{"dp_type": "Project", "free_text": "Sulfate"}
[{"awards": "1543361 Kurbatov, Andrei; 1543454 Dunbar, Nelia", "bounds_geometry": "POINT(0 -90)", "dataset_titles": "Cryptotephra in SPC-14 ice core; SPICEcore visable tephra", "datasets": [{"dataset_uid": "601667", "doi": "10.15784/601667", "keywords": "Antarctica; Electron Microprobe; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; South Pole; Tephra", "people": "Iverson, Nels", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SPICEcore visable tephra", "url": "https://www.usap-dc.org/view/dataset/601667"}, {"dataset_uid": "601666", "doi": "10.15784/601666", "keywords": "Antarctica; Cryptotephra; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; South Pole; SPICEcore; Tephra", "people": "Helmick, Meredith; Kurbatov, Andrei V.; Hartman, Laura; Yates, Martin", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Cryptotephra in SPC-14 ice core", "url": "https://www.usap-dc.org/view/dataset/601666"}], "date_created": "Fri, 01 Apr 2022 00:00:00 GMT", "description": "Dunbar/1543454 Antarctic ice cores offer unparalleled records of earth?s climate back to almost one million years and perhaps beyond. Layers of volcanic ash (tephra) embedded in glacial ice can be used to establish an accurate ice core chronology. In order to use a visible or ultrafine volcanic ash layer as a time-stratigraphic marker, a unique geochemical fingerprint must be established, and this forms the basis of our research. This award will investigate the volcanic record in the 1751 m ice core that was completed at the South Pole during the 2015/16 field season. The core is in an ideal location to link the existing, established, volcanic records in East and West Antarctica, and therefore to connect and integrate those records, allowing the climate records of ice cores to be directly compared, as well as to focus research on the most widespread and significant volcanic eruptions from West Antarctica. Tephra derived from well-dated, large, tropical volcanic eruptions that may have had an impact on climate will also be studied. Recent success in identifying and analyzing very fine ash particles from these types of eruptions makes it likely that we will be able to pinpoint some of these eruptions, which will allow the sulfate peaks associated with these layers to be positively identified and dated. Volcanic forcing time series developed from earlier South Pole ice cores based on preserved sulfate were crucial for testing climate models, but without tephra analysis, the origin of these layers remains uncertain. Work on the tephra layers in the South Pole ice core has a number of significant specific objectives, some with practical applications to the basic science goals of Antarctic ice coring, and others that represent independent scientific contributions in their own right. These include: (1) providing independently dated time-intervals in the core, particularly for the deepest ice, (2) quantitatively linking tephra records across Antarctica with the goal of allowing direct and robust climate comparisons between these different parts of the continent, (3) providing information for large local eruptions, that will lead to direct estimates of eruption magnitude and dispersal patterns of Antarctic volcanoes, several of which will likely erupt again. The initial stages of the work will be carried out by identifying silicate-bearing horizons in the ice core, using several methods. Once found, silicate particles will be imaged so that morphological characteristics of the particles can be used to identify volcanic origin. Particles identified as tephra will then be chemically analyzed using electron microprobe and laser ablation ICP-MS. Samples that yield a robust chemical fingerprint will be statistically correlated to known eruptions, and this will be used to address the goals described above. Broader impacts of this project fall into the areas of education of future generation of researchers, outreach and international cooperation. These activities will continue to promote forward progress in integrating the Antarctic tephra record and more broadly tying it to the global volcanic record.", "east": 0.0, "geometry": "POINT(0 -90)", "instruments": null, "is_usap_dc": true, "keywords": "VOLCANIC DEPOSITS; South Pole", "locations": "South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Dunbar, Nelia; Iverson, Nels; Kurbatov, Andrei V.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: Tephrochronology of a South Pole Ice Core", "uid": "p0010311", "west": 0.0}, {"awards": "2032463 Talghader, Joseph; 2032473 Kurbatov, Andrei", "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": "Visual, thermal, chemical, and stable isotope effects of near-infrared laser cutting on freezer ice", "datasets": [{"dataset_uid": "601753", "doi": "10.15784/601753", "keywords": "Antarctica; Sampling", "people": "Talghader, Joseph; Kurbatov, Andrei V.; Mah, Merlin", "repository": "USAP-DC", "science_program": null, "title": "Visual, thermal, chemical, and stable isotope effects of near-infrared laser cutting on freezer ice", "url": "https://www.usap-dc.org/view/dataset/601753"}], "date_created": "Wed, 30 Jun 2021 00:00:00 GMT", "description": "This project will take initial development steps toward a laser-cut ice-sampling capability in glaciers and ice sheets. The collection of ice samples from the Polar Ice Sheets involves large amounts of time, effort, and expense. However, the most important science data are often retrieved from small sections of an ice core and, while replicate coring can supplement this section of ice core, there is often a need to retrieve additional ice samples based on subsequent scientific findings or borehole logging at a research site. In addition, there are currently no easy methods of extracting ice samples from a borehole drilled by non-coring mechanical drills that are faster, lighter, and less expensive to operate. There are numerous science applications that could potentially benefit from laser-cut ice samples, including sampling ice overlying buried impact craters and bolides, filling critical gaps in chemical records retrieved from damaged ice cores, and obtaining ice samples from sites where coring drills apply stresses that may fracture the ice. This award will explore a laser cutting technology to rapidly extract high-quality ice samples from a borehole wall. The project will investigate and validate the existing technology of laser ice sampling and will use a fiberoptic cable to deliver light pulses to a borehole instrument rather than attempting to assemble a complete laser system in an instrument deployed in a borehole. This offers a new way of retrieving ice samples from a polar ice sheet without the need to drill a borehole to collect ice-core samples (i.e., the hole could be mechanically drilled). This technology could also be used in existing boreholes or those that are made by augering through ice (i.e., not coring) or made with hot water. If successful, this technique would create the ability to rapidly retrieve ice samples with a small logistical footprint and enable science that might not be supportable otherwise. The proposed technology could eventually provide better access to ice-core samples to study past atmospheric composition for understanding past climate and inform on future potential for ice-sheet change. This 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": "Amd/Us; Laser Cutting; Ice Core; USA/NSF; AMD; SULFATE; FIELD SURVEYS; 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": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "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": "Code for calculating mean gradient for EDC sulfate data; EPICA Dome C Sulfate Data 7-3190m; Forward Diffusion Model used to calculate widening of volcanic layer widths; Volcanic Widths in Dome C Interglacials and Glacials", "datasets": [{"dataset_uid": "601855", "doi": "10.15784/601855", "keywords": "Antarctica; Cryosphere", "people": "Fudge, T. J.", "repository": "USAP-DC", "science_program": null, "title": "Volcanic Widths in Dome C Interglacials and Glacials", "url": "https://www.usap-dc.org/view/dataset/601855"}, {"dataset_uid": "601759", "doi": "10.15784/601759", "keywords": "Antarctica", "people": "Fudge, T. J.; Severi, Mirko", "repository": "USAP-DC", "science_program": "COLDEX", "title": "EPICA Dome C Sulfate Data 7-3190m", "url": "https://www.usap-dc.org/view/dataset/601759"}, {"dataset_uid": "601857", "doi": "10.15784/601857", "keywords": "Antarctica; Cryosphere", "people": "Fudge, T. J.", "repository": "USAP-DC", "science_program": null, "title": "Forward Diffusion Model used to calculate widening of volcanic layer widths", "url": "https://www.usap-dc.org/view/dataset/601857"}, {"dataset_uid": "601856", "doi": "10.15784/601856", "keywords": "Antarctica; Cryosphere", "people": "Fudge, T. J.", "repository": "USAP-DC", "science_program": null, "title": "Code for calculating mean gradient for EDC sulfate data", "url": "https://www.usap-dc.org/view/dataset/601856"}], "date_created": "Mon, 28 Jun 2021 00:00:00 GMT", "description": "The ice of the polar ice sheets is among the purest substances on Earth, yet the small amount of impurities --such as acids-- are important to how the ice flows and what can be learned from ice cores about past climate. The goal of this project is to understand the role of such acids on the deformation of polycrystalline ice by comparing the deformation behavior of pure and sulfuric acid-doped samples. Sulfuric acid was chosen both because of its importance for interpreting past climate and because it can lead to water veins in ice at low temperatures. This work will focus on the location, movement, and impact of acids in polycrystalline ice that are more complex than in single crystals of ice. By deforming samples and performing microstructural characterization, the role of acids on deformation rate, grain evolution, and the movement of the acids themselves, will be assessed. The work will lead to the education of a Ph.D. student at Dartmouth College, introduce undergraduate students to research at both the University of Washington and Dartmouth College. Despite the ubiquitous use of the constitutive relation for ice commonly referred to as \"Glen\u0027s Flow Law\", significant uncertainty exists particularly with regard to the role of impurities and the development of oriented fabrics. The aim of this project is to improve the constitutive relationship for ice by performing deformation tests and microstructural characterization of pure and sulfuric acid-doped ice. The project will focus on sulfuric acid\u0027s impact on ice viscosity, fabric evolution, and diffusivity. Sulfuric acid can have both direct and indirect effects on the mechanical properties of polycrystalline ice. The direct effects change the dislocation velocity and/or density, and the indirect effects change the grain size and fabric. The complexity and interaction of these effects means that it is not possible to understand the effects of sulfuric acid by simply examining ice core specimens. In this project, the team will deform four types of ice: lab-grown ice samples doped with similar-to-natural concentrations of sulfuric acid, lab-grown high-purity ice, layered doped and pure ice, and natural ice from Antarctic ice cores. Deformation will be performed in both uniaxial compression and simple shear. The addition of simple shear tests is critical for relating the laboratory-observed deformation behavior to the behavior of polar ice sheets where the shear strain dominates ice motion in basal ice. After deformation to strains from 5 percent up to 25 percent, the microstructural development will be assessed with methods including a variety of scanning electron microscope techniques, Raman microscopy, synchrotron-based Nano-X-ray fluorescence, and ion chromatography. These analysis techniques will allow the determination of 1) the segregation and movement of impurities, 2) the rate of grain-boundary migration, 3) the number of recrystallized grains; and 4) the full orientation of the ice crystals. The results will enable both microstructural modeling of the effects of sulfuric acid and numerical modeling of diffusion in ice cores. The net result will be a better understanding of ice deformation that improves ice-core interpretation and ice-sheet modeling. This 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": "AMD; Polycrystalline Ice; LABORATORY; Epica Dome C; SNOW/ICE; USA/NSF; USAP-DC; Ice Core; Amd/Us", "locations": "Epica Dome C", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Science and Technology; Antarctic Glaciology", "paleo_time": null, "persons": "Baker, Ian; Fudge, T. J.