{"dp_type": "Dataset", "free_text": "Pressure"}
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29 record(s) found
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Dataset Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Project Links | Abstract | Geometry |
---|---|---|---|---|---|---|
High-resolution nearshore benthic seawater temperature from around McMurdo Sound, Antarctica (2017-2019)
|
1644196 |
2021-01-03 | Cziko, Paul |
Habitat Severity and Internal Ice in Antarctic Notothenioid Fishes |
Nearshore benthic seawater temperature (plus pressure and salinity for some sites) in McMurdo Sound, Antarctica for 2017-2019. Data includes those from standalone temperature (sometimes pressure) for several sites around McMurdo Sound as well as data from the cabled McMurdo Oceanographic Observatory moored conductivity-temperature-depth (CTD) sensor at the McMurdo Station seawater intake jetty. Data are from high precision SeaBird sensors (SBE56, SBE39, SBE19Plus and SBE37), with sample intervals from 90 sec to 15 min, depending on site. Sampled sites include Explorer's Cove at New Harbor, Cape Evans, Granite Harbor, and the McMurdo Station jetty. All sensors were deployed near or on the benthos at 20-25 m deep, in typical nearshore benthic fish and invertebrate habitat. | ["POLYGON((162.647931 -77.000624,163.049652 -77.000624,163.451373 -77.000624,163.853094 -77.000624,164.254815 -77.000624,164.656536 -77.000624,165.058257 -77.000624,165.459978 -77.000624,165.861699 -77.000624,166.26342 -77.000624,166.665141 -77.000624,166.665141 -77.0856883,166.665141 -77.1707526,166.665141 -77.2558169,166.665141 -77.3408812,166.665141 -77.4259455,166.665141 -77.5110098,166.665141 -77.5960741,166.665141 -77.6811384,166.665141 -77.7662027,166.665141 -77.851267,166.26342 -77.851267,165.861699 -77.851267,165.459978 -77.851267,165.058257 -77.851267,164.656536 -77.851267,164.254815 -77.851267,163.853094 -77.851267,163.451373 -77.851267,163.049652 -77.851267,162.647931 -77.851267,162.647931 -77.7662027,162.647931 -77.6811384,162.647931 -77.5960741,162.647931 -77.5110098,162.647931 -77.4259455,162.647931 -77.3408812,162.647931 -77.2558169,162.647931 -77.1707526,162.647931 -77.0856883,162.647931 -77.000624))"] |
Acclimation of cardiovascular function in Notothenia coriiceps
|
1341663 |
2020-12-18 | Joyce, William; Egginton, Stuart; Farrell, Anthony; Axelsson, Michael; Crockett, Elizabeth; O'Brien, Kristin |
Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes |
The Southern Ocean has experienced stable, cold temperatures for over 10 million years, yet particular regions are currently undergoing rapid warming. To investigate the impacts of warming on cardiovascular oxygen transport, we compared the cardio-respiratory performance in an Antarctic notothenioid (Notothenia coriiceps) that was maintained at 0 or 5°C for 6.0-9.5 weeks. When compared at the fish's respective acclimation temperature, the oxygen consumption rate and cardiac output were significantly higher in 5°C-acclimated than 0°C-acclimated fish. The 2.7-fold elevation in cardiac output in 5°C-acclimated fish (17.4 vs. 6.5 ml min-1 kg-1) was predominantly due to a doubling of stroke volume, likely in response to increased cardiac preload, as measured by higher central venous pressure (0.15 vs. 0.08 kPa); tachycardia was minor (29.5 vs. 25.2 beats min-1). When fish were acutely warmed, oxygen consumption rate increased by similar amounts in 0°C- and 5°C-acclimated fish at equivalent test temperatures. In both acclimation groups, the increases in oxygen consumption rate during acute heating were supported by increased cardiac output achieved by elevating heart rate, while stroke volume changed relatively little. Cardiac output was similar between both acclimation groups until 12°C when cardiac output became significantly higher in 5°C-acclimated fish, driven largely by their higher stroke volume. Although cardiac arrhythmias developed at a similar temperature (~14.5°C) in both acclimation groups, the hearts of 5°C-acclimated fish continued to pump until significantly higher temperatures (CTmax for cardiac function 17.7 vs. 15.0°C for 0°C-acclimated fish). These results demonstrate that N. coriiceps is capable of increasing routine cardiac output during both acute and chronic warming, although the mechanisms are different (heart rate-dependent versus primarily stroke volume-dependent regulation, respectively). Cardiac performance was enhanced at higher temperatures following 5°C acclimation, suggesting cardiovascular function may not constrain the capacity of N. coriiceps to withstand a warming climate. | [] |
Multi-site ice core Krypton stable isotope ratios
|
1543267 1543229 |
2020-10-22 | Buizert, Christo; Shackleton, Sarah; Severinghaus, Jeffrey P.; Brook, Edward J.; Baggenstos, Daniel; Bereiter, Bernhard; Etheridge, David; Bertler, Nancy; Pyne, Rebecca L.; Mulvaney, Robert; Mosley-Thompson, Ellen |
Collaborative research: Kr-86 as a proxy for barometric pressure variability and movement of the SH westerlies during the last
deglaciation |
Stable isotope ratios of atmospheric krypton, argon, nitrogen and oxygen were measured in late-Holocene ice core samples from nine sites in Antarctica and Greenland, for the purpose of calibrating the Kr-86 excess proxy as defined in Buizert and Severinghaus (2016). | ["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))"] |
ICECAP Basal Interface Specularity Content Profiles: IPY and OIB
|
0733025 1543452 0636724 1443690 |
2020-08-24 | Young, Duncan A.; Blankenship, Donald D.; Roberts, Jason; Siegert, Martin; van Ommen, Tas; Greenbaum, Jamin; Schroeder, Dustin |
Collaborative Research: Southern Plateau Ice-sheet Characterization and Evolution of the Central Antarctic Plate (SPICECAP) Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System IPY Research: Investigating the Cryospheric Evolution of the Central Antarctic Plate (ICECAP) East Antarctic Grounding Line Experiment (EAGLE) |
The International Collaborative Exploration of the Cryosphere though Airborne Profiling (ICECAP) collected five seasons of aerogeophysical data data through the NSFs International Polar Year and NASAs Operation Ice Bridge programs in East Antarctica, using the coherent HiCARS 60 MHz radar system. By comparing echo strengths for different focusing apertures, and accounting for the ranges and angles involved, we can derive the "specularity content" of the bed echo, a proxy for small scale bed roughness and a good indicator for subglacial water pressure in regions of distributed subglacial water (Schroeder et al., 2014, IEEE GRSL, 10.1109/LGRS.2014.2337878; IEEE; Dow et al., 2019, EPSL https://doi.org/10.1016/j.epsl.2019.115961). Specularity data are inherently noisy, so these products have been smoothed with a 1 km filter. | ["POLYGON((80 -65,89 -65,98 -65,107 -65,116 -65,125 -65,134 -65,143 -65,152 -65,161 -65,170 -65,170 -66.5,170 -68,170 -69.5,170 -71,170 -72.5,170 -74,170 -75.5,170 -77,170 -78.5,170 -80,161 -80,152 -80,143 -80,134 -80,125 -80,116 -80,107 -80,98 -80,89 -80,80 -80,80 -78.5,80 -77,80 -75.5,80 -74,80 -72.5,80 -71,80 -69.5,80 -68,80 -66.5,80 -65))"] |
Antarctic Tide Gauge Database, version 1
|
0125602 1443677 0125252 |
2020-07-10 | Howard, Susan L.; Padman, Laurence; King, Matt |
