{"dp_type": "Dataset", "free_text": "Pot"}
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Dataset Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Project Links | Abstract | Geometry |
---|---|---|---|---|---|---|
SPICEcore 400-480 m Major Ions SDSU
|
1443663 |
2021-01-30 | Cole-Dai, Jihong; Larrick, Carleigh |
Collaborative Research: South Pole Ice Core Chronology and Climate Records using Chemical and Microparticle Measurements |
Major ion concentrations in SPICEcore samples from the section of 400-480 m were measured with ion chromatography. The ions are chloride, nitrate, sulfate, sodium, potassium, magnesium, and calcium. This section was analyzed to replicate the measurement of the same section at Dartmouth College. | ["POLYGON((-180 -89.99,-152.184 -89.99,-124.368 -89.99,-96.552 -89.99,-68.736 -89.99,-40.92 -89.99,-13.104 -89.99,14.712 -89.99,42.528 -89.99,70.344 -89.99,98.16 -89.99,98.16 -89.99,98.16 -89.99,98.16 -89.99,98.16 -89.99,98.16 -89.99,98.16 -89.99,98.16 -89.99,98.16 -89.99,98.16 -89.99,98.16 -89.99,70.344 -89.99,42.528 -89.99,14.712 -89.99,-13.104 -89.99,-40.92 -89.99,-68.736 -89.99,-96.552 -89.99,-124.368 -89.99,-152.184 -89.99,180 -89.99,152.184 -89.99,124.368 -89.99,96.552 -89.99,68.736 -89.99,40.92 -89.99,13.104 -89.99,-14.712 -89.99,-42.528 -89.99,-70.344 -89.99,-98.16 -89.99,-98.16 -89.99,-98.16 -89.99,-98.16 -89.99,-98.16 -89.99,-98.16 -89.99,-98.16 -89.99,-98.16 -89.99,-98.16 -89.99,-98.16 -89.99,-98.16 -89.99,-70.344 -89.99,-42.528 -89.99,-14.712 -89.99,13.104 -89.99,40.92 -89.99,68.736 -89.99,96.552 -89.99,124.368 -89.99,152.184 -89.99,-180 -89.99))"] |
Thermal sensitivity of membrane fluidity and integrity in hearts of Antarctic fishes that vary in expression of hemoglobin and myoglobin
|
1341663 1341602 |
2020-12-24 | O'Brien, Kristin; Evans, Elizabeth; Farnoud, Amir; Crockett, Elizabeth |
Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes |
Antarctic notothenioids are noted for extreme stenothermy, yet underpinnings of their thermal limits are not fully understood. We hypothesized that properties of ventricular membranes could explain previously observed differences among notothenioids in temperature onset of cardiac arrhythmias and persistent asystole. Microsomes were prepared using ventricles from six species of notothenioids, including four species from the hemoglobin-less (Hb-) family Channichthyidae (icefishes), which also differentially express cardiac myoglobin (Mb), and two species from the (Hb+) Nototheniidae. We determined membrane fluidity and structural integrity by quantifying fluorescence depolarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) and leakage of 5(6)-carboxyfluorescein, respectively, over a temperature range from ambient (0 °C) to 20 °C. Compositions of membrane phospholipids and cholesterol contents were also quantified. Membranes from all four species of icefishes exhibited greater fluidity than membranes from the red-blooded species N. coriiceps. Thermal sensitivity of fluidity did not vary among species. The greatest thermal sensitivity to leakage occurred between 0 and 5 °C for all species, while membranes from the icefish, Chaenocephalus aceratus (Hb-/Mb-) displayed leakage that was nearly 1.5-fold greater than leakage in N. coriiceps (Hb+/Mb+). Contents of phosphatidylethanolamine (PE) were approximately 1.5-fold greater in icefishes than in red-blooded fishes, and phospholipids had a higher degree of unsaturation in icefishes than in Hb + notothenioids. Cholesterol contents were lowest in Champsocephalus gunnari (Hb-/Mb-) and highest in the two Hb+/Mb + species, G. gibberifrons and N. coriiceps. Our results reveal marked differences in membrane properties and indicate a breach in membrane fluidity and structural integrity at a lower temperature in icefishes than in red-blooded notothenioids. | [] |
Effects of acute warming on cardiovascular performance of Antarctic fishes
|
1341663 1341602 |
2020-12-18 | Joyce, William; Farrell, Anthony; Axelsson, Michael; Egginton, Stuart; Crockett, Elizabeth; O'Brien, Kristin |
Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes |
We tested the hypothesis that blackfin icefish (Chaenocephalus aceratus), one of the six species in the family Channichthyidae (the icefishes) that do not express haemoglobin and myoglobin, lack regulatory cardiovascular flexibility during acute warming and activity. The experimental protocols were designed to optimize the surgical protocol and minimize stress. First, minimally invasive heart rate (fH) measurements were made during a thermal ramp until cardiac failure in C. aceratus and compared with those from the closely related red-blooded black rockcod (Notothenia coriiceps). Then, integrative cardiovascular adjustments were more extensively studied using flow probes and intravascular catheters in C. aceratus during acute warming (from 0 to 8°C) at rest and after imposed activity. Chaenocephalus aceratus had a lower routine fH than N. coriiceps (9 beats min-1 versus 14 beats min-1) and a lower peak fH during acute warming (38 beats min-1 versus 55 beats min-1) with a similar cardiac breakpoint temperature (13 and 14°C, respectively). Routine cardiac output (Q̇) for C. aceratus at ∼0°C was much lower (26.6 ml min-1 kg-1) than previously reported, probably because fish in the present study had a low fH (12 beats min-1) indicative of a high routine vagal tone and low stress. Chaenocephalus aceratus increased oxygen consumption during acute warming and with activity. Correspondingly, Q̇ increased considerably (maximally 86.3 ml min-1 kg-1), as did vascular conductance (5-fold). Thus, unlike earlier suggestions, these data provide convincing evidence that icefish can mount a well-developed cardiovascular regulation of heart rate, cardiac output and vascular conductance, and this regulatory capacity provides flexibility during acute warming. | [] |
Cardiac metabolism in Antarctic fishes in response to an acute increase in temperature
|
1341663 |
2020-12-18 | O'Brien, Kristin |
Collaborative Research: The Physiological and Biochemical Underpinnings of Thermal Tolerance in Antarctic Notothenioid Fishes |
Studies in temperate fishes provide evidence that cardiac mitochondrial function and the capacity to fuel cardiac work contribute to thermal tolerance. Here, we tested the hypothesis that decreased cardiac aerobic metabolic capacity contributes to the lower thermal tolerance of the haemoglobinless Antarctic icefish, Chaenocephalus aceratus, compared with that of the red-blooded Antarctic species, Notothenia coriiceps. Maximal activities of citrate synthase (CS) and lactate dehydrogenase (LDH), respiration rates of isolated mitochondria, adenylate levels and changes in mitochondrial protein expression were quantified from hearts of animals held at ambient temperature or exposed to their critical thermal maximum (CTmax). Compared with C. aceratus, activity of CS, ATP concentration and energy charge were higher in hearts of N. coriiceps at ambient temperature and CTmax While state 3 mitochondrial respiration rates were not impaired by exposure to CTmax in either species, state 4 rates, indicative of proton leakage, increased following exposure to CTmax in C. aceratus but not N. coriiceps The interactive effect of temperature and species resulted in an increase in antioxidants and aerobic metabolic enzymes in N. coriiceps but not in C. aceratus Together, our results support the hypothesis that the lower aerobic metabolic capacity of C. aceratus hearts contributes to its low thermal tolerance. | [] |
3He input data
|
1443213 |
2020-09-30 | Kaplan, Michael; Winckler, Gisela; Schaefer, Joerg |
Collaborative Research: Multidisciplinary Analysis of Antarctic Blue Ice Moraine Formation and their Potential as Climate Archives over Multiple Glacial Cycles |
Input and other information for 3He surface exposure data | [] |
10Be and 26Al cosmogenic nuclide surface exposure data
|
1443213 |
2020-09-30 | Kaplan, Michael; Schaefer, Joerg; Winckler, Gisela |
Collaborative Research: Multidisciplinary Analysis of Antarctic Blue Ice Moraine Formation and their Potential as Climate Archives over Multiple Glacial Cycles |
Sample metadata or information for cosmogenic-nuclide exposure data from the Mt. Achernar area. | ["POLYGON((-180 -84.1,-176.97 -84.1,-173.94 -84.1,-170.91 -84.1,-167.88 -84.1,-164.85 -84.1,-161.82 -84.1,-158.79 -84.1,-155.76 -84.1,-152.73 -84.1,-149.7 -84.1,-149.7 -84.43,-149.7 -84.76,-149.7 -85.09,-149.7 -85.42,-149.7 -85.75,-149.7 -86.08,-149.7 -86.41,-149.7 -86.74,-149.7 -87.07,-149.7 -87.4,-152.73 -87.4,-155.76 -87.4,-158.79 -87.4,-161.82 -87.4,-164.85 -87.4,-167.88 -87.4,-170.91 -87.4,-173.94 -87.4,-176.97 -87.4,180 -87.4,178.12 -87.4,176.24 -87.4,174.36 -87.4,172.48 -87.4,170.6 -87.4,168.72 -87.4,166.84 -87.4,164.96 -87.4,163.08 -87.4,161.2 -87.4,161.2 -87.07,161.2 -86.74,161.2 -86.41,161.2 -86.08,161.2 -85.75,161.2 -85.42,161.2 -85.09,161.2 -84.76,161.2 -84.43,161.2 -84.1,163.08 -84.1,164.96 -84.1,166.84 -84.1,168.72 -84.1,170.6 -84.1,172.48 -84.1,174.36 -84.1,176.24 -84.1,178.12 -84.1,-180 -84.1))"] |
The rise and fall of an ancient Adelie penguin 'supercolony' at Cape Adare, Antarctica
|
1443386 |
2020-06-02 | McKenzie, Ashley; Patterson, William; Emslie, Steven |
Collaborative Research: Investigating Holocene Shifts in the Diets and Paleohistory of Antarctic Krill Predators |