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: The Impact of Impurities and Stress State on Polycrystalline Ice Deformation", "uid": "p0010211", "west": null}, {"awards": "1341736 Adams, Byron", "bounds_geometry": "POLYGON((-177.4099 -84.4661,-177.08229 -84.4661,-176.75468 -84.4661,-176.42707 -84.4661,-176.09946 -84.4661,-175.77185 -84.4661,-175.44424 -84.4661,-175.11663000000001 -84.4661,-174.78902 -84.4661,-174.46141 -84.4661,-174.1338 -84.4661,-174.1338 -84.56828,-174.1338 -84.67045999999999,-174.1338 -84.77264,-174.1338 -84.87482,-174.1338 -84.977,-174.1338 -85.07918,-174.1338 -85.18136,-174.1338 -85.28354,-174.1338 -85.38571999999999,-174.1338 -85.4879,-174.46141 -85.4879,-174.78902 -85.4879,-175.11663000000001 -85.4879,-175.44424 -85.4879,-175.77185 -85.4879,-176.09946 -85.4879,-176.42707 -85.4879,-176.75468 -85.4879,-177.08229 -85.4879,-177.4099 -85.4879,-177.4099 -85.38571999999999,-177.4099 -85.28354,-177.4099 -85.18136,-177.4099 -85.07918,-177.4099 -84.977,-177.4099 -84.87482,-177.4099 -84.77264,-177.4099 -84.67045999999999,-177.4099 -84.56828,-177.4099 -84.4661))", "dataset_titles": "Dataset DS-TAMS: Genetic diversity of Collembola from the Transantarctic Mountains; GenBank accession numbers MN619477 to MN619610; Meteoric 10Be data of soils from the Shackleton Glacier region; Shackleton Glacier region soil water-soluble geochemical data; Shackleton Glacier region water-soluble salt isotopes; Soil invertebrate surveys from the Shackleton Glacier region of Antarctica during the 2017-2018 austral summer", "datasets": [{"dataset_uid": "601419", "doi": "10.15784/601419", "keywords": "Antarctica; Geochemistry; Nitrate; Shackleton Glacier; Stable Isotopes; Sulfate; Transantarctic Mountains", "people": "Gardner, Christopher B.; Lyons, W. Berry; Diaz, Melisa A.", "repository": "USAP-DC", "science_program": null, "title": "Shackleton Glacier region water-soluble salt isotopes", "url": "https://www.usap-dc.org/view/dataset/601419"}, {"dataset_uid": "200174", "doi": "10.5883/DS-TAMS", "keywords": null, "people": null, "repository": "Barcode of Life Datasystems (BOLD)", "science_program": null, "title": "Dataset DS-TAMS: Genetic diversity of Collembola from the Transantarctic Mountains", "url": "http://dx.doi.org/10.5883/DS-TAMS"}, {"dataset_uid": "200175", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "GenBank accession numbers MN619477 to MN619610", "url": "https://www.ncbi.nlm.nih.gov/nuccore/MN619477"}, {"dataset_uid": "200258", "doi": "doi:10.6073/pasta/7959821e5f6f8d56d94bb6a26873b3ae", "keywords": null, "people": null, "repository": "EDI", "science_program": null, "title": "Soil invertebrate surveys from the Shackleton Glacier region of Antarctica during the 2017-2018 austral summer", "url": "https://doi.org/10.6073/pasta/7959821e5f6f8d56d94bb6a26873b3ae"}, {"dataset_uid": "601418", "doi": "10.15784/601418", "keywords": "Antarctica; Geochemistry; Shackleton Glacier", "people": "Diaz, Melisa A.; Lyons, W. Berry; Gardner, Christopher B.", "repository": "USAP-DC", "science_program": null, "title": "Shackleton Glacier region soil water-soluble geochemical data", "url": "https://www.usap-dc.org/view/dataset/601418"}, {"dataset_uid": "601421", "doi": "10.15784/601421", "keywords": "Antarctica; Be-10; Beryllium-10; Cosmogenic Radionuclides; Geochemistry; Geomorphology; Shackleton Glacier; Surface Exposure Dates", "people": "Diaz, Melisa A.", "repository": "USAP-DC", "science_program": null, "title": "Meteoric 10Be data of soils from the Shackleton Glacier region", "url": "https://www.usap-dc.org/view/dataset/601421"}], "date_created": "Mon, 02 Nov 2020 00:00:00 GMT", "description": "The project will characterize the functional, taxonomic, biotic and abiotic drivers of soil ecosystems in the Trans Antarctic Mountains (one of the most remote and harsh terrestrial landscapes on the planet). The work will utilize new high-throughput DNA and RNA sequencing technologies to identify members of the microbial communities and determine if the microbial community structures are independent of local environmental heterogeneities. In addition the project will determine if microbial diversity and function are correlated with time since the last glacial maximum (LGM). The expected results will greatly contribute to our knowledge regarding rates of microbial succession and help define the some of the limits to life and life-maintaining processes on Earth. The project will analyze genomes and RNA derived from these genomes to describe the relationships between biodiversity and ecosystem functioning from soils above and below LGM elevations and to correlate these with the environmental drivers associated with their development during the last ~18,000 years. The team will identify the taxonomic diversity and the functional genetic composition within a broad suite of soil biota and examine their patterns of assembly and distribution within the framework of their geological legacies. The project will mentor participants from undergraduate students to postdoctoral researchers and prepare them to effectively engage in research to meet their career aspirations. The project will contribute to ongoing public education efforts through relationships with K-12 teachers and administrators- to include University-Public School partnerships. Less formal activities include public lecture series and weblogs aimed at providing information on Antarctic polar desert ecosystems to the general public. Targeted classrooms near each PI\u0027s institution will participate in online, real-time discussions about current topics in Antarctic ecosystems research.", "east": -174.1338, "geometry": "POINT(-175.77185 -84.977)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; LABORATORY; AMD; Amd/Us; USA/NSF; TERRESTRIAL ECOSYSTEMS; Transantarctic Mountains; USAP-DC", "locations": "Transantarctic Mountains", "north": -84.4661, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Adams, Byron; Fierer, Noah; Wall, Diana; Diaz, Melisa A.; Gardner, Christopher B.; Lyons, W. Berry", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "Barcode of Life Datasystems (BOLD); EDI; NCBI GenBank; USAP-DC", "science_programs": null, "south": -85.4879, "title": "Collaborative Research: The Role of Glacial History on the Structure and Functioning of Ecological Communities in the Shackleton Glacier Region of the Transantarctic Mountains", "uid": "p0010140", "west": -177.4099}, {"awards": "1643864 Talghader, Joseph", "bounds_geometry": "POINT(-112.085 -79.467)", "dataset_titles": " Automated c-axis stage images of WDC-06A 420 vertical thin section from WAIS Divide, Antarctica", "datasets": [{"dataset_uid": "601254", "doi": "10.15784/601254", "keywords": "Antarctica; C-axis; Ice; Microscopy; Thin Sections", "people": "Talghader, Joseph; Mah, Merlin", "repository": "USAP-DC", "science_program": null, "title": " Automated c-axis stage images of WDC-06A 420 vertical thin section from WAIS Divide, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601254"}], "date_created": "Sat, 08 Feb 2020 00:00:00 GMT", "description": "Part I: Nontechnical One of the most interesting historical records that science can provide is contained in the ice of Antarctica. Layer by layer over hundreds of thousands of years, snow has precipitated on the ice sheet, become compacted, and turned into additional ice. Any dust or other impurities in the air or snow have been precipitated as well and thus each snowfall leaves a snapshot record of the atmosphere that existed at or near the time of deposition. A detailed chronology of volcanic eruptions can be obtained from the ice layers where ash and other volcanic products were deposited. Normally, the analysis of volcanic layers requires the physical extraction of a core from the ice sheet; however, chronologies from cores have discontinuities and are difficult, time-consuming, and expensive to obtain. Borehole logging is a measurement method where one lowers instrumentation into a drilled hole in the ice, whether or not core has been retrieved. To date, this technology has only been used to measure optical systems to identify volcanic ash and other impurity layers. In this program, a profiling technology will be developed that measures the conductivity of the ice. A radio-frequency emitter lowered into the borehole will create a return signal that changes depending on the local conductivity, which depends on the concentration of dissolved ions. For example, dissolved sulfates are a critical marker of volcanic activity that may not be coincident with deposited ash. Other dissolved ions, such as chloride, can be indicative of other processes. It is expected that this borehole profiling instrument will be able to help rapidly identify volcanic eruptions that had potentially global impact, distinguish between different dissolved ions via their frequency dependencies, and assist in establishing chronologies between different ice cores and boreholes. Part II: Technical Description Borehole logging of the polar ice sheets is one of the most important methods that earth scientists have to identify and date volcanic eruptions. However, current technology only indicates the presence and depth of ash from an eruption. In order to extract more detailed information, one must obtain an ice core, and laboriously measure each section in the laboratory using electrical conductivity or dielectric measurements to determine the presence or absence of dissolved sulfate and its location relative to the corresponding ash, if any. This program will investigate and demonstrate a borehole logging-compatible radio-frequency dielectric sensor to detect and measure spikes in dissolved major ions chemistry in ice, particularly in intervals corresponding to volcanically produced sulfates. The sulfate layers are one of the primary signatures of volcanic products. However, other ions, such as chlorides, calcium, and others are also commonly seen in ice, and the dielectric logging technology of this program would also measure these. It is expected that certain sets of ions will be distinguishable by their frequency dependencies. This technique could guide other investigators, who are using conventional core scanning and sampling methods, to regions of special interest in corresponding core. We plan to construct a ring-based electrode system and test this system on a variety of artificial ice boreholes and ice cores. This unit will not include a pressure vessel or other borehole logger packing. We will test different means of applying electrical signals including short pulses and periodic waves. We will further utilize differential measurements with low noise circuits and filters to achieve maximum sensitivity. We will correlate the signals extracted with known molarities of sulfates and other ions and measured ECM records. We will perform scaled-down experiments using real ice cores stored in Bay?s lab at UC Berkeley. This will permit testing of different designs in ice with natural impurities and polycrystalline structure. This small collection includes cores from a variety of locations in Antarctica and Greenland, and a variety of ages as old as a million years.", "east": -112.085, "geometry": "POINT(-112.085 -79.467)", "instruments": null, "is_usap_dc": true, "keywords": "WAIS Divide; USAP-DC; Amd/Us; GLACIERS/ICE SHEETS; USA/NSF; FIELD INVESTIGATION; Ice Core; AMD", "locations": "WAIS Divide", "north": -79.467, "nsf_funding_programs": "Antarctic Instrumentation and Support; Antarctic Instrumentation and Facilities", "paleo_time": null, "persons": "Talghader, Joseph", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.467, "title": "Collaborative Research: Borehole Logging to Classify Volcanic Signatures in Antarctic Ice", "uid": "p0010080", "west": -112.085}, {"awards": "1443397 Kreutz, Karl; 1443663 Cole-Dai, Jihong; 1443336 Osterberg, Erich", "bounds_geometry": "POINT(-180 -90)", "dataset_titles": "Preliminary SPC14 high-resolution Fe and Mn biologically relevant and dissolved trace metal concentrations spanning -42 \u2013 54,300 years BP.; South Pole Ice Core Holocene Major Ion Dataset; South Pole Ice Core Sea Salt and Major Ions; South Pole ice core (SPC14) discrete methane data; South Pole (SPC14) microparticle concentration, mass concentration, flux, particle-size-distribution mode, and aspect ratio measurements; SPICEcore 400-480 m Major Ions SDSU; The South Pole Ice Core (SPICEcore) chronology and supporting data", "datasets": [{"dataset_uid": "601206", "doi": "10.15784/601206", "keywords": "Antarctica; Calcium (ca); Chemistry:ice; Chemistry:Ice; Depth; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciochemistry; Glaciology; Ice; Ice Core; Ice Core Chemistry; Ice Core Data; Ice Core Records; Ice Core Stratigraphy; Nitrate; Nitrogen Isotopes; Paleoclimate; Snow/ice; Snow/Ice; South Pole; SPICEcore", "people": "Brook, Edward J.; Severinghaus, Jeffrey P.; Osterberg, Erich; Waddington, Edwin D.; Iverson, Nels; Alley, Richard; Casey, Kimberly A.; Nicewonger, Melinda R.; Aydin, Murat; Ferris, David G.; Jones, Tyler R.; Kahle, Emma; Morris, Valerie; Steig, Eric J.; Sowers, Todd A.; Beaudette, Ross; Ortman, Nikolas; Epifanio, Jenna; Kreutz, Karl; Cox, Thomas S.; Thundercloud, Zayta; Cole-Dai, Jihong; Fegyveresi, John; McConnell, Joseph; Sigl, Michael; Souney, Joseph Jr.; Bay, Ryan; Buizert, Christo; Dunbar, Nelia; Fudge, T. J.; Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "The South Pole Ice Core (SPICEcore) chronology and supporting data", "url": "https://www.usap-dc.org/view/dataset/601206"}, {"dataset_uid": "601851", "doi": "10.15784/601851", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Sea Salt and Major Ions", "url": "https://www.usap-dc.org/view/dataset/601851"}, {"dataset_uid": "601675", "doi": "10.15784/601675", "keywords": "Antarctica; South