Ocean Tides around Antarctica and in the Southern Ocean |
The Antarctic Tide Gauge (AntTG) database provides tidal harmonic coefficients (amplitude and phase) for ocean surface height (tide-induced height perturbation relative to the seabed) at many coastal, ocean and ice shelf locations around Antarctica. The coefficients are provided for up to 8 tidal constituents (Q1, O1, P1, K1, N2 , M2, S2, K2) where data is available. These coefficients are primarily intended for users interested in validation of tide models for the Antarctic seas including the areas covered by the floating ice shelves (e.g., King and Padman, 2005; King et al., 2011; Stammer et al., 2014). The database is provided as single files in ASCII text and MATLAB *.mat formats, as well as in a KML package that can be viewed in Google Earth. Several different measurement systems were used to collect the data. The quality of database entries varies widely, from short records of unknown accuracy to very precise, long-term records from bottom pressure recorders in the ocean and GPS systems installed on ice shelves. This database provides sufficient quality control information (record length, time step, and measurement type) for a user to judge whether a tidal analysis at a particular site is likely to be useful for their application. | ["POLYGON((-180 -53,-144 -53,-108 -53,-72 -53,-36 -53,0 -53,36 -53,72 -53,108 -53,144 -53,180 -53,180 -56.7,180 -60.4,180 -64.1,180 -67.8,180 -71.5,180 -75.2,180 -78.9,180 -82.6,180 -86.3,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -86.3,-180 -82.6,-180 -78.9,-180 -75.2,-180 -71.5,-180 -67.8,-180 -64.1,-180 -60.4,-180 -56.7,-180 -53))"] |
Processed Current Measurement, Pressure and Temperature Data from the Southern Mid-Atlantic Ridge Spreading acquired during R/V Nathaniel B. Palmer expedition NBP1508 (2015)
|
1235094 |
2020-07-02 | Thurnherr, Andreas |
Collaborative Research: Flow, Turbulence and Mixing in Mid-Ocean Ridge Fracture Zone Canyons |
This data set was acquired with a Nortek Aquadopp Current Meter during R/V Nathaniel B. Palmer expedition NBP1508 conducted in 2015 (Chief Scientist: Dr. Louis St.Laurent, Investigator: Dr. Andreas Thurnherr). These data files are of NetCDF format and include Current Measurement, Pressure and Temperature data that were processed after acquisition. Data were acquired as part of the project(s): Collaborative Research: Flow, Turbulence and Mixing in Mid-Ocean Ridge Fracture Zone Canyons. Funding was provided by NSF award(s): OCE12-35094. | ["POINT(-14.5787 -21.1215)"] |
Processed Current Measurement, Pressure, Salinity and Temperature Data from the Southern Mid-Atlantic Ridge Spreading acquired during R/V Nathaniel B. Palmer expedition NBP1508
|
1235094 |
2020-07-02 | Thurnherr, Andreas |
Collaborative Research: Flow, Turbulence and Mixing in Mid-Ocean Ridge Fracture Zone Canyons |
This data set was acquired with a McLane Research Laboratories and Inc. MMP Mooring Profiler during R/V Nathaniel B. Palmer expedition NBP1508 conducted in 2015 (Chief Scientist: Dr. Louis St.Laurent, Investigator: Dr. Andreas Thurnherr). These data files are of NetCDF format and include Current Measurement, Pressure, Salinity and Temperature data that were processed after acquisition. Data were acquired as part of the project(s): Collaborative Research: Flow, Turbulence and Mixing in Mid-Ocean Ridge Fracture Zone Canyons. Funding was provided by NSF award(s): OCE12-35094. | ["POLYGON((-14.5787 -20.9223,-14.49208 -20.9223,-14.40546 -20.9223,-14.31884 -20.9223,-14.23222 -20.9223,-14.1456 -20.9223,-14.05898 -20.9223,-13.97236 -20.9223,-13.88574 -20.9223,-13.79912 -20.9223,-13.7125 -20.9223,-13.7125 -20.94222,-13.7125 -20.96214,-13.7125 -20.98206,-13.7125 -21.00198,-13.7125 -21.0219,-13.7125 -21.04182,-13.7125 -21.06174,-13.7125 -21.08166,-13.7125 -21.10158,-13.7125 -21.1215,-13.79912 -21.1215,-13.88574 -21.1215,-13.97236 -21.1215,-14.05898 -21.1215,-14.1456 -21.1215,-14.23222 -21.1215,-14.31884 -21.1215,-14.40546 -21.1215,-14.49208 -21.1215,-14.5787 -21.1215,-14.5787 -21.10158,-14.5787 -21.08166,-14.5787 -21.06174,-14.5787 -21.04182,-14.5787 -21.0219,-14.5787 -21.00198,-14.5787 -20.98206,-14.5787 -20.96214,-14.5787 -20.94222,-14.5787 -20.9223))"] |
South Pole ice core total air content
|
1443464 |
2019-12-11 | Sowers, Todd A. |
Collaborative Research: Inert Gas and Methane Based Climate Records throughout the South Pole Deep Ice Core |
The total air content in ice core samples are a fundamental indication of the multitude of processes that impact densification of snow in polar regions. In addition, variations in the elevation of the ice sheet directly control the pressure in the bubble close off region and thereby the total gas content. Attempts to remove the physical factors (temperature, accumulation rate, dust content, seasonality) impacting the total air content could provide a means of assessing variations in the elevation of the South Pole over the last 50,000 years. | ["POINT(0 -90)"] |
Noble Gas Data from recent ice in Antarctica for 86Kr problem
|
1543229 |
2019-08-02 | Severinghaus, Jeffrey; Shackleton, Sarah |
Collaborative research: Kr-86 as a proxy for barometric pressure variability and movement of the SH westerlies during the last
deglaciation |
This data comprises a survey of Recent ice from multiple sites in Antarctica using shallow ice cores to examine noble gas values in ice that nominally has the same Mean Ocean Temperature as today. The goal is to elucidate fractionation that occurs in the firn before air is trapped in bubbles in the ice, by making the assumption that the atmosphere noble gas content has not changed since this air was trappped. The ages of the air samples are typically early Industrial Revolution or late Holocene. | ["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))"] |
SUMO unmanned aerial system (UAS) atmospheric data
|
1341606 |
2019-07-10 | Cassano, John |
Collaborative Research: Seasonal Sea Ice Production in the Ross Sea, Antarctica |
Atmospheric boundary layer temperature, humidity, pressure, and wind profile data collected with the Small Unmanned Meteorological Observer (SUMO) unmanned aerial system (UAS) during the NBP1704 PIPERS cruise. | ["POLYGON((-180 -71.088,-179.7593 -71.088,-179.5186 -71.088,-179.2779 -71.088,-179.0372 -71.088,-178.7965 -71.088,-178.5558 -71.088,-178.3151 -71.088,-178.0744 -71.088,-177.8337 -71.088,-177.593 -71.088,-177.593 -71.5318,-177.593 -71.9756,-177.593 -72.4194,-177.593 -72.8632,-177.593 -73.307,-177.593 -73.7508,-177.593 -74.1946,-177.593 -74.6384,-177.593 -75.0822,-177.593 -75.526,-177.8337 -75.526,-178.0744 -75.526,-178.3151 -75.526,-178.5558 -75.526,-178.7965 -75.526,-179.0372 -75.526,-179.2779 -75.526,-179.5186 -75.526,-179.7593 -75.526,180 -75.526,179.1926 -75.526,178.3852 -75.526,177.5778 -75.526,176.7704 -75.526,175.963 -75.526,175.1556 -75.526,174.3482 -75.526,173.5408 -75.526,172.7334 -75.526,171.926 -75.526,171.926 -75.0822,171.926 -74.6384,171.926 -74.1946,171.926 -73.7508,171.926 -73.307,171.926 -72.8632,171.926 -72.4194,171.926 -71.9756,171.926 -71.5318,171.926 -71.088,172.7334 -71.088,173.5408 -71.088,174.3482 -71.088,175.1556 -71.088,175.963 -71.088,176.7704 -71.088,177.5778 -71.088,178.3852 -71.088,179.1926 -71.088,-180 -71.088))"] |