We report new discoveries and radiocarbon dates on active and abandoned Adélie penguin (Pygoscelis adeliae) colonies at Cape Adare, Antarctica. This colony, first established at approximately 2000 BP (calendar years before present, i.e. 1950), is currently the largest for this species with approximately 338 000 breeding pairs, most located on lowlying Ridley Beach. We hypothesize that this colony first formed after fast ice began blocking open-water access by breeding penguins to the Scott Coast in the southern Ross Sea during a cooling period also at approximately 2000 BP. Our results suggest that the new colony at Cape Adare continued to grow, expanding to a large upper terrace above Ridley Beach, until it exceeded approximately 500 000 breeding pairs (a 'supercolony') by approximately 1200 BP. The high marine productivity associated with the Ross Sea polynya and continental shelf break supported this growth, but the colony collapsed to its present size for unknown reasons after approximately 1200 BP. Ridley Beach will probably be abandoned in the near future due to rising sea level in this region. We predict that penguins will retreat to higher elevations at Cape Adare and that the Scott Coast will be reoccupied by breeding penguins as fast ice continues to dissipate earlier each summer, restoring open-water access to beaches there. | ["POLYGON((-180 -60,-180 -60,-180 -60,-180 -60,-180 -60,-180 -60,-180 -60,-180 -60,-180 -60,-180 -60,-180 -60,-180 -61.130769444,-180 -62.261538888,-180 -63.392308332,-180 -64.523077776,-180 -65.65384722,-180 -66.784616664,-180 -67.915386108,-180 -69.046155552,-180 -70.176924996,-180 -71.30769444,-180 -71.30769444,-180 -71.30769444,-180 -71.30769444,-180 -71.30769444,-180 -71.30769444,-180 -71.30769444,-180 -71.30769444,-180 -71.30769444,-180 -71.30769444,180 -71.30769444,179.019305556 -71.30769444,178.038611112 -71.30769444,177.057916668 -71.30769444,176.077222224 -71.30769444,175.09652778 -71.30769444,174.115833336 -71.30769444,173.135138892 -71.30769444,172.154444448 -71.30769444,171.173750004 -71.30769444,170.19305556 -71.30769444,170.19305556 -70.176924996,170.19305556 -69.046155552,170.19305556 -67.915386108,170.19305556 -66.784616664,170.19305556 -65.65384722,170.19305556 -64.523077776,170.19305556 -63.392308332,170.19305556 -62.261538888,170.19305556 -61.130769444,170.19305556 -60,171.173750004 -60,172.154444448 -60,173.135138892 -60,174.115833336 -60,175.09652778 -60,176.077222224 -60,177.057916668 -60,178.038611112 -60,179.019305556 -60,-180 -60))"] |
SOAR-Lake Vostok survey magnetic anomaly data
|
9978236 9911617 |
2020-04-28 | Studinger, Michael S.; Bell, Robin |
Continuation of Activities for the Support Office for Aerogeophysical Research (SOAR) Understanding the Boundary Conditions of the Lake Vostok Environment: A Site Survey for Future Work |
Processed Magnetometer Data acquired during the SOAR Twin Otter expedition SOAR-LVS (2000) This data set was acquired with a Magnetometer during SOAR Twin Otter expedition SOAR-LVS conducted in 2000 (Chief Scientist: Dr. Robin Bell; Investigator(s): Dr. Robin Bell and Dr. Michael Studinger). These data files are of ASCII format and include IGRF Anomaly Magnetic data and were processed after data collection. Data were acquired as part of the project(s): SOAR-Lake Vostok Survey (LVS) and Understanding the Boundary Conditions of the Lake Vostok Environment: A Site Survey for Future Work | ["POLYGON((101.5 -75.5,102.15 -75.5,102.8 -75.5,103.45 -75.5,104.1 -75.5,104.75 -75.5,105.4 -75.5,106.05 -75.5,106.7 -75.5,107.35 -75.5,108 -75.5,108 -75.85,108 -76.2,108 -76.55,108 -76.9,108 -77.25,108 -77.6,108 -77.95,108 -78.3,108 -78.65,108 -79,107.35 -79,106.7 -79,106.05 -79,105.4 -79,104.75 -79,104.1 -79,103.45 -79,102.8 -79,102.15 -79,101.5 -79,101.5 -78.65,101.5 -78.3,101.5 -77.95,101.5 -77.6,101.5 -77.25,101.5 -76.9,101.5 -76.55,101.5 -76.2,101.5 -75.85,101.5 -75.5))"] |
SOAR-Lake Vostok Survey Gravity data
|
9911617 9978236 |
2020-04-28 | Studinger, Michael S.; Bell, Robin |
Understanding the Boundary Conditions of the Lake Vostok Environment: A Site Survey for Future Work
Continuation of Activities for the Support Office for Aerogeophysical Research (SOAR) |
Processed Gravimeter Data acquired during the SOAR Twin Otter expedition SOAR-LVS (2000). This data set was acquired with a Gravimeter during SOAR Twin Otter expedition SOAR-LVS conducted in 2000 (Investigator(s): Dr. Robin Bell and Dr. Michael Studinger). These data files are of ASCII format and include Free Air Anomaly Gravity data and were processed after data collection. Data were acquired as part of the project(s): SOAR-Lake Vostok Survey (LVS) and Understanding the Boundary Conditions of the Lake Vostok Environment: A Site Survey for Future Work. | ["POLYGON((101.5 -75.5,102.15 -75.5,102.8 -75.5,103.45 -75.5,104.1 -75.5,104.75 -75.5,105.4 -75.5,106.05 -75.5,106.7 -75.5,107.35 -75.5,108 -75.5,108 -75.85,108 -76.2,108 -76.55,108 -76.9,108 -77.25,108 -77.6,108 -77.95,108 -78.3,108 -78.65,108 -79,107.35 -79,106.7 -79,106.05 -79,105.4 -79,104.75 -79,104.1 -79,103.45 -79,102.8 -79,102.15 -79,101.5 -79,101.5 -78.65,101.5 -78.3,101.5 -77.95,101.5 -77.6,101.5 -77.25,101.5 -76.9,101.5 -76.55,101.5 -76.2,101.5 -75.85,101.5 -75.5))"] |
SOAR-WMB Airborne gravity data
|
9615281 |
2020-04-24 | Bell, Robin |
Air-Ground Study of Tectonics at the Boundary Between the Eastern Ross Embayment and Western Marie Byrd Land, Antarctica: Basement Geology and Structure |
Free air gravity anomaly data collected along flight tracks of the Western Marie Byrd Land and Ross Sea Boundary | ["POLYGON((-175 -76,-171 -76,-167 -76,-163 -76,-159 -76,-155 -76,-151 -76,-147 -76,-143 -76,-139 -76,-135 -76,-135 -76.8,-135 -77.6,-135 -78.4,-135 -79.2,-135 -80,-135 -80.8,-135 -81.6,-135 -82.4,-135 -83.2,-135 -84,-139 -84,-143 -84,-147 -84,-151 -84,-155 -84,-159 -84,-163 -84,-167 -84,-171 -84,-175 -84,-175 -83.2,-175 -82.4,-175 -81.6,-175 -80.8,-175 -80,-175 -79.2,-175 -78.4,-175 -77.6,-175 -76.8,-175 -76))"] |
SOAR-WLK Airborne gravity data
|
9615704 |
2020-04-24 | Bell, Robin |
Contrasting Architecture and Dynamics of the Transantarctic Mountains |
Free air gravity anomaly data collected along flight tracks of the Wilkes Basin Corridor as part of the Contrasting Architecture and Dynamics in the Transantarctic Mountains project. | ["POLYGON((115 -74,121 -74,127 -74,133 -74,139 -74,145 -74,151 -74,157 -74,163 -74,169 -74,175 -74,175 -74.4,175 -74.8,175 -75.2,175 -75.6,175 -76,175 -76.4,175 -76.8,175 -77.2,175 -77.6,175 -78,169 -78,163 -78,157 -78,151 -78,145 -78,139 -78,133 -78,127 -78,121 -78,115 -78,115 -77.6,115 -77.2,115 -76.8,115 -76.4,115 -76,115 -75.6,115 -75.2,115 -74.8,115 -74.4,115 -74))"] |
SOAR-PPT Airborne gravity data
|
9615704 |
2020-04-24 | Bell, Robin |
Contrasting Architecture and Dynamics of the Transantarctic Mountains |
Free air gravity anomaly data collected along flight tracks of the Pensacola-Pole Transect as part of the Contrasting Architecture and Dynamics in the Transantarctic Mountains project. | ["POLYGON((-180 -84,-176 -84,-172 -84,-168 -84,-164 -84,-160 -84,-156 -84,-152 -84,-148 -84,-144 -84,-140 -84,-140 -84.6,-140 -85.2,-140 -85.8,-140 -86.4,-140 -87,-140 -87.6,-140 -88.2,-140 -88.8,-140 -89.4,-140 -90,-144 -90,-148 -90,-152 -90,-156 -90,-160 -90,-164 -90,-168 -90,-172 -90,-176 -90,180 -90,179.5 -90,179 -90,178.5 -90,178 -90,177.5 -90,177 -90,176.5 -90,176 -90,175.5 -90,175 -90,175 -89.4,175 -88.8,175 -88.2,175 -87.6,175 -87,175 -86.4,175 -85.8,175 -85.2,175 -84.6,175 -84,175.5 -84,176 -84,176.5 -84,177 -84,177.5 -84,178 -84,178.5 -84,179 -84,179.5 -84,-180 -84))"] |
SOAR-WAZ Airborne gravity data for the CASERTZ/WAIS project
|
9319854 |
2020-04-24 | Bell, Robin; Arko, Robert A. |
Collaborative Research: Lithospheric Controls on the Behavior of the West Antarctic Ice Sheet: Corridor Aerogeophysics of Eastern Ross Transect Zone |
Free air gravity anomaly data collected as part of the Corridor Aerogeophysics of Eastern Ross Transect Zone CASERTZ/WAIS project. | ["POLYGON((-155 -77.5,-150 -77.5,-145 -77.5,-140 -77.5,-135 -77.5,-130 -77.5,-125 -77.5,-120 -77.5,-115 -77.5,-110 -77.5,-105 -77.5,-105 -78.2,-105 -78.9,-105 -79.6,-105 -80.3,-105 -81,-105 -81.7,-105 -82.4,-105 -83.1,-105 -83.8,-105 -84.5,-110 -84.5,-115 -84.5,-120 -84.5,-125 -84.5,-130 -84.5,-135 -84.5,-140 -84.5,-145 -84.5,-150 -84.5,-155 -84.5,-155 -83.8,-155 -83.1,-155 -82.4,-155 -81.7,-155 -81,-155 -80.3,-155 -79.6,-155 -78.9,-155 -78.2,-155 -77.5))"] |
SOAR-IRE airborne gravity data for the CASERTZ/WAIS project
|
9319854 |
2020-04-24 | Bell, Robin; Arko, Robert A. |
Collaborative Research: Lithospheric Controls on the Behavior of the West Antarctic Ice Sheet: Corridor Aerogeophysics of Eastern Ross Transect Zone |
Free air gravity anomaly data collected as part of the Corridor Aerogeophysics of Eastern Ross Transect Zone CASERTZ/WAIS project. IRE field season | ["POLYGON((-155 -77.5,-150 -77.5,-145 -77.5,-140 -77.5,-135 -77.5,-130 -77.5,-125 -77.5,-120 -77.5,-115 -77.5,-110 -77.5,-105 -77.5,-105 -78.2,-105 -78.9,-105 -79.6,-105 -80.3,-105 -81,-105 -81.7,-105 -82.4,-105 -83.1,-105 -83.8,-105 -84.5,-110 -84.5,-115 -84.5,-120 -84.5,-125 -84.5,-130 -84.5,-135 -84.5,-140 -84.5,-145 -84.5,-150 -84.5,-155 -84.5,-155 -83.8,-155 -83.1,-155 -82.4,-155 -81.7,-155 -81,-155 -80.3,-155 -79.6,-155 -78.9,-155 -78.2,-155 -77.5))"] |
SOAR-TKD airborne gravity data for the CASERTZ/WAIS project
|
9319854 |
2020-04-24 | Bell, Robin; Arko, Robert A. |
Collaborative Research: Lithospheric Controls on the Behavior of the West Antarctic Ice Sheet: Corridor Aerogeophysics of Eastern Ross Transect Zone |