Pole; SPICEcore", "people": "Kreutz, Karl", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Preliminary SPC14 high-resolution Fe and Mn biologically relevant and dissolved trace metal concentrations spanning -42 \u2013 54,300 years BP.", "url": "https://www.usap-dc.org/view/dataset/601675"}, {"dataset_uid": "601430", "doi": "10.15784/601430", "keywords": "Antarctica; Ions; South Pole; SPICEcore", "people": "Cole-Dai, Jihong; Larrick, Carleigh", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SPICEcore 400-480 m Major Ions SDSU", "url": "https://www.usap-dc.org/view/dataset/601430"}, {"dataset_uid": "601553", "doi": "10.15784/601553", "keywords": "Antarctica; Dust; Ice Core; South Pole", "people": "Kreutz, Karl", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole (SPC14) microparticle concentration, mass concentration, flux, particle-size-distribution mode, and aspect ratio measurements", "url": "https://www.usap-dc.org/view/dataset/601553"}, {"dataset_uid": "601381", "doi": "10.15784/601381", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Methane; South Pole; SPICEcore", "people": "Aydin, Murat; Severinghaus, Jeffrey P.; Kennedy, Joshua A.; Ferris, David G.; Kalk, Michael; Hood, Ekaterina; Fudge, T. J.; Osterberg, Erich; Winski, Dominic A.; Steig, Eric J.; Kahle, Emma; Sowers, Todd A.; Edwards, Jon S.; Kreutz, Karl; Buizert, Christo; Brook, Edward J.; Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core (SPC14) discrete methane data", "url": "https://www.usap-dc.org/view/dataset/601381"}, {"dataset_uid": "601850", "doi": "10.15784/601850", "keywords": "Antarctica; Cryosphere; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Holocene Major Ion Dataset", "url": "https://www.usap-dc.org/view/dataset/601850"}], "date_created": "Thu, 29 Aug 2019 00:00:00 GMT", "description": "This collaborative project explores the signatures and causes of natural climate change in the region surrounding Antarctica over the last 40,000 years as the Earth transitioned from an ice age into the modern warm period. The researchers will investigate how the wind belts that surround Antarctica changed in their strength and position through time, and document explosive volcanic eruptions and CO2 cycling in the Southern Ocean as potential climate forcing mechanisms over this interval. Understanding how and why the climate varied naturally in the past is critical for improving understanding of modern climate change and projections of future climate under higher levels of atmospheric CO2. The investigators plan to conduct a suite of chemical measurements along the 1500m length of the South Pole Ice Core, including major ion and trace element concentrations, and microparticle (dust) concentrations and size distributions. These measurements will (1) extend the South Pole record of explosive volcanic eruptions to 40,000 years using sulfate and particle data; (2) establish the relative timing of climate changes in dust source regions of Patagonia, New Zealand, and Australia using dust flux data; (3) investigate changes in the strength and position of the westerly wind belt using dust size distribution data; and (4) quantify the flux of bioavailable trace metals deposited as dust to the Southern Ocean over time. These chemistry records will also be critical for creating the timescale that will be used by all researchers studying records from the South Pole core. The project will support four graduate students and several undergraduate students across three different institutions, and become a focus of the investigators\u0027 efforts to disseminate outcomes of climate change science to the broader community.", "east": -180.0, "geometry": "POINT(-180 -90)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; ICE CORE RECORDS; USAP-DC; Amd/Us; USA/NSF; LABORATORY; AMD", "locations": "Antarctica", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Osterberg, Erich", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements", "uid": "p0010051", "west": -180.0}, {"awards": "0538049 Steig, Eric; 0538520 Thiemens, Mark", "bounds_geometry": "POINT(-112.085 -79.5)", "dataset_titles": "Multiple Isotope Analysis of Sulfate in the West Antarctic Ice Sheet Divide Ice Core; WAIS Divide sulfate and nitrate isotopes; WAIS ice core isotope data #387, 385 (full data link not provided)", "datasets": [{"dataset_uid": "609479", "doi": "10.7265/N5BG2KXH", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Thiemens, Mark H.", "repository": "USAP-DC", "science_program": null, "title": "Multiple Isotope Analysis of Sulfate in the West Antarctic Ice Sheet Divide Ice Core", "url": "https://www.usap-dc.org/view/dataset/609479"}, {"dataset_uid": "601007", "doi": "10.15784/601007", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Nitrate; Oxygen Isotope; Sulfate; WAIS Divide; WAIS Divide Ice Core", "people": "Steig, Eric J.; Alexander, Becky", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide sulfate and nitrate isotopes", "url": "https://www.usap-dc.org/view/dataset/601007"}, {"dataset_uid": "002512", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "WAIS ice core isotope data #387, 385 (full data link not provided)", "url": "http://www.waisdivide.unh.edu/"}], "date_created": "Tue, 25 Apr 2017 00:00:00 GMT", "description": "0538520\u003cbr/\u003eThiemens\u003cbr/\u003eThis award supports a project to develop the first complete record of multiple isotope ratios of nitrate and sulfate covering the last ~100,000 years, from the deep ice core planned for the central ice divide of the West Antarctic Ice Sheet (WAIS). The WAIS Divide ice core will be the highest resolution long ice core obtained from Antarctica and we can expect important complementary information to be available, including accurate knowledge of past accumulation rates, temperatures, and compounds such as H2O2, CO and CH4. These compounds play significant roles in global atmospheric chemistry and climate. Especially great potential lies in the use of multiple isotope signatures. The unique mass independent fractionation (MIF) 17O signature of ozone is observed in both nitrate and sulfate, due to the interaction of their precursors with ozone. The development of methods to measure the multiple-isotope composition of small samples of sulfate and nitrate makes continuous high resolution measurements on ice cores feasible for the first time. Recent work has shown that such measurements can be used to determine the hydroxyl radial (OH) and ozone (O3) concentrations in the paleoatmosphere as well as to apportion sulfate and nitrate sources. There is also considerable potential in using these isotope measurements to quantify post depositional changes. In the first two years, continuous measurements from the upper ~100-m of ice at WAIS divide will be obtained, to provide a detailed look at seasonal through centennial scale variability. In the third year, measurements will be made throughout the available depth of the deep core (expected to reach ~500 m at this time). The broader impacts of the project include applications to diverse fields including atmospheric chemistry, glaciology, meteorology, and paleoclimatology. Because nitrate and sulfate are important atmospheric pollutants, the results will also have direct and relevance to global environmental policy. This project will coincide with the International Polar Year (2007-2008), and contributes to goals of the IPY, which include the fostering of interdisciplinary research toward enhanced understanding of atmospheric chemistry and climate in the polar regions.", "east": -112.085, "geometry": "POINT(-112.085 -79.5)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Isotope Ratios; Temperature; Sulfate; West Antarctic; Paleoatmosphere; LABORATORY; Ice Core; Ice Core Data; Mass Independent Fractionation; FIELD SURVEYS; Not provided; Accumulation Rate; Oxygen Isotope; FIELD INVESTIGATION; Ice Core Chemistry; Isotope", "locations": "West Antarctic", "north": -79.5, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Alexander, Becky; Steig, Eric J.; Thiemens, Mark H.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "Project website; USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.5, "title": "Collaborative Research: Multiple-isotope Analysis of Nitrate and Sulfate in the West Antarctic Ice Sheet Divide Ice Core", "uid": "p0000020", "west": -112.085}, {"awards": "1043780 Aydin, Murat", "bounds_geometry": null, "dataset_titles": "Ice Core Air Carbonyl Sulfide Measurements - Taylor Dome M3C1 Ice Core; Ultra-trace Measurements in the WAIS Divide 06A Ice Core", "datasets": [{"dataset_uid": "609659", "doi": "10.7265/N5CV4FPK", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Aydin, Murat; Saltzman, Eric", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Ultra-trace Measurements in the WAIS Divide 06A Ice Core", "url": "https://www.usap-dc.org/view/dataset/609659"}, {"dataset_uid": "601361", "doi": "10.15784/601361", "keywords": "Antarctica; Carbonyl Sulfide; Trace Gases", "people": "Saltzman, Eric; Aydin, Murat", "repository": "USAP-DC", "science_program": null, "title": "Ice Core Air Carbonyl Sulfide Measurements - Taylor Dome M3C1 Ice Core", "url": "https://www.usap-dc.org/view/dataset/601361"}], "date_created": "Tue, 27 Oct 2015 00:00:00 GMT", "description": "Aydin/1043780 This award supports the analysis of the trace gas carbonyl sulfide (COS) in a deep ice core from West Antarctic Ice Sheet Divide (WAIS-D), Antarctica. COS is the most abundant sulfur gas in the troposphere and a precursor of stratospheric sulfate. It has a large terrestrial COS sink that is tightly coupled to the photosynthetic uptake of atmospheric carbon dioxide (CO2). The primary goal of this project is to develop high a resolution Holocene record of COS from the WAIS-D 06A ice core. The main objectives are 1) to assess the natural variability of COS and the extent to which its atmospheric variability was influenced by climate variability, and 2) to examine the relationship between changes in atmospheric COS and CO2. This project also includes low-resolution sampling and analysis of COS from 10,000-30,000 yrs BP, covering the transition from the Last Glacial Maximum into the early Holocene. The goal of this work is to assess the stability of COS in ice core air over long time scales and to establish the COS levels during the last glacial maximum and the magnitude of the change between glacial and interglacial conditions. The results of this work will be disseminated via peer-review publications and will contribute to environmental assessments such as the WMO Stratospheric Ozone Assessment and IPCC Climate Assessment. This project will support a PhD student and undergraduate researcher in the Department of Earth System Science at the University of California, Irvine, and will create summer research opportunities for undergraduates from non-research active Universities.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Ethane; LABORATORY; N-Butane; Carbonyl Sulfide; Propane; Methyl Bromide; Methyl Chloride; Carbon Disulfide", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Aydin, Murat; Saltzman, Eric", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Carbonyl Sulfide Measurements in the Deep West Antarctic Ice Sheet Divide Ice Core", "uid": "p0000055", "west": null}, {"awards": "1043421 Severinghaus, Jeffrey; 1043522 Brook, Edward J.", "bounds_geometry": "POINT(-112.09 -79.47)", "dataset_titles": "WAIS Divide Replicate Core Methane Isotopic Data Set", "datasets": [{"dataset_uid": "601059", "doi": "10.15784/601059", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Brook, Edward J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Replicate Core Methane Isotopic Data Set", "url": "https://www.usap-dc.org/view/dataset/601059"}], "date_created": "Mon, 13 Jul 2015 00:00:00 GMT", "description": "1043421/Severinghaus This award supports a project to obtain samples of ice in selected intervals for replication and verification of the validity and spatial representativeness of key results in the WAIS Divide ice core, and to obtain additional ice samples in areas of intense scientific interest where demand is high. The US Ice Core Working Group recommended in 2003 that NSF pursue the means to take replicate samples, termed \"replicate coring\". This recommendation was part of an agreement to reduce the diameter of the (then) new drilling system (the DISC drill) core to 12.2 cm to lighten logistics burdens, and the science community accepted the reduction in ice sample with the understanding that replicate coring would be able to provide extra sample volume in key intervals. The WAIS Divide effort would particularly benefit from replicate coring, because of the unique quality of the expected gas record and the large samples needed for gases and gas isotopes; thus this proposal to employ replicate coring at WAIS Divide. In addition, scientific demand for ice samples has been, and will continue to be, very unevenly distributed, with the ice core archive being completely depleted in depth intervals of high scientific interest (abrupt climate changes, volcanic sulfate horizons, meteor impact horizons, for example). The broader impacts of the proposed research may include identification of leads and lags between Greenland, tropical, and Antarctic climate change, enabling