PIPERS Meteorology Rawinsonde Data
|
1341725 |
2019-06-12 | Guest, Peter |
Collaborative Research: Seasonal Sea Ice Production in the Ross Sea, Antarctica |
This file contains rawinsonde data from 134 rawisnonde soundings performed during the 2017 PIPERS cruise for the period 14 April 2330 – 5 June 1130 (UT). | ["POLYGON((-180 -62,-179.5 -62,-179 -62,-178.5 -62,-178 -62,-177.5 -62,-177 -62,-176.5 -62,-176 -62,-175.5 -62,-175 -62,-175 -63.6,-175 -65.2,-175 -66.8,-175 -68.4,-175 -70,-175 -71.6,-175 -73.2,-175 -74.8,-175 -76.4,-175 -78,-175.5 -78,-176 -78,-176.5 -78,-177 -78,-177.5 -78,-178 -78,-178.5 -78,-179 -78,-179.5 -78,180 -78,178.8 -78,177.6 -78,176.4 -78,175.2 -78,174 -78,172.8 -78,171.6 -78,170.4 -78,169.2 -78,168 -78,168 -76.4,168 -74.8,168 -73.2,168 -71.6,168 -70,168 -68.4,168 -66.8,168 -65.2,168 -63.6,168 -62,169.2 -62,170.4 -62,171.6 -62,172.8 -62,174 -62,175.2 -62,176.4 -62,177.6 -62,178.8 -62,-180 -62))"] |
AU1402 mooring data
|
1313826 |
2018-12-24 | Orsi, Alejandro |
Collaborative Research: Totten Glacier System and the Marine Record of Cryosphere - Ocean Dynamics |
An array of three moorings (M1-M3) with current meters, temperature, conductivity, and pressure (TCP) recorders were deployed along the eastern flank of the continental shelf off Sabrina Coast, at the main path of the Antarctic Coastal Current indicated by the uCTD data collected earlier during the cruise. These three US mooring were deployed at the 625-m (M1), 620-m (M2) and 1051-m (M3) isobaths. M1 was recovered on 25 February 2014, with a full data return from all of its instruments; whereas M2 and M3 were recovered in early 2015 on board of the Australian RVI Aurora Australis next year (cruise AU1402). The location and schematics of the mooring array design is described below, and also provided among the uploaded files. | ["POLYGON((119 -66,119.3 -66,119.6 -66,119.9 -66,120.2 -66,120.5 -66,120.8 -66,121.1 -66,121.4 -66,121.7 -66,122 -66,122 -66.1,122 -66.2,122 -66.3,122 -66.4,122 -66.5,122 -66.6,122 -66.7,122 -66.8,122 -66.9,122 -67,121.7 -67,121.4 -67,121.1 -67,120.8 -67,120.5 -67,120.2 -67,119.9 -67,119.6 -67,119.3 -67,119 -67,119 -66.9,119 -66.8,119 -66.7,119 -66.6,119 -66.5,119 -66.4,119 -66.3,119 -66.2,119 -66.1,119 -66))"] |
AU1402 Final UCTD data
|
1143833 |
2018-12-24 | Orsi, Alejandro |
Collaborative Research: Totten Glacier System and the Marine Record of Cryosphere - Ocean Dynamics |
Underway Salinity (Conductivity), Temperature, Depth (Pressure) profiles from AU1402, final, reduced, quality control version. Data are reported as an ascii table suitable for import to Ocean Data View. | ["POLYGON((119 -66,119.3 -66,119.6 -66,119.9 -66,120.2 -66,120.5 -66,120.8 -66,121.1 -66,121.4 -66,121.7 -66,122 -66,122 -66.1,122 -66.2,122 -66.3,122 -66.4,122 -66.5,122 -66.6,122 -66.7,122 -66.8,122 -66.9,122 -67,121.7 -67,121.4 -67,121.1 -67,120.8 -67,120.5 -67,120.2 -67,119.9 -67,119.6 -67,119.3 -67,119 -67,119 -66.9,119 -66.8,119 -66.7,119 -66.6,119 -66.5,119 -66.4,119 -66.3,119 -66.2,119 -66.1,119 -66))"] |
NBP1402 Final UCTD data
|
1143833 |
2018-12-23 | Orsi, Alejandro |
Collaborative Research: Totten Glacier System and the Marine Record of Cryosphere - Ocean Dynamics |
Underway Salinity (Conductivity), Temperature, Depth (Pressure) profiles from NBP1402, final, reduced, quality control version. Data are reported as an ascii table suitable for import to Ocean Data View. | ["POLYGON((117 -64,119.9 -64,122.8 -64,125.7 -64,128.6 -64,131.5 -64,134.4 -64,137.3 -64,140.2 -64,143.1 -64,146 -64,146 -64.4,146 -64.8,146 -65.2,146 -65.6,146 -66,146 -66.4,146 -66.8,146 -67.2,146 -67.6,146 -68,143.1 -68,140.2 -68,137.3 -68,134.4 -68,131.5 -68,128.6 -68,125.7 -68,122.8 -68,119.9 -68,117 -68,117 -67.6,117 -67.2,117 -66.8,117 -66.4,117 -66,117 -65.6,117 -65.2,117 -64.8,117 -64.4,117 -64))"] |
Supraglacial Lake Depths on McMurdo Ice Shelf, Antarctica
|
1443126 |
2018-09-04 | MacAyeal, Douglas; Banwell, Alison |
Impact of Supraglacial Lakes on Ice-Shelf Stability |
During the melt seasons of 2015/6 and 2016/7, water pressure gages were deployed on the McMurdo Ice Shelf to observe water depth in supraglacial lakes and streams. This was done in support of research directed toward understanding how filling and draining supraglacial lakes would induce ice-shelf flexure and fracture. | ["POLYGON((165.911079 -77.872851,165.941267 -77.872851,165.971455 -77.872851,166.001643 -77.872851,166.031831 -77.872851,166.062019 -77.872851,166.092207 -77.872851,166.122395 -77.872851,166.152583 -77.872851,166.182771 -77.872851,166.212959 -77.872851,166.212959 -77.8781411,166.212959 -77.8834312,166.212959 -77.8887213,166.212959 -77.8940114,166.212959 -77.8993015,166.212959 -77.9045916,166.212959 -77.9098817,166.212959 -77.9151718,166.212959 -77.9204619,166.212959 -77.925752,166.182771 -77.925752,166.152583 -77.925752,166.122395 -77.925752,166.092207 -77.925752,166.062019 -77.925752,166.031831 -77.925752,166.001643 -77.925752,165.971455 -77.925752,165.941267 -77.925752,165.911079 -77.925752,165.911079 -77.9204619,165.911079 -77.9151718,165.911079 -77.9098817,165.911079 -77.9045916,165.911079 -77.8993015,165.911079 -77.8940114,165.911079 -77.8887213,165.911079 -77.8834312,165.911079 -77.8781411,165.911079 -77.872851))"] |
Weather data from LARISSA / SCAR Inlet Rapid AMIGOS and cGPS stations
|
1565576 |
2018-02-13 | Scambos, Ted |
RAPID: Observing the Disintegration of the Scar Inlet Ice Shelf |
Weather and instrument data from the Automated Meterology Ice Geophysics Observation System (AMIGOS) stations installed as part of the LARISSA and RAPID Scar Inlet funded grants from NSF-PLR. The data include temperature, wind, pressure, humidity, station position (coarse), and station health. | ["POLYGON((-63 -64.75,-62.6 -64.75,-62.2 -64.75,-61.8 -64.75,-61.4 -64.75,-61 -64.75,-60.6 -64.75,-60.2 -64.75,-59.8 -64.75,-59.4 -64.75,-59 -64.75,-59 -64.9,-59 -65.05,-59 -65.2,-59 -65.35,-59 -65.5,-59 -65.65,-59 -65.8,-59 -65.95,-59 -66.1,-59 -66.25,-59.4 -66.25,-59.8 -66.25,-60.2 -66.25,-60.6 -66.25,-61 -66.25,-61.4 -66.25,-61.8 -66.25,-62.2 -66.25,-62.6 -66.25,-63 -66.25,-63 -66.1,-63 -65.95,-63 -65.8,-63 -65.65,-63 -65.5,-63 -65.35,-63 -65.2,-63 -65.05,-63 -64.9,-63 -64.75))"] |
SUMO unmanned aerial system (UAS) atmospheric data
|
1245737 |
2017-09-07 | Cassano, John |
Collaborative Research: Antarctic Automatic Weather Station Program 2013-2017 |
Atmospheric boundary layer temperature, humidity, pressure, and wind profile data collected with the Small Unmanned Meteorological Observer (SUMO) unmanned aerial system (UAS) | ["POLYGON((161.714 -77.522,162.6077 -77.522,163.5014 -77.522,164.3951 -77.522,165.2888 -77.522,166.1825 -77.522,167.0762 -77.522,167.9699 -77.522,168.8636 -77.522,169.7573 -77.522,170.651 -77.522,170.651 -77.6702,170.651 -77.8184,170.651 -77.9666,170.651 -78.1148,170.651 -78.263,170.651 -78.4112,170.651 -78.5594,170.651 -78.7076,170.651 -78.8558,170.651 -79.004,169.7573 -79.004,168.8636 -79.004,167.9699 -79.004,167.0762 -79.004,166.1825 -79.004,165.2888 -79.004,164.3951 -79.004,163.5014 -79.004,162.6077 -79.004,161.714 -79.004,161.714 -78.8558,161.714 -78.7076,161.714 -78.5594,161.714 -78.4112,161.714 -78.263,161.714 -78.1148,161.714 -77.9666,161.714 -77.8184,161.714 -77.6702,161.714 -77.522))"] |