Free air gravity anomaly data collected as part of the Corridor Aerogeophysics of Eastern Ross Transect Zone CASERTZ/WAIS project. | ["POLYGON((-155 -77.5,-150 -77.5,-145 -77.5,-140 -77.5,-135 -77.5,-130 -77.5,-125 -77.5,-120 -77.5,-115 -77.5,-110 -77.5,-105 -77.5,-105 -78.2,-105 -78.9,-105 -79.6,-105 -80.3,-105 -81,-105 -81.7,-105 -82.4,-105 -83.1,-105 -83.8,-105 -84.5,-110 -84.5,-115 -84.5,-120 -84.5,-125 -84.5,-130 -84.5,-135 -84.5,-140 -84.5,-145 -84.5,-150 -84.5,-155 -84.5,-155 -83.8,-155 -83.1,-155 -82.4,-155 -81.7,-155 -81,-155 -80.3,-155 -79.6,-155 -78.9,-155 -78.2,-155 -77.5))"] |
NBP1402 diatom data
|
1143836 |
2020-02-27 | Leventer, Amy; NBP1402 science party, |
Collaborative Research: Totten Glacier System and the Marine Record of Cryosphere - Ocean Dynamics |
Totten Glacier is the termination of the largest marine-based portion of the East Antarctic Ice Sheet, the Aurora Subglacial Basin. Yet little is known about the glacial evolution of the catchment and the factors influencing its present and past behavior. Due its remote location and heavy sea ice, the continental shelf in front of the Totten Glacier had not been comprehensively surveyed prior to this study. Satellite observations indicate that the Totten ice drainage system is thinning, and it has been hypothesized that this thinning is in response to undermelting by warm ocean waters over the continental shelf. While this process is observed elsewhere in Antarctica (e.g. the rapidly retreating Pine Island Glacier in West Antarctica), the Totten Glacier system is potentially Antarcticas most important glacial drainage system due to its large size; it is three times larger than any system in West Antarctica. </br>The main goals of this proposal were: </br>To generate multibeam bathymetric maps of the continental shelf proximal to the Totten Glacier system to understand the recent regional glacial history and to document the pathways, if any, for circumpolar deep water to move onto the shelf. </br>To conduct a physical oceanographic survey of the region proximal to the Totten Glacier system, to determine the presence, if any, of warm ocean waters over the continental shelf.</br>To conduct a seismic survey of the continental shelf to assess the long-term evolution of the glacial system in the Aurora Subglacial Basin.</br>To collect marine sediment cores to determine the regional deglacial to Holocene climate history and the influence of warm circumpolar deep water. | ["POLYGON((117 -66,119.9 -66,122.8 -66,125.7 -66,128.6 -66,131.5 -66,134.4 -66,137.3 -66,140.2 -66,143.1 -66,146 -66,146 -66.1,146 -66.2,146 -66.3,146 -66.4,146 -66.5,146 -66.6,146 -66.7,146 -66.8,146 -66.9,146 -67,143.1 -67,140.2 -67,137.3 -67,134.4 -67,131.5 -67,128.6 -67,125.7 -67,122.8 -67,119.9 -67,117 -67,117 -66.9,117 -66.8,117 -66.7,117 -66.6,117 -66.5,117 -66.4,117 -66.3,117 -66.2,117 -66.1,117 -66))"] |
Sediment macrofaunal abundance and family richness from inner Andvord Bay to the open continental shelf
|
1443680 |
2019-12-31 | Smith, Craig |
Collaborative Research: Fjord Ecosystem Structure and Function on the West Antarctic Peninsula - Hotspots of Productivity and Biodiversity? (FjordEco) |
Sediment macrofaunal data collected by megacore (10-cm diameter sample tubes) along a down-fjord transect from inner Andvord Bay out onto the open continental shelf on the West Antarctic Peninsula. Sediment core samples from 0 - 10 cm depths were fixed in 4% formaldehyde, sieved on a 300 micron seive, and sorted with a dissecting microscope. | ["POLYGON((-66 -64,-65.6 -64,-65.2 -64,-64.8 -64,-64.4 -64,-64 -64,-63.6 -64,-63.2 -64,-62.8 -64,-62.4 -64,-62 -64,-62 -64.1,-62 -64.2,-62 -64.3,-62 -64.4,-62 -64.5,-62 -64.6,-62 -64.7,-62 -64.8,-62 -64.9,-62 -65,-62.4 -65,-62.8 -65,-63.2 -65,-63.6 -65,-64 -65,-64.4 -65,-64.8 -65,-65.2 -65,-65.6 -65,-66 -65,-66 -64.9,-66 -64.8,-66 -64.7,-66 -64.6,-66 -64.5,-66 -64.4,-66 -64.3,-66 -64.2,-66 -64.1,-66 -64))"] |
Andvord Bay sediment core data collected during the FjordEco project (LMG1510 and NBP1603)
|
1443680 |
2019-07-16 | Eidam, Emily; Nittrouer, Charles; Homolka, Khadijah; Smith, Craig |
Collaborative Research: Fjord Ecosystem Structure and Function on the West Antarctic Peninsula - Hotspots of Productivity and Biodiversity? (FjordEco) |
This dataset includes Pb-210 activities, grain-size distributions, and x-radiograph negatives for cores collected primarily during NBP1603 (and also LMG1510) as part of the FjordEco project in Andvord Bay and surrounding areas (Gerlache Strait, and Station B on the shelf). Data are from subsampled intervals of kasten cores and box cores, as well as one megacore. Samples were x-rayed, sliced, and bagged onboard the vessel. Grain-size and Pb-210 analyses were completed in the Sediment Dynamics Lab within the University of Washington School of Oceanography (PI C. Nittrouer). | ["POLYGON((-65.561 -64.6538,-65.2471 -64.6538,-64.9332 -64.6538,-64.6193 -64.6538,-64.3054 -64.6538,-63.9915 -64.6538,-63.6776 -64.6538,-63.3637 -64.6538,-63.0498 -64.6538,-62.7359 -64.6538,-62.422 -64.6538,-62.422 -64.67842,-62.422 -64.70304,-62.422 -64.72766,-62.422 -64.75228,-62.422 -64.7769,-62.422 -64.80152,-62.422 -64.82614,-62.422 -64.85076,-62.422 -64.87538,-62.422 -64.9,-62.7359 -64.9,-63.0498 -64.9,-63.3637 -64.9,-63.6776 -64.9,-63.9915 -64.9,-64.3054 -64.9,-64.6193 -64.9,-64.9332 -64.9,-65.2471 -64.9,-65.561 -64.9,-65.561 -64.87538,-65.561 -64.85076,-65.561 -64.82614,-65.561 -64.80152,-65.561 -64.7769,-65.561 -64.75228,-65.561 -64.72766,-65.561 -64.70304,-65.561 -64.67842,-65.561 -64.6538))"] |
FjordEco Phytoplankton Ecology Dataset in Andvord Bay
|
1443705 |
2019-02-27 | Vernet, Maria; Pan, B. Jack; Manck, Lauren; Forsch, Kiefer |
Collaborative Research: Fjord Ecosystem Structure and Function on the West Antarctic Peninsula - Hotspots of Productivity and Biodiversity? (FjordEco) |
Phytoplankton ecology dataset from the FjordEco Project (PLR-1443705) | ["POLYGON((-63.3 -64.5,-63.17 -64.5,-63.04 -64.5,-62.91 -64.5,-62.78 -64.5,-62.65 -64.5,-62.52 -64.5,-62.39 -64.5,-62.26 -64.5,-62.13 -64.5,-62 -64.5,-62 -64.545,-62 -64.59,-62 -64.635,-62 -64.68,-62 -64.725,-62 -64.77,-62 -64.815,-62 -64.86,-62 -64.905,-62 -64.95,-62.13 -64.95,-62.26 -64.95,-62.39 -64.95,-62.52 -64.95,-62.65 -64.95,-62.78 -64.95,-62.91 -64.95,-63.04 -64.95,-63.17 -64.95,-63.3 -64.95,-63.3 -64.905,-63.3 -64.86,-63.3 -64.815,-63.3 -64.77,-63.3 -64.725,-63.3 -64.68,-63.3 -64.635,-63.3 -64.59,-63.3 -64.545,-63.3 -64.5))"] |
Fjord-Eco_Sediment_OrgC_OrgN_Data - Craig Smith
|
1443680 |
2019-02-13 | Smith, Craig |
Collaborative Research: Fjord Ecosystem Structure and Function on the West Antarctic Peninsula - Hotspots of Productivity and Biodiversity? (FjordEco) |
Sediment organic carbon and organic nitrogen content (percent mass) in 6 depth intervals (0-1cm, 1-2cm, 3-4cm, 5-6cm, 7-8cm , 9-10cm) in sediment cores collected by OSIL Megacore (10 cm diameter tubes) along the five-station FjordEco Transect from inner Andvord Bay to the open continental shelf at FOODBANCS Station B. | ["POLYGON((-65 -64,-64.7 -64,-64.4 -64,-64.1 -64,-63.8 -64,-63.5 -64,-63.2 -64,-62.9 -64,-62.6 -64,-62.3 -64,-62 -64,-62 -64.1,-62 -64.2,-62 -64.3,-62 -64.4,-62 -64.5,-62 -64.6,-62 -64.7,-62 -64.8,-62 -64.9,-62 -65,-62.3 -65,-62.6 -65,-62.9 -65,-63.2 -65,-63.5 -65,-63.8 -65,-64.1 -65,-64.4 -65,-64.7 -65,-65 -65,-65 -64.9,-65 -64.8,-65 -64.7,-65 -64.6,-65 -64.5,-65 -64.4,-65 -64.3,-65 -64.2,-65 -64.1,-65 -64))"] |
Antarctic Ice Sheet simulations for role of freshwater in future warming scenarios
|
1443394 |
2019-02-04 | Pollard, David |
Collaborative Research: Assessing the Global Climate Response to Melting of the Antarctic Ice Sheet |
The dataset consists of two tar files for two distinct sets of simulations. Each tar file contains a number of Netcdf files with model output for one simulation each, and also contains a DIF file (Directory Interchange Format, in xml form) with information on that part of the dataset. Set 1: There are 4 Netcdf files with output from the PSU 3D Antarctic ice sheet model including ice melange, showing role of melange in potentially providing buttressing and possibly slowing down ice retreat in strong climate warming scenarios. Set two: There are 2 Netcdf files with output from the PSU 3D Antarctic ice sheet model, for two future warming scenarios RCP4.5 and RCP8.5, contributing to oceanic meltwater discharge fields for future climate and ocean model simulations performed at Univ. Massachusetts by other PIs on the NSF project. More details on file names and model fields is provided in "Data Section" of the Readme file. | ["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))"] |
Linking oceanographic conditions, migratory schedules and foraging behaviour during the non-breeding season to reproductive performance in a long-lived seabird
|
1246407 |
2018-12-03 | Jenouvrier, Stephanie |
Linking Foraging Behaviors to Demography to understand Albatrosses Population Responses to Climate Change |
