USAP-DC

{"dp_type": "Dataset", "free_text": "Organic Matter"}

[{"awards": "1745080 Gillikin, David; 1745057 Walker, Sally; 0739512 Walker, Sally; 1745064 Perez-Huerta, Alberto", "bounds_geometry": null, "date_created": "Mon, 05 Feb 2024 00:00:00 GMT", "description": "Adamussium colbecki is a large thin-shelled scallop common in Antarctic waters and well represented in the fossil record. Shell nitrogen isotopes in carbonate bound organic matter (d15NCBOM) have the potential to record sea ice state over time. Recent studies illustrated that d15NCBOM values provide a similar proxy as soft tissue d15N values which are in turn are predicably related to food d15N values (Gillikin et al., 2017, GCA, 200, 55\u201366, doi: 10.1016/j.gca.2016.12.008). Sea-ice organic N should have higher d15N values compared to open water organics due to nitrate draw down in the ice (Fripiat et al., 2014, Global Biogeochem. Cycles, 28, 115\u2013130, doi:10.1002/2013GB004729). To test this hypothesis we analyzed A. colbecki shells from Explorers Cove and Bay of Sails, western McMurdo Sound, Antarctica. These sites have different sea ice states: persistent (multiannual) sea ice at Explorers Cove and annual sea ice (that melts out every year) at Bay of Sails. Six adults shells collected at these sites in 2008 (3 from each site) and two juveniles collected in 2016 from Explorers Cove were be serially sampled for d15NCBOM values from the growing shell margin to the umbo. d15NCBOM values from Explorers Cove with persistent sea ice cover were consistently higher (+10 \u00b1 0.7 \u2030) than those from Bay of Sails where the sea ice melts out every year (+8 \u00b1 0.5 \u2030; t-test p\u003c0.0001). d15NCBOM data from Mid- to Late Holocene shells that grew in these locations will also be presented. We posit that nitrogen isotopes in A. colbecki shells have a high potential to record sea ice cover.", "east": null, "geometry": null, "keywords": "Adamussium Colbecki; Antarctica; Biota; Carbon Isotopes; Explorers Cove; Nitrogen Isotopes; Oxygen Isotope; Scallop", "locations": "Explorers Cove; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "persons": "Gillikin, David; Puhalski, Emma; Camarra, Steve; Cronin, Kelly; Verheyden, Anouk; Walker, Sally", "project_titles": "Collaborative Research: Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores; Collaborative research: The Antarctic Scallop as Key to Paleoenvironments and Sea Ice Conditions: Understanding the Modern to Predict the Past", "projects": [{"proj_uid": "p0000203", "repository": "USAP-DC", "title": "Collaborative Research: Linking Modern Benthic Communities and Taphonomic Processes to the Stratigraphic Record of Antarctic Cores"}, {"proj_uid": "p0010238", "repository": "USAP-DC", "title": "Collaborative research: The Antarctic Scallop as Key to Paleoenvironments and Sea Ice Conditions: Understanding the Modern to Predict the Past"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Nitrogen, carbon, and oxygen isotopes in the shell of the Antarctic scallop Adamussium colbecki as a proxy for sea ice cover in Antarctica.", "uid": "601764", "west": null}, {"awards": "1850988 Teets, Nicholas", "bounds_geometry": ["POLYGON((-64.366767 -62.681,-51.868477 -62.681,-39.370186999999994 -62.681,-26.87189699999999 -62.681,-14.373606999999993 -62.681,-1.875316999999996 -62.681,10.622973000000016 -62.681,23.121263000000013 -62.681,35.61955300000001 -62.681,48.11784300000001 -62.681,60.616133 -62.681,60.616133 -62.9536677,60.616133 -63.226335399999996,60.616133 -63.4990031,60.616133 -63.7716708,60.616133 -64.04433850000001,60.616133 -64.31700620000001,60.616133 -64.58967390000001,60.616133 -64.86234160000001,60.616133 -65.13500930000001,60.616133 -65.407677,48.11784299999999 -65.407677,35.619552999999996 -65.407677,23.121262999999992 -65.407677,10.622972999999995 -65.407677,-1.875317000000003 -65.407677,-14.373607000000014 -65.407677,-26.87189700000001 -65.407677,-39.37018700000001 -65.407677,-51.868477000000006 -65.407677,-64.366767 -65.407677,-64.366767 -65.13500930000001,-64.366767 -64.86234160000001,-64.366767 -64.58967390000001,-64.366767 -64.31700620000001,-64.366767 -64.04433850000001,-64.366767 -63.7716708,-64.366767 -63.4990031,-64.366767 -63.226335399999996,-64.366767 -62.9536677,-64.366767 -62.681))"], "date_created": "Sun, 11 Jun 2023 00:00:00 GMT", "description": "Antarctic winters are challenging for terrestrial invertebrates, and species that\r\nlive there have specialised adaptations to conserve energy and protect against\r\ncold injury in the winter. However, rapidly occurring climate change in these\r\nregions will increase the unpredictability of winter conditions, and there is\r\ncurrently a dearth of knowledge on how the highly adapted invertebrates of\r\nAntarctica will respond to changes in winter temperatures.\r\n2. We evaluated the response of larvae of the Antarctic midge, Belgica antarctica,\r\nto simulated winters at three ecologically relevant mean temperature scenarios:\r\nwarm (\u22121\u00b0C), normal (\u22123\u00b0C) and cold (\u22125\u00b0C). Within each scenario, larvae were\r\nplaced into three distinct habitat types in which they are commonly observed\r\n(decaying organic matter, living moss, and Prasiola crispa algae). Following the\r\nsimulated overwintering period, a range of physiological outcomes were measured,\r\nnamely survival, locomotor activity, tissue damage, energy store levels and\r\nmolecular stress responses.\r\n3. Survival, energy stores and locomotor activity were significantly lower following\r\nthe Warm overwintering environment than at lower temperatures, but tissue\r\ndamage and heat shock protein expression (a proxy for protein damage) did not\r\nsignificantly differ between the three temperatures. Survival was also significantly\r\nlower in larvae overwintered in Prasiola crispa algae, although the underlying\r\nmechanism is unclear. Heat shock proteins were expressed least in larvae\r\noverwintering in living moss, suggesting it is less stressful to overwinter in this\r\nsubstrate, perhaps due to a more defined structure affording less direct contact\r\nwith ice.