critical tests of hypotheses for the mechanism of abrupt climate change. Improved understanding of volcanic impacts on atmospheric chemistry and climate may also emerge. This understanding may ultimately help improve climate models and prediction of the Earth System feedback response to ongoing human perturbation in coming centuries. Outreach and public education about climate change are integral components of the PIs\u0027 activities and the proposed work will enhance these efforts. Broader impacts also include education and training of 2 postdoctoral scholars and 1 graduate student, and invaluable field experience for the graduate and undergraduate students who will likely make up the core processing team at WAIS Divide.", "east": -112.09, "geometry": "POINT(-112.09 -79.47)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": false, "keywords": "Ice Core Gas Records; Firn Air Isotopes; LABORATORY; FIELD SURVEYS; Mass Spectrometry; Not provided; FIELD INVESTIGATION; Ice Core; WAIS Divide", "locations": "WAIS Divide", "north": -79.47, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Severinghaus, Jeffrey P.; Brook, Edward J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.47, "title": "Collaborative Research: Replicate Coring at WAIS Divide to Obtain Additional Samples at Events of High Scientific Interest", "uid": "p0000751", "west": -112.09}, {"awards": "0538553 Cole-Dai, Jihong", "bounds_geometry": "POINT(-112.085 -79.467)", "dataset_titles": "Major Ion Concentrations in WDC05Q and WDC06A Ice Cores (WAIS Divide)", "datasets": [{"dataset_uid": "609544", "doi": "10.7265/N54M92H3", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ion Chromatograph; WAIS Divide; WAIS Divide Ice Core", "people": "Cole-Dai, Jihong", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Major Ion Concentrations in WDC05Q and WDC06A Ice Cores (WAIS Divide)", "url": "https://www.usap-dc.org/view/dataset/609544"}], "date_created": "Wed, 25 Aug 2010 00:00:00 GMT", "description": "Cole-Dai\u003cbr/\u003e0538553\u003cbr/\u003e\u003cbr/\u003eThis award supports a project that will contribute to the US West Antarctica Ice Sheet Ice Divide ice core (WAIS Divide) project by developing new instrumentation and analytical procedures to measure concentrations of major ions (Cl-, NO3-, SO42-, Na+, K+, NH4+, Mg2+, Ca2+). A melter-based, continuous flow, multi-ion-chromatograph technique (CFA-IC) has been developed recently at South Dakota State University (SDSU). This project will further expand and improve the CFA-IC technique and instrumentation and develop procedures for routine analysis of major ions in ice cores. In addition, training of personnel (operators) to perform continuous, high resolution major ion analysis of the deep core will be accomplished through this project. The temporal resolution of the major ion measurement will be as low as 0.5 cm with the fully developed CFA-IC technique. At this resolution, it will be possible to use annual cycles of sulfate and sea-salt ion concentrations to determine annual layers in the WAIS Divide ice core. Annual layer counting using CFA-IC chemical measurements and other high resolution measurements will contribute significantly to the major WAIS Divide project objective of producing precisely (i.e., annually) dated climate records. The project will support the integration of research and education, train future scientists and promote human resource development through the participation of graduate and undergraduate students. In particular, undergraduate participation will contribute to a current REU (Research Experience for Undergraduates) chemistry site program at SDSU. Development and utilization of multi-user instrumentation will promote research collaboration and advance environmental science. NSF support for SDSU will contribute to the economic development and strengthen the infrastructure for research and education in South Dakota.", "east": -112.085, "geometry": "POINT(-112.085 -79.467)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "LABORATORY; WAIS Divide; Ice Core; West Antarctic Ice Sheet; Ion Chromatograph; GROUND-BASED OBSERVATIONS; Not provided; Major Ion; Ions", "locations": "WAIS Divide; West Antarctic Ice Sheet", "north": -79.467, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Cole-Dai, Jihong", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.467, "title": "Major Ion Chemistry of WAIS Divide Ice Core", "uid": "p0000035", "west": -112.085}, {"awards": "0440609 Price, P. Buford", "bounds_geometry": "POINT(-112.06556 -79.469444)", "dataset_titles": null, "datasets": null, "date_created": "Tue, 03 Jun 2008 00:00:00 GMT", "description": "This award supports a project to use three downhole instruments - an optical logger; a\u003cbr/\u003eminiaturized biospectral logger at 420 nm (miniBSL-420); and an Acoustic TeleViewer (ATV) - to log a 350-m borehole at the WAIS Divide drill site. In addition, miniBSL-224 (at 224 nm) and miniBSL-420 will scan ice core sections at NICL to look for abrupt climate changes, volcanic ash, microbial concentrations, and correlations among them. Using the optical logger and ATV to log bubble number densities vs depth in a WAIS Divide borehole, we will detect annual layers, from which we can establish the age vs depth relation to the bottom of the borehole that will be available during the three-year grant period. With the same instruments we will search for long-period modulation of bubble and dust concentrations in order to provide definitive evidence for or against an effect of long-period variability of the sun or solar wind on climate. We will detect and accurately date ash layers in a WAIS Divide borehole. We will match them with ash layers that we previously detected in the Siple Dome borehole, and also match them with sulfate and ash layers found by others at Vostok, Dome Fuji, Dome C, and GISP2. The expected new data will allow us to extend our recent study which showed that the Antarctic record of volcanism correlates with abrupt climate change at a 95% to \u003e99.8% significance level and that the volcanic signatures at bipolar locations match at better than 3 sigma during the interval 2 to 45 kiloyears. The results to be obtained during this grant period will position us to extend an accurate age vs depth relation and volcano-climate correlations to earlier than 150 kiloyears ago in the future WAIS Divide borehole to be drilled to bedrock. Using the miniBSLs to identify biomolecules via their fluorescence, we will log a 350-m borehole at WAIS Divide, and we will scan selected lengths of ice core at NICL. Among the biomolecules the miniBSLs can identify will be chlorophyll, which will provide the first map of aerobic microbes in ice, and F420, which will provide the first map of methanogens in ice. We will collaborate with others in relating results from WAIS Divide and NICL ice cores to broader topics in climatology, volcanology, and microbial ecology. We will continue to give broad training to undergraduate and graduate students, to attract underrepresented minorities to science, engineering, and math, and to educate the press and college teachers. A deeper understanding of the causes of abrupt climate change, including a causal relationship with strong volcanic eruptions, can enable us to understand and mitigate adverse effects on climate.", "east": -112.06556, "geometry": "POINT(-112.06556 -79.469444)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUORESCENCE SPECTROSCOPY; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e OPTICAL DUST LOGGERS", "is_usap_dc": false, "keywords": "Volcanic Ash; Dust Concentration; Antarctica; FIELD INVESTIGATION; Liquid Veins In Ice; Optical Logger; Borehole; Ash Layer; FIELD SURVEYS; Microbial Metabolism; Climate; Biospectral Logger; Not provided; Protein Fluorescence; Gas Artifacts; Aerosol Fluorescence; Volcanism; WAIS Divide; Ice Core", "locations": "WAIS Divide; Antarctica", "north": -79.469444, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bay, Ryan; Price, Buford", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided", "repositories": null, "science_programs": null, "south": -79.469444, "title": "Climatology, Volcanism, and Microbial Life in Ice with Downhole Loggers", "uid": "p0000746", "west": -112.06556}, {"awards": "0229490 Conway, Howard", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 30 Apr 2007 00:00:00 GMT", "description": "This award supports a project to improve understanding of post-glacial retreat and thinning of the Siple Coast region. Research has shown how age-depth relationships from ice cores can be extrapolated over wide areas by tracking continuous radar layers. By comparing radar-derived timescales with one from a model of ice- flow, glacial conditions over regional scales were inferred. High-resolution radar profiles have been collected across most of the inter-stream ridges in the Siple Coast region, and an age- depth relationship has been established from the Siple Dome ice core. Application of the techniques used by others is problematic because the ice streams that surround Siple Dome have disrupted the continuity of the internal layers. A specific goal of this project is to search for other less direct ways to match radar layers between unconnected profiles. The correspondence between radar reflections and measurements of electrical conductivity and volcanic sulfates along the Siple Dome core will be investigated. The strategy is to search for distinctive patterns in the echoes that will facilitate layer matching. Preliminary results are encouraging: at least four distinct echoes at Siple Dome can be matched to spikes in the conductivity profile and the signature of one (at 210m depth, which is ~1,800 yrs BP) closely resembles that of a layer at ~200m on Ridge BC. Matching layers (and hence timescales) across the ice streams will allow reconstruction of spatial patterns of past flow, thinning and accumulation rate in the Siple Coast region, which is needed to predict future possible changes of the West Antarctic Ice Sheet. Data necessary for the proposed work are already available; additional fieldwork in Antarctica is not required. The project will take two years to complete and will provide core education for a doctoral student in Earth and Space Sciences, with an emphasis on radioglaciology.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR", "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Conway, Howard; Sylvester, John; Winebrenner, Dale", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Investigation of the Glacial History of the Siple Coast Using Radar-Detected Internal Layers and the Ice Core from Siple Dome", "uid": "p0000723", "west": null}, {"awards": "0338363 Thiemens, Mark; 0337933 Cole-Dai, Jihong", "bounds_geometry": null, "dataset_titles": "Major Ion Concentrations in 2004 South Pole Ice Core", "datasets": [{"dataset_uid": "609542", "doi": "10.7265/N5HX19N8", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ion Chromatograph; South Pole", "people": "Cole-Dai, Jihong", "repository": "USAP-DC", "science_program": null, "title": "Major Ion Concentrations in 2004 South Pole Ice Core", "url": "https://www.usap-dc.org/view/dataset/609542"}], "date_created": "Fri, 11 Aug 2006 00:00:00 GMT", "description": "This award supports a collaborative study between South Dakota State University (SDSU) and University of California, San Diego (UCSD) to investigate the oxygen and sulfur isotope composition of sulfates from a number of large volcanic eruptions in the past 1000 years. The project aims to drill a number of shallow ice cores at South Pole and return them to SDSU and UCSD lab for chemical and isotope analysis. Preliminary results from measurements of isotopes in sulfate samples from several volcanic eruptions in Antarctic snow and ice indicate that isotopic composition of volcanic sulfate contains abundant valuable information on atmospheric chemical and dynamic processes that have not been previously investigated. One tentative conclusion is that mass-independently fractionated sulfur isotopes reveal that atmospheric photolysis of sulfur compounds occurs at longer UV wavelengths than those in the Archean atmosphere, possibly reflecting the atmospheric ozone and/or oxygen concentration. This suggests that isotopic composition of atmospheric sulfate may be used to understand the role of UV radiation in sulfur dioxide conversion in the atmosphere and to track the evolution (i.e., oxygenation) of the atmosphere and the origin of life on Earth. Other major research objectives include understanding what impact massive volcanic eruptions have on the oxidative capacity of the atmosphere, what oxidants and mechanisms are involved in the oxidation or conversion of volcanic sulfur dioxide to sulfate in the stratosphere and what isotopic criteria may be used to differentiate ice core signals of stratospheric eruptions from those of tropospheric eruptions. By providing educational and research opportunities to graduate and undergraduate students at both SDSU and UCSD, the proposed project will promote the integration of research and education and contribute to human resource development in science and engineering. The project will contribute to a proposed REU chemistry site program at SDSU. This collaboration will utilize the complementary strengths of both labs and promote exchange between the two institutions. International collaboration will enhance scientific cooperation between France and US.