Biosamples and observations from Weddell Seal colonies in McMurdo Sound during the 2015-2016 Antarctic field season
|
1443554 |
2017-05-27 | Hindle, Allyson; Buys, Emmanuel |
Unraveling the Genomic and Molecular Basis of the Dive Response: Nitric Oxide Signaling and Vasoregulation in the Weddell Seal |
The Weddell seal is a champion diving mammal - key elements of their physiological specializations to breath-hold are their ability for remarkable adjustment of their heart and blood vessel system, coordinating blood pressure and flow to specific body regions based on their metabolic requirements, and their ability to sustain periods without oxygen. The goal of this study is to unravel the molecular mechanisms underlying the dive response, specifically, to study a signaling pathway that coordinates local blood flow. This dataset identifies what animals were sampled and the details of what biosamples were collected to test the hypothesis that signaling modifications prevent local blood vessel changes under low oxygen conditions, thereby allowing the centrally mediated diving reflex to override local perfusion control. The metadata also details cryopreserved cells and cell lines that can be used to study the molecular effects of low oxygen conditions in the laboratory | ["POLYGON((166.163 -76.665,166.2635 -76.665,166.364 -76.665,166.4645 -76.665,166.565 -76.665,166.6655 -76.665,166.766 -76.665,166.8665 -76.665,166.967 -76.665,167.0675 -76.665,167.168 -76.665,167.168 -76.782,167.168 -76.899,167.168 -77.016,167.168 -77.133,167.168 -77.25,167.168 -77.367,167.168 -77.484,167.168 -77.601,167.168 -77.718,167.168 -77.835,167.0675 -77.835,166.967 -77.835,166.8665 -77.835,166.766 -77.835,166.6655 -77.835,166.565 -77.835,166.4645 -77.835,166.364 -77.835,166.2635 -77.835,166.163 -77.835,166.163 -77.718,166.163 -77.601,166.163 -77.484,166.163 -77.367,166.163 -77.25,166.163 -77.133,166.163 -77.016,166.163 -76.899,166.163 -76.782,166.163 -76.665))"] |
Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antarctica
|
1142156 |
2015-01-01 | Marschall, Horst |
Zircon Hf Isotopes and the Continental Evolution of Dronning Maud Land, East Antacrtica |
Geochemical studies of single mineral grains in rocks can be probed to reconstruct the history of our planet. The mineral zircon (ZrSiO4) is of unique importance in that respect because of its reliability as a geologic clock due to its strong persistence against weathering, transport and changes in temperature and pressure. Uranium-Lead (U-Pb) dating of zircon grains is, perhaps, the most frequently employed method of extracting time information on geologic processes that shaped the continental crust, and has been used to constrain the evolution of continents and mountain belts through time. In addition, the isotopic composition of the element Hafnium (Hf) in zircon is used to date when the continental crust was generated by extraction of magma from the underlying mantle. Melting of rocks in the mantle and deep in the continental crust are key processes in the evolution of the continents, and they are recorded in the Hf isotopic signatures of zircon. Although the analytical procedures for U-Pb dating and Hf isotope analyses of zircon are robust now, our understanding of zircon growth and its exchange of elements and isotopes with its surrounding rock or magma are still underdeveloped. The focus of the proposed study, therefore, is to unravel the evolution of zircon Hf isotopes in rocks that were formed deep in the Earth's crust, and more specifically, to apply these isotopic methods to rocks collected in Dronning Maud Land (DML), East Antarctica. Dronning Maud Land (DML) occupied a central location during the formation of supercontinents - large landmasses made up of all the continents that exist today - more than 500 million years ago. It is currently thought that supercontinents were formed and dismembered five or six times throughout Earth's history. The area of DML is key for understanding the formation history of the last two supercontinents. The boundaries of continents that were merged to form those supercontinents are most likely hidden in DML. In this study, the isotopic composition of zircon grains recovered from DML rocks will be employed to identify these boundaries across an extensive section through the area. The rock samples were collected by the investigator during a two-month expedition to Antarctica in the austral summer of 2007-2008. The results of dating and isotope analyses of zircon of the different DML crustal domains will deliver significant insight into the regional geology of East Antarctica and its previous northern extension into Africa. This has significance for the reconstruction of the supercontinents and defining the continental boundaries in DML. | ["POLYGON((-6.44 -71.93,-5.378 -71.93,-4.316 -71.93,-3.254 -71.93,-2.192 -71.93,-1.13 -71.93,-0.068 -71.93,0.994 -71.93,2.056 -71.93,3.118 -71.93,4.18 -71.93,4.18 -71.998,4.18 -72.066,4.18 -72.134,4.18 -72.202,4.18 -72.27,4.18 -72.338,4.18 -72.406,4.18 -72.474,4.18 -72.542,4.18 -72.61,3.118 -72.61,2.056 -72.61,0.994 -72.61,-0.068 -72.61,-1.13 -72.61,-2.192 -72.61,-3.254 -72.61,-4.316 -72.61,-5.378 -72.61,-6.44 -72.61,-6.44 -72.542,-6.44 -72.474,-6.44 -72.406,-6.44 -72.338,-6.44 -72.27,-6.44 -72.202,-6.44 -72.134,-6.44 -72.066,-6.44 -71.998,-6.44 -71.93))"] |
The Chemical Ecology of Shallow-water Marine Macroalgae and Invertebrates on the Antarctic Peninsula
|
0838773 |
2011-01-01 | McClintock, James; Amsler, Charles |
Collaborative Research: The Chemical Ecology of Shallow-water Marine Macroalgae and Invertebrates on the Antarctic Peninsula - continuing Collaborative Research: The Chemical Ecology of Shallow-water Marine Macroalgae and Invertebrates on the Antarctic Peninsula |
The near shore environments of the western Antarctic Peninsula (WAP) harbor extremely high densities of mesograzers (small invertebrate predators approximately 1-25 mm in length) such as benthic amphipods, as well as rich assemblages of macroalgae, endophytes, and macroinvertebrates. Unlike temperate and tropical shallow marine environments, where fish and sea urchins are key grazers structuring the community, mesograzers appear to be much more important in the WAP. Accordingly, the proposed research has two main objectives: (1) To further investigate the interactions between the ecologically dominant large macrophytes, filamentous epi/endophytes, and mesograzers and (2) To determine the nature of interactions between mesograzers and sessile invertebrates. Specifically, the research will examine the following hypotheses: 1: The effects of endophytes on macrophytes are often negative, and consequently macrophytes defend against endophytic infection. 2: Mesoherbivores prevent filamentous algal species, common in the intertidal, from dominating subtidal assemblages. 3: Mesograzer predation pressure on sessile benthic macroinvertebrates, primarily sponges and tunicates, is greatest in shallow habitats dominated by macrophytes, and this impacts depth distributions of macroinvertebrate species. 4: Benthic macroinvertebrates may defend against mesograzers with secondary metabolites which effect molting and/or deter feeding. Broader impacts include involvement of undergraduates, including minorities, in research; training of graduate students, and continuation of the highly successful UAB IN ANTARCTICA interactive web program (two time recipient of awards of excellence from the US Council for Advancement and Support of Education). The researchers also will share their scientific endeavors with teachers, K-12 students, and other members of the community at large while in residence in Antarctica. In addition, the investigators will request the participation of a PolarTREC teacher. | ["POLYGON((-79 -60,-76.4 -60,-73.8 -60,-71.2 -60,-68.6 -60,-66 -60,-63.4 -60,-60.8 -60,-58.2 -60,-55.6 -60,-53 -60,-53 -61,-53 -62,-53 -63,-53 -64,-53 -65,-53 -66,-53 -67,-53 -68,-53 -69,-53 -70,-55.6 -70,-58.2 -70,-60.8 -70,-63.4 -70,-66 -70,-68.6 -70,-71.2 -70,-73.8 -70,-76.4 -70,-79 -70,-79 -69,-79 -68,-79 -67,-79 -66,-79 -65,-79 -64,-79 -63,-79 -62,-79 -61,-79 -60))"] |