\r\n4. Our results demonstrate that a realistic 2\u00b0C increase in winter microhabitat temperature\r\nreduces survival and causes energy deficits that have implications for subsequent\r\ndevelopment and reproduction. While our Warm winter scenario was close tothe range of observed overwintering temperatures for this species, warmer winters\r\nare expected to become more common in response to climate change. Conversely,\r\nif climate change reduces the length of winter, some of the negative consequences\r\nof winter warming may be attenuated, so it will be important to consider this factor\r\nin future studies. Nonetheless, our results indicate that winter warming could\r\nnegatively impact cold-adapted insects such as the Antarctic midge.", "east": 60.616133, "geometry": ["POINT(-1.875316999999996 -64.04433850000001)"], "keywords": "Antarctica", "locations": "Antarctica", "north": -62.681, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Devlin, Jack; Unfried, Laura; McCabe, Eleanor; Gantz, Josiah D.; Kawarasaki, Yuta; Elnitsky, Michael; Hotaling, Scott; Michel, Andrew; Convey, Peter; Hayward, Scott; Teets, Nicholas", "project_titles": null, "projects": null, "repositories": null, "science_programs": null, "south": -65.407677, "title": "Simulated winter warming negatively impacts survival of Antarctica\u0027s only endemic insect", "uid": "601694", "west": -64.366767}, {"awards": "1847067 Levy, Joseph", "bounds_geometry": ["POLYGON((160.6263 -77.575,160.91780999999997 -77.575,161.20932 -77.575,161.50083 -77.575,161.79234 -77.575,162.08384999999998 -77.575,162.37536 -77.575,162.66687000000002 -77.575,162.95838 -77.575,163.24989 -77.575,163.5414 -77.575,163.5414 -77.6003,163.5414 -77.6256,163.5414 -77.65090000000001,163.5414 -77.67620000000001,163.5414 -77.70150000000001,163.5414 -77.7268,163.5414 -77.7521,163.5414 -77.7774,163.5414 -77.8027,163.5414 -77.828,163.24989 -77.828,162.95838 -77.828,162.66687000000002 -77.828,162.37536 -77.828,162.08384999999998 -77.828,161.79234 -77.828,161.50083 -77.828,161.20932 -77.828,160.91780999999997 -77.828,160.6263 -77.828,160.6263 -77.8027,160.6263 -77.7774,160.6263 -77.7521,160.6263 -77.7268,160.6263 -77.70150000000001,160.6263 -77.67620000000001,160.6263 -77.65090000000001,160.6263 -77.6256,160.6263 -77.6003,160.6263 -77.575))"], "date_created": "Mon, 01 May 2023 00:00:00 GMT", "description": "This dataset contains soil properties data from the McMurdo Dry Valleys, focused on the properties of water tracks and adjacent dry soils. The dataset is surface and near-surface soil sample data, including sample location, water content by weight, organic matter content by weight, soluble salt extract composition by ion, and cation exchange extract concentrations from the soils. ", "east": 163.5414, "geometry": ["POINT(162.08384999999998 -77.70150000000001)"], "keywords": "Antarctica; Cation Exchange; Chemistry:soil; Chemistry:Soil; Dry Valleys; Organic Matter; Salt; Soil", "locations": "Dry Valleys; Antarctica", "north": -77.575, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Levy, Joseph", "project_titles": "Linking Antarctic Cold Desert Groundwater to Thermokarst \u0026 Chemical Weathering in Partnership with the Geoscience UAV Academy", "projects": [{"proj_uid": "p0010286", "repository": "USAP-DC", "title": "Linking Antarctic Cold Desert Groundwater to Thermokarst \u0026 Chemical Weathering in Partnership with the Geoscience UAV Academy"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.828, "title": "Biogeochemical measurements of water tracks and adjacent dry soils from the McMurdo Dry Valleys", "uid": "601684", "west": 160.6263}, {"awards": "1744602 Iken, Katrin", "bounds_geometry": ["POLYGON((-68 -64.5,-67.5 -64.5,-67 -64.5,-66.5 -64.5,-66 -64.5,-65.5 -64.5,-65 -64.5,-64.5 -64.5,-64 -64.5,-63.5 -64.5,-63 -64.5,-63 -64.95,-63 -65.4,-63 -65.85,-63 -66.3,-63 -66.75,-63 -67.2,-63 -67.65,-63 -68.1,-63 -68.55,-63 -69,-63.5 -69,-64 -69,-64.5 -69,-65 -69,-65.5 -69,-66 -69,-66.5 -69,-67 -69,-67.5 -69,-68 -69,-68 -68.55,-68 -68.1,-68 -67.65,-68 -67.2,-68 -66.75,-68 -66.3,-68 -65.85,-68 -65.4,-68 -64.95,-68 -64.5))"], "date_created": "Tue, 10 Jan 2023 00:00:00 GMT", "description": "The purpose of this dataset was to determine the importance of macroalgal primary producers to the coastal invertebrate food webs along a gradient of sites with increasing mean annual sea ice cover. This dataset contains the carbon and nitrogen stable isotope values, in addition to carbon and nitrogen content, of various coastal primary producers and invertebrate consumers from 15 stations along the Antarctic Peninsula from 64 to 69 degree latitude south collected in 2019. Primary producers included multiple species of macroalgae, particulate organic matter (POM) as a proxy of phytoplankton production, and benthic diatoms (where they occurred). Consumers included various benthic invertebrates of different feeding types, from suspension feeders (like sponges and ascidians) to predators/omnivores (like sea stars). ", "east": -63.0, "geometry": ["POINT(-65.5 -66.75)"], "keywords": "Antarctica; Antarctic Peninsula; Biota; Carbon; Carbon Isotopes; LMG1904; Nitrogen Isotopes; Oceans", "locations": "Antarctic Peninsula; Antarctica", "north": -64.5, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Iken, Katrin", "project_titles": "Collaborative Research: Sea ice as a driver of Antarctic benthic macroalgal community composition and nearshore trophic connectivity", "projects": [{"proj_uid": "p0010104", "repository": "USAP-DC", "title": "Collaborative Research: Sea ice as a driver of Antarctic benthic macroalgal community composition and nearshore trophic connectivity"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -69.0, "title": "Carbon and nitrogen isotope data along a gradient at the Antarctic Peninsula", "uid": "601653", "west": -68.0}, {"awards": "2031442 Learman, Deric", "bounds_geometry": null, "date_created": "Thu, 08 Sep 2022 00:00:00 GMT", "description": "Shelf sediment samples were collected around the Antarctic Peninsular with the mega corer in 2020 (Nov. to Dec.). The sample locations and water depths are recorded in this dataset. These samples were used to collect data on organic matter (total organic carbon, total nitrogen, delta 13C (organic), delta 15N, and C to N ratios). Nutrient data (nitrate, nitrite, sulfate, and ammonia) and grain size analysis were collected on a subsample set (10). ", "east": null, "geometry": null, "keywords": "Antarctica; Antarctic Peninsula; Grain Size; Grain Size Analysis; Marine Geoscience; Marine Sediments; Organic Matter Geochemistry; Sediment Core Data; Shelf Sediments; Weddell Sea", "locations": "Antarctic Peninsula; Weddell Sea; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Learman, Deric", "project_titles": "RAPID: Meta-genomic and Transcriptomic Investigation of Complex Organic Matter Degradation in Antarctic Benthic Sediments", "projects": [{"proj_uid": "p0010235", "repository": "USAP-DC", "title": "RAPID: Meta-genomic and Transcriptomic Investigation of Complex Organic Matter Degradation in Antarctic Benthic Sediments"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Physical and geochemical data from shelf sediments near the Antartic Pennisula", "uid": "601607", "west": null}, {"awards": "1743643 Passchier, Sandra", "bounds_geometry": ["POINT(-42.933 -61.849)"], "date_created": "Tue, 21 Jun 2022 00:00:00 GMT", "description": "This dataset contains measurements of terrigenous particle-size distributions on Eocene-Oligocene sediment from Ocean Drilling Program Site 696 drilled in 650 m water depth on the South Orkney Microcontinent. Carbonate and organic matter were removed through addition of 10mL aliquots of 30% H2O2, 2mL aliquots of 10% HCl to ~50-100mL suspension on a hot plate. Diatoms were generally either absent or present in trace amounts in the Eocene-Oligocene interval and were not removed. Dispersion was through heating with sodium pyrophosphate. Samples were measured on a Malvern Mastersizer 2000 with a Hydro 2000MU (A) accessory, using a Refractive Index of 1.6 (Illite) and an absorption coefficient of 0.9. Results are in (vol. %) per size class, with diameter range equivalent to the diameter of spheres with the same volume as measured particles.", "east": -42.933, "geometry": ["POINT(-42.933 -61.849)"], "keywords": "Antarctica; Glaciation; IODP 696; Marine Geoscience; Marine Sediments; Paleoceanography; Sediment Core Data; Weddell Sea", "locations": "Weddell Sea; Antarctica", "north": -61.849, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Passchier, Sandra; Lepp, Allison; Horowitz Castaldo, Josie; Light, Jennifer", "project_titles": "Timing and Spatial Distribution of Antarctic Ice Sheet Growth and Sea-ice Formation across the Eocene-Oligocene Transition", "projects": [{"proj_uid": "p0010101", "repository": "USAP-DC", "title": "Timing and Spatial Distribution of Antarctic Ice Sheet Growth and Sea-ice Formation across the Eocene-Oligocene Transition"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -61.849, "title": "Particle-size distributions of Eocene-Oligocene sediment from ODP Site 696, South Orkney Microcontinent", "uid": "601581", "west": -42.933}, {"awards": "1341464 Robinson, Rebecca", "bounds_geometry": ["POLYGON((-170.4 -60.8,-170.36 -60.8,-170.32 -60.8,-170.28 -60.8,-170.24 -60.8,-170.2 -60.8,-170.16 -60.8,-170.12 -60.8,-170.08 -60.8,-170.04 -60.8,-170 -60.8,-170 -61.34,-170 -61.88,-170 -62.42,-170 -62.96,-170 -63.5,-170 -64.04,-170 -64.58,-170 -65.12,-170 -65.66,-170 -66.2,-170.04 -66.2,-170.08 -66.2,-170.12 -66.2,-170.16 -66.2,-170.2 -66.2,-170.24 -66.2,-170.28 -66.2,-170.32 -66.2,-170.36 -66.2,-170.4 -66.2,-170.4 -65.66,-170.4 -65.12,-170.4 -64.58,-170.4 -64.04,-170.4 -63.5,-170.4 -62.96,-170.4 -62.42,-170.4 -61.88,-170.4 -61.34,-170.4 -60.8))"], "date_created": "Mon, 14 Feb 2022 00:00:00 GMT", "description": "Tracking variations in the surface ocean supply and demand of nitrate, a key marine nutrient, can help constrain the contribution of biological production in driving past climate shifts. The nitrogen isotopic composition (as \u03b415N) of organic matter in marine sediments is a proxy for surface ocean nitrate supply and demand over time but it may be subject to alteration during sinking and burial. The isotopic composition of nitrogen contained in the shells, or frustules, of diatoms (\u03b415NDB) is protected and is therefore a potentially more robust tracer of nitrate use in the past. Here we show that \u03b415NDB in Southern Ocean community cultures does not depend on species composition. We found the \u03b5DB (= biomass \u03b415N - \u03b415NDB) of the community growouts was -4.8 \u00b1 0.8\u2030, more than 10\u2030 different from previous monospecific growouts, but statistically indistinguishable from previous Southern Ocean and North Pacific surface ocean observations. The two community growouts, seeded with populations from 66\u00b0 and 61\u00b0S, had distinct community compositions but indistinguishable \u03b5DB, suggesting species composition does not primarily set \u03b415NDB values in the Southern Ocean. Our results demonstrate that under nitrate-replete conditions, \u03b415NDB values of frustules sinking from the surface ocean robustly track surface ocean nitrate \u03b415N values and therefore nitrate supply and demand. ", "east": -170.0, "geometry": ["POINT(-170.2 -63.5)"], "keywords": "Antarctica; Nitrogen Isotopes; Oceans; Paleoproxies; Southern Ocean", "locations": "Southern Ocean; Antarctica", "north": -60.8, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Jones, Colin; Robinson, Rebecca; Brzezinski, Mark; Riesselman, Christina; Closset, Ivia; Kelly, Roger; Robinson, Rebecca ", "project_titles": "Collaborative Proposal: A Field and Laboratory Examination of the Diatom N and Si Isotope Proxies: Implications for Assessing the Southern Ocean Biological Pump", "projects": [{"proj_uid": "p0010083", "repository": "USAP-DC", "title": "Collaborative Proposal: A Field and Laboratory Examination of the Diatom N and Si Isotope Proxies: Implications for Assessing the Southern Ocean Biological Pump"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -66.2, "title": "Surface Southern Ocean community growouts to evaluate the diatom bound N isotope proxy", "uid": "601522", "west": -170.4}, {"awards": "1245283 Passchier, Sandra", "bounds_geometry": ["POINT(74.787 -67.696167)"], "date_created": "Mon, 21 Jun 2021 00:00:00 GMT", "description": "This dataset contains measurements of terrigenous particle-size distributions on Eocene sediment from Ocean Drilling Program Site 1166 in Prydz Bay. Carbonate and organic matter were removed through addition of 10mL aliquots of 30% H2O2, 2mL aliquots of 10% HCl to ~50-100mL suspension on a hot plate. Dispersion was through heating with sodium pyrophosphate. Samples were measured on a Malvern Mastersizer 2000 with a Hydro 2000MU (A) accessory, using a Refractive index of 1.544 (Quartz) and an absorption coefficient of 0.9. Results are in (vol. %) per size class, with diameter range equivalent to the diameter of spheres with the same volume as measured particles.", "east": 74.787, "geometry": ["POINT(74.787 -67.696167)"], "keywords": "Antarctica; Eocene; Marine Geoscience; ODP1166; Particle Size; Prydz Bay; Sediment Core Data", "locations": "Prydz Bay; Antarctica", "north": -67.696167, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Passchier, Sandra; Ciarletta, Daniel", "project_titles": "The Stratigraphic Expression of the Onset of Glaciation in Eocene-Oligocene Successions on the Antarctic Continental Margin", "projects": [{"proj_uid": "p0000309", "repository": "USAP-DC", "title": "The Stratigraphic Expression of the Onset of Glaciation in Eocene-Oligocene Successions on the Antarctic Continental Margin"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -67.696167, "title": "Particle-size distributions of Eocene sediment from ODP Site 1166, Prydz Bay", "uid": "601455", "west": 74.787}, {"awards": "1245283 Passchier, Sandra", "bounds_geometry": ["POINT(75.4045 -67.549667)"], "date_created": "Mon, 21 Jun 2021 00:00:00 GMT", "description": "This dataset contains measurements of terrigenous particle-size distributions on Eocene-Oligocene sediment from Ocean Drilling Program Site 742 in Prydz Bay. Carbonate and organic matter were removed through addition of 10mL aliquots of 30% H2O2, 2mL aliquots of 10% HCl to ~50-100mL suspension on a hot plate. Dispersion was through heating with sodium pyrophosphate. Samples were measured on a Malvern Mastersizer 2000 with a Hydro 2000MU (A) accessory, using a Refractive index of 1.544 (Quartz) and an absorption coefficient of 0.9. Results are in (vol. %) per size class, with diameter range equivalent to the diameter of spheres with the same volume as measured particles.", "east": 75.4045, "geometry": ["POINT(75.4045 -67.549667)"], "keywords": "Antarctica; Eocene; Marine Geoscience; ODP742; Oligocene; Particle Size; Prydz Bay; Sediment Core Data", "locations": "Prydz Bay; Antarctica", "north": -67.549667, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Passchier, Sandra; Ciarletta, Daniel", "project_titles": "The Stratigraphic Expression of the Onset of Glaciation in Eocene-Oligocene Successions on the Antarctic Continental Margin", "projects": [{"proj_uid": "p0000309", "repository": "USAP-DC", "title": "The Stratigraphic Expression of the Onset of Glaciation in Eocene-Oligocene Successions on the Antarctic Continental Margin"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -67.549667, "title": "Particle-size distributions of Eocene-Oligocene sediment from ODP Site 742, Prydz Bay", "uid": "601454", "west": 75.4045}, {"awards": "1245283 Passchier, Sandra", "bounds_geometry": ["POINT(75.081833 -67.276167)"], "date_created": "Mon, 21 Jun 2021 00:00:00 GMT", "description": "This dataset contains measurements of terrigenous particle-size distributions on Eocene-Oligocene sediment from Ocean Drilling Program Site 739 in Prydz Bay. Carbonate, and organic matter were removed through addition of 10mL aliquots of 30% H2O2, 2mL aliquots of 10% HCl to ~50-100mL suspension on a hot plate. Dispersion was through heating with sodium pyrophosphate. Samples were measured on a Malvern Mastersizer 2000 with a Hydro 2000MU (A) accessory, using a Refractive index of 1.544 (Quartz) and an absorption coefficient of 0.9. Results are in (vol. %) per size class, with diameter range equivalent to the diameter of spheres with the same volume as measured particles.", "east": 75.081833, "geometry": ["POINT(75.081833 -67.276167)"], "keywords": "Antarctica; Eocene; Marine Geoscience; ODP739; Oligocene; Particle Size; Prydz Bay; Sediment Core Data", "locations": "Prydz Bay; Antarctica", "north": -67.276167, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Passchier, Sandra; Ciarletta, Daniel", "project_titles": "The Stratigraphic Expression of the Onset of Glaciation in Eocene-Oligocene Successions on the Antarctic Continental Margin", "projects": [{"proj_uid": "p0000309", "repository": "USAP-DC", "title": "The Stratigraphic Expression of the Onset of Glaciation in Eocene-Oligocene Successions on the Antarctic Continental Margin"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -67.276167, "title": "Particle-size distributions of Eocene-Oligocene sediment from ODP Site 739, Prydz Bay", "uid": "601453", "west": 75.081833}, {"awards": "0838842 Passchier, Sandra", "bounds_geometry": ["POINT(167.0833 -77.8889)"], "date_created": "Mon, 14 Jun 2021 00:00:00 GMT", "description": "This dataset contains measurements of particle-size distributions on four intervals of diamicitites from ANDRILL Site AND-2A. Carbonate, and organic matter were removed through addition of 10mL aliquots of 30% H2O2 and 2mL aliquots of 10% HCl to ~50-100mL suspension on a hot plate. Dispersion was through heating with sodium pyrophosphate. Samples were measured on a Malvern Mastersizer 2000 with a Hydro 2000MU (A) accessory, using a Refractive index of 1.544 (Quartz) and an absorption coefficient of 0.9. Results are in (vol. %) per size class, with diameter range equivalent to the diameter of spheres with the same volume as measured particles.", "east": 167.0833, "geometry": ["POINT(167.0833 -77.8889)"], "keywords": "Antarctica; McMurdo Sound; Miocene; Particle Size; Pleistocene; Pliocene", "locations": "McMurdo Sound; Antarctica", "north": -77.8889, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Passchier, Sandra; Hansen, Melissa A.", "project_titles": "Determining Middle Miocene through Pliocene Changes in Paleo Ice-flow and Basal Ice Conditions in East Antarctica through Sedimentological Analyses of Core Samples", "projects": [{"proj_uid": "p0000147", "repository": "USAP-DC", "title": "Determining Middle Miocene through Pliocene Changes in Paleo Ice-flow and Basal Ice Conditions in East Antarctica through Sedimentological Analyses of Core Samples"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -77.8889, "title": "Particle-size measurements for diamictites