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Not provided; Ion Chromatograph; Ions; LABORATORY; GROUND-BASED OBSERVATIONS", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Cole-Dai, Jihong", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Investigating Atmospheric Chemistry and Dynamics through Oxygen and Sulfur Isotopes in Volcanic Sulfate from South Pole Ice Cores", "uid": "p0000031", "west": null}, {"awards": "9316564 Mayewski, Paul", "bounds_geometry": null, "dataset_titles": "Ross Ice Drainage System (RIDS) Glaciochemical Analysis; Siple Dome Ice Core Chemistry and Ion Data", "datasets": [{"dataset_uid": "609266", "doi": "10.7265/N5M906KG", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Snow/ice; Snow/Ice; Snow Pit", "people": "Kreutz, Karl; Mayewski, Paul A.; Twickler, Mark; Whitlow, Sallie; Meeker, Loren D.", "repository": "USAP-DC", "science_program": null, "title": "Ross Ice Drainage System (RIDS) Glaciochemical Analysis", "url": "https://www.usap-dc.org/view/dataset/609266"}, {"dataset_uid": "609251", "doi": "", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; Siple Dome; Siple Dome Ice Core", "people": "Severinghaus, Jeffrey P.; Dunbar, Nelia; Mayewski, Paul A.; Kreutz, Karl; Brook, Edward J.; Blunier, Thomas", "repository": "NCEI", "science_program": "Siple Dome Ice Core", "title": "Siple Dome Ice Core Chemistry and Ion Data", "url": "https://www.ncei.noaa.gov/access/paleo-search/study/2461"}], "date_created": "Thu, 26 Aug 2004 00:00:00 GMT", "description": "9316564 Mayewski This award is for support for a three year program to provide a high resolution record of the Antarctic climate through the acquisition, analysis, and interpretation of records of atmospheric chemical deposition taken from three ice cores located at sites within or immediately adjacent to the Ross Ice Drainage System (RIDS). These cores include one from Taylor Dome, and two from West Antarctic locations identified as potential deep drilling sites for the WAISCORES program. Collection of the two West Antarctic cores is intended to be a lightweight dry-drilling operation to depths of ~ 200 m, which will provide records of \u003e 2 kyr. Glaciochemical analyses will focus on the major cations and anions found in the antarctic atmosphere, plus methanesulfonic acid and selected measurements of the hydrogen ion, aluminum, iron, and silica. These analyses, and companion stable isotope and particle measurements to be carried out by other investigators require \u003c 7% by volume of each core, leaving \u003e 90% for other investigators and storage at the U.S. National Ice Core Laboratory. These records are intended to solve a variety of scientific objectives while also providing spatial sampling and reconnaissance for future U.S. efforts in West Antarctica. ***", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Magnesium; GROUND STATIONS; Nitrate; Methane Sulfonic Acid; Sodium; Ice Core Chemistry; Ammonium (NH4); Sulfate; Ice Core; Chloride; Potassium (k); Calcium (ca)", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Kreutz, Karl; Twickler, Mark; Whitlow, Sallie; Blunier, Thomas; Dunbar, Nelia; Brook, Edward J.; Mayewski, Paul A.; Meeker, Loren D.; Severinghaus, Jeffrey P.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS", "repo": "USAP-DC", "repositories": "NCEI; USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Ross Ice Drainage System (RIDS) Late Holocene Climate Variability", "uid": "p0000145", "west": null}, {"awards": "0126286 McConnell, Joseph", "bounds_geometry": "POLYGON((-180 -62.83,-144 -62.83,-108 -62.83,-72 -62.83,-36 -62.83,0 -62.83,36 -62.83,72 -62.83,108 -62.83,144 -62.83,180 -62.83,180 -65.547,180 -68.264,180 -70.981,180 -73.698,180 -76.415,180 -79.132,180 -81.849,180 -84.566,180 -87.283,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87.283,-180 -84.566,-180 -81.849,-180 -79.132,-180 -76.415,-180 -73.698,-180 -70.981,-180 -68.264,-180 -65.547,-180 -62.83))", "dataset_titles": "Siple Shallow Core Density Data", "datasets": [{"dataset_uid": "609129", "doi": "10.7265/N52F7KCD", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Physical Properties; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Lamorey, Gregg W.", "repository": "USAP-DC", "science_program": null, "title": "Siple Shallow Core Density Data", "url": "https://www.usap-dc.org/view/dataset/609129"}], "date_created": "Mon, 19 Apr 2004 00:00:00 GMT", "description": "This award provides one year of support to use newly developed technology in which an ice-core melter is coupled with both an Inductively Coupled Plasma - Mass Spectrometer (ICP-MS) and a traditional Continuous Flow Analysis (CFA) system, to measure a continuous time series of chemical and trace element deposition on the Siple Dome ice core from West Antarctica. A coupled ice-core melter, ICP-MS, and CFA system will be used to measure concentrations of a number of elements, isotopes and chemical species at very high depth resolution (~2-cm) in the top 54 m of the Siple Dome A-core. Pilot data from analyses of ~6 m from the nearby but much lower accumulation J-core site at Siple Dome, together with more extensive results from Summit, Greenland, indicate that it will be possible to obtain exactly co-registered, high-quality records of at least 12 seasonally varying elements (sodium, magnesium, aluminum, potassium, calcium, iron, manganese, rubidium, strontium, zirconium, barium, lead) and three other chemical species and ions (ammonium, nitrate, calcium ion) with this system. Under this proposed research, we will also add continuous measurements of sulfate to our system. Because more than sufficient core from Siple Dome for these depths is archived at the National Ice Core Laboratory, the proposed research will require no fieldwork. The continuous, very high-resolution, ~350-y record of these elemental tracers will enhance the value of previous chemical and isotopic measurements that have been made on the Siple Dome core and will be particularly valuable for comparisons between ice-core proxies and modern instrumental data related to El Nino-Southern Oscillation (ENSO) as well as for validation of model simulations of atmospheric circulation. These data, and the expertise gained through this research, will be invaluable when this novel chemical analysis technology is eventually applied to deep ice-core records for the study of rapid climate-change events.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "WAISCORES; Siple Coast; Glaciology; Not provided; GROUND-BASED OBSERVATIONS; Ice Core; Siple; Antarctica; Density; Snow; Ice Sheet; Siple Dome; Shallow Core; GROUND STATIONS; Stratigraphy", "locations": "Antarctica; Siple; Siple Coast; Siple Dome", "north": -62.83, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Lamorey, Gregg W.; McConnell, Joseph", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -90.0, "title": "Continuous High Resolution Ice-Core Chemistry using ICP-MS at Siple Dome", "uid": "p0000159", "west": -180.0}, {"awards": "0087151 Cole-Dai, Jihong", "bounds_geometry": null, "dataset_titles": "Sulfate-Based Volcanic Record from South Pole Ice Core", "datasets": [{"dataset_uid": "609215", "doi": "10.7265/N5CR5R88", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Solid Earth; South Pole", "people": "Cole-Dai, Jihong", "repository": "USAP-DC", "science_program": null, "title": "Sulfate-Based Volcanic Record from South Pole Ice Core", "url": "https://www.usap-dc.org/view/dataset/609215"}], "date_created": "Fri, 09 Apr 2004 00:00:00 GMT", "description": "This award supports a two year project to analyze shallow (~150 m) ice cores from South Pole in order to construct an annually resolved, sulfate-based volcanic record covering the last 1400 years. Two shallow ice cores will be recovered at the South Pole during the 00/01 field season and will be used for this work. Volcanic records from polar ice cores provide valuable information for studies of the connection between volcanism and climate. The new records are expected to be continuous and to cover at least the last 1400 years. The information from these records will verify the volcanic events found in the few existing Antarctic records and resolve discrepancies in the timing and magnitude of major explosive eruptions \u003cbr/\u003edetermined from those earlier records. In order to achieve the objectives of the proposed research, funds are provided to assist with the construction of an analytical laboratory for ice core and environmental \u003cbr/\u003echemistry research.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Ice Core; Snow Chemistry; West Antarctica; GROUND-BASED OBSERVATIONS; Antarctica; Ice Core Gas Records; Ion Chemistry; Ice Core Data", "locations": "West Antarctica; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Cole-Dai, Jihong", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "A Sulfate-based Volcanic Record from South Pole Ice Cores", "uid": "p0000167", "west": null}, {"awards": "9526449 Mayewski, Paul", "bounds_geometry": null, "dataset_titles": "WAISCORES Snow Pit Chemistry, Antarctica", "datasets": [{"dataset_uid": "609420", "doi": "10.7265/N5SQ8XBR", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; Snow/ice; Snow/Ice; Snow Pit; WAIS; WAISCORES", "people": "Kreutz, Karl; Mayewski, Paul A.", "repository": "USAP-DC", "science_program": null, "title": "WAISCORES Snow Pit Chemistry, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609420"}], "date_created": "Thu, 11 Jul 2002 00:00:00 GMT", "description": "This award is for support for a program of glaciochemical analyses of shallow and deep ice cores from Siple Dome, West Antarctica. Measurements that have been proposed include chloride, nitrate, sulfate, calcium, magnesium, sodium, potassium, ammonium and methansulfonic acid. These measurements will provide information about past volcanic events, biomass source strength, sea ice fluctuations, atmospheric circulation, changes in ice-free areas and the environmental response to Earth orbit insolation changes and solar variability. The glaciochemical records from the Siple Dome core will be developed at a resolution sufficient to compare with the Summit, Greenland record, thus allowing a bipolar comparison of climate change event timing and magnitude. As part of this award, an international workshop will be held during the first year to formulate a science plan for the International Transantarctic Scientific Expedition (ITASE), a program of regional surveys documenting the spatial distribution of properties measured in ice cores .", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Ion Chemistry; Antarctic; Snow Chemistry; Stable Isotopes; Snow Density; Siple Dome; GROUND-BASED OBSERVATIONS", "locations": "Antarctic; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Kreutz, Karl; Mayewski, Paul 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": "Siple Dome Deep Ice Core Glaciochemistry and Regional Survey - A Contribution to the WAIS Initiative", "uid": "p0000012", "west": null}]
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Project Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Dataset Links and Repositories | Abstract | Bounds Geometry | Geometry | Selected | Visible | |||||
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Collaborative Research: Tephrochronology of a South Pole Ice Core
|
1543361 1543454 |
2022-04-01 | Dunbar, Nelia; Iverson, Nels; Kurbatov, Andrei V. |
|
Dunbar/1543454 Antarctic ice cores offer unparalleled records of earth?s climate back to almost one million years and perhaps beyond. Layers of volcanic ash (tephra) embedded in glacial ice can be used to establish an accurate ice core chronology. In order to use a visible or ultrafine volcanic ash layer as a time-stratigraphic marker, a unique geochemical fingerprint must be established, and this forms the basis of our research. This award will investigate the volcanic record in the 1751 m ice core that was completed at the South Pole during the 2015/16 field season. The core is in an ideal location to link the existing, established, volcanic records in East and West Antarctica, and therefore to connect and integrate those records, allowing the climate records of ice cores to be directly compared, as well as to focus research on the most widespread and significant volcanic eruptions from West Antarctica. Tephra derived from well-dated, large, tropical volcanic eruptions that may have had an impact on climate will also be studied. Recent success in identifying and analyzing very fine ash particles from these types of eruptions makes it likely that we will be able to pinpoint some of these eruptions, which will allow the sulfate peaks associated with these layers to be positively identified and dated. Volcanic forcing time series developed from earlier South Pole ice cores based on preserved sulfate were crucial for testing climate models, but without tephra analysis, the origin of these layers remains uncertain. Work on the tephra layers in the South Pole ice core has a number of significant specific objectives, some with practical applications to the basic science goals of Antarctic ice coring, and others that represent independent scientific contributions in their own right. These include: (1) providing independently dated time-intervals in the core, particularly for the deepest ice, (2) quantitatively linking tephra records across Antarctica with the goal of allowing direct and robust climate comparisons between these different parts of the continent, (3) providing information for large local eruptions, that will lead to direct estimates of eruption magnitude and dispersal patterns of Antarctic volcanoes, several of which will likely erupt again. The initial stages of the work will be carried out by identifying silicate-bearing horizons in the ice core, using several methods. Once found, silicate particles will be imaged so that morphological characteristics of the particles can be used to identify volcanic origin. Particles identified as tephra will then be chemically analyzed using electron microprobe and laser ablation ICP-MS. Samples that yield a robust chemical fingerprint will be statistically correlated to known eruptions, and this will be used to address the goals described above. Broader impacts of this project fall into the areas of education of future generation of researchers, outreach and international cooperation. These activities will continue to promote forward progress in integrating the Antarctic tephra record and more broadly tying it to the global volcanic record. | POINT(0 -90) | POINT(0 -90) | false | false | |||||