The Chemical Ecology of Shallow-water Marine Macroalgae and Invertebrates on the Antarctic Peninsula
|
0838776 |
2011-01-01 | Baker, Bill |
Collaborative Research: The Chemical Ecology of Shallow-water Marine Macroalgae and Invertebrates on the Antarctic Peninsula - continuing Collaborative Research: The Chemical Ecology of Shallow-water Marine Macroalgae and Invertebrates on the Antarctic Peninsula |
The near shore environments of the western Antarctic Peninsula (WAP) harbor extremely high densities of mesograzers (small invertebrate predators approximately 1-25 mm in length) such as benthic amphipods, as well as rich assemblages of macroalgae, endophytes, and macroinvertebrates. Unlike temperate and tropical shallow marine environments, where fish and sea urchins are key grazers structuring the community, mesograzers appear to be much more important in the WAP. Accordingly, the proposed research has two main objectives: (1) To further investigate the interactions between the ecologically dominant large macrophytes, filamentous epi/endophytes, and mesograzers and (2) To determine the nature of interactions between mesograzers and sessile invertebrates. Specifically, the research will examine the following hypotheses: 1: The effects of endophytes on macrophytes are often negative, and consequently macrophytes defend against endophytic infection. 2: Mesoherbivores prevent filamentous algal species, common in the intertidal, from dominating subtidal assemblages. 3: Mesograzer predation pressure on sessile benthic macroinvertebrates, primarily sponges and tunicates, is greatest in shallow habitats dominated by macrophytes, and this impacts depth distributions of macroinvertebrate species. 4: Benthic macroinvertebrates may defend against mesograzers with secondary metabolites which effect molting and/or deter feeding. Broader impacts include involvement of undergraduates, including minorities, in research; training of graduate students, and continuation of the highly successful UAB IN ANTARCTICA interactive web program (two time recipient of awards of excellence from the US Council for Advancement and Support of Education). The researchers also will share their scientific endeavors with teachers, K-12 students, and other members of the community at large while in residence in Antarctica. In addition, the investigators will request the participation of a PolarTREC teacher. | ["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))"] |
Abandoned Elephant Seal Colonies in Antarctica: Integration of Genetic, Isotopic, and Geologic Approaches toward Understanding Holocene Environmental Change
|
0439906 |
2010-01-01 | Koch, Paul |
Collaborative Research: Abandoned Elephant Seal Colonies in Antarctica: Integration of Genetic, Isotopic, and Geologic Approaches toward Understanding Holocene Environmental Change |
During previous NSF-sponsored research, the PI's discovered that southern elephant seal colonies once existed along the Victoria Land coast (VLC) of Antarctica, a region where they are no longer observed. Molted seal skin and hair occur along 300 km of coastline, more than 1000 km from any extant colony. The last record of a seal at a former colony site is at ~A.D. 1600. Because abandonment occurred prior to subantarctic sealing, disappearance of the VLC colony probably was due to environmental factors, possibly cooling and encroachment of land-fast, perennial sea ice that made access to haul-out sites difficult. The record of seal inhabitation along the VLC, therefore, has potential as a proxy for climate change. Elephant seals are a predominantly subantarctic species with circumpolar distribution. Genetic studies have revealed significant differentiation among populations, particularly with regard to that at Macquarie I., which is the extant population nearest to the abandoned VLC colony. Not only is the Macquarie population unique genetically, but it is has undergone unexplained decline of 2%/yr over the last 50 years3. In a pilot study, genetic analyses showed a close relationship between the VLC seals and those at Macquarie I. An understanding of the relationship between the two populations, as well as of the environmental pressures that led to the demise of the VLC colonies, will provide a better understanding of present-day population genetic structure, the effect of environmental change on seal populations, and possibly the reasons underlying the modern decline at Macquarie Island. This project addresses several key research problems: (1) Why did elephant seals colonize and then abandon the VLC? (2) What does the elephant seal record reveal about Holocene climate change and sea-ice conditions? (3) What were the foraging strategies of the seals and did these strategies change over time as climate varied? (4) How does the genetic structure of the VLC seals relate to extant populations? (5) How did genetic diversity change over time and with colony decline? (6) Using ancient samples to estimate mtDNA mutation rates, what can be learned about VLC population dynamics over time? (7) What was the ecological relationship between elephant seals and Adelie penguins that occupied the same sites, but apparently at different times? The proposed work includes the professional training of young researchers and incorporation of data into graduate and undergraduate courses. Because of extreme isolation of the Antarctic continent since the Early Oligocene, one expects a unique invertebrate benthic fauna with a high degree of endemism. Yet some invertebrate taxa that constitute important ecological components of sedimentary benthic communities include more than 40 percent non-endemic species (e.g., benthic polychaetes). To account for non-endemic species, intermittent genetic exchange must occur between Antarctic and other (e.g. South American) populations. The most likely mechanism for such gene flow, at least for in-faunal and mobile macrobenthos, is dispersal of planktonic larvae across the sub- Antarctic and Antarctic polar fronts. To test for larval dispersal as a mechanism of maintaining genetic continuity across polar fronts, the scientists propose to (1) take plankton samples along transects across Drake passage during both the austral summer and winter seasons while concurrently