1. Studies of the mechanisms underlying climate-induced population changes are critically needed to better understand and accurately predict population responses to climate change. Long-lived migratory species might be particularly vulnerable to climate change as they are constrained by different climate conditions and energetic requirements during the breeding and non-breeding seasons. Yet, most studies primarily focus on the breeding season of these species life cycle. Environmental conditions experienced in the non-breeding season may have downstream effects on the other stages of the annual life cycle. Not investigating such effects may potentially lead to erroneous inferences about population dynamics. 2. Combining demographic and tracking data collected between 2006 and 2013 at Kerguelen Island on a long-lived migratory seabird, the Black-Browed Albatross (Thalassarche melanophris), we investigated the links between sea surface temperature during the non-breeding season and behavioural and phenological traits (at-sea behaviour and migratory schedules) while accounting for different responses between birds of different sex and reproductive status (previously failed or successful breeders). We then explored whether variation in the foraging behaviour and timing of spring migration influenced subsequent reproductive performance. 3. Our results showed that foraging activity and migratory schedules varied by both sex and reproductive status suggesting different energetic requirements and constraints among individuals. Higher sea surface temperatures during late winter, assumed to reflect poor winter conditions, were associated with an earlier departure from the wintering grounds and an extended pre-breeding period. However, an earlier spring migration and an earlier return to Kerguelen grounds were associated with a lower breeding success. 4. Our results highlighted that behaviour during some periods of the non-breeding season, particularly towards the end of the wintering period and the pre-breeding period, had a significant effect on the subsequent reproductive success. Therefore caution needs to be given to all stages of the annual cycle when predicting the influence of climate on population dynamics. | ["POLYGON((68.5 -48.5,68.725 -48.5,68.95 -48.5,69.175 -48.5,69.4 -48.5,69.625 -48.5,69.85 -48.5,70.075 -48.5,70.3 -48.5,70.525 -48.5,70.75 -48.5,70.75 -48.65,70.75 -48.8,70.75 -48.95,70.75 -49.1,70.75 -49.25,70.75 -49.4,70.75 -49.55,70.75 -49.7,70.75 -49.85,70.75 -50,70.525 -50,70.3 -50,70.075 -50,69.85 -50,69.625 -50,69.4 -50,69.175 -50,68.95 -50,68.725 -50,68.5 -50,68.5 -49.85,68.5 -49.7,68.5 -49.55,68.5 -49.4,68.5 -49.25,68.5 -49.1,68.5 -48.95,68.5 -48.8,68.5 -48.65,68.5 -48.5))"] |
U-Pb ages and mineral compositions from Dufek Intrusion
|
1543313 |
2018-10-29 | VanTongeren, Jill |
Collaborative Research: Testing the Hypothesis that Bigger Magma Chambers Crystallize Faster |
The dataset contains preliminary CA-ID-TIMS U-Pb zircon ages for 4 samples from the Dufek Intrusion, as well as major element mineral compositions for samples throughout the stratigraphy. | ["POLYGON((-55 -82,-54.5 -82,-54 -82,-53.5 -82,-53 -82,-52.5 -82,-52 -82,-51.5 -82,-51 -82,-50.5 -82,-50 -82,-50 -82.2,-50 -82.4,-50 -82.6,-50 -82.8,-50 -83,-50 -83.2,-50 -83.4,-50 -83.6,-50 -83.8,-50 -84,-50.5 -84,-51 -84,-51.5 -84,-52 -84,-52.5 -84,-53 -84,-53.5 -84,-54 -84,-54.5 -84,-55 -84,-55 -83.8,-55 -83.6,-55 -83.4,-55 -83.2,-55 -83,-55 -82.8,-55 -82.6,-55 -82.4,-55 -82.2,-55 -82))"] |
Andvord Bay Glacier Timelapse
|
1443733 |
2018-08-07 | Truffer, Martin; Winsor, Peter |
Collaborative Research: Fjord Ecosystem Structure and Function on the West Antarctic Peninsula - Hotspots of Productivity and Biodiversity? (FjordEco) |
This dataset includes timelapse images from five cameras set up at four different locations in and just outside of Andvord Bay on the Western Antarctic Peninsula. The cameras were set up to track glacier ice motion, calving and tracking of ice bergs, and sea ice formation and melt. Two cameras (hi-res) were Canon Rebel DSLR in a timelapse system designed by Harbortronics; the remaining three cameras (lo-res) were from Campbell Scientific and were part of a weather station. | ["POLYGON((-62.68 -64.72,-62.648 -64.72,-62.616 -64.72,-62.584 -64.72,-62.552 -64.72,-62.52 -64.72,-62.488 -64.72,-62.456 -64.72,-62.424 -64.72,-62.392 -64.72,-62.36 -64.72,-62.36 -64.74,-62.36 -64.76,-62.36 -64.78,-62.36 -64.8,-62.36 -64.82,-62.36 -64.84,-62.36 -64.86,-62.36 -64.88,-62.36 -64.9,-62.36 -64.92,-62.392 -64.92,-62.424 -64.92,-62.456 -64.92,-62.488 -64.92,-62.52 -64.92,-62.552 -64.92,-62.584 -64.92,-62.616 -64.92,-62.648 -64.92,-62.68 -64.92,-62.68 -64.9,-62.68 -64.88,-62.68 -64.86,-62.68 -64.84,-62.68 -64.82,-62.68 -64.8,-62.68 -64.78,-62.68 -64.76,-62.68 -64.74,-62.68 -64.72))"] |
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))"] |
Vertebrate fossils from the Hanson Formation at Mt. Kirkpatrick, in the Beardmore Glacier region of Antarctica
|
1246379 |
2017-03-29 | Smith, Nathan |
Collaborative Research: Continued Research on the Jurassic Vertebrate Fauna from the Beardmore Glacier Region of Antarctica |
This proposal supports research on the Early Jurassic Hanson Formation vertebrate fauna of the Beardmore Glacier region of Antarctica. The project supports preparation and systematic and paleobiological research on four Antarctic dinosaurs, including two new species, collected in the Central Transantarctic Mountains. With the new material Cryolophosaurus will become one of the most complete Early Jurassic theropods known, and thus has the potential to become a keystone taxon for resolving the debated early evolutionary history of theropod dinosaurs, the group that gave rise to birds. Two new dinosaur specimens include a nearly complete articulated skeleton of a juvenile sauropodomorph, and the articulated hip region of another small individual. Both appear to be new taxa. The dinosaurs from the Hanson Formation represent some of the highest paleolatitude vertebrates known from the Jurassic. The PIs generated CT datasets for Cryolophosaurus and the more complete new sauropodomorph species to mine for phylogenetic trait information, and to investigate their comparative neuroanatomy and feeding behavior. Histological datasets have been generated from multiple skeletal elements for all four Mt. Kirkpatrick taxa to understand patterns of growth in different clades of polar dinosaurs and compare them to relatives from lower paleolatitudes. This paleohistological study of a relatively diverse sample of sauropodomorph taxa from Antarctica may contribute to determining whether and how these dinosaurs responded to contemporary climatic extremes. The PIs have established a successful undergraduate training program as part of previous research. Summer interns from Augustana are trained at the Field Museum in specimen preparation, curation, molding/casting, and histological sampling. They also participate in existing Field Museum REU programs, including a course on phylogenetic systematics. Four undergraduate internships and student research projects will be supported through this proposal. A postdoctoral researcher has also been supported on this project The PIs are developing a traveling exhibit on Antarctic Dinosaurs that they estimate will be seen by over 2 million people over the five-year tour (opening June 2018 at the Field Museum of Natural History). | ["POLYGON((160 -85,160.6 -85,161.2 -85,161.8 -85,162.4 -85,163 -85,163.6 -85,164.2 -85,164.8 -85,165.4 -85,166 -85,166 -85.2,166 -85.4,166 -85.6,166 -85.8,166 -86,166 -86.2,166 -86.4,166 -86.6,166 -86.8,166 -87,165.4 -87,164.8 -87,164.2 -87,163.6 -87,163 -87,162.4 -87,161.8 -87,161.2 -87,160.6 -87,160 -87,160 -86.8,160 -86.6,160 -86.4,160 -86.2,160 -86,160 -85.8,160 -85.6,160 -85.4,160 -85.2,160 -85))"] |
WD2014: Timescale for WAIS Divide Core 2006 A (WDC-06A)
|
0944197 |
2017-03-28 | Fudge, T. J. |
Collaborative Research: Establishing the Chronology and Histories of Accumulation and Ice Dynamics for the WAIS Divide Core |
The West Antarctic Ice Sheet Divide (WAIS Divide, WD) ice core is a newly drilled, high-accumulation deep ice core that provides Antarctic climate records of the past ~68 ka at unprecedented temporal resolution. The upper 2850 m (back to 31.2 ka BP) have been dated using annual-layer counting. Here we present a chronology for the deep part of the core (67.8-31.2 ka BP), which is based on stratigraphic matching to annual-layer-counted Greenland ice cores using globally well-mixed atmospheric methane. We calculate the WD gas age-ice age difference (Delta age) using a combination of firn densification modeling, ice-flow modeling, and a data set of d15N-N2, a proxy for past firn column thickness. The largest Delta age at WD occurs during the Last Glacial Maximum, and is 525 +/- 120 years. Internally consistent solutions can be found only when assuming little to no influence of impurity content on densification rates, contrary to a recently proposed hypothesis. We synchronize the WD chronology to a linearly scaled version of the layer-counted Greenland Ice Core Chronology (GICC05), which brings the age of Dansgaard-Oeschger (DO) events into agreement with the U/Th absolutely dated Hulu Cave speleothem record. The small Delta age at WD provides valuable opportunities to investigate the timing of atmospheric greenhouse gas variations relative to Antarctic climate, as well as the interhemispheric phasing of the \"bipolar seesaw\". We present the WD2014 chronology for the upper part (0-2850 m; 31.2 ka BP) of the West Antarctic Ice Sheet (WAIS) Divide (WD) ice core. The chronology is based on counting of annual layers observed in the chemical, dust and electrical conductivity records. These layers are caused by seasonal changes in the source, transport, and deposition of aerosols. The measurements were interpreted manually and with the aid of two automated methods. We validated the chronology by comparing to two high-accuracy, absolutely dated chronologies. For the Holocene, the cosmogenic isotope records of 10Be from WAIS Divide and 14C for IntCal13 demonstrated that WD2014 was consistently accurate to better than 0.5% of the age. For the glacial period, comparisons to the Hulu Cave chronology demonstrated that WD2014 had an accuracy of better than 1% of the age at three abrupt climate change events between 27 and 31ka. WD2014 has consistently younger ages than Greenland ice core chronologies during most of the Holocene. For the Younger Dryas-Preboreal transition (11.595 ka; 24 years younger) and the Bolling-Allerod Warming (14.621 ka; 7 years younger), WD2014 ages are within the combined uncertainties of the timescales. Given its high accuracy, WD2014 can become a reference chronology for the Southern Hemisphere, with synchronization to other chronologies feasible using high-quality proxies of volcanism, solar activity, atmospheric mineral dust, and atmospheric methane concentrations. | ["POINT(-112.1115 -79.481)"] |