Collaborative Research: Laser Cutting Technology for Borehole Sampling
|
2032463 2032473 |
2021-06-30 | Talghader, Joseph; Kurbatov, Andrei V. |
|
This project will take initial development steps toward a laser-cut ice-sampling capability in glaciers and ice sheets. The collection of ice samples from the Polar Ice Sheets involves large amounts of time, effort, and expense. However, the most important science data are often retrieved from small sections of an ice core and, while replicate coring can supplement this section of ice core, there is often a need to retrieve additional ice samples based on subsequent scientific findings or borehole logging at a research site. In addition, there are currently no easy methods of extracting ice samples from a borehole drilled by non-coring mechanical drills that are faster, lighter, and less expensive to operate. There are numerous science applications that could potentially benefit from laser-cut ice samples, including sampling ice overlying buried impact craters and bolides, filling critical gaps in chemical records retrieved from damaged ice cores, and obtaining ice samples from sites where coring drills apply stresses that may fracture the ice. This award will explore a laser cutting technology to rapidly extract high-quality ice samples from a borehole wall. The project will investigate and validate the existing technology of laser ice sampling and will use a fiberoptic cable to deliver light pulses to a borehole instrument rather than attempting to assemble a complete laser system in an instrument deployed in a borehole. This offers a new way of retrieving ice samples from a polar ice sheet without the need to drill a borehole to collect ice-core samples (i.e., the hole could be mechanically drilled). This technology could also be used in existing boreholes or those that are made by augering through ice (i.e., not coring) or made with hot water. If successful, this technique would create the ability to rapidly retrieve ice samples with a small logistical footprint and enable science that might not be supportable otherwise. The proposed technology could eventually provide better access to ice-core samples to study past atmospheric composition for understanding past climate and inform on future potential for ice-sheet 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. | 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)) | POINT(0 -89.999) | false | false | |||||
Collaborative Research: The Impact of Impurities and Stress State on Polycrystalline Ice Deformation
|
1851022 1851094 |
2021-06-28 | Baker, Ian; Fudge, T. J. | The ice of the polar ice sheets is among the purest substances on Earth, yet the small amount of impurities --such as acids-- are important to how the ice flows and what can be learned from ice cores about past climate. The goal of this project is to understand the role of such acids on the deformation of polycrystalline ice by comparing the deformation behavior of pure and sulfuric acid-doped samples. Sulfuric acid was chosen both because of its importance for interpreting past climate and because it can lead to water veins in ice at low temperatures. This work will focus on the location, movement, and impact of acids in polycrystalline ice that are more complex than in single crystals of ice. By deforming samples and performing microstructural characterization, the role of acids on deformation rate, grain evolution, and the movement of the acids themselves, will be assessed. The work will lead to the education of a Ph.D. student at Dartmouth College, introduce undergraduate students to research at both the University of Washington and Dartmouth College. Despite the ubiquitous use of the constitutive relation for ice commonly referred to as "Glen's Flow Law", significant uncertainty exists particularly with regard to the role of impurities and the development of oriented fabrics. The aim of this project is to improve the constitutive relationship for ice by performing deformation tests and microstructural characterization of pure and sulfuric acid-doped ice. The project will focus on sulfuric acid's impact on ice viscosity, fabric evolution, and diffusivity. Sulfuric acid can have both direct and indirect effects on the mechanical properties of polycrystalline ice. The direct effects change the dislocation velocity and/or density, and the indirect effects change the grain size and fabric. The complexity and interaction of these effects means that it is not possible to understand the effects of sulfuric acid by simply examining ice core specimens. In this project, the team will deform four types of ice: lab-grown ice samples doped with similar-to-natural concentrations of sulfuric acid, lab-grown high-purity ice, layered doped and pure ice, and natural ice from Antarctic ice cores. Deformation will be performed in both uniaxial compression and simple shear. The addition of simple shear tests is critical for relating the laboratory-observed deformation behavior to the behavior of polar ice sheets where the shear strain dominates ice motion in basal ice. After deformation to strains from 5 percent up to 25 percent, the microstructural development will be assessed with methods including a variety of scanning electron microscope techniques, Raman microscopy, synchrotron-based Nano-X-ray fluorescence, and ion chromatography. These analysis techniques will allow the determination of 1) the segregation and movement of impurities, 2) the rate of grain-boundary migration, 3) the number of recrystallized grains; and 4) the full orientation of the ice crystals. The results will enable both microstructural modeling of the effects of sulfuric acid and numerical modeling of diffusion in ice cores. The net result will be a better understanding of ice deformation that improves ice-core interpretation and ice-sheet modeling. 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. | None | None | false | false | ||||||
Collaborative Research: The Role of Glacial History on the Structure and Functioning of Ecological Communities in the Shackleton Glacier Region of the Transantarctic Mountains
|
1341736 |
2020-11-02 | Adams, Byron; Fierer, Noah; Wall, Diana; Diaz, Melisa A.; Gardner, Christopher B.; Lyons, W. Berry | The project will characterize the functional, taxonomic, biotic and abiotic drivers of soil ecosystems in the Trans Antarctic Mountains (one of the most remote and harsh terrestrial landscapes on the planet). The work will utilize new high-throughput DNA and RNA sequencing technologies to identify members of the microbial communities and determine if the microbial community structures are independent of local environmental heterogeneities. In addition the project will determine if microbial diversity and function are correlated with time since the last glacial maximum (LGM). The expected results will greatly contribute to our knowledge regarding rates of microbial succession and help define the some of the limits to life and life-maintaining processes on Earth. The project will analyze genomes and RNA derived from these genomes to describe the relationships between biodiversity and ecosystem functioning from soils above and below LGM elevations and to correlate these with the environmental drivers associated with their development during the last ~18,000 years. The team will identify the taxonomic diversity and the functional genetic composition within a broad suite of soil biota and examine their patterns of assembly and distribution within the framework of their geological legacies. The project will mentor participants from undergraduate students to postdoctoral researchers and prepare them to effectively engage in research to meet their career aspirations. The project will contribute to ongoing public education efforts through relationships with K-12 teachers and administrators- to include University-Public School partnerships. Less formal activities include public lecture series and weblogs aimed at providing information on Antarctic polar desert ecosystems to the general public. Targeted classrooms near each PI's institution will participate in online, real-time discussions about current topics in Antarctic ecosystems research. | POLYGON((-177.4099 -84.4661,-177.08229 -84.4661,-176.75468 -84.4661,-176.42707 -84.4661,-176.09946 -84.4661,-175.77185 -84.4661,-175.44424 -84.4661,-175.11663000000001 -84.4661,-174.78902 -84.4661,-174.46141 -84.4661,-174.1338 -84.4661,-174.1338 -84.56828,-174.1338 -84.67045999999999,-174.1338 -84.77264,-174.1338 -84.87482,-174.1338 -84.977,-174.1338 -85.07918,-174.1338 -85.18136,-174.1338 -85.28354,-174.1338 -85.38571999999999,-174.1338 -85.4879,-174.46141 -85.4879,-174.78902 -85.4879,-175.11663000000001 -85.4879,-175.44424 -85.4879,-175.77185 -85.4879,-176.09946 -85.4879,-176.42707 -85.4879,-176.75468 -85.4879,-177.08229 -85.4879,-177.4099 -85.4879,-177.4099 -85.38571999999999,-177.4099 -85.28354,-177.4099 -85.18136,-177.4099 -85.07918,-177.4099 -84.977,-177.4099 -84.87482,-177.4099 -84.77264,-177.4099 -84.67045999999999,-177.4099 -84.56828,-177.4099 -84.4661)) | POINT(-175.77185 -84.977) | false | false | ||||||
Collaborative Research: Borehole Logging to Classify Volcanic Signatures in Antarctic Ice
|
1643864 |
2020-02-08 | Talghader, Joseph |
|
Part I: Nontechnical One of the most interesting historical records that science can provide is contained in the ice of Antarctica. Layer by layer over hundreds of thousands of years, snow has precipitated on the ice sheet, become compacted, and turned into additional ice. Any dust or other impurities in the air or snow have been precipitated as well and thus each snowfall leaves a snapshot record of the atmosphere that existed at or near the time of deposition. A detailed chronology of volcanic eruptions can be obtained from the ice layers where ash and other volcanic products were deposited. Normally, the analysis of volcanic layers requires the physical extraction of a core from the ice sheet; however, chronologies from cores have discontinuities and are difficult, time-consuming, and expensive to obtain. Borehole logging is a measurement method where one lowers instrumentation into a drilled hole in the ice, whether or not core has been retrieved. To date, this technology has only been used to measure optical systems to identify volcanic ash and other impurity layers. In this program, a profiling technology will be developed that measures the conductivity of the ice. A radio-frequency emitter lowered into the borehole will create a return signal that changes depending on the local conductivity, which depends on the concentration of dissolved ions. For example, dissolved sulfates are a critical marker of volcanic activity that may not be coincident with deposited ash. Other dissolved ions, such as chloride, can be indicative of other processes. It is expected that this borehole profiling instrument will be able to help rapidly identify volcanic eruptions that had potentially global impact, distinguish between different dissolved ions via their frequency dependencies, and assist in establishing chronologies between different ice cores and boreholes. Part II: Technical Description Borehole logging of the polar ice sheets is one of the most important methods that earth scientists have to identify and date volcanic eruptions. However, current technology only indicates the presence and depth of ash from an eruption. In order to extract more detailed information, one must obtain an ice core, and laboriously measure each section in the laboratory using electrical conductivity or dielectric measurements to determine the presence or absence of dissolved sulfate and its location relative to the corresponding ash, if any. This program will investigate and demonstrate a borehole logging-compatible radio-frequency dielectric sensor to detect and measure spikes in dissolved major ions chemistry in ice, particularly in intervals corresponding to volcanically produced sulfates. The sulfate layers are one of the primary signatures of volcanic products. However, other ions, such as chlorides, calcium, and others are also commonly seen in ice, and the dielectric logging technology of this program would also measure these. It is expected that certain sets of ions will be distinguishable by their frequency dependencies. This technique could guide other investigators, who are using conventional core scanning and sampling methods, to regions of special interest in corresponding core. We plan to construct a ring-based electrode system and test this system on a variety of artificial ice boreholes and ice cores. This unit will not include a pressure vessel or other borehole logger packing. We will test different means of applying electrical signals including short pulses and periodic waves. We will further utilize differential measurements with low noise circuits and filters to achieve maximum sensitivity. We will correlate the signals extracted with known molarities of sulfates and other ions and measured ECM records. We will perform scaled-down experiments using real ice cores stored in Bay?s lab at UC Berkeley. This will permit testing of different designs in ice with natural impurities and polycrystalline structure. This small collection includes cores from a variety of locations in Antarctica and Greenland, and a variety of ages as old as a million years. | POINT(-112.085 -79.467) | POINT(-112.085 -79.467) | false | false | |||||
Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements
|
1443397 1443663 1443336 |
2019-08-29 | Osterberg, Erich | This collaborative project explores the signatures and causes of natural climate change in the region surrounding Antarctica over the last 40,000 years as the Earth transitioned from an ice age into the modern warm period. The researchers will investigate how the wind belts that surround Antarctica changed in their strength and position through time, and document explosive volcanic eruptions and CO2 cycling in the Southern Ocean as potential climate forcing mechanisms over this interval. Understanding how and why the climate varied naturally in the past is critical for improving understanding of modern climate change and projections of future climate under higher levels of atmospheric CO2. The investigators plan to conduct a suite of chemical measurements along the 1500m length of the South Pole Ice Core, including major ion and trace element concentrations, and microparticle (dust) concentrations and size distributions. These measurements will (1) extend the South Pole record of explosive volcanic eruptions to 40,000 years using sulfate and particle data; (2) establish the relative timing of climate changes in dust source regions of Patagonia, New Zealand, and Australia using dust flux data; (3) investigate changes in the strength and position of the westerly wind belt using dust size distribution data; and (4) quantify the flux of bioavailable trace metals deposited as dust to the Southern Ocean over time. These chemistry records will also be critical for creating the timescale that will be used by all researchers studying records from the South Pole core. The project will support four graduate students and several undergraduate students across three different institutions, and become a focus of the investigators' efforts to disseminate outcomes of climate change science to the broader community. | POINT(-180 -90) | POINT(-180 -90) | false | false | ||||||
Collaborative Research: Multiple-isotope Analysis of Nitrate and Sulfate in the West Antarctic Ice Sheet Divide Ice Core
|
0538049 0538520 |
2017-04-25 | Alexander, Becky; Steig, Eric J.; Thiemens, Mark H. | 0538520<br/>Thiemens<br/>This award supports a project to develop the first complete record of multiple isotope ratios of nitrate and sulfate covering the last ~100,000 years, from the deep ice core planned for the central ice divide of the West Antarctic Ice Sheet (WAIS). The WAIS Divide ice core will be the highest resolution long ice core obtained from Antarctica and we can expect important complementary information to be available, including accurate knowledge of past accumulation rates, temperatures, and compounds such as H2O2, CO and CH4. These compounds play significant roles in global atmospheric chemistry and climate. Especially great potential lies in the use of multiple isotope signatures. The unique mass independent fractionation (MIF) 17O signature of ozone is observed in both nitrate and sulfate, due to the interaction of their precursors with ozone. The development of methods to measure the multiple-isotope composition of small samples of sulfate and nitrate makes continuous high resolution measurements on ice cores feasible for the first time. Recent work has shown that such measurements can be used to determine the hydroxyl radial (OH) and ozone (O3) concentrations in the paleoatmosphere as well as to apportion sulfate and nitrate sources. There is also considerable potential in using these isotope measurements to quantify post depositional changes. In the first two years, continuous measurements from the upper ~100-m of ice at WAIS divide will be obtained, to provide a detailed look at seasonal through centennial scale variability. In the third year, measurements will be made throughout the available depth of the deep core (expected to reach ~500 m at this time). The broader impacts of the project include applications to diverse fields including atmospheric chemistry, glaciology, meteorology, and paleoclimatology. Because nitrate and sulfate are important atmospheric pollutants, the results will also have direct and relevance to global environmental policy. This project will coincide with the International Polar Year (2007-2008), and contributes to goals of the IPY, which include the fostering of interdisciplinary research toward enhanced understanding of atmospheric chemistry and climate in the polar regions. | POINT(-112.085 -79.5) | POINT(-112.085 -79.5) | false | false | ||||||
Carbonyl Sulfide Measurements in the Deep West Antarctic Ice Sheet Divide Ice Core
|
1043780 |
2015-10-27 | Aydin, Murat; Saltzman, Eric |
|
Aydin/1043780 This award supports the analysis of the trace gas carbonyl sulfide (COS) in a deep ice core from West Antarctic Ice Sheet Divide (WAIS-D), Antarctica. COS is the most abundant sulfur gas in the troposphere and a precursor of stratospheric sulfate. It has a large terrestrial COS sink that is tightly coupled to the photosynthetic uptake of atmospheric carbon dioxide (CO2). The primary goal of this project is to develop high a resolution Holocene record of COS from the WAIS-D 06A ice core. The main objectives are 1) to assess the natural variability of COS and the extent to which its atmospheric variability was influenced by climate variability, and 2) to examine the relationship between changes in atmospheric COS and CO2. This project also includes low-resolution sampling and analysis of COS from 10,000-30,000 yrs BP, covering the transition from the Last Glacial Maximum into the early Holocene. The goal of this work is to assess the stability of COS in ice core air over long time scales and to establish the COS levels during the last glacial maximum and the magnitude of the change between glacial and interglacial conditions. The results of this work will be disseminated via peer-review publications and will contribute to environmental assessments such as the WMO Stratospheric Ozone Assessment and IPCC Climate Assessment. This project will support a PhD student and undergraduate researcher in the Department of Earth System Science at the University of California, Irvine, and will create summer research opportunities for undergraduates from non-research active Universities. | None | None | false | false | |||||
Collaborative Research: Replicate Coring at WAIS Divide to Obtain Additional Samples at Events of High Scientific Interest
|
1043421 1043522 |
2015-07-13 | Severinghaus, Jeffrey P.; Brook, Edward J. |
|
1043421/Severinghaus This award supports a project to obtain samples of ice in selected intervals for replication and verification of the validity and spatial representativeness of key results in the WAIS Divide ice core, and to obtain additional ice samples in areas of intense scientific interest where demand is high. The US Ice Core Working Group recommended in 2003 that NSF pursue the means to take replicate samples, termed "replicate coring". This recommendation was part of an agreement to reduce the diameter of the (then) new drilling system (the DISC drill) core to 12.2 cm to lighten logistics burdens, and the science community accepted the reduction in ice sample with the understanding that replicate coring would be able to provide extra sample volume in key intervals. The WAIS Divide effort would particularly benefit from replicate coring, because of the unique quality of the expected gas record and the large samples needed for gases and gas isotopes; thus this proposal to employ replicate coring at WAIS Divide. In addition, scientific demand for ice samples has been, and will continue to be, very unevenly distributed, with the ice core archive being completely depleted in depth intervals of high scientific interest (abrupt climate changes, volcanic sulfate horizons, meteor impact horizons, for example). The broader impacts of the proposed research may include identification of leads and lags between Greenland, tropical, and Antarctic climate change, enabling critical tests of hypotheses for the mechanism of abrupt climate change. Improved understanding of volcanic impacts on atmospheric chemistry and climate may also emerge. This understanding may ultimately help improve climate models and prediction of the Earth System feedback response to ongoing human perturbation in coming centuries. Outreach and public education about climate change are integral components of the PIs' activities and the proposed work will enhance these efforts. Broader impacts also include education and training of 2 postdoctoral scholars and 1 graduate student, and invaluable field experience for the graduate and undergraduate students who will likely make up the core processing team at WAIS Divide. | POINT(-112.09 -79.47) | POINT(-112.09 -79.47) | false | false | |||||
Major Ion Chemistry of WAIS Divide Ice Core
|
0538553 |
2010-08-25 | Cole-Dai, Jihong |
|
Cole-Dai<br/>0538553<br/><br/>This award supports a project that will contribute to the US West Antarctica Ice Sheet Ice Divide ice core (WAIS Divide) project by developing new instrumentation and analytical procedures to measure concentrations of major ions (Cl-, NO3-, SO42-, Na+, K+, NH4+, Mg2+, Ca2+). A melter-based, continuous flow, multi-ion-chromatograph technique (CFA-IC) has been developed recently at South Dakota State University (SDSU). This project will further expand and improve the CFA-IC technique and instrumentation and develop procedures for routine analysis of major ions in ice cores. In addition, training of personnel (operators) to perform continuous, high resolution major ion analysis of the deep core will be accomplished through this project. The temporal resolution of the major ion measurement will be as low as 0.5 cm with the fully developed CFA-IC technique. At this resolution, it will be possible to use annual cycles of sulfate and sea-salt ion concentrations to determine annual layers in the WAIS Divide ice core. Annual layer counting using CFA-IC chemical measurements and other high resolution measurements will contribute significantly to the major WAIS Divide project objective of producing precisely (i.e., annually) dated climate records. The project will support the integration of research and education, train future scientists and promote human resource development through the participation of graduate and undergraduate students. In particular, undergraduate participation will contribute to a current REU (Research Experience for Undergraduates) chemistry site program at SDSU. Development and utilization of multi-user instrumentation will promote research collaboration and advance environmental science. NSF support for SDSU will contribute to the economic development and strengthen the infrastructure for research and education in South Dakota. | POINT(-112.085 -79.467) | POINT(-112.085 -79.467) | false | false | |||||
Climatology, Volcanism, and Microbial Life in Ice with Downhole Loggers
|
0440609 |
