USAP-DC

{"dp_type": "Dataset", "free_text": "Taylor Valley"}

[{"awards": "1644171 Blackburn, Terrence; 2042495 Blackburn, Terrence", "bounds_geometry": ["POLYGON((161.9 -77.65,161.96 -77.65,162.02 -77.65,162.08 -77.65,162.14000000000001 -77.65,162.2 -77.65,162.26 -77.65,162.32 -77.65,162.38 -77.65,162.44 -77.65,162.5 -77.65,162.5 -77.66000000000001,162.5 -77.67,162.5 -77.68,162.5 -77.69,162.5 -77.7,162.5 -77.71000000000001,162.5 -77.72,162.5 -77.73,162.5 -77.74,162.5 -77.75,162.44 -77.75,162.38 -77.75,162.32 -77.75,162.26 -77.75,162.2 -77.75,162.14000000000001 -77.75,162.08 -77.75,162.02 -77.75,161.96 -77.75,161.9 -77.75,161.9 -77.74,161.9 -77.73,161.9 -77.72,161.9 -77.71000000000001,161.9 -77.7,161.9 -77.69,161.9 -77.68,161.9 -77.67,161.9 -77.66000000000001,161.9 -77.65))"], "date_created": "Mon, 01 Jul 2024 00:00:00 GMT", "description": "This dataset contains uranium and thorium isotopic compositions (U-234, U-235, U-238, Th-230, Th-232) and major element compositions (Al, K, Na, Ca, Fe, Mn, reported as oxides) for silicate sediments from glaciogenic drifts associated with advances of Taylor Glacier in Taylor Valley, Antarctica. Isotopic measurements were obtained by ID-TIMS in the Keck Isotope Facility at UC Santa Cruz and elemental measurements were obtained by ICP-OES in the Plasma Analytical Laboratory. All measurements include fully propagated analytical and systematic (e.g. isotopic tracer) uncertainties. Chemical index of alteration was calculated from major element data. Prior to measurements, sediments were sieved to \u2264125 \u03bcm grain sizes, separated into quartz-feldspar-rich and clay-rich aliquots by hydraulic settling, and subjected to sequential chemical extractions (\"leaching\") prior to silicate digestion.", "east": 162.5, "geometry": ["POINT(162.2 -77.7)"], "keywords": "Antarctica; Cryosphere; Erosion; Isotope Data; Major Elements; Soil; Taylor Glacier; Taylor Valley", "locations": "Taylor Valley; Taylor Glacier; Antarctica", "north": -77.65, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "persons": "Edwards, Graham; Piccione, Gavin; Blackburn, Terrence; Tulaczyk, Slawek", "project_titles": "Collaborative Research: Reconstructing East Antarctica\u2019s Past Response to Climate using Subglacial Precipitates; U-Series Comminution Age Constraints on Taylor Valley Erosion", "projects": [{"proj_uid": "p0010192", "repository": "USAP-DC", "title": "Collaborative Research: Reconstructing East Antarctica\u2019s Past Response to Climate using Subglacial Precipitates"}, {"proj_uid": "p0010243", "repository": "USAP-DC", "title": "U-Series Comminution Age Constraints on Taylor Valley Erosion"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.75, "title": "U-Th isotopes and major elements in sediments from Taylor Valley, Antarctica", "uid": "601806", "west": 161.9}, {"awards": "2044924 Barrett, John", "bounds_geometry": ["POLYGON((161.70776367188 -77.519802097166,161.899475097661 -77.519802097166,162.091186523442 -77.519802097166,162.282897949223 -77.519802097166,162.474609375004 -77.519802097166,162.666320800785 -77.519802097166,162.858032226566 -77.519802097166,163.049743652347 -77.519802097166,163.241455078128 -77.519802097166,163.433166503909 -77.519802097166,163.62487792969 -77.519802097166,163.62487792969 -77.54867059480199,163.62487792969 -77.57753909243799,163.62487792969 -77.606407590074,163.62487792969 -77.63527608771,163.62487792969 -77.664144585346,163.62487792969 -77.69301308298199,163.62487792969 -77.72188158061799,163.62487792969 -77.750750078254,163.62487792969 -77.77961857589,163.62487792969 -77.808487073526,163.433166503909 -77.808487073526,163.241455078128 -77.808487073526,163.049743652347 -77.808487073526,162.858032226566 -77.808487073526,162.666320800785 -77.808487073526,162.474609375004 -77.808487073526,162.282897949223 -77.808487073526,162.091186523442 -77.808487073526,161.899475097661 -77.808487073526,161.70776367188 -77.808487073526,161.70776367188 -77.77961857589,161.70776367188 -77.750750078254,161.70776367188 -77.72188158061799,161.70776367188 -77.69301308298199,161.70776367188 -77.664144585346,161.70776367188 -77.63527608771,161.70776367188 -77.606407590074,161.70776367188 -77.57753909243799,161.70776367188 -77.54867059480199,161.70776367188 -77.519802097166))"], "date_created": "Wed, 03 Apr 2024 00:00:00 GMT", "description": "Microbial communities are the primary drivers of carbon cycling in the McMurdo Dry Valleys of Antarctica. Dense microbial mats, consisting mainly of photosynthetic cyanobacteria, occupy aquatic areas associated with streams and lakes. Other microbial communities also occur at lower densities as patchy surface biological soil crusts (biocrusts) across the terrestrial landscape. Multispectral satellite data have been used to model microbial mat abundance in high-density areas like stream and lake margins, but no previous studies had investigated the lower detection limits of biocrusts. Here, we describe remote sensing and field-based survey and sampling approaches to study the detectability and distribution of biocrusts in the McMurdo Dry Valleys. Using a combination of multi- and hyperspectral tools and spectral linear unmixing, we modeled the abundances of biocrust in eastern Taylor Valley. Our spectral approaches can detect low masses of biocrust material in laboratory microcosms down to biocrust concentrations of 1% by mass. These techniques also distinguish the spectra of biocrust from both surface rock and mineral signatures from orbit. We found that biocrusts are present throughout the soils of eastern Taylor Valley and are associated with diverse underlying soil communities. The densest biocrust communities identified in this study had total organic carbon 5x greater than the content of typical arid soils. The most productive biocrusts were located downslope of melting snowpacks in unique soil ecosystems that are distinct from the surrounding arid landscape. There are similarities between the snowpack and stream sediment communities (high diversity of soil invertebrates) as well as their ecosystem properties (e.g., persistence of liquid water, high transfer of available nutrients, lower salinity from flushing) compared to the typical arid terrestrial ecosystem of the dry valleys. Our approach extends the capability of orbital remote sensing of photosynthetic communities out of the aquatic margins and into the drier soils which comprise most of this landscape. This interdisciplinary work is critical for measuring and monitoring terrestrial carbon stocks and predicting future ecosystem dynamics in this currently water-limited but increasingly dynamic Antarctic landscape, which is particularly climate-sensitive and difficult to access.\r\n", "east": 163.62487792969, "geometry": ["POINT(162.666320800785 -77.664144585346)"], "keywords": "Antarctica; Carbon; Cryosphere; McMurdo Dry Valleys; Snow", "locations": "McMurdo Dry Valleys; Antarctica", "north": -77.519802097166, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Barrett, John", "project_titles": null, "projects": null, "repositories": null, "science_programs": null, "south": -77.808487073526, "title": "Hyperspectral reflectance values and biophysicochemical properties of biocrusts and soils in the Fryxell Basin, McMurdo Dry Valleys, Antarctica", "uid": "601773", "west": 161.70776367188}, {"awards": "1543344 Soreghan, Gerilyn", "bounds_geometry": ["POLYGON((162.322717 -77.417633,162.444362 -77.417633,162.566007 -77.417633,162.687652 -77.417633,162.80929700000002 -77.417633,162.93094200000002 -77.417633,163.052587 -77.417633,163.174232 -77.417633,163.295877 -77.417633,163.417522 -77.417633,163.539167 -77.417633,163.539167 -77.4501507,163.539167 -77.4826684,163.539167 -77.5151861,163.539167 -77.5477038,163.539167 -77.5802215,163.539167 -77.61273920000001,163.539167 -77.6452569,163.539167 -77.6777746,163.539167 -77.7102923,163.539167 -77.74281,163.417522 -77.74281,163.295877 -77.74281,163.174232 -77.74281,163.052587 -77.74281,162.93094200000002 -77.74281,162.80929700000002 -77.74281,162.687652 -77.74281,162.566007 -77.74281,162.444362 -77.74281,162.322717 -77.74281,162.322717 -77.7102923,162.322717 -77.6777746,162.322717 -77.6452569,162.322717 -77.61273920000001,162.322717 -77.5802215,162.322717 -77.5477038,162.322717 -77.5151861,162.322717 -77.4826684,162.322717 -77.4501507,162.322717 -77.417633))"], "date_created": "Tue, 16 Aug 2022 00:00:00 GMT", "description": "This data file contains locations and descriptions of the samples collected for the NSF project titled \"Quantifying surface area in muds from the Antarctic Dry Valleys: Implications for weathering in glacial systems\". Data collected includes BET surface area, LPSA grain size, granulometry, mineralogy (XRD) and whole rock geochemistry (ICP-MS).", "east": 163.539167, "geometry": ["POINT(162.93094200000002 -77.5802215)"], "keywords": "Antarctica; Anza Borrego; Iceland; McMurdo Dry Valleys; Norway; Peru; Puerto Rico; Taylor Valley; Washington; Wright Valley", "locations": "Antarctica; Taylor Valley; Wright Valley; McMurdo Dry Valleys; Peru; Norway; Anza Borrego; Puerto Rico; Iceland; Washington; Antarctica", "north": -77.417633, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Demirel-Floyd, Cansu", "project_titles": "Quantifying surface area in muds from the Antarctic Dry Valleys: Implications for weathering in glacial systems", "projects": [{"proj_uid": "p0010181", "repository": "USAP-DC", "title": "Quantifying surface area in muds from the Antarctic Dry Valleys: Implications for weathering in glacial systems"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.74281, "title": "Data and metadata for \"Quantifying surface area in muds from the Antarctic Dry Valleys: Implications for weathering in glacial systems\"", "uid": "601599", "west": 162.322717}, {"awards": "1946326 Doran, Peter", "bounds_geometry": ["POLYGON((163.079602 -77.585467,163.1197073 -77.585467,163.1598126 -77.585467,163.1999179 -77.585467,163.2400232 -77.585467,163.2801285 -77.585467,163.3202338 -77.585467,163.3603391 -77.585467,163.4004444 -77.585467,163.4405497 -77.585467,163.480655 -77.585467,163.480655 -77.5924303,163.480655 -77.5993936,163.480655 -77.6063569,163.480655 -77.6133202,163.480655 -77.6202835,163.480655 -77.6272468,163.480655 -77.6342101,163.480655 -77.6411734,163.480655 -77.6481367,163.480655 -77.6551,163.4405497 -77.6551,163.4004444 -77.6551,163.3603391 -77.6551,163.3202338 -77.6551,163.2801285 -77.6551,163.2400232 -77.6551,163.1999179 -77.6551,163.1598126 -77.6551,163.1197073 -77.6551,163.079602 -77.6551,163.079602 -77.6481367,163.079602 -77.6411734,163.079602 -77.6342101,163.079602 -77.6272468,163.079602 -77.6202835,163.079602 -77.6133202,163.079602 -77.6063569,163.079602 -77.5993936,163.079602 -77.5924303,163.079602 -77.585467))"], "date_created": "Wed, 09 Feb 2022 00:00:00 GMT", "description": "Location and metadata of C-14 samples from Taylor Valley, East Antarctica", "east": 163.480655, "geometry": ["POINT(163.2801285 -77.6202835)"], "keywords": "Antarctica; Carbon-14; Sample/collection Description; Sample/Collection Description; Sample Location; Taylor Valley", "locations": "Taylor Valley; Antarctica", "north": -77.585467, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Doran, Peter; Stone, Michael", "project_titles": "EAGER: Refining glacial lake history in Taylor Valley, East Antarctica with alternative geochronometers", "projects": [{"proj_uid": "p0010294", "repository": "USAP-DC", "title": "EAGER: Refining glacial lake history in Taylor Valley, East Antarctica with alternative geochronometers"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.6551, "title": "EAGER: Refining glacial lake history in Taylor Valley, East Antarctica with