevation alluvial fans in the Transantarctic Mountains - a proxy for Plio-Pleistocene warmth along East Antarctic ice margins", "projects": [{"proj_uid": "p0000429", "repository": "USAP-DC", "title": "Collaborative Research: Activation of high-elevation alluvial fans in the Transantarctic Mountains - a proxy for Plio-Pleistocene warmth along East Antarctic ice margins"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.5, "title": "Activation of high-elevation alluvial fans in the Transantarctic Mountains - a proxy for Plio-Pleistocene warmth along East Antarctic ice margins", "uid": "600379", "west": 161.5}, {"awards": "1043740 Lenczewski, Melissa", "bounds_geometry": ["POLYGON((165 -77.5,165.3 -77.5,165.6 -77.5,165.9 -77.5,166.2 -77.5,166.5 -77.5,166.8 -77.5,167.1 -77.5,167.4 -77.5,167.7 -77.5,168 -77.5,168 -77.6,168 -77.7,168 -77.8,168 -77.9,168 -78,168 -78.1,168 -78.2,168 -78.3,168 -78.4,168 -78.5,167.7 -78.5,167.4 -78.5,167.1 -78.5,166.8 -78.5,166.5 -78.5,166.2 -78.5,165.9 -78.5,165.6 -78.5,165.3 -78.5,165 -78.5,165 -78.4,165 -78.3,165 -78.2,165 -78.1,165 -78,165 -77.9,165 -77.8,165 -77.7,165 -77.6,165 -77.5))"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "The PI proposes to utilize computer models used by hydrogeologists to establish the fate and transport of contamination and determine the extent of drilling fluid contamination in the ANDRILL SMS core. For these models, previously collected logs of lithology, porosity, fracture density, fracture type, fracture orientation, drilling fluid loss, drilling fluid characteristics and temperature will be used as input parameters. In addition, biodegradation and sorption constants for the drilling fluid will be determined and incorporated into the models. Samples of drilling fluids used during coring as well as the return fluids were collected at the drill site using standard microbiological sampling techniques. Fluids will be tested at in situ temperatures under aerobic and anaerobic conditions to determine biodegradation constants. Sorption will be determined between the drilling fluids and core samples using standard isotherm methods. Geochemical and microbial fingerprints of the fluids and the changes during biodegradation will determine the potential impact of the drilling fluids on the isolated microbial communities and the geochemistry within various subsurface lithologic units beneath the southern McMurdo Sound in Antarctica. The results of this study could potentially provide guidelines on developing less detrimental methods for future exploration, if deemed necessary through this research.\nThis proposed project will train a graduate student. The methods developed for analyses of samples in this project will serve as a guide for future studies of similar interest and will improve the understanding of ecological impacts of geologic drilling in Antarctica. The results of this study will be used as a reference for comparison with future studies examining newly developed, and improved, sample collection methods in future exploratory drilling projects in pristine environments. The PI is new to Antarctic research.\n", "east": 168.0, "geometry": ["POINT(166.5 -78)"], "keywords": "Andrill; Antarctica; Chemistry:fluid; Chemistry:Fluid; Chemistry:rock; Chemistry:Rock; Drilling Fluid; Geochemistry; Mcmurdo; Ross Sea; Sediment Core", "locations": "Mcmurdo; Ross Sea; Antarctica", "north": -77.5, "nsf_funding_programs": null, "persons": "Lenczewski, Melissa", "project_titles": "Fate of Drilling Fluids during the South McMurdo Sound Project (SMS) of the Antarctic Geological Drilling Program (ANDRILL)", "projects": [{"proj_uid": "p0000468", "repository": "USAP-DC", "title": "Fate of Drilling Fluids during the South McMurdo Sound Project (SMS) of the Antarctic Geological Drilling Program (ANDRILL)"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -78.5, "title": "Fate of Drilling Fluids during the South McMurdo Sound Project (SMS) of the Antarctic Geological Drilling Program (ANDRILL)", "uid": "600129", "west": 165.0}, {"awards": "1354231 Kowalewski, Douglas", "bounds_geometry": ["POLYGON((-160 -70,-156 -70,-152 -70,-148 -70,-144 -70,-140 -70,-136 -70,-132 -70,-128 -70,-124 -70,-120 -70,-120 -71.5,-120 -73,-120 -74.5,-120 -76,-120 -77.5,-120 -79,-120 -80.5,-120 -82,-120 -83.5,-120 -85,-124 -85,-128 -85,-132 -85,-136 -85,-140 -85,-144 -85,-148 -85,-152 -85,-156 -85,-160 -85,-160 -83.5,-160 -82,-160 -80.5,-160 -79,-160 -77.5,-160 -76,-160 -74.5,-160 -73,-160 -71.5,-160 -70))"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "Intellectual Merit: Neogene sediment records recovered by ANDRILL suggest multiple events of open water conditions and elevated sea surface temperatures at times when terrestrial data from the McMurdo Dry Valleys indicate hyper arid, cold, desert conditions. Interpretation of the ANDRILL data suggests the West Antarctic Ice Sheet is highly sensitive to changes in Pliocene sea surface temperatures and this conclusion has been supported by recent Global Circulation Model results for the early to mid Pliocene. The PIs propose to model paleo-ice configurations and warm orbits associated with a WAIS collapse to assess potential