collecting the appropriate hydrographic data. Such data will help elucidate the hydrographic mechanisms that allow dispersal across Drake Passage. Using a molecular phylogenetic approach, they will (2) compare seemingly identical adult forms from Antarctic and South America continents to identify genetic breaks, historical gene flow, and control for the presence of cryptic species. (3) Similar molecular tools will be used to relate planktonic larvae to their adult forms. Through this procedure, they propose to link the larval forms respectively to their Antarctic or South America origins. The proposed work builds on previous research that provides the basis for this effort to develop a synthetic understanding of historical gene flow and present day dispersal mechanism in South American/Drake Passage/ Antarctic Peninsular region. Furthermore, this work represents one of the first attempts to examine recent gene flow in Antarctic benthic invertebrates. Graduate students and a postdoctoral fellow will be trained during this research | ["POLYGON((162 -72,162.6 -72,163.2 -72,163.8 -72,164.4 -72,165 -72,165.6 -72,166.2 -72,166.8 -72,167.4 -72,168 -72,168 -72.6,168 -73.2,168 -73.8,168 -74.4,168 -75,168 -75.6,168 -76.2,168 -76.8,168 -77.4,168 -78,167.4 -78,166.8 -78,166.2 -78,165.6 -78,165 -78,164.4 -78,163.8 -78,163.2 -78,162.6 -78,162 -78,162 -77.4,162 -76.8,162 -76.2,162 -75.6,162 -75,162 -74.4,162 -73.8,162 -73.2,162 -72.6,162 -72))"] |
Impacts of Elevated pCO2 on a Dominant Aragonitic Pteropod (Thecosomata) and its Specialist Predator (Gymnosomata) in the Ross Sea
|
0538479 |
2010-01-01 | Seibel, Brad |
Collaborative Research: Impacts of Elevated pCO2 on a Dominant Aragonitic Pteropod (Thecosomata) and its Specialist Predator (Gymnosomata) in the Ross Sea |
Rising atmospheric carbon dioxide concentrations have resulted in greater oceanic uptake of anthropogenic carbon dioxide. Elevated partial pressure of carbon dioxide can impact marine organisms both via decreased carbonate saturation that affects calcification rates and via disturbance to acid-base (metabolic) physiology. Pteropod molluscs (Thecosomata) form shells made of aragonite, a type of calcium carbonate that is highly soluble, suggesting that these organisms may be particularly sensitive to increasing carbon dioxide and reduced carbonate ion concentration. Thecosome pteropods, which dominate the calcium carbonate export south of the Antarctic Polar Front, will be the first major group of marine calcifying organisms to experience carbonate undersaturation within parts of their present-day geographical ranges as a result of anthropogenic carbon dioxide. An unusual, co-evolved relationship between thecosomes and their specialized gymnosome predators provides a unique backdrop against which to assess the physiological and ecological importance of elevated partial pressure of carbon dioxide. Pteropods are functionally important components of the Antarctic ecosystem with potential to influence phytoplankton stocks, carbon export, and dimethyl sulfide levels that, in turn, influence global climate through ocean-atmosphere feedback loops. The research will quantify the impact of elevated carbon dioxide on a dominant aragonitic pteropod, Limacina helicina, and its specialist predator, the gymnosome Clione antarctica, in the Ross Sea through laboratory experimentation. Results will be disseminated broadly to enhance scientific understanding in this field. The project involves collaboration between researchers at a predominantly undergraduate institution with a significant enrollment of students that are typically underrepresented in the research environment (California State University San Marcos - CSUSM) and at a Ph.D.-granting institution (University of Rhode Island - URI). The program will promote education and learning through the joint education of undergraduate students and graduate students at CSUSM and URI as part of a research team, as well as through the teaching activities of the principal investigators. Dr. Keating, CSUSM professor of science education, will participate in the McMurdo fieldwork and lead the outreach opportunities for the project. | ["POLYGON((166 -77,166.1 -77,166.2 -77,166.3 -77,166.4 -77,166.5 -77,166.6 -77,166.7 -77,166.8 -77,166.9 -77,167 -77,167 -77.1,167 -77.2,167 -77.3,167 -77.4,167 -77.5,167 -77.6,167 -77.7,167 -77.8,167 -77.9,167 -78,166.9 -78,166.8 -78,166.7 -78,166.6 -78,166.5 -78,166.4 -78,166.3 -78,166.2 -78,166.1 -78,166 -78,166 -77.9,166 -77.8,166 -77.7,166 -77.6,166 -77.5,166 -77.4,166 -77.3,166 -77.2,166 -77.1,166 -77))"] |
Atmospheric Boundary Layer Measurements on the Weddell Sea Drifting Station
|
9024544 |
2010-01-01 | Andreas, Edgar |
Atmospheric Boundary Layer Measurements on the Weddell Sea Drifting Station |
Location: Ice camp on perennial sea ice in the southwestern corner of the Weddell Sea, Antarctic The first direct radiative and turbulent surface flux measurements ever made over floating Antarctic sea ice. The data are from Ice Station Weddell as it drifted in the western Weddell Sea from February to late May 1992. Data Types: Hourly measurements of the turbulent surface fluxes of momentum and sensible and latent heat by eddy covariance at a height of 4.65 m above snow-covered sea ice. Instruments were a 3-axis sonic anemometer/thermometer and a Lyman-alpha hygrometer. Hourly, surface-level measurements of the four radiation components: in-coming and out-going longwave and shortwave radiation. Instruments were hemispherical pyranometers and pyrgeometers. Hourly mean values of standard meteorological variables: air temperature, dew point temperature, wind speed and direction, barometric pressure, surface temperature. Instruments were a propeller-vane for wind speed and direction and cooled-mirror dew-point hygrometers and platinum resistance thermometers for dew-points and temperatures. Surface temperature came from a Barnes PRT-5 infrared thermometer. Flux Data The entire data kit is bundled as a zip file named ISW_Flux_Data.zip The main data file is comma delimited. The README file is ASCII. The associated reprints of publications are in pdf. Radiosounding data: On Ice Station Weddell, typically twice a day from 21 February through 4 June 1992 made with both tethered (i.e., only boundary-layer profiles) and (more rarely) free-flying sondes that did not measure wind speed. (168 soundings). ISW Radiosoundings The entire data kit is bundled as a zip file named ISW_Radiosounding.zip. The README file is in ASCII. Two summary files that include the list of sounding and the declinations are in ASCII. The 168 individual sounding files are in ASCII. Two supporting publications that describe the data and some analyses are in pdf. Radiosounding data collected from the Russian ship Akademic Fedorov from 26 May through 5 June 1992 at 6-hourly intervals as it approached Ice Station Weddell from the north. These soundings include wind vector, temperature, humidity, and pressure. (40 soundings) Akademic Federov Radiosoundings The entire data kit is bundled as a zip file named Akad_Federov_Radiosounding.zip. The README file is in ASCII. A summary file that lists the soundings is in ASCII. The 40 individual sounding files are in ASCII. Two