AND-2A sediment core, McMurdo Sound", "uid": "601452", "west": 167.0833}, {"awards": "0342484 Harwood, David", "bounds_geometry": ["POINT(167 -78)"], "date_created": "Mon, 14 Jun 2021 00:00:00 GMT", "description": "This dataset contains measurements of particle-size distributions on sediment from ANDRILL Site AND-2A. Carbonate, and organic matter were removed through addition of 10mL aliquots of 30% H2O2 and 2mL aliquots of 10% HCl to ~50-100mL suspension on a hot plate. Dispersion was through heating with sodium pyrophosphate. Samples were measured on a Malvern Mastersizer 2000 with a Hydro 2000MU (A) accessory, using a Refractive index of 1.544 (Quartz) and an absorption coefficient of 0.9. Results are in (vol. %) per size class, with diameter range equivalent to the diameter of spheres with the same volume as measured particles.", "east": 167.0, "geometry": ["POINT(167 -78)"], "keywords": "Andrill; Antarctica; Continental Shelf; Diamict; McMurdo Sound; Miocene; Paleoclimate; Particle Size", "locations": "McMurdo Sound; Antarctica", "north": -78.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "Passchier, Sandra; Candice, Falk", "project_titles": "Collaborative Research: ANDRILL - - Investigating Antarcticas Role in Cenozoic Global Environmental Change", "projects": [{"proj_uid": "p0010297", "repository": "USAP-DC", "title": "Collaborative Research: ANDRILL - - Investigating Antarcticas Role in Cenozoic Global Environmental Change"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -78.0, "title": "Particle-size measurements at 3-m intervals for AND-2A sediment core, McMurdo Sound", "uid": "601451", "west": 167.0}, {"awards": "1060080 TBD", "bounds_geometry": ["POINT(144 -65)"], "date_created": "Mon, 14 Jun 2021 00:00:00 GMT", "description": "This dataset contains measurements of terrigenous particle-size distributions on Pliocene sediment from Integrated Ocean Drilling Program Site U1359 on the Wilkes Land margin. Biogenic silica, carbonate, and organic matter were removed through addition of 10mL aliquots of 30% H2O2, 2mL aliquots of 10% HCl to ~50-100mL suspension on a hot plate, and after supernatant was removed, digestion in 0.2 N NaOH at ~85 degrees for 1 hour. Dispersion was through heating with sodium pyrophosphate. Samples were measured on a Malvern Mastersizer 2000 with a Hydro 2000MU (A) accessory, using a Refractive index of 1.6 (Illite) and an absorption coefficient of 0.9. Results are in (vol. %) per size class, with diameter range equivalent to the diameter of spheres with the same volume as measured particles.", "east": 144.0, "geometry": ["POINT(144 -65)"], "keywords": "Antarctica; Ice-Rafting; Marine Geoscience; Paleoclimate; Particle Size; Sediment Core Data; Wilkes Land", "locations": "Wilkes Land; Antarctica", "north": -65.0, "nsf_funding_programs": null, "persons": "Passchier, Sandra; Hansen, Melissa A.; Rosenberg, Jessica", "project_titles": null, "projects": null, "repositories": null, "science_programs": null, "south": -65.0, "title": "Particle-size distributions of Pliocene sediment from IODP Site U1359", "uid": "601450", "west": 144.0}, {"awards": "1141978 Foreman, Christine", "bounds_geometry": ["POLYGON((161.1667 -77.117,161.21673 -77.117,161.26676 -77.117,161.31679 -77.117,161.36682 -77.117,161.41685 -77.117,161.46688 -77.117,161.51691 -77.117,161.56694 -77.117,161.61697 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.667 -77.117,161.61697 -77.117,161.56694 -77.117,161.51691 -77.117,161.46688 -77.117,161.41685 -77.117,161.36682 -77.117,161.31679 -77.117,161.26676 -77.117,161.21673 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117,161.1667 -77.117))"], "date_created": "Fri, 23 Mar 2018 00:00:00 GMT", "description": "Mass spectra of external metabolites were obtained with a 1290 Ultra Performance Liquid Chromatography system coupled to a 6538 Ultra High Definition Accurate-Mass Quadrupole-Time of Flight mass spectrometer operated in positive mode with an electrospray ionization source (Agilent Technologies). 30 mL of filtered media was concentrated per sample by solid phase extraction. External metabolites were re-suspended in 50% (v/v) acetonitrile, and were separated using a reverse-phase Kinetix 1.7 um C18, 100A, 150 mm - 2.1 mm column. Data presented are from UPLC-Q-TOF measurements of mass to charge ratio, retention time, and replicate-averaged extracted ion chromatogram abundance values (counts) of molecular species that demonstrated a significant change in abundance (Two-way ANOVA, adjusted P\u003c0.01) during incubations based on time point (T0: d0, T1: d27, T2: d63, T3: d98) and carbon source (Cotton Glacier: CG, Pony Lake: PL, Suwannee River: SR).", "east": 161.667, "geometry": ["POINT(161.41685 -77.117)"], "keywords": "Antarctica; Biota; Exometabolites; Mass Spectrometry; Microbes; Microbiology", "locations": "Antarctica", "north": -77.117, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Foreman, Christine; Tigges, Michelle; Bothner, Brian", "project_titles": "Multidimensional \"omics\" characterization of microbial metabolism and dissolved organic matter in Antarctica", "projects": [{"proj_uid": "p0000408", "repository": "USAP-DC", "title": "Multidimensional \"omics\" characterization of microbial metabolism and dissolved organic matter in Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.117, "title": "UPLC-Q-TOF data of Cotton Glacier exometabolites", "uid": "601089", "west": 161.1667}, {"awards": "1341669 DeMaster, David", "bounds_geometry": ["POLYGON((-70 -62,-68.8 -62,-67.6 -62,-66.4 -62,-65.2 -62,-64 -62,-62.8 -62,-61.6 -62,-60.4 -62,-59.2 -62,-58 -62,-58 -62.6,-58 -63.2,-58 -63.8,-58 -64.4,-58 -65,-58 -65.6,-58 -66.2,-58 -66.8,-58 -67.4,-58 -68,-59.2 -68,-60.4 -68,-61.6 -68,-62.8 -68,-64 -68,-65.2 -68,-66.4 -68,-67.6 -68,-68.8 -68,-70 -68,-70 -67.4,-70 -66.8,-70 -66.2,-70 -65.6,-70 -65,-70 -64.4,-70 -63.8,-70 -63.2,-70 -62.6,-70 -62))"], "date_created": "Sat, 03 Feb 2018 00:00:00 GMT", "description": "This file has C-14 data from the organic matter fraction of Antarctic marine sediments, collected from the collapsed Larsen Ice Shelf and the West Antarctic Peninsula", "east": -58.0, "geometry": ["POINT(-64 -65)"], "keywords": null, "locations": null, "north": -62.0, "nsf_funding_programs": "Antarctic Earth