alternative geochronometers: in situ 14C data", "uid": "601521", "west": 163.079602}, {"awards": "1946326 Doran, Peter", "bounds_geometry": ["POLYGON((163.093642 -77.592484,163.1049267 -77.592484,163.1162114 -77.592484,163.1274961 -77.592484,163.1387808 -77.592484,163.1500655 -77.592484,163.1613502 -77.592484,163.1726349 -77.592484,163.1839196 -77.592484,163.1952043 -77.592484,163.206489 -77.592484,163.206489 -77.5986389,163.206489 -77.6047938,163.206489 -77.6109487,163.206489 -77.6171036,163.206489 -77.6232585,163.206489 -77.6294134,163.206489 -77.6355683,163.206489 -77.6417232,163.206489 -77.6478781,163.206489 -77.654033,163.1952043 -77.654033,163.1839196 -77.654033,163.1726349 -77.654033,163.1613502 -77.654033,163.1500655 -77.654033,163.1387808 -77.654033,163.1274961 -77.654033,163.1162114 -77.654033,163.1049267 -77.654033,163.093642 -77.654033,163.093642 -77.6478781,163.093642 -77.6417232,163.093642 -77.6355683,163.093642 -77.6294134,163.093642 -77.6232585,163.093642 -77.6171036,163.093642 -77.6109487,163.093642 -77.6047938,163.093642 -77.5986389,163.093642 -77.592484))"], "date_created": "Wed, 09 Feb 2022 00:00:00 GMT", "description": "Location and metadata of samples collected from perched delta deposits along modern stream channels in lower Taylor Valley. Sample collection used equipment and followed procedures from the Desert Research Institute Luminescence Laboratory in Reno, NV.", "east": 163.206489, "geometry": ["POINT(163.1500655 -77.6232585)"], "keywords": "Antarctica; Sample/collection Description; Sample/Collection Description; Sample Location; Taylor Valley", "locations": "Taylor Valley; Antarctica", "north": -77.592484, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Doran, Peter; Stone, Michael", "project_titles": "EAGER: Refining glacial lake history in Taylor Valley, East Antarctica with alternative geochronometers", "projects": [{"proj_uid": "p0010294", "repository": "USAP-DC", "title": "EAGER: Refining glacial lake history in Taylor Valley, East Antarctica with alternative geochronometers"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "LTER", "south": -77.654033, "title": "EAGER: Refining glacial lake history in Taylor Valley, East Antarctica with alternative geochronometers: Infrared Stimulated Luminescence data", "uid": "601520", "west": 163.093642}, {"awards": "1246203 Gooseff, Michael", "bounds_geometry": ["POLYGON((163.1778 -77.6233,163.17792 -77.6233,163.17804 -77.6233,163.17816 -77.6233,163.17828 -77.6233,163.1784 -77.6233,163.17852 -77.6233,163.17864 -77.6233,163.17876 -77.6233,163.17888 -77.6233,163.179 -77.6233,163.179 -77.63331,163.179 -77.64332,163.179 -77.65333,163.179 -77.66334,163.179 -77.67335,163.179 -77.68336,163.179 -77.69337,163.179 -77.70338,163.179 -77.71339,163.179 -77.7234,163.17888 -77.7234,163.17876 -77.7234,163.17864 -77.7234,163.17852 -77.7234,163.1784 -77.7234,163.17828 -77.7234,163.17816 -77.7234,163.17804 -77.7234,163.17792 -77.7234,163.1778 -77.7234,163.1778 -77.71339,163.1778 -77.70338,163.1778 -77.69337,163.1778 -77.68336,163.1778 -77.67335,163.1778 -77.66334,163.1778 -77.65333,163.1778 -77.64332,163.1778 -77.63331,163.1778 -77.6233))"], "date_created": "Mon, 18 Dec 2017 00:00:00 GMT", "description": "As a part of the project titled \"Collaborative Research: The McMurdo Dry Valleys: A landscape on the threshold of change\", we measured ground temperatures from 0-20cm at three stream bank positions (base, mid-slope, and top) at 4 locations along Crescent Stream in Taylor Valley - 2 on the east bank, 2 on the west bank. The goal was to evaluate differences in thermal conduction and temperature dynamics of the active layers of these locations, in particular, in a stream that has undergone extensive bank erosion since 2012 due to permafrost degradation. One of the datalogging stations had significant technical problems and has very little data compared to the almost 2 years of temperature