supporting publications that describe the data and some analyses are in pdf. Documentation: Andreas, E. L, and K. J. Claffey, 1995: Air-ice drag coefficients in the western Weddell Sea: 1. Values deduced from profile measurements. Journal of Geophysical Research, 100, 4821–4831. Andreas, E. L, K. J. Claffey, and A. P. Makshtas, 2000: Low-level atmospheric jets and inversions over the western Weddell Sea. Boundary-Layer Meteorology, 97, 459–486. Andreas, E. L, R. E. Jordan, and A. P. Makshtas, 2004: Simulations of snow, ice, and near-surface atmospheric processes on Ice Station Weddell. Journal of Hydrometeorology, 5, 611–624. Andreas, E. L, R. E. Jordan, and A. P. Makshtas, 2005: Parameterizing turbulent exchange over sea ice: The Ice Station Weddell results. Boundary-Layer Meteorology, 114, 439–460. Andreas, E. L, P. O. G. Persson, R. E. Jordan, T. W. Horst, P. S. Guest, A. A. Grachev, and C. W. Fairall, 2010: Parameterizing turbulent exchange over sea ice in winter. Journal of Hydrometeorology, 11, 87–104. Claffey, K. J., E. L Andreas, and A. P. Makshtas, 1994: Upper-air data collected on Ice Station Weddell. Special Report 94-25, U.S. Army Cold Regions Research and Engineering Laboratory, Hanover, NH, 62 pp. ISW Group, 1993: Weddell Sea exploration from ice station. Eos, Transactions, American Geophysical Union, 74, 121–126. Makshtas, A. P., E. L Andreas, P. N. Svyaschennikov, and V. F. Timachev, 1999: Accounting for clouds in sea ice models. Atmospheric Research, 52, 77–113. | ["POLYGON((-53.8 -61.2,-52.74 -61.2,-51.68 -61.2,-50.62 -61.2,-49.56 -61.2,-48.5 -61.2,-47.44 -61.2,-46.38 -61.2,-45.32 -61.2,-44.26 -61.2,-43.2 -61.2,-43.2 -62.22,-43.2 -63.24,-43.2 -64.26,-43.2 -65.28,-43.2 -66.3,-43.2 -67.32,-43.2 -68.34,-43.2 -69.36,-43.2 -70.38,-43.2 -71.4,-44.26 -71.4,-45.32 -71.4,-46.38 -71.4,-47.44 -71.4,-48.5 -71.4,-49.56 -71.4,-50.62 -71.4,-51.68 -71.4,-52.74 -71.4,-53.8 -71.4,-53.8 -70.38,-53.8 -69.36,-53.8 -68.34,-53.8 -67.32,-53.8 -66.3,-53.8 -65.28,-53.8 -64.26,-53.8 -63.24,-53.8 -62.22,-53.8 -61.2))"] |
Boron in Antarctic granulite-facies rocks: under what conditions is boron retained in the middle crust?
|
0228842 |
2009-01-01 | Grew, Edward |
Boron in Antarctic granulite-facies rocks: under what conditions is boron retained in the middle crust? |
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to investigate the role and fate of Boron in high-grade metamorphic rocks of the Larsemann Hills region of Antarctica. Trace elements provide valuable information on the changes sedimentary rocks undergo as temperature and pressure increase during burial. One such element, boron, is particularly sensitive to increasing temperature because of its affinity for aqueous fluids, which are lost as rocks are buried. Boron contents of unmetamorphosed pelitic sediments range from 20 to over 200 parts per million, but rarely exceed 5 parts per million in rocks subjected to conditions of the middle and lower crust, that is, temperatures of 700 degrees C or more in the granulite-facies, which is characterized by very low water activities at pressures of 5 to 10 kbar (18-35 km burial). Devolatization reactions with loss of aqueous fluid and partial melting with removal of melt have been cited as primary causes for boron depletion under granulite-facies conditions. Despite the pervasiveness of both these processes, rocks rich in boron are locally found in the granulite-facies, that is, there are mechanisms for retaining boron during the metamorphic process. The Larsemann Hills, Prydz Bay, Antarctica, are a prime example. More than 20 lenses and layered bodies containing four borosilicate mineral species crop out over a 50 square kilometer area, which thus would be well suited for research on boron-rich granulite-facies metamorphic rocks. While most investigators have focused on the causes for loss of boron, this work will investigate how boron is retained during high-grade metamorphism. Field observations and mapping in the Larsemann Hills, chemical analyses of minerals and their host rocks, and microprobe age dating will be used to identify possible precursors and deduce how the precursor materials recrystallized into borosilicate rocks under granulite-facies conditions. The working hypothesis is that high initial boron content facilitates retention of boron during metamorphism because above a certain threshold boron content, a mechanism 'kicks in' that facilitates retention of boron in metamorphosed rocks. For example, in a rock with large amounts of the borosilicate tourmaline, such as stratabound tourmalinite, the breakdown of tourmaline to melt could result in the formation of prismatine and grandidierite, two borosilicates found in the Larsemann Hills. This situation is rarely observed in rocks with modest boron content, in which breakdown of tourmaline releases boron into partial melts, which in turn remove boron when they leave the system. Stratabound tourmalinite is associated with manganese-rich quartzite, phosphorus-rich rocks and sulfide concentrations that could be diagnostic for recognizing a tourmalinite protolith in a highly metamorphosed complex where sedimentary features have been destroyed by deformation. Because partial melting plays an important role in the fate of boron during metamorphism, our field and laboratory research will focus on the relationship between the borosilicate units, granite pegmatites and other granitic intrusives. The results of our study will provide information on cycling of boron at deeper levels in the Earth's crust and on possible sources of boron for granites originating from deep-seated rocks. An undergraduate student will participate in the electron microprobe age-dating of monazite and xenotime as part of a senior project, thereby integrating the proposed research into the educational mission of the University of Maine. In response to a proposal for fieldwork, the Australian Antarctic Division, which maintains Davis station near the Larsemann Hills, has indicated that they will support the Antarctic fieldwork. | ["POLYGON((76 -69.3,76.05 -69.3,76.1 -69.3,76.15 -69.3,76.2 -69.3,76.25 -69.3,76.3 -69.3,76.35 -69.3,76.4 -69.3,76.45 -69.3,76.5 -69.3,76.5 -69.32,76.5 -69.34,76.5 -69.36,76.5 -69.38,76.5 -69.4,76.5 -69.42,76.5 -69.44,76.5 -69.46,76.5 -69.48,76.5 -69.5,76.45 -69.5,76.4 -69.5,76.35 -69.5,76.3 -69.5,76.25 -69.5,76.2 -69.5,76.15 -69.5,76.1 -69.5,76.05 -69.5,76 -69.5,76 -69.48,76 -69.46,76 -69.44,76 -69.42,76 -69.4,76 -69.38,76 -69.36,76 -69.34,76 -69.32,76 -69.3))"] |
Diving Physiology and Behavior of Emperor Penguins
|
0229638 |
2008-01-01 | Ponganis, Paul |
Diving Physiology and Behavior of Emperor Penguins |