Sciences", "persons": "DeMaster, David", "project_titles": "Using Radiochemical Data from Collapsed Ice Shelf Sediments to Understand the Nature and Timing of the Benthic Response to High-Latitude Climate Change", "projects": [{"proj_uid": "p0000382", "repository": "USAP-DC", "title": "Using Radiochemical Data from Collapsed Ice Shelf Sediments to Understand the Nature and Timing of the Benthic Response to High-Latitude Climate Change"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "LARISSA", "south": -68.0, "title": "DeMaster Compiled Larsen Ice Shelf and the West Antarctic Peninsula C14 Data", "uid": "601082", "west": -70.0}, {"awards": "1141978 Foreman, Christine", "bounds_geometry": ["POINT(161.667 -77.117)"], "date_created": "Tue, 19 Dec 2017 00:00:00 GMT", "description": "Metadata presented include Fourier transform ion cyclotron resonance mass spectrometry characterization of carbon source material molecular composition for three isolated lyophilized OM samples: Cotton Glacier Supraglacial stream, IHSS Pony Lake, and IHSS Suwannee River", "east": 161.667, "geometry": ["POINT(161.667 -77.117)"], "keywords": "Antarctica; Biota; Chemistry:fluid; Chemistry:Fluid; Fluorescence Spectroscopy; Mass Spectrometry", "locations": "Antarctica", "north": -77.117, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "D\u0027Andrilli, Juliana; Foreman, Christine", "project_titles": "Multidimensional \"omics\" characterization of microbial metabolism and dissolved organic matter in Antarctica", "projects": [{"proj_uid": "p0000408", "repository": "USAP-DC", "title": "Multidimensional \"omics\" characterization of microbial metabolism and dissolved organic matter in Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.117, "title": "FT-ICR MS Metadata", "uid": "601077", "west": 161.667}, {"awards": "1141978 Foreman, Christine", "bounds_geometry": ["POINT(161.667 -77.117)"], "date_created": "Tue, 19 Dec 2017 00:00:00 GMT", "description": "Metadata presented include high resolution respiration data from Janthinobacterium sp. CG3 for three dissolved organic matter samples Cotton Glacier Supraglacial stream, Pony Lake fulvic acid, and Suwannee River Natural Organic Matter (NOM).", "east": 161.667, "geometry": ["POINT(161.667 -77.117)"], "keywords": "Antarctica; Biota; Chemistry:fluid; Chemistry:Fluid; Fluorescence Spectroscopy; Mass Spectrometry", "locations": "Antarctica", "north": -77.117, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "persons": "Foreman, Christine; Smith, Heidi", "project_titles": "Multidimensional \"omics\" characterization of microbial metabolism and dissolved organic matter in Antarctica", "projects": [{"proj_uid": "p0000408", "repository": "USAP-DC", "title": "Multidimensional \"omics\" characterization of microbial metabolism and dissolved organic matter in Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.117, "title": "Respiration Metadata", "uid": "601076", "west": 161.667}, {"awards": "0839075 Priscu, John", "bounds_geometry": ["POINT(-112.08648 -79.46763)"], "date_created": "Mon, 06 Mar 2017 00:00:00 GMT", "description": "This data set include depth (WDC06A-7 dating) and fluorescence intensity measurements for five fluorophore regions (A, C, M, B, and T) commonly found in natural organic matter. Data from 1300-1700m, 1700-2100m, and 2100-2700m correspond to the early Holocene, deglaciation period, and the Last Glacial Maximum.", "east": -112.08648, "geometry": ["POINT(-112.08648 -79.46763)"], "keywords": "Antarctica; Fluorescence Spectroscopy; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Physical Properties; WAIS Divide; WAIS Divide Ice Core", "locations": "WAIS Divide; Antarctica", "north": -79.46763, "nsf_funding_programs": null, "persons": "Priscu, John; D\u0027Andrilli, Juliana", "project_titles": "Collaborative Research: Integrated High Resolution Chemical and Biological Measurements on the Deep WAIS Divide Core", "projects": [{"proj_uid": "p0000273", "repository": "USAP-DC", "title": "Collaborative Research: Integrated High Resolution Chemical and Biological Measurements on the Deep WAIS Divide Core"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.46763, "title": "Fluorescence spectroscopy data from the West Antarctic Ice Sheet (WAIS) Divide ice core, WDC06A", "uid": "601006", "west": -112.08648}, {"awards": "0838970 Foreman, Christine", "bounds_geometry": ["POINT(161.667 -77.117)"], "date_created": "Wed, 01 Jan 2014 00:00:00 GMT", "description": "Dissolved organic matter (DOM) comprises a significant pool of Earth\u0027s organic carbon that dwarfs the amount present in living aquatic organisms. The properties and reactivity of DOM are not well defined, and the evolution of autochthonous DOM from its precursor materials in freshwater has not been observed. Recent sampling of a supraglacial stream formed on the Cotton Glacier in the Transantarctic Mountains revealed DOM that more closely resembles an assemblage of recognizable precursor organic compounds, based upon its UV-VIS and fluorescence spectra. It is suggested that the DOM from this water evolved over time to resemble materials present in marine and many inland surface waters. The transient nature of the system i.e., it reforms seasonally, also prevents any accumulation of the refractory DOM present in most surface waters. Thus, the Cotton Glacier provides us with a unique environment to study the formation of DOM from precursor materials. An interdisciplinary team will study the biogeochemistry of this progenitor DOM and how microbes modify it. By focusing on the chemical composition of the DOM as it shifts from precursor material to the more humified fractions, the investigators will relate this transition to bioavailability, enzymatic activity, community composition and microbial growth efficiency. This project will support education at all levels, K-12, high school, undergraduate, graduate and post-doc and will increase participation by under-represented groups in science. Towards these goals, the investigators have established relationships with girls\u0027 schools and Native American programs. Additional outreach will be carried out in coordination with PolarTREC, PolarPalooza, and if possible, an Antarctic Artist and Writer.