Gravity disturbance data over central Marie Byrd Land, West Antarctica (GIMBLE.GGCMG2)
|
1043761 |
2017-02-20 | Young, Duncan A.; Holt, John W.; Blankenship, Donald D. |
Geophysical Investigations of Marie Byrd Land Lithospheric Evolution (GIMBLE) |
GIMBLE was proposed as the first systematic aerogeophysical investigation of the subglacial massif underlying central Marie Byrd Land. Aerogeophysically configured Baslers conducted 14 flights from Byrd Surface Camp and WAIS Divide Camp over two field seasons (January 2013 and December 2014). Airborne ice penetrating radar, gravity and magnetics were the primary datasets collected. Level 2 data represent geolocated geophysical properties (e.g ice thickness), derived from Level 1B measurements (e.g. radar echo delay). Dataset structures are based on those used for Operation Ice Bridge, and are line based data in ASCII space delimited .txt files, with a header delimited by leading "#" characters documenting column assignment and metadata. Georefering data is contained in .met files. GIMBLE.GGCMG2 contains line based data relating to gravity disturbance, processed from raw acceleration and position data by propriety software from Gravimetric Technologies and Novatel. The raw data was obtained a Canadian MicroGravity GT-1A gravimeter in ICP5, and a GT-2A gravimeter in ICP6. Data reduction was led by T. Richter. | ["POLYGON((-156 -74.5,-151.4 -74.5,-146.8 -74.5,-142.2 -74.5,-137.6 -74.5,-133 -74.5,-128.4 -74.5,-123.8 -74.5,-119.2 -74.5,-114.6 -74.5,-110 -74.5,-110 -75.05,-110 -75.6,-110 -76.15,-110 -76.7,-110 -77.25,-110 -77.8,-110 -78.35,-110 -78.9,-110 -79.45,-110 -80,-114.6 -80,-119.2 -80,-123.8 -80,-128.4 -80,-133 -80,-137.6 -80,-142.2 -80,-146.8 -80,-151.4 -80,-156 -80,-156 -79.45,-156 -78.9,-156 -78.35,-156 -77.8,-156 -77.25,-156 -76.7,-156 -76.15,-156 -75.6,-156 -75.05,-156 -74.5))"] |
Magnetic anomaly data over central Marie Byrd Land, West Antarctica (GIMBLE.GMGEO2)
|
1043761 |
2017-02-20 | Young, Duncan A.; Holt, John W.; Blankenship, Donald D. |
Geophysical Investigations of Marie Byrd Land Lithospheric Evolution (GIMBLE) |
GIMBLE was proposed as the first systematic aerogeophysical investigation of the subglacial massif underlying central Marie Byrd Land. Aerogeophysically configured Baslers conducted 14 flights from Byrd Surface Camp and WAIS Divide Camp over two field seasons (January 2013 and December 2014). Airborne ice penetrating radar, gravity and magnetics were the primary datasets collected. Level 2 data represent geolocated geophysical properties (e.g ice thickness), derived from Level 1B measurements (e.g. radar echo delay). Dataset structures are based on those used for Operation Ice Bridge, and are line based data in ASCII space delimited .txt files, with a header delimited by leading "#" characters documenting column assignment and metadata. Georefering data is contained in .met files. GIMBLE.GMGEO2 contains line based data (in ASCII space delimited txt files) relating to magnetic anomaly. The raw data was obtained by a tail mounted Geometrics G-823A magnetometer. No heading correction, cross over correction, continuation or base correction have been applied. Data with significant geomagnetic activity (restricted to 07-Dec-2014 and 23-Dec-2014) were removed. | ["POLYGON((-156 -74.5,-151.4 -74.5,-146.8 -74.5,-142.2 -74.5,-137.6 -74.5,-133 -74.5,-128.4 -74.5,-123.8 -74.5,-119.2 -74.5,-114.6 -74.5,-110 -74.5,-110 -75.05,-110 -75.6,-110 -76.15,-110 -76.7,-110 -77.25,-110 -77.8,-110 -78.35,-110 -78.9,-110 -79.45,-110 -80,-114.6 -80,-119.2 -80,-123.8 -80,-128.4 -80,-133 -80,-137.6 -80,-142.2 -80,-146.8 -80,-151.4 -80,-156 -80,-156 -79.45,-156 -78.9,-156 -78.35,-156 -77.8,-156 -77.25,-156 -76.7,-156 -76.15,-156 -75.6,-156 -75.05,-156 -74.5))"] |
Decoding & Predicting Antarctic Surface Melt Dynamics with Observations, Regional Atmospheric Modeling and GCMs
|
1043580 |
2016-01-01 | Reusch, David |
Collaborative Research: Decoding & Predicting Antarctic Surface Melt Dynamics with Observations, Regional Atmospheric Modeling and GCMs |
The presence of ice ponds from surface melting of glacial ice can be a significant threshold in assessing the stability of ice sheets, and their overall response to a warming climate. Snow melt has a much reduced albedo, leading to additional seasonal melting from warming insolation. Water run-off not only contributes to the mass loss of ice sheets directly, but meltwater reaching the glacial ice bed may lubricate faster flow of ice sheets towards the ocean. Surficial meltwater may also reach the grounding lines of glacial ice through the wedging open of existing crevasses. The occurrence and amount of meltwater refreeze has even been suggested as a paleo proxy of near-surface atmospheric temperature regimes. Using contemporary remote sensing (microwave) satellite assessment of surface melt occurrence and extent, the predictive skill of regional meteorological models and reanalyses (e.g. WRF, ERA-Interim) to describe the synoptic conditions favourable to surficial melt is to be investigated. Statistical approaches and pattern recognition techniques are argued to provide a context for projecting future ice sheet change. The previous Intergovernmental Panel on Climate Change (IPCC AR4) commented on our lack of understanding of ice-sheet mass balance processes in polar regions and the potential for sea-level change. The IPPC suggested that the forthcoming AR5 efforts highlight regional cryosphere modeling efforts, such as is proposed here. | ["POLYGON((-180 -47,-144 -47,-108 -47,-72 -47,-36 -47,0 -47,36 -47,72 -47,108 -47,144 -47,180 -47,180 -51.3,180 -55.6,180 -59.9,180 -64.2,180 -68.5,180 -72.8,180 -77.1,180 -81.4,180 -85.7,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -85.7,-180 -81.4,-180 -77.1,-180 -72.8,-180 -68.5,-180 -64.2,-180 -59.9,-180 -55.6,-180 -51.3,-180 -47))"] |
Measurements of in situ cosmogenic 14C from Taylor Glacier, Antarctica
|
0839031 |
2016-01-01 | Severinghaus, Jeffrey |
Collaborative Research: A "Horizontal Ice Core" for Large-Volume Samples of the Past Atmosphere, Taylor Glacier, Antarctica |
This award supports a project to develop a precise gas-based chronology for an archive of large-volume samples of the ancient atmosphere, which would enable ultra-trace gas measurements that are currently precluded by sample size limitations of ice cores. The intellectual merit of the proposed work is that it will provide a critical test of the 'clathrate hypothesis' that methane clathrates contributed to the two abrupt atmospheric methane concentration increases during the last deglaciation 15 and 11 kyr ago. This approach employs large volumes of ice (>1 ton) to measure carbon-14 on past atmospheric methane across the abrupt events. Carbon-14 is an ideal discriminator of fossil sources of methane to the atmosphere, because most methane sources (e.g., wetlands, termites, biomass burning) are rich in carbon-14, whereas clathrates and other fossil sources are devoid of carbon-14. The proposed work is a logical extension to Taylor Glacier, Antarctica, of an approach pioneered at the margin of the Greenland ice sheet over the past 7 years. The Greenland work found higher-than-expected carbon-14 values, likely due in part to contaminants stemming from the high impurity content of Greenland ice and the interaction of the ice with sediments from the glacier bed. The data also pointed to the possibility of a previously unknown process, in-situ cosmogenic production of carbon-14 methane (radiomethane) in the ice matrix. Antarctic ice in Taylor Glacier is orders of magnitude cleaner than the ice at the Greenland site, and is much colder and less stratigraphically disturbed, offering the potential for a clear resolution of this puzzle and a definitive test of the cosmogenic radiomethane hypothesis. Even if cosmogenic radiomethane in ice is found, it still may be possible to reconstruct atmospheric radiomethane with a correction enabled by a detailed understanding of the process, which will be sought by co-measuring carbon-14 in carbon monoxide and carbon dioxide. The broader impacts of the proposed work are that the clathrate test may shed light on the stability of the clathrate reservoir and its potential for climate feedbacks under human-induced warming. Development of Taylor Glacier as a 'horizontal ice core' would provide a community resource for other researchers. Education of one postdoc, one graduate student, and one undergraduate, would add to human resources. This award has field work in Antarctica. | ["POINT(161.71965 -77.76165)"] |
The Taylor Glacier, Antarctica, Horizontal Ice Core: Exploring changes in the Natural Methane Budget in a Warming World and Expanding the Paleo-archive
|
1245821 |
2016-01-01 | Brook, Edward J. |
Collaborative Research: The Taylor Glacier, Antarctica, Horizontal Ice Core: Exploring changes in the Natural Methane Budget in a Warming World and Expanding the Paleo-archive |