climate change in East Antarctica. During such episodes of polar warmth they propose to answer: What is the limit of ablation along the East Antarctic Ice Sheet?; Are relict landforms in the Dry Valleys susceptible to modification from increase in maximum summertime temperatures?; and Is there sufficient increase in minimum wintertime temperatures to sustain a tundra environment in the Dry Valleys? Integration of depositional records and model outputs have the potential to test the performance of numerical models currently under development as part of ANDRILL; reconcile inconsistencies between marine and terrestrial paleoclimate records in high Southern Latitudes; and improve understanding of Antarctic climate and ice volume sensitivity to forcing for both the East Antarctic and West Antarctic Ice Sheets. Broader impacts: Results from this study have the potential to be used widely by the research community. Outreach to local elementary schools from other funded efforts will continue and be extended to homeschooled students. A Post Doc will be supported as part of this award.\n", "east": -120.0, "geometry": ["POINT(-140 -77.5)"], "keywords": "Antarctica; Atmosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Model Data; Paleoclimate; Transantarctic Mountains", "locations": "Transantarctic Mountains; Antarctica", "north": -70.0, "nsf_funding_programs": null, "persons": "Kowalewski, Douglas", "project_titles": "Validating contrasting terrestrial climate-sensitive Pliocene deposits through high resolution modeling of paleo-environments in the Transantarctic Mountains", "projects": [{"proj_uid": "p0000463", "repository": "USAP-DC", "title": "Validating contrasting terrestrial climate-sensitive Pliocene deposits through high resolution modeling of paleo-environments in the Transantarctic Mountains"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.0, "title": "Validating contrasting terrestrial climate-sensitive Pliocene deposits through high resolution modeling of paleo-environments in the Transantarctic Mountains", "uid": "600140", "west": -160.0}, {"awards": "1043619 Hemming, Sidney", "bounds_geometry": ["POLYGON((-180 -63.997,-179.7982 -63.997,-179.5964 -63.997,-179.3946 -63.997,-179.1928 -63.997,-178.991 -63.997,-178.7892 -63.997,-178.5874 -63.997,-178.3856 -63.997,-178.1838 -63.997,-177.982 -63.997,-177.982 -66.3324,-177.982 -68.6678,-177.982 -71.0032,-177.982 -73.3386,-177.982 -75.674,-177.982 -78.0094,-177.982 -80.3448,-177.982 -82.6802,-177.982 -85.0156,-177.982 -87.351,-178.1838 -87.351,-178.3856 -87.351,-178.5874 -87.351,-178.7892 -87.351,-178.991 -87.351,-179.1928 -87.351,-179.3946 -87.351,-179.5964 -87.351,-179.7982 -87.351,180 -87.351,172.54273 -87.351,165.08546 -87.351,157.62819 -87.351,150.17092 -87.351,142.71365 -87.351,135.25638 -87.351,127.79911 -87.351,120.34184 -87.351,112.88457 -87.351,105.4273 -87.351,105.4273 -85.0156,105.4273 -82.6802,105.4273 -80.3448,105.4273 -78.0094,105.4273 -75.674,105.4273 -73.3386,105.4273 -71.0032,105.4273 -68.6678,105.4273 -66.3324,105.4273 -63.997,112.88457 -63.997,120.34184 -63.997,127.79911 -63.997,135.25638 -63.997,142.71365 -63.997,150.17092 -63.997,157.62819 -63.997,165.08546 -63.997,172.54273 -63.997,-180 -63.997))"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "Intellectual Merit: The PIs proposed a provenance study of glacial deposits in the Ross Embayment that will provide a broad scale geochronologic survey of detrital minerals in till to help characterize bedrock beneath the East Antarctic ice sheet and constrain Antarctica?s glacial history. This project capitalizes on previous investments in field sampling. Analytical tools applied to single mineral grains extracted from existing collections of glacial till will generate ?fingerprints? of East Antarctic outlet glaciers and West Antarctic till to refine paleo-ice flow models for the Ross Embayment during the last glacial maximum, older records from ANDRILL cores, and to assess IRD sources in the Southern Ocean. New provenance tracers will include a suite of geochronological methods that together provide greater insights into the orogenic and erosional history the region. This project will include U/Pb of detrital zircons, (U-Th)/He on a subset of the U/Pb dated zircons, as well as Ar-Ar of detrital hornblende, mica and feldspars.\nBroader Impacts: This research will train one M.S. student at IUPUI, a Ph.D. student at Columbia, and several undergraduates at both institutions. Graduate students involved in the project will be involved in mentoring undergraduate researchers. Incorporation of research discoveries will be brought into the classroom by providing concrete examples and exercises at the appropriate level. Licht and Columbia graduate student E. Pierce are developing outreach projects with local secondary school teachers to investigate the provenance of glacial materials in their local areas. The research will have broad applicability to many fields.", "east": 105.4273, "geometry": ["POINT(143.72265 -75.674)"], "keywords": "Antarctica; East Antarctica; Geochemistry; Ross Sea; Sample/collection Description; Sample/Collection Description; Solid Earth; Southern Ocean; West