date from the other 3 stations (2015-2017). ", "east": 163.179, "geometry": ["POINT(163.1784 -77.67335)"], "keywords": "Antarctica; Dry Valleys; Glaciology; Paleoclimate; Permafrost; Soil Temperature; Taylor Valley", "locations": "Dry Valleys; Taylor Valley; Antarctica", "north": -77.6233, "nsf_funding_programs": "Antarctic Integrated System Science", "persons": "Gooseff, Michael N.", "project_titles": "Collaborative Research: THE MCMURDO DRY VALLEYS: A landscape on the Threshold of Change", "projects": [{"proj_uid": "p0000076", "repository": "USAP-DC", "title": "Collaborative Research: THE MCMURDO DRY VALLEYS: A landscape on the Threshold of Change"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.7234, "title": "Active Layer Temperatures from Crescent Stream banks, Taylor Valley Antarctica", "uid": "601075", "west": 163.1778}, {"awards": "1245580 Castro, M. Clara", "bounds_geometry": ["POINT(162.3667 -77.7166)", "POINT(163.1833 -77.6767)"], "date_created": "Mon, 30 Jan 2017 00:00:00 GMT", "description": null, "east": 163.1833, "geometry": ["POINT(162.3667 -77.7166)", "POINT(163.1833 -77.6767)"], "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Critical Zone; Geochemistry; Noble Gas; Paleoclimate; Ross Ice Shelf; Ross Sea; Taylor Valley", "locations": "Ross Ice Shelf; Ross Sea; Taylor Valley; Antarctica", "north": -77.6767, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Castro, M. Clara", "project_titles": "Developing a New Paleoclimate Proxy for Polar and Alpine Glacial Regions Based on Noble Gases", "projects": [{"proj_uid": "p0000388", "repository": "USAP-DC", "title": "Developing a New Paleoclimate Proxy for Polar and Alpine Glacial Regions Based on Noble Gases"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.7166, "title": "Developing a New Paleoclimate Proxy for Polar and Alpine Glacial Regions Based on Noble Gases", "uid": "600389", "west": 162.3667}, {"awards": "1343649 Levy, Joseph", "bounds_geometry": ["POLYGON((162.852 -77.6111,162.9893 -77.6111,163.1266 -77.6111,163.2639 -77.6111,163.4012 -77.6111,163.5385 -77.6111,163.6758 -77.6111,163.8131 -77.6111,163.9504 -77.6111,164.0877 -77.6111,164.225 -77.6111,164.225 -77.65331,164.225 -77.69552,164.225 -77.73773,164.225 -77.77994,164.225 -77.82215,164.225 -77.86436,164.225 -77.90657,164.225 -77.94878,164.225 -77.99099,164.225 -78.0332,164.0877 -78.0332,163.9504 -78.0332,163.8131 -78.0332,163.6758 -78.0332,163.5385 -78.0332,163.4012 -78.0332,163.2639 -78.0332,163.1266 -78.0332,162.9893 -78.0332,162.852 -78.0332,162.852 -77.99099,162.852 -77.94878,162.852 -77.90657,162.852 -77.86436,162.852 -77.82215,162.852 -77.77994,162.852 -77.73773,162.852 -77.69552,162.852 -77.65331,162.852 -77.6111))"], "date_created": "Thu, 01 Jan 2015 00:00:00 GMT", "description": "The PIs propose to quantify the hillslope water, solute, and carbon budgets for Taylor Valley in the McMurdo Dry Valleys, using water tracks to investigate near-surface geological processes and challenge the paradigm that shallow groundwater is minimal or non-exixtant. Water tracks are linear zones of high soil moisture that route shallow groundwater downslope in permafrost dominated soils. Four hypotheses will be tested: 1) water tracks are important pathways for water and solute transport; 2) water tracks transport more dissolved silica than streams in Taylor Valley indicating they are the primary site of chemical weathering for cold desert soils and bedrock; 3) water tracks that drain highland terrains are dominated by humidity-separated brines while water tracks that drain lowland terrains are dominated by marine aerosols; 4) water tracks are the sites of the highest terrestrial soil carbon concentrations and the strongest CO2 fluxes in Taylor Valley and their carbon content increases with soil age, while carbon flux decreases with age. To test these hypotheses the PIs will carry out a suite of field measurements supported by modeling and remote sensing. They will install shallow permafrost wells in water tracks that span the range of geological, climatological, and topographic conditions in Taylor Valley. Multifrequency electromagnetic induction sounding of the upper ~1 m of the permafrost will create the first comprehensive map of soil moisture in Taylor Valley, and will permit direct quantification of water track discharge across the valley. The carbon contents of water track soils will be measured and linked to global carbon dynamics.