This award supports a project to use the Taylor Glacier, Antarctica, ablation zone to collect ice samples for a range of paleoenvironmental studies. A record of carbon-14 of atmospheric methane (14CH4) will be obtained for the last deglaciation and the Early Holocene, together with a supporting record of CH4 stable isotopes. In-situ cosmogenic 14C content and partitioning of 14C between different species (14CH4, C-14 carbon monoxide (14CO) and C-14 carbon dioxide (14CO2)) will be determined with unprecedented precision in ice from the surface down to ~67 m. Further age-mapping of the ablating ice stratigraphy will take place using a combination of CH4, CO2, and delta 18O of oxygen gas and H2O stable isotopes. High precision, high-resolution records of CO2, delta 13C of CO2, nitrous oxide (N2O) and N2O isotopes will be obtained for the last deglaciation and intervals during the last glacial period. The potential of 14CO2 and Krypton-81 (81Kr) as absolute dating tools for glacial ice will be investigated. The intellectual merit of proposed work includes the fact that the response of natural methane sources to continuing global warming is uncertain, and available evidence is insufficient to rule out the possibility of catastrophic releases from large 14C-depleted reservoirs such as CH4 clathrates and permafrost. The proposed paleoatmospheric 14CH4 record will improve our understanding of the possible magnitude and timing of CH4 release from these reservoirs during a large climatic warming. A thorough understanding of in-situ cosmogenic 14C in glacial ice (production rates by different mechanisms and partitioning between species) is currently lacking. Such an understanding will likely enable the use of in-situ 14CO in ice at accumulation sites as a reliable, uncomplicated tracer of the past cosmic ray flux and possibly past solar activity, as well as the use of 14CO2 at both ice accumulation and ice ablation sites as an absolute dating tool. Significant gaps remain in our understanding of the natural carbon cycle, as well as in its responses to global climate change. The proposed high-resolution, high-precision records of delta 13C of CO2 would provide new information on carbon cycle changes both during times of rising CO2 in a warming climate and falling CO2 in a cooling climate. N2O is an important greenhouse gas that increased by ~30% during the last deglaciation. The causes of this increase are still largely uncertain, and the proposed high-precision record of N2O concentration and isotopes would provide further insights into N2O source changes in a warming world. The broader impacts of proposed work include an improvement in our understanding of the response of these greenhouse gas budgets to global warming and inform societally important model projections of future climate change. The continued age-mapping of Taylor Glacier ablation ice will add value to this high-quality, easily accessible archive of natural environmental variability. Establishing 14CO as a robust new tracer for past cosmic ray flux would inform paleoclimate studies and constitute a valuable contribution to the study of the societally important issue of climate change. The proposed work will contribute to the development of new laboratory and field analytical systems. The data from the study will be made available to the scientific community and the broad public through the NSIDC and NOAA Paleoclimatology data centers. 1 graduate student each will be trained at UR, OSU and SIO, and the work will contribute to the training of a postdoc at OSU. 3 UR undergraduates will be involved in fieldwork and research. The work will support a new, junior UR faculty member, Petrenko. All PIs have a strong history of and commitment to scientific outreach in the forms of media interviews, participation in filming of field projects, as well as speaking to schools and the public about their research, and will continue these activities as part of the proposed work. This award has field work in Antarctica. | ["POINT(162.167 -77.733)"] |
Glacial-interglacial History of West Antarctic Nunataks and Site Reconnaissance for Subglacial Bedrock Sampling
|
1142162 |
2016-01-01 | Stone, John |
Glacial-interglacial History of West Antarctic Nunataks and Site Reconnaissance for Subglacial Bedrock Sampling |
This award supports a reconnaissance geological and radar-sounding study of promising sites in West Antarctica for a future project to measure cosmogenic nuclides in subglacial bedrock. Field work will take place in the Whitmore Mountains, close to the WAIS divide, and on the Nash and Pirrit Hills, downflow from the divide in the Weddell Sea drainage. At each site geological indicators of higher (and lower) ice levels in the past will be mapped and evidence of subglacial erosion or its absence will be documented. Elevation transects of both glacial erratics and adjacent bedrock samples will be collected to establish the timing of recent deglaciation at the sites and provide a complement to similar measurements on material from depth transects obtained by future subglacial drilling. At each site, bedrock ridges will be traced into the subsurface with closely-spaced ice-penetrating radar surveys, using a combination of instruments and frequencies to obtain the highest possible surface detail. Collectively the results will define prospective sites for subglacial sampling, and maximize the potential information to be obtained from such samples in future studies. The intellectual merit of this project is that measurements of cosmogenic nuclides in subglacial bedrock hold promise for resolving the questions of whether the West Antarctic ice sheet collapsed completely in the past, whether it is prone to repeated large deglaciations, and if so, what is their magnitude and frequency. Such studies will require careful choice of targets, to locate sites where bedrock geology is favorable, cosmogenic nuclide records are likely to have been protected from subglacial erosion, and the local ice-surface response is indicative of large-scale ice sheet behavior. The broader impacts of this work include helping to determine whether subglacial surfaces in West Antarctica were ever exposed to cosmic rays, which will provide unambiguous evidence for or against a smaller ice sheet in the past. This is an important step towards establishing whether the WAIS is vulnerable to collapse in future, and will ultimately help to address uncertainty in forecasting sea level change. The results will also provide ground truth for models of ice-sheet dynamics and long-term ice sheet evolution, and will help researchers use these models to identify paleoclimate conditions responsible for WAIS deglaciation. The education and training of students (both undergraduate and graduate students) will play an important role in the project, which will involve Antarctic fieldwork, technically challenging labwork, data collection and interpretation, and communication of the outcome to scientists and the general public. | ["POLYGON((-104.14 -81.07,-102.24 -81.07,-100.34 -81.07,-98.44 -81.07,-96.54 -81.07,-94.64 -81.07,-92.74 -81.07,-90.84 -81.07,-88.94 -81.07,-87.04 -81.07,-85.14 -81.07,-85.14 -81.207,-85.14 -81.344,-85.14 -81.481,-85.14 -81.618,-85.14 -81.755,-85.14 -81.892,-85.14 -82.029,-85.14 -82.166,-85.14 -82.303,-85.14 -82.44,-87.04 -82.44,-88.94 -82.44,-90.84 -82.44,-92.74 -82.44,-94.64 -82.44,-96.54 -82.44,-98.44 -82.44,-100.34 -82.44,-102.24 -82.44,-104.14 -82.44,-104.14 -82.303,-104.14 -82.166,-104.14 -82.029,-104.14 -81.892,-104.14 -81.755,-104.14 -81.618,-104.14 -81.481,-104.14 -81.344,-104.14 -81.207,-104.14 -81.07))"] |
Long-Term and Interannual Variability of Antarctic Ice Sheet Mass Balance From Satellite Gravimetry and Other Geodetic Measurements
|
1043750 |
2016-01-01 | Chen, Jianli |
Collaborative Research: Long-Term and Interannual Variability of Antarctic Ice Sheet Mass Balance From Satellite Gravimetry and Other Geodetic Measurements |
This award supports a project to improve the estimate of long-term and inter-annual variability of Antarctic ice sheet mass balance at continental, regional, and catchment scales, using satellite gravity measurements from the Gravity Recovery and Climate Experiment (GRACE) and other geodetic measurements. The work will improve the quantification of long-term mass change rates over Antarctica using GRACE gravity data with a longer record and newer generation(s) of products and will develop advanced numerical forward modeling techniques that can accurately correct leakage effects associated with GRACE data processing, and significantly improve spatial resolution of GRACE mass rate estimates over Antarctica. The work will also contribute to a better understanding of crustal uplift rates due to postglacial rebound (PGR) and present day ice load change over Antarctica via PGR models, GPS measurements, and combined analysis of GRACE and ICESat elevation changes. Inter-annual variations of ice mass over Antarctica will be investigated at continental and catchment scales and connections to regional climate change will be studied. The major deliverables from this study will be improved assessments of ice mass balance for the entire Antarctic ice sheet and potential contribution to global mean sea level rise. The work will also provide estimates of regional ice mass change rates over Antarctica, with a focus along the coast in the Amundsen Sea Embayment, the Peninsula in West Antarctica, and in Wilkes Land and Victoria Land in East Antarctica. Estimates of inter-annual ice mass change over Antarctica at various spatial scales, and assessments of uncertainty of GRACE ice rate estimates and PGR models errors over Antarctica will also be made. The intellectual merits of the proposed investigation include 1) providing improved assessments of Antarctic ice mass balance at different temporal and spatial scales with unprecedented accuracy, an important contribution to broad areas of polar science research; 2) combining high accuracy GPS vertical uplift measurements and PGR models to better quantify long-term crust uplift effects that are not distinguishable from ice mass changes by GRACE; and 3) unifying the work of several investigations at the forefront of quantifying ice sheet and glacier mass balance and crustal uplift based on a variety of modern space geodetic observations. The broader impacts include the fact that the project will actively involve student participation and training, through the support of two graduate students. In addition the project will contribute to general education and public outreach (E/PO) activities and the results from this investigation will help inspire future geoscientists and promote public awareness of significant manifestations of climate change. | ["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))"] |
Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats - Robotic Access to Grounding-zones for Exploration and Science (RAGES)
|
0839107 |
2016-01-01 | Powell, Ross |
Collaborative Research: Integrative Study of Marine Ice Sheet Stability & Subglacial Life Habitats in W Antarctica - Lake & Ice Stream Subglacial Access Research Drilling (LISSARD) |
The RAGES project (Robotic Access to Grounding zones for Exploration and Science) is one of three research components of the WISSARD (Whillans Ice Stream Subglacial Access Research Drilling) integrative initiative that is being funded by the Antarctic Integrated System Science Program of NSF's Office of Polar Programs, Antarctic Division. The overarching scientific objective of WISSARD is to assess the role of water beneath a West Antarctic ice stream in interlinked glaciological, geological, microbiological, geochemical, and oceanographic systems. The RAGES component of WISSARD concentrates on the stability of ice stream grounding zones (GZ), the area where the ice, ocean waters and glacial and sea floor sediment interact. Based on our present limited data and modeling efforts, GZs can be perturbed by (i) internal ice stream dynamics, (ii) filling/draining cycles of subglacial lakes, (iii) increased melting by warming ocean waters, and/or (iv) rates of subglacial sediment (till) supply to the GZ. GZs are seen as high priority targets to investigate due to their unknown contributions to ice sheet stability under future global warming scenarios. The three main science goals for RAGES are to assess: (a) West Antarctic Ice Sheet (WAIS) stability relative to the magnitudes of the four main variables listed above; (b) the degree to which grounding-zone sedimentary systems house important records of past WAIS dynamics; and (c) the importance of microbial activity and subglacial geochemical weathering in supplying nutrients to the WAIS grounding zone, the Ross Ice Shelf (RIS) cavity, and the highly productive Southern Ocean that may ultimately influence global biogeochemical cycles. The RAGES field sampling plan integrates surface geophysical surveys with borehole and subglacial sampling and measurements. The boreholes provide: (1) samples of subglacial water, sediments, and basal ice for biological, geochemical, glaciological, sedimentological, and micropaleontological analyses; (2) measures of subglacial and sub-ice-shelf cavity physical and chemical conditions and their spatial variability; and (3) data on sediment types, state and change of the subglacial water discharge, oceanography, and basal ice at the grounding line and within the nearby sub-ice-shelf cavity. Unique tools to be deployed include a multisensor Sub-Ice ROVer (Remotely Operated Vehicle) and long-term, sub-ice oceanographic moorings. The latest report of the Intergovernmental Panel on Climate Change recognized that the greatest uncertainties in assessing future global sea-level change stem from a poor understanding of ice sheet dynamics and ice sheet vulnerability to oceanic and atmospheric warming. Disintegration of the WAIS (West Antarctic Ice Sheet) alone would contribute 3-5 m to global sea-level rise, making WAIS a focus of scientific concern due to its potential susceptibility to internal or ocean-driven instability. The overall WISSARD project will test the overarching hypothesis that active water drainage connects various subglacial environments and exerts major control on ice sheet flow, geochemistry, metabolic and phylogenetic diversity, and biogeochemical transformations. Societal Relevance: Global warming, melting of ice sheets and consequential sea-level rise are of high societal relevance. Science Resource Development: After a 9-year hiatus WISSARD will provide the US-science community with a renewed capability to access and study sub-ice sheet environments. Developing this technological infrastructure will benefit the broader science community and assets will be accessible for future use through the NSF-OPP drilling contractor. The RAGES project represents a significant advance in polar technology by incorporating the use of complex new instrumentation like the Sub-Ice ROVer and subglacial ocean/lake mooring systems. Furthermore, these projects will pioneer an approach implementing recommendations from the National Research Council committee on Principles of Environmental Stewardship for the Exploration and Study of Subglacial Environments (2007). Education and Outreach (E/O): These activities are grouped into four categories: i) increasing student participation in polar research by fully integrating them in our research programs; ii) introducing new investigators to the polar sciences by incorporating promising young investigators in our programs, iii) promotion of K-12 teaching and learning programs by incorporating various teachers and NSTA programs, and iv) reaching a larger public audience through such venues as popular science magazines, museum based activities and videography and documentary films. In summary, WISSARD will promote scientific exploration of Antarctica by conveying to the public the excitement of accessing and studying what may be some of the last unexplored aquatic environments on Earth, and which represent a potential analogue for extraterrestrial life habitats on Europa and Mars. | ["POLYGON((-163.7 -84,-163.68 -84,-163.66 -84,-163.64 -84,-163.62 -84,-163.6 -84,-163.58 -84,-163.56 -84,-163.54 -84,-163.52 -84,-163.5 -84,-163.5 -84.05,-163.5 -84.1,-163.5 -84.15,-163.5 -84.2,-163.5 -84.25,-163.5 -84.3,-163.5 -84.35,-163.5 -84.4,-163.5 -84.45,-163.5 -84.5,-163.52 -84.5,-163.54 -84.5,-163.56 -84.5,-163.58 -84.5,-163.6 -84.5,-163.62 -84.5,-163.64 -84.5,-163.66 -84.5,-163.68 -84.5,-163.7 -84.5,-163.7 -84.45,-163.7 -84.4,-163.7 -84.35,-163.7 -84.3,-163.7 -84.25,-163.7 -84.2,-163.7 -84.15,-163.7 -84.1,-163.7 -84.05,-163.7 -84))"] |
Integrative Study of Marine Ice Sheet Stability and Subglacial Life Habitats in W Antarctica - Lake and Ice Stream Subglacial Access Research Drilling (LISSARD)
|
0839059 |
2016-01-01 | Powell, Ross |
Collaborative Research: Integrative Study of Marine Ice Sheet Stability & Subglacial Life Habitats in W Antarctica - Lake & Ice Stream Subglacial Access Research Drilling (LISSARD) |
The LISSARD project (Lake and Ice Stream Subglacial Access Research Drilling) is one of three research components of the WISSARD integrative initiative (Whillans Ice Stream Subglacial Access Research Drilling) that is being funded by the Antarctic Integrated System Science Program of NSF's Office of Polar Programs, Antarctic Division. The overarching scientific objective of WISSARD is to assess the role of water beneath a West Antarctic ice stream in interlinked glaciological, geological, microbiological, geochemical, and oceanographic systems. The LISSARD component of WISSARD focuses on the role of active subglacial lakes in determining how fast the West Antarctic ice sheet loses mass to the global ocean and influences global sea level changes. The importance of Antarctic subglacial lakes has only been recently recognized, and the lakes have been identified as high priority targets for scientific investigations because of their unknown contributions to ice sheet stability under future global warming scenarios. LISSARD has several primary science goals: A) To provide an observational basis for improving treatments of subglacial hydrological and mechanical processes in models of ice sheet mass balance and stability; B) To reconstruct the past history of ice stream stability by analyzing archives of past basal water and ice flow variability contained in subglacial sediments, porewater, lake water, and basal accreted ice; C) To provide background understanding of subglacial lake environments to benefit RAGES and GBASE (the other two components of the WISSARD project); and D) To synthesize data and concepts developed as part of this project to determine whether subglacial lakes play an important role in (de)stabilizing Antarctic ice sheets. We propose an unprecedented synthesis of approaches to studying ice sheet processes, including: (1) satellite remote sensing, (2) surface geophysics, (3) borehole observations and measurements and, (4) basal and subglacial sampling. The latest report of the Intergovernmental Panel on Climate Change recognized that the greatest uncertainties in assessing future global sea-level change stem from a poor understanding of ice sheet dynamics and ice sheet vulnerability to oceanic and atmospheric warming. Disintegration of the WAIS (West Antarctic Ice Sheet) alone