Antarctica", "locations": "East Antarctica; West Antarctica; Ross Sea; Antarctica; Southern Ocean", "north": -63.997, "nsf_funding_programs": null, "persons": "Hemming, Sidney R.", "project_titles": "Collaborative Research: East Antarctic outlet glacier contributions to the Ross Sea from chronology of detrital grains", "projects": [{"proj_uid": "p0000333", "repository": "USAP-DC", "title": "Collaborative Research: East Antarctic outlet glacier contributions to the Ross Sea from chronology of detrital grains"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.351, "title": "East Antarctic outlet glacier contributions to the Ross Sea from chronology of detrital grains", "uid": "600124", "west": -177.982}, {"awards": "1043690 Scherer, Reed", "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))"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "Intellectual Merit: Diatom abundance in sediment cores is typically used as a proxy for paleo primary productivity. This record is complicated by variable preservation, with most loss occurring in the water column via dissolution and zooplankton grazing. This study will investigate preservational biases via a series of controlled experiments to create proxies of original productivity based on morphological changes associated with diatom dissolution and fracture. The PIs will utilize fresh diatoms from culture. Specific objectives include: (1) Linking changes in diatom morphology to availability of dissolved silica and other physical and chemical parameters; (2) Documenting the dissolution process under controlled conditions; (3) Assessment of changes in morphology and diatom surface roughness with increased dissolution; (4) Documenting the physical effects of grazing and fecal pellet formation on diatom fragmentation and dissolution; and (5) Analyzing the impact of diatom dissolution on silica and carbon export. These objectives will be achieved by growing Southern Ocean diatom species in the laboratory under differing physical and chemical conditions; controlled serial dissolution experiments on cultured diatoms; analysis of the dissolution process by imaging frustules under scanning electron microscopy (SEM) and with micro-analysis of surface texture by atomic force microscopy (AFM); making the cultures available to krill and other live zooplankton crustaceans in order to analyze the specific effects of grazing and pelletization on diatom morphology; and comparing experimental results with natural plankton, sediment trap material, and selected Holocene, Pleistocene and Pliocene sediment core material.\nBroader impacts: This work will contribute to understanding of the use of diatom abundance as an indicator of paleoproductivity. The proposed experiments are multi-disciplinary in nature. Importantly, the project was designed, and the proposal largely written, by a Ph.D. candidate. The research proposed here will lead to peer-reviewed publications and provide a base for future studies over the course of an extremely promising scientific career. The project will also support an undergraduate research student at NIU. The PI is heavily involved in science outreach, including classroom visits, museum events and webinars related to evolution and climate change, and is active with NSF-funded outreach activities linked to the ANDRILL and WISSARD programs. He will continue these efforts with this project.", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Antarctica; Biota; Diatom; Marine Sediments; Oceans; Sediment Core; Southern Ocean", "locations": "Antarctica; Southern Ocean", "north": -60.0, "nsf_funding_programs": null, "persons": "Haji-Sheikh, Michael; Scherer, Reed Paul", "project_titles": "Southern Ocean Diatom Taphonomy and Paleoproductivity: A Laboratory Study of Silica Degradation and Export", "projects": [{"proj_uid": "p0000360", "repository": "USAP-DC", "title": "Southern Ocean Diatom Taphonomy and Paleoproductivity: A Laboratory Study of Silica Degradation and Export"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Southern Ocean Diatom Taphonomy and Paleoproductivity: A Laboratory Study of Silica Degradation and Export", "uid": "600127", "west": -180.0}, {"awards": "1043700 Harry, Dennis", "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))"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "Intellectual Merit: 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. Broader impacts: 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.\n", "east": 180.0, "geometry": ["POINT(0 -89.999)"], "keywords": "Andrill; Antarctica; Continental Rift; Geology/Geophysics - Other; Lithosphere; Model; Ross Sea; Solid Earth; Tectonic; Transantarctic Mountains", "locations": "Ross Sea; Transantarctic Mountains; Antarctica", "north": -60.0, "nsf_funding_programs": null, "persons": "Harry, Dennis L.", "project_titles": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History", "projects": [{"proj_uid": "p0000467", "repository": "USAP-DC", "title": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -90.0, "title": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History", "uid": "600128", "west": -180.0}]

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