2008-06-03 | Bay, Ryan; Price, Buford | No dataset link provided | This award supports a project to use three downhole instruments - an optical logger; a<br/>miniaturized biospectral logger at 420 nm (miniBSL-420); and an Acoustic TeleViewer (ATV) - to log a 350-m borehole at the WAIS Divide drill site. In addition, miniBSL-224 (at 224 nm) and miniBSL-420 will scan ice core sections at NICL to look for abrupt climate changes, volcanic ash, microbial concentrations, and correlations among them. Using the optical logger and ATV to log bubble number densities vs depth in a WAIS Divide borehole, we will detect annual layers, from which we can establish the age vs depth relation to the bottom of the borehole that will be available during the three-year grant period. With the same instruments we will search for long-period modulation of bubble and dust concentrations in order to provide definitive evidence for or against an effect of long-period variability of the sun or solar wind on climate. We will detect and accurately date ash layers in a WAIS Divide borehole. We will match them with ash layers that we previously detected in the Siple Dome borehole, and also match them with sulfate and ash layers found by others at Vostok, Dome Fuji, Dome C, and GISP2. The expected new data will allow us to extend our recent study which showed that the Antarctic record of volcanism correlates with abrupt climate change at a 95% to >99.8% significance level and that the volcanic signatures at bipolar locations match at better than 3 sigma during the interval 2 to 45 kiloyears. The results to be obtained during this grant period will position us to extend an accurate age vs depth relation and volcano-climate correlations to earlier than 150 kiloyears ago in the future WAIS Divide borehole to be drilled to bedrock. Using the miniBSLs to identify biomolecules via their fluorescence, we will log a 350-m borehole at WAIS Divide, and we will scan selected lengths of ice core at NICL. Among the biomolecules the miniBSLs can identify will be chlorophyll, which will provide the first map of aerobic microbes in ice, and F420, which will provide the first map of methanogens in ice. We will collaborate with others in relating results from WAIS Divide and NICL ice cores to broader topics in climatology, volcanology, and microbial ecology. We will continue to give broad training to undergraduate and graduate students, to attract underrepresented minorities to science, engineering, and math, and to educate the press and college teachers. A deeper understanding of the causes of abrupt climate change, including a causal relationship with strong volcanic eruptions, can enable us to understand and mitigate adverse effects on climate. | POINT(-112.06556 -79.469444) | POINT(-112.06556 -79.469444) | false | false | |||||
Investigation of the Glacial History of the Siple Coast Using Radar-Detected Internal Layers and the Ice Core from Siple Dome
|
0229490 |
2007-04-30 | Conway, Howard; Sylvester, John; Winebrenner, Dale | No dataset link provided | This award supports a project to improve understanding of post-glacial retreat and thinning of the Siple Coast region. Research has shown how age-depth relationships from ice cores can be extrapolated over wide areas by tracking continuous radar layers. By comparing radar-derived timescales with one from a model of ice- flow, glacial conditions over regional scales were inferred. High-resolution radar profiles have been collected across most of the inter-stream ridges in the Siple Coast region, and an age- depth relationship has been established from the Siple Dome ice core. Application of the techniques used by others is problematic because the ice streams that surround Siple Dome have disrupted the continuity of the internal layers. A specific goal of this project is to search for other less direct ways to match radar layers between unconnected profiles. The correspondence between radar reflections and measurements of electrical conductivity and volcanic sulfates along the Siple Dome core will be investigated. The strategy is to search for distinctive patterns in the echoes that will facilitate layer matching. Preliminary results are encouraging: at least four distinct echoes at Siple Dome can be matched to spikes in the conductivity profile and the signature of one (at 210m depth, which is ~1,800 yrs BP) closely resembles that of a layer at ~200m on Ridge BC. Matching layers (and hence timescales) across the ice streams will allow reconstruction of spatial patterns of past flow, thinning and accumulation rate in the Siple Coast region, which is needed to predict future possible changes of the West Antarctic Ice Sheet. Data necessary for the proposed work are already available; additional fieldwork in Antarctica is not required. The project will take two years to complete and will provide core education for a doctoral student in Earth and Space Sciences, with an emphasis on radioglaciology. | None | None | false | false | |||||
Collaborative Research: Investigating Atmospheric Chemistry and Dynamics through Oxygen and Sulfur Isotopes in Volcanic Sulfate from South Pole Ice Cores
|
0338363 0337933 |
2006-08-11 | Cole-Dai, Jihong |
|
This award supports a collaborative study between South Dakota State University (SDSU) and University of California, San Diego (UCSD) to investigate the oxygen and sulfur isotope composition of sulfates from a number of large volcanic eruptions in the past 1000 years. The project aims to drill a number of shallow ice cores at South Pole and return them to SDSU and UCSD lab for chemical and isotope analysis. Preliminary results from measurements of isotopes in sulfate samples from several volcanic eruptions in Antarctic snow and ice indicate that isotopic composition of volcanic sulfate contains abundant valuable information on atmospheric chemical and dynamic processes that have not been previously investigated. One tentative conclusion is that mass-independently fractionated sulfur isotopes reveal that atmospheric photolysis of sulfur compounds occurs at longer UV wavelengths than those in the Archean atmosphere, possibly reflecting the atmospheric ozone and/or oxygen concentration. This suggests that isotopic composition of atmospheric sulfate may be used to understand the role of UV radiation in sulfur dioxide conversion in the atmosphere and to track the evolution (i.e., oxygenation) of the atmosphere and the origin of life on Earth. Other major research objectives include understanding what impact massive volcanic eruptions have on the oxidative capacity of the atmosphere, what oxidants and mechanisms are involved in the oxidation or conversion of volcanic sulfur dioxide to sulfate in the stratosphere and what isotopic criteria may be used to differentiate ice core signals of stratospheric eruptions from those of tropospheric eruptions. By providing educational and research opportunities to graduate and undergraduate students at both SDSU and UCSD, the proposed project will promote the integration of research and education and contribute to human resource development in science and engineering. The project will contribute to a proposed REU chemistry site program at SDSU. This collaboration will utilize the complementary strengths of both labs and promote exchange between the two institutions. International collaboration will enhance scientific cooperation between France and US. | None | None | false | false | |||||
Ross Ice Drainage System (RIDS) Late Holocene Climate Variability
|
9316564 |
2004-08-26 | Kreutz, Karl; Twickler, Mark; Whitlow, Sallie; Blunier, Thomas; Dunbar, Nelia; Brook, Edward J.; Mayewski, Paul A.; Meeker, Loren D.; Severinghaus, Jeffrey P. |
|
9316564 Mayewski This award is for support for a three year program to provide a high resolution record of the Antarctic climate through the acquisition, analysis, and interpretation of records of atmospheric chemical deposition taken from three ice cores located at sites within or immediately adjacent to the Ross Ice Drainage System (RIDS). These cores include one from Taylor Dome, and two from West Antarctic locations identified as potential deep drilling sites for the WAISCORES program. Collection of the two West Antarctic cores is intended to be a lightweight dry-drilling operation to depths of ~ 200 m, which will provide records of > 2 kyr. Glaciochemical analyses will focus on the major cations and anions found in the antarctic atmosphere, plus methanesulfonic acid and selected measurements of the hydrogen ion, aluminum, iron, and silica. These analyses, and companion stable isotope and particle measurements to be carried out by other investigators require < 7% by volume of each core, leaving > 90% for other investigators and storage at the U.S. National Ice Core Laboratory. These records are intended to solve a variety of scientific objectives while also providing spatial sampling and reconnaissance for future U.S. efforts in West Antarctica. *** | None | None | false | false | |||||
Continuous High Resolution Ice-Core Chemistry using ICP-MS at Siple Dome
|
0126286 |
2004-04-19 | Lamorey, Gregg W.; McConnell, Joseph |
|
This award provides one year of support to use newly developed technology in which an ice-core melter is coupled with both an Inductively Coupled Plasma - Mass Spectrometer (ICP-MS) and a traditional Continuous Flow Analysis (CFA) system, to measure a continuous time series of chemical and trace element deposition on the Siple Dome ice core from West Antarctica. A coupled ice-core melter, ICP-MS, and CFA system will be used to measure concentrations of a number of elements, isotopes and chemical species at very high depth resolution (~2-cm) in the top 54 m of the Siple Dome A-core. Pilot data from analyses of ~6 m from the nearby but much lower accumulation J-core site at Siple Dome, together with more extensive results from Summit, Greenland, indicate that it will be possible to obtain exactly co-registered, high-quality records of at least 12 seasonally varying elements (sodium, magnesium, aluminum, potassium, calcium, iron, manganese, rubidium, strontium, zirconium, barium, lead) and three other chemical species and ions (ammonium, nitrate, calcium ion) with this system. Under this proposed research, we will also add continuous measurements of sulfate to our system. Because more than sufficient core from Siple Dome for these depths is archived at the National Ice Core Laboratory, the proposed research will require no fieldwork. The continuous, very high-resolution, ~350-y record of these elemental tracers will enhance the value of previous chemical and isotopic measurements that have been made on the Siple Dome core and will be particularly valuable for comparisons between ice-core proxies and modern instrumental data related to El Nino-Southern Oscillation (ENSO) as well as for validation of model simulations of atmospheric circulation. These data, and the expertise gained through this research, will be invaluable when this novel chemical analysis technology is eventually applied to deep ice-core records for the study of rapid climate-change events. | POLYGON((-180 -62.83,-144 -62.83,-108 -62.83,-72 -62.83,-36 -62.83,0 -62.83,36 -62.83,72 -62.83,108 -62.83,144 -62.83,180 -62.83,180 -65.547,180 -68.264,180 -70.981,180 -73.698,180 -76.415,180 -79.132,180 -81.849,180 -84.566,180 -87.283,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87.283,-180 -84.566,-180 -81.849,-180 -79.132,-180 -76.415,-180 -73.698,-180 -70.981,-180 -68.264,-180 -65.547,-180 -62.83)) | POINT(0 -89.999) | false | false | |||||
A Sulfate-based Volcanic Record from South Pole Ice Cores
|
0087151 |
2004-04-09 | Cole-Dai, Jihong |
|
This award supports a two year project to analyze shallow (~150 m) ice cores from South Pole in order to construct an annually resolved, sulfate-based volcanic record covering the last 1400 years. Two shallow ice cores will be recovered at the South Pole during the 00/01 field season and will be used for this work. Volcanic records from polar ice cores provide valuable information for studies of the connection between volcanism and climate. The new records are expected to be continuous and to cover at least the last 1400 years. The information from these records will verify the volcanic events found in the few existing Antarctic records and resolve discrepancies in the timing and magnitude of major explosive eruptions <br/>determined from those earlier records. In order to achieve the objectives of the proposed research, funds are provided to assist with the construction of an analytical laboratory for ice core and environmental <br/>chemistry research. | None | None | false | false | |||||
Siple Dome Deep Ice Core Glaciochemistry and Regional Survey - A Contribution to the WAIS Initiative
|
9526449 |
2002-07-11 | Kreutz, Karl; Mayewski, Paul A. |
|
This award is for support for a program of glaciochemical analyses of shallow and deep ice cores from Siple Dome, West Antarctica. Measurements that have been proposed include chloride, nitrate, sulfate, calcium, magnesium, sodium, potassium, ammonium and methansulfonic acid. These measurements will provide information about past volcanic events, biomass source strength, sea ice fluctuations, atmospheric circulation, changes in ice-free areas and the environmental response to Earth orbit insolation changes and solar variability. The glaciochemical records from the Siple Dome core will be developed at a resolution sufficient to compare with the Summit, Greenland record, thus allowing a bipolar comparison of climate change event timing and magnitude. As part of this award, an international workshop will be held during the first year to formulate a science plan for the International Transantarctic Scientific Expedition (ITASE), a program of regional surveys documenting the spatial distribution of properties measured in ice cores . | None | None | false | false |