\n", "east": 161.667, "geometry": ["POINT(161.667 -77.117)"], "keywords": "Antarctica; Biota; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Microbiology", "locations": "Antarctica", "north": -77.117, "nsf_funding_programs": null, "persons": "Foreman, Christine", "project_titles": "Collaborative Research: The Biogeochemical Evolution of Dissolved Organic Matter in a Fluvial System on the Cotton Glacier, Antarctica", "projects": [{"proj_uid": "p0000458", "repository": "USAP-DC", "title": "Collaborative Research: The Biogeochemical Evolution of Dissolved Organic Matter in a Fluvial System on the Cotton Glacier, Antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.117, "title": "The Biogeochemical Evolution of Dissolved Organic Matter in a Fluvial System on the Cotton Glacier, Antarctica", "uid": "600104", "west": 161.667}, {"awards": "1039365 Rimmer, Susan", "bounds_geometry": null, "date_created": "Tue, 01 Jan 2013 00:00:00 GMT", "description": "This project studies the Permian-Triassic extinction event as recorded in sedimentary rocks from the Transantarctic Mountains of Antarctica. Two hundred and fifty million years ago most life on Earth was wiped out in a geologic instant. The cause is a subject of great debate. Researchers have identified a unique stratigraphic section near Shackleton glacier laid down during the extinction event. Organic matter from these deposits will be analyzed by density gradient centrifugation (DGC), which will offer detailed information on the carbon isotope composition. The age of these layers will be precisely dated by U/Pb-zircon-dating of intercalated volcanics. Combined, these results will offer detailed constraints on the timing and duration of carbon isotope excursions during the extinction, and offer insight into the coupling of marine and terrestrial carbon cycles. The broader impacts of this project include graduate and undergraduate student research, K12 outreach and teacher involvement, and societal relevance of the results, since the P/T extinction may have been caused by phenomena such as methane release, which could accompany global warming.\n", "east": null, "geometry": null, "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochemistry; Solid Earth; Transantarctic Mountains", "locations": "Transantarctic Mountains; Antarctica", "north": null, "nsf_funding_programs": null, "persons": "Rimmer, Susan", "project_titles": "Collaborative Research: The Permian -Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuatios in Terrestrial Organic Matter", "projects": [{"proj_uid": "p0000507", "repository": "USAP-DC", "title": "Collaborative Research: The Permian -Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuatios in Terrestrial Organic Matter"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "The Permian-Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuations in Terrestrial Organic Matter", "uid": "600121", "west": null}, {"awards": "0838830 Cottrell, Matthew", "bounds_geometry": ["POLYGON((-64.079666 -64.77966,-64.0757659 -64.77966,-64.0718658 -64.77966,-64.0679657 -64.77966,-64.0640656 -64.77966,-64.0601655 -64.77966,-64.0562654 -64.77966,-64.0523653 -64.77966,-64.0484652 -64.77966,-64.0445651 -64.77966,-64.040665 -64.77966,-64.040665 -64.783261,-64.040665 -64.786862,-64.040665 -64.790463,-64.040665 -64.794064,-64.040665 -64.797665,-64.040665 -64.801266,-64.040665 -64.804867,-64.040665 -64.808468,-64.040665 -64.812069,-64.040665 -64.81567,-64.0445651 -64.81567,-64.0484652 -64.81567,-64.0523653 -64.81567,-64.0562654 -64.81567,-64.0601655 -64.81567,-64.0640656 -64.81567,-64.0679657 -64.81567,-64.0718658 -64.81567,-64.0757659 -64.81567,-64.079666 -64.81567,-64.079666 -64.812069,-64.079666 -64.808468,-64.079666 -64.804867,-64.079666 -64.801266,-64.079666 -64.797665,-64.079666 -64.794064,-64.079666 -64.790463,-64.079666 -64.786862,-64.079666 -64.783261,-64.079666 -64.77966))"], "date_created": "Tue, 01 Jan 2013 00:00:00 GMT", "description": "Light quality and availability are likely to change in polar ecosystems as ice coverage and thickness decrease. How microbes adjust to these and other changes will have huge impacts on the polar marine ecosystems. Little is known about photoheterotrophic prokaryotes, which are hypothesized to gain a metabolic advantage by harvesting light energy in addition to utilizing dissolved organic matter (DOM). Photoheterotrophy is not included in current models of carbon cycling and energy flow. This research will examine three questions: 1. Are photoheterotrophic microbes present and active in Antarctic waters in winter and summer? 2. Does community structure of photoheterotrophs shift between summer and winter? 3. Which microbial groups assimilate more DOM in light than in the dark? The research will test hypotheses about activity of photoheterotrophs in winter and in summer, shifts in community structure between light and dark seasons and the potentially unique impacts of photoheterotrophs on biogeochemical processes in the Antarctic. The project will directly support a graduate student, will positively impact the NSF REU program at the College of Marine and Earth Studies, and will include students from the nation\u0027s oldest historical minority college. The results will be featured during weekly tours of Lewes facilities (about 1000 visitors per year) and during Coast Day, an annual open-house that attracts about 10,000 visitors.", "east": -64.040665, "geometry": ["POINT(-64.0601655 -64.797665)"], "keywords": "Antarctic Peninsula; Biota; LTER Palmer Station; Microbiology; Oceans; Southern Ocean", "locations": "Antarctic Peninsula; Southern Ocean", "north": -64.77966, "nsf_funding_programs": null, "persons": "Cottrell, Matthew; Kirchman, David", "project_titles": "Photoheterotrophic Microbes in the West Antarctic Peninsula Marine Ecosystem", "projects": [{"proj_uid": "p0000473", "repository": "USAP-DC", "title": "Photoheterotrophic Microbes in the West Antarctic Peninsula Marine Ecosystem"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -64.81567, "title": "Photoheterotrophic Microbes in the West Antarctic Peninsula Marine Ecosystem", "uid": "600097", "west": -64.079666}, {"awards": "0338342 Foreman, Christine; 0338260 Chin, Yu-Ping", "bounds_geometry": ["POINT(166.167 -77.55)"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "Dissolved organic matter (DOM) is a significant chemical component in aquatic systems because it acts as an important carbon source for microorganisms, absorbs harmful radiation in sunlight, is able to complex metals, and can participate in important biogeochemical reactions. This study will investigate the biogeochemical cycling of DOM in a small coastal Antarctic pond, Pony Lake, located on Cape Royds, Ross Island. Because there are no higher plants present at this site all of the DOM in this lake is derived from microorganisms. Thus, Pony Lake is an ideal site to study the effect of physical, chemical, and microbial processes on the composition and character of the DOM pool. Finally, Pony Lake is also an ideal site to collect an International Humic Substances Society (IHSS) fulvic acid standard. Unlike other IHSS standards, this standard will not contain DOM components derived from higher land plants. To better understand the role of physical influences, the project will study the changes in the DOM pool as the lake evolves from ice-covered to ice-free conditions during the summer, as well as the relationship of DOM to the observed turnover of dominant microbial communities in the lake. Scientists will also monitor changes in microbial abundance, diversity, and productivity that may occur during the ice to open-water transition period. This research will provide much needed information regarding the relationship between microbial diversity and DOM biogeochemistry. Middle school science students will be active participants in this project through the Internet, while scientists are in the field, and in the lab.", "east": 166.167, "geometry": ["POINT(166.167 -77.55)"], "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Critical Zone; Ross Island; Sample/collection Description; Sample/Collection Description; Water Samples", "locations": "Ross Island; Antarctica", "north": -77.55, "nsf_funding_programs": null, "persons": "Chin, Yu-Ping; Foreman, Christine", "project_titles": "Collaborative Research: Biogeochemistry of Dissolved Organic Matter in Pony Lake, Ross Island", "projects": [{"proj_uid": "p0000548", "repository": "USAP-DC", "title": "Collaborative Research: Biogeochemistry of Dissolved Organic Matter in Pony Lake, Ross Island"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.55, "title": "Biogeochemistry of Dissolved Organic Matter in Pony Lake, Ross Island", "uid": "600168", "west": 166.167}, {"awards": "0440478 Tang, Kam", "bounds_geometry": ["POINT(166.66267 -77.85067)"], "date_created": "Thu, 01 Jan 2009 00:00:00 GMT", "description": "Phaeocystis Antarctica is a widely distributed phytoplankton that forms dense blooms and aggregates in the Southern Ocean. This phytoplankton and plays important roles in polar ecology and biogeochemistry, in part because it is a dominant primary producer, a main component of organic matter vertical fluxes, and the principal producer of volatile organic sulfur in the region. Yet P. Antarctica is also one of the lesser known species in terms of its physiology, life history and trophic relationships with other organisms; furthermore, information collected on other Phaeocystis species and from different locations may not be applicable to P. Antarctica in the Ross Sea. P. Antarctica occurs mainly as two morphotypes: solitary cells and mucilaginous colonies, which differ significantly in size, architecture and chemical composition. Relative dominance between solitary cells and colonies determines not only the size spectrum of the population, but also its carbon dynamics, nutrient uptake and utilization. Conventional thinking of the planktonic trophic processes is also challenged by the fact that colony formation could effectively alter the predator-prey interactions and interspecific competition. However, the factors that regulate the differences between solitary and colonial forms of P. Antarctica are not well-understood. \n\nThe research objective of this proposal is therefore to address these over-arching questions: \n1. Do P. Antarctica solitary cells and colonies differ in growth, composition and photosynthetic rates? 2. How do nutrients and grazers affect colony development and size distribution of P. Antarctica? \n3. How do nutrients and grazers act synergistically to affect the long-term population dynamics of P. Antarctica? \n\nExperiments will be conducted in the McMurdo station with natural P. Antarctica assemblages and co-occurring grazers. Laboratory experiments will be conducted to study size-specific growth and photosynthetic rates of P. Antarctica, size-specific grazing mortality due to microzooplankton and mesozooplankton, the effects of macronutrients on the (nitrogen compounds) relative dominance of solitary cells and colonies, and the effects of micronutrient (Fe) and grazing related chemical signals on P. Antarctica colony development. Because this species is of critical importance in the Southern Ocean, and because this research will provide critical information on factors that regulate the role of P.Antarctica in food webs and biogeochemical cycles, a major gap in knowledge will be addressed. This project will train two marine science Ph.D. students. The investigators will also collaborate with the School of Education and a marine science museum to communicate polar science to a broader audience.", "east": 166.66267, "geometry": ["POINT(166.66267 -77.85067)"], "keywords": "Biota; McMurdo Sound; Oceans; Phytoplankton; Ross Sea; Southern Ocean; Zooplankton", "locations": "McMurdo Sound; Ross Sea; Southern Ocean", "north": -77.85067, "nsf_funding_programs": null, "persons": "Smith, Walker; Tang, Kam", "project_titles": "Environmental and Ecological Regulation of Differences and Interactions between Solitary and Colonial forms of Phaeocystis antarctica", "projects": [{"proj_uid": "p0000214", "repository": "USAP-DC", "title": "Environmental and Ecological Regulation of Differences and Interactions between Solitary and Colonial forms of Phaeocystis antarctica"}], "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.85067, "title": "Environmental and Ecological Regulation of Differences and Interactions between Solitary and Colonial Forms of Phaeocystis Antarctica", "uid": "600043", "west": 166.66267}]

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