\n\nNon-science majors at Oregon State University will be integrated into the proposed research through a new Global Environmental Change course focusing on the scientific method in Antarctica. Three undergraduate students, members of underrepresented minorities, will be entrained in the research, will contribute to all aspects of field and laboratory science, and will present results at national meetings.\n", "east": 164.225, "geometry": ["POINT(163.5385 -77.82215)"], "keywords": "Antarctica; Chemistry:soil; Chemistry:Soil; Critical Zone; Dry Valleys; Permafrost; Sample/collection Description; Sample/Collection Description; Well Measurements", "locations": "Dry Valleys; Antarctica", "north": -77.6111, "nsf_funding_programs": null, "persons": "Levy, Joseph", "project_titles": "Cryptic Hydrology of the McMurdo Dry Valleys: Water Track Contributions to Water and Geochemical Budgets in Taylor Valley, Antarctica", "projects": [{"proj_uid": "p0000407", "repository": "USAP-DC", "title": "Cryptic Hydrology of the McMurdo Dry Valleys: Water Track Contributions to Water and Geochemical Budgets in Taylor Valley, Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0332, "title": "Cryptic Hydrology of the McMurdo Dry Valleys: Water Track Contributions to Water and Geochemical Budgets in Taylor Valley, Antarctica", "uid": "600139", "west": 162.852}, {"awards": "0086645 Fountain, Andrew", "bounds_geometry": ["POLYGON((161.04 -77.3,161.239 -77.3,161.438 -77.3,161.637 -77.3,161.836 -77.3,162.035 -77.3,162.234 -77.3,162.433 -77.3,162.632 -77.3,162.831 -77.3,163.03 -77.3,163.03 -77.378,163.03 -77.456,163.03 -77.534,163.03 -77.612,163.03 -77.69,163.03 -77.768,163.03 -77.846,163.03 -77.924,163.03 -78.002,163.03 -78.08,162.831 -78.08,162.632 -78.08,162.433 -78.08,162.234 -78.08,162.035 -78.08,161.836 -78.08,161.637 -78.08,161.438 -78.08,161.239 -78.08,161.04 -78.08,161.04 -78.002,161.04 -77.924,161.04 -77.846,161.04 -77.768,161.04 -77.69,161.04 -77.612,161.04 -77.534,161.04 -77.456,161.04 -77.378,161.04 -77.3))"], "date_created": "Mon, 31 Aug 2009 00:00:00 GMT", "description": "As part of the Long Term Ecological Research (LTER) project in the McMurdo Dry Valleys of Antarctica, a systematic sampling program has been undertaken to monitor mass balance of the Taylor Valley glaciers. Data were collected from the Canada, Commonwealth, Howard, Hughes, Suess and Taylor glaciers, located in the Taylor Valley of Antarctica. Monitoring the changes in these measurements over time provides a record of mass balance, and aids in determining the role of glaciers in the polar hydrologic cycle.", "east": 163.03, "geometry": ["POINT(162.035 -77.69)"], "keywords": "Antarctica; Dry Valleys; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; LTER; LTER Mcmurdo Dry Valleys", "locations": "Dry Valleys; Antarctica", "north": -77.3, "nsf_funding_programs": "Antarctic Glaciology", "persons": "Fountain, Andrew; Nylen, Thomas; Basagic, Hassan; Lyons, W. Berry; Langevin, Paul", "project_titles": "SGER Proposal:Glaciological change in the McMurdo Dry Valleys, Antarctica", "projects": [{"proj_uid": "p0000541", "repository": "USAP-DC", "title": "SGER Proposal:Glaciological change in the McMurdo Dry Valleys, Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.08, "title": "McMurdo Dry Valleys Long-Term Ecological Research (MCM LTER) Core Glacier Mass Balance