The emperor penguin, Aptenodytes forsteri, is the premier avian diver and a top predator in the Antarctic ecosystem. The routine occurrence of 500-m diver during foraging trips to sea is both a physiological and behavior enigma. The objectives of this project address how and why emperors dive as deep and long as they do. The project examines four major topics in the diving biology of emperor penguins: pressure tolerance, oxygen store management, end-organ tolerance of diving hypoxemia/ischemia, and deep-dive foraging behavior. These subjects are relevant to the role of the emperor as a top predator in the Antarctic ecosystem, and to critical concepts in diving physiology, including decompression sickness, nitrogen narcosis, shallow water blackout, hypoxemic tolerance, and extension of aerobic dive time. The following hypotheses will be tested: 1) Prevention of nitrogen narcosis and decompression sickness in emperor penguins is achieved by inhibition of pulmonary gas exchange at depth. 2) Shallow water black out does not occur because of greater cerebral hypoxemic tolerance, and, in deep dives, because of resumption of pulmonary gas exchange during final ascent. 3) The rate of depletion of the blood oxygen store is a function of depth of dive and heart rate. 4) The aerobic dive limit (ADL) reflects the onset of lactate accumulation in locomotory muscle, not total depletion of all oxygen stores. 5) Elevation of tissue antioxidant capacity and free-radical scavenging enzyme activities protect against the routine ischemia/reperfusion which occur during diving. 6) During deep dives, the Antarctic silverfish, Pleuorogramma antarcticum, is the primary prey item for emperors. In addition to evaluation of the hypotheses below, the project has broader impacts in several areas such as partnership with foreign and national institutes and organizations (e.g., the National Institute of Polar Research of Japan, Centro de Investigacioines del Noroeste of Mexico, National Geographic, the University of Texas Southwestern Medical Center, and Sea World). Participation in National Geographic television documentaries will provide unique educational opportunities for the general public; development of state-of-the-art technology (e.g., blood oxygen electrode recorders, blood samplers, and miniaturized digital cameras) will lay the groundwork for future research by this group and others; and the effects of the B15 iceberg on breeding success of emperor penguins will continue to be evaluated with population censuses during planned fieldwork at several Ross Sea emperor penguin colonies. | ["POLYGON((163 -77,163.4 -77,163.8 -77,164.2 -77,164.6 -77,165 -77,165.4 -77,165.8 -77,166.2 -77,166.6 -77,167 -77,167 -77.1,167 -77.2,167 -77.3,167 -77.4,167 -77.5,167 -77.6,167 -77.7,167 -77.8,167 -77.9,167 -78,166.6 -78,166.2 -78,165.8 -78,165.4 -78,165 -78,164.6 -78,164.2 -78,163.8 -78,163.4 -78,163 -78,163 -77.9,163 -77.8,163 -77.7,163 -77.6,163 -77.5,163 -77.4,163 -77.3,163 -77.2,163 -77.1,163 -77))"] |
Comprehensive Biological Study of Vostok Accretion Ice
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0536870 |
2008-01-01 | Rogers, Scott O. |
Comprehensive Biological Study of Vostok Accretion Ice |
The large subglacial Lake Vostok in Antarctica is unique ecological site with a novel microbial biota. The temperatures, pressures and lack of light all select for organisms that may not exist anywhere else on Earth. The accretion ice (lake water frozen to the bottom of the lower surface of the glacier) has preserved microbial samples from each region of Lake Vostok as the glacier passes over and into the lake. Thus, without contaminating the lake with microorganisms from the surface, microbes originating from the lake can be collected, transported to the laboratory and studied. Two of the deepest ice cores sections in this project are part of the international allocation. The will be shared between four researchers (Sergey Bulat from Russia, Jean-Robert Petit and Daniel Prieur from France, Scott Rogers from USA). The United States team will study, isolate, and characterize bacteria, fungi, and viruses that have been sampled from the lake through the process of ice accretion to the lower surface of 3500+m thick glacier overriding the lake. The project will involve a suite of methods, including molecular, morphological, and cultural. This includes observation and description by fluorescence, light, and electron microscopy, isolation on thirteen separate cultural media, polymerase chain reaction amplification, DNA sequencing, and phylogenetic analyses. Eleven accretion ice core sections, as well as two glacial ice core sections. As well as two glacial ice core sections will be studied. The accretion ice core sections, as well as two glacial ice core sections will be studied. The accretion ice core sections represent all of the major regions of the lake that have been sampled by the accretion process in the vicinity of the Vostok 5G ice core. The broader impacts of the work relate to the impact the results will have on the filed. These long=isolated lakes, deep below the Antarctic ice sheet may contain novel uniquely adapted organisms. Glacial ice contains an enormous diversity of entrapped microbes, some of which may be metabolically active in the ice. The microbes from Lake Vostok are of special interest, since they are adapted to cold, dark, and high pressure. Thus, their enzyme systems and biochemical pathways may be significantly different from those in the microbes that are the subject of current studies. As such, these organisms may form compounds that may have useful applications. Also, study of the accretion ice, and eventually the water, from Lake Vostok will provide a basis for the study of other subglacial lakes. Additionally, study of the microbes in the accretion ice will be useful to those planning to study analogous systems on ice-covered planets and moons. | ["POINT(106.8 -72.4667)"] |
Extended Advanced Very High Resolution Radiometer Polar Pathfinder Satellite Product
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None | 2004-12-14 | Key, Jeffrey R. | No project link provided | This data set consists of AVHRR retrievals of surface and cloud properties as well as radiative fluxes for the period 1982 - 1999 over the Arctic and Antarctic at a 25 km resolution. The images times are 1400 and 0400 (Arctic) or 0200 (Antarctic) local solar times. Resulsts are calculated on a twice-daily basis, but only monthly mean images and area-averaged values are currently online. The standard AVHRR Polar Pathfinder (APP) product includes gridded radiances, viewing and illumination geometry, clear sky surface temperature and albedo, and three cloud masks at a 5 km resolution. We have extended the standard APP product to include all-sky surface temperature, all-sky surface albedo, cloud properties (particle phase, effective radius, optical depth, temperature and pressure), and radiative fluxes as well as cloud radiative effect (“forcing”). We refer to this dataset as APP-x | [] |
Antarctic Oscillation (AO) Time Series Data since 1948 from JISAO
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None | 2003-02-10 | Mitchell, Todd | No project link provided | The Antarctic Oscillation (AAO) is the dominant pattern of non-seasonal tropospheric circulation variations south of 30S, and it is characterized by pressure anomalies of one sign centered in the Antarctic and anomalies of the opposite sign centered about 40-50S. The AAO is also referred to as the Southern Annular Mode (SAM). The AAO is defined as the leading principal component (PC) of 850 hPa geopotential height anomalies south of 30S (Thompson and Wallace 2000). For more information on the construction and analyses of this data, see: http://www.jisao.washington.edu/data/aao/ | [] |