Data, Antarctica", "uid": "609421", "west": 161.04}, {"awards": "0230276 Ward, Bess", "bounds_geometry": ["POLYGON((162 -77.2,162.16 -77.2,162.32 -77.2,162.48 -77.2,162.64 -77.2,162.8 -77.2,162.96 -77.2,163.12 -77.2,163.28 -77.2,163.44 -77.2,163.6 -77.2,163.6 -77.26,163.6 -77.32,163.6 -77.38,163.6 -77.44,163.6 -77.5,163.6 -77.56,163.6 -77.62,163.6 -77.68,163.6 -77.74,163.6 -77.8,163.44 -77.8,163.28 -77.8,163.12 -77.8,162.96 -77.8,162.8 -77.8,162.64 -77.8,162.48 -77.8,162.32 -77.8,162.16 -77.8,162 -77.8,162 -77.74,162 -77.68,162 -77.62,162 -77.56,162 -77.5,162 -77.44,162 -77.38,162 -77.32,162 -77.26,162 -77.2))"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "Denitrification is the main process by which fixed nitrogen is lost from ecosystems and the regulation of this process may directly affect primary production and carbon cycling over short and long time scales. Previous investigations of the role of bioactive metals in regulating denitrification in bacteria from permanently ice-covered Lake Bonney in the Taylor Valley of East Antarctica indicated that denitrifying bacteria can be negatively affected by metals such as copper, iron, cadmium, lead, chromium, nickel, silver and zinc; and that there is a distinct difference in denitrifying activity between the east and west lobes of the lake. \n\nLow iron concentrations were found to exacerbate the potential toxicity of the other metals, while silver has the potential to specifically inhibit denitrification because of its ability to interfere with copper binding in redox proteins, such as nitrite reductase and nitrous oxide reductase. High silver concentrations might prevent the functioning of nitrous oxide reductase in the same way that simple copper limitation does, thereby causing the buildup of nitrous oxide and resulting in a nonfunctional nitrogen cycle. Other factors, such as oxygen concentration, are likely also to affect bacterial activity in Lake Bonney.\n\nThis project will investigate silver toxicity, general metal toxicity and oxygen concentration to determine their effect on denitrification in the lake by using a suite of \u0027sentinel\u0027 strains of denitrifying bacteria (isolated from the lake) incubated in Lake Bonney water and subjected to various treatments. The physiological responses of these strains to changes in metal and oxygen concentration will be quantified by flow cytometric detection of single cell molecular probes whose sensitivity and interpretation have been optimized for the sentinel strains. Understanding the relationships between metals and denitrification is expected to enhance our understanding of not only Lake Bonney\u0027s unusual nitrogen cycle, but more generally, of the potential role of metals in the regulation of microbial nitrogen transformations. The broader impacts of this work include not only a better understanding of regional biogeochemistry and global perspectives on these processes; but also the training of graduate students and a substantial outreach effort for school children.", "east": 163.6, "geometry": ["POINT(162.8 -77.5)"], "keywords": "Antarctica; Biota; CTD Data; Dry Valleys; Lake Bonney; Lake Vanda; Microbiology; Taylor Valley", "locations": "Dry Valleys; Lake Bonney; Lake Vanda; Taylor Valley; Antarctica", "north": -77.2, "nsf_funding_programs": null, "persons": "Ward, Bess", "project_titles": "Collaborative Research: What Limits Denitrification and Bacterial Growth in Lake Bonney, Taylor Valley, Antarctica?", "projects": [{"proj_uid": "p0000223", "repository": "USAP-DC", "title": "Collaborative Research: What Limits Denitrification and Bacterial Growth in Lake Bonney, Taylor Valley, Antarctica?"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.8, "title": "What Limits Denitrification and Bacterial Growth in Lake Bonney, Taylor Valley, Antarctica?", "uid": "600033", "west": 162.0}]

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