would contribute 3-5 m to global sea-level rise, making WAIS a focus of scientific concern due to its potential susceptibility to internal or ocean-driven instability. The overall WISSARD project will test the overarching hypothesis that active water drainage connects various subglacial environments and exerts major control on ice sheet flow, geochemistry, metabolic and phylogenetic diversity, and biogeochemical transformations. Societal Relevance: Global warming, melting of ice sheets and consequential sea-level rise are of high societal relevance. Science Resource Development: After a 9-year hiatus WISSARD will provide the US-science community with a renewed capability to access and study sub-ice sheet environments. Developing this technological infrastructure will benefit the broader science community and assets will be accessible for future use through the NSF-OPP drilling contractor. Furthermore, these projects will pioneer an approach implementing recommendations from the National Research Council committee on Principles of Environmental Stewardship for the Exploration and Study of Subglacial Environments (2007). Education and Outreach (E/O): These activities are grouped into four categories: i) increasing student participation in polar research by fully integrating them in our research programs; ii) introducing new investigators to the polar sciences by incorporating promising young investigators in our programs, iii) promotion of K-12 teaching and learning programs by incorporating various teachers and NSTA programs, and iv) reaching a larger public audience through such venues as popular science magazines, museum based activities and videography and documentary films. In summary, WISSARD will promote scientific exploration of Antarctica by conveying to the public the excitement of accessing and studying what may be some of the last unexplored aquatic environments on Earth, and which represent a potential analogue for extraterrestrial life habitats on Europa and Mars. | ["POLYGON((-168.7 -82.3,-168.69 -82.3,-168.68 -82.3,-168.67 -82.3,-168.66 -82.3,-168.65 -82.3,-168.64 -82.3,-168.63 -82.3,-168.62 -82.3,-168.61 -82.3,-168.6 -82.3,-168.6 -82.31,-168.6 -82.32,-168.6 -82.33,-168.6 -82.34,-168.6 -82.35,-168.6 -82.36,-168.6 -82.37,-168.6 -82.38,-168.6 -82.39,-168.6 -82.4,-168.61 -82.4,-168.62 -82.4,-168.63 -82.4,-168.64 -82.4,-168.65 -82.4,-168.66 -82.4,-168.67 -82.4,-168.68 -82.4,-168.69 -82.4,-168.7 -82.4,-168.7 -82.39,-168.7 -82.38,-168.7 -82.37,-168.7 -82.36,-168.7 -82.35,-168.7 -82.34,-168.7 -82.33,-168.7 -82.32,-168.7 -82.31,-168.7 -82.3))"] |
Tomographic Imaging of the Velocity and Magnetic Fields in the Sun's Atmosphere
|
0632399 |
2016-01-01 | Jefferies, Stuart M. |
Tomographic Imaging of the Velocity and Magnetic Fields in the Sun's Atmosphere |
The ultimate goal of this project is to determine the structure and dynamics of the Sun's atmosphere, assess the role of MHD waves in heating the chromosphere/corona and driving the solar wind, and better understand how the Sun's atmosphere couples to the solar interior. As the solar atmosphere is 'home' to many of the solar phenomena that can have a direct impact on the biosphere, including flares, coronal mass ejections, and the solar wind, the broader impact of such studies is that they will lead to an improved understanding of the Sun-Earth connection. Under the current award we have developed a suite of instruments that can simultaneously image the line-of-sight Doppler velocity and longitudinal magnetic field at four heights in the solar atmosphere at high temporal cadence. The instruments use magneto-optical filters (see Cacciani, Moretti and Rodgers, Solar Physics 174, p.115, 2004) tuned to the solar absorption lines at 422 nm (Ca I), 589 nm (Na D2), 770 nm (K) and 1083 nm (He). These lines sample the solar atmosphere from the mid-photosphere to the high-chromosphere. A proof-of-concept run was made in the Austral summer of 2007/2008 using the Na and K versions of the instruments. Here we recorded over 40 hours of full-disk, intensity images of the Sun in the red and blue wings of the Na and K Fraunhofer lines, in both right- and left-circularly polarized light. The images were obtained at a rate of one every five seconds with a nominal spatial resolution of 4 arc-seconds. The run started at 09:44 UT on February 2, 2008 and ended at 03:30 UT on February 4, 2008. Data Quality Assessment: The temperature controls of the instrument housings were unable to fully compensate for the harse Antartic winds encountered during the observing run. This led to large (~15 C) temperature swings which adversely affected the instruments (and thus data quality) in two ways: 1) Crystals of Na and K were deposited on the magneto-optical filter windows leading to "hot spots" in the images. These "hot spots" come and go with time as the temperature changes. 2) The changing temperature caused the optical rails to contract and expand causing the final images to go in- and out-of-focus, thus reducing the resolution to greater than 4 arc-seconds. Both these effect are worse in the K data. Despite these problems, the intensity images can be combined to provide magnetic images that show a very high sensitivity (< 5 Gauss in a 5 second integration). Data Description: The raw data are stored as a series of 1024x1024x4 FITS images. The format is: blue image (left circulary polarized light), blue image (right circularly polarized light), red image (left circulary polarized light), red image (right circularly polarized light). The naming convention for the images is: Type_Instrument_Day_hour_minutes_seconds where Type is I (intensity), F (flatfield), D (dark) Instrument is 0 (Na), 1 (K) Day is the day number from the beginning of the year where January 1 is day 0 For example, I_0_32_12_34_40.fits is an intensity image taken with the Na instrument at 12:34.40 UT on February 2, 2008. Notes: 1) The flatfield images were acquired by moving a diffuser in front of the Sun during the integration. The resulting images therefore have to be corrected for residual low-spatial frequencies due to the non-flat nature of the light source. 2) Each FITS file header contains a variety of information on the observation, e.g., F_CNTO : number of summed frames in each 5 second integration (*) FPS : Camera frame rate (Frames Per Second) FLIP : Rate at which the half-wave rotator (magnetic switch) was switched INT_PER : Integration time (in seconds) MOF : Temperature of magneto-optical filter cell WS : Temperature of wing selector cell TEMP_0 : Temperature of camera 0 TEMP_1 : Temperature of camera 1 TEMP_2 : Temperature inside instrument (location 1) TEMP_3 : Temperature of narrowband filter TEMP_5 : Temperature of magnets surrounding MOF cell TEMP_6 : Temperature inside instrument (location 2) TEMP_7 : Temperature of housing for magnetic switch (*) This is the frame count for the camera. The number of frames in each image for the two different polarization states, is half this number. The measured temperatures are only coarse measurements. 3) Due to reflection in the final polarizing beam splitter (which separates the "red" and "blue" signals into the two cameras), the camera 1 data need to "reversed" along the x-axis (i.e. listed as [1024:1] instead of [1:1024]) 4) Line-of-sight velocity and magnetic field images are generated from the observed intensity images. Doppler images as (red-blue)/(red+blue), magnetic images as the difference between the Doppler images for right- and left-circularly polarized light. | ["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))"] |
Linking the Movement Patterns and Foraging Behavior of Humpback Whales to their Prey across Multiple Spatial Scales within the LTER Study Region
|
1250208 |
2016-01-01 | Friedlaender, Ari; Johnston, David; Nowacek, Douglas |
RAPID: Linking the Movement Patterns and Foraging Behavior of Humpback Whales to their Prey across Multiple Spatial Scales within the LTER Study Region |
Whales play a central role in the ecology and biogeochemistry of the Southern Ocean. However, little is known regarding their distribution and behavior, in part because of challenges associated with studying these organisms from large research vessels. This research will take advantage of the unique opportunity presented by the 2012-2013 test run of the smaller, more mobile R/V Point Sur. This work will use the Point Sur to investigate humpback whales in the waters studied by the Palmer Long Term Ecological Research (LTER) Station off the Western Antarctic Peninsula (WAP). Employing a combination of long-term satellite-linked tags and short-term suction cup tags, researchers will investigate the distribution, abundance and foraging behaviors of whales in this region. Whale biogeography will then be related to quantitative surveys of krill, their primary food source. Hypotheses regarding whale distribution and foraging strategies as well as physical oceanographic features will be tested. The WAP is undergoing some of the most dramatic warming on the planet, and a better understanding of the ecology of top predators is central to developing an understanding of the impacts of this change. Results will be widely disseminated through publications as well as through presentations at national and international meetings. In addition, raw data will be made available through open-access databases. Finally, this work will be coordinated with the extensive infrastructure of the Palmer LTER site, enabling outreach and educational activities. | ["POLYGON((-80 -63,-78 -63,-76 -63,-74 -63,-72 -63,-70 -63,-68 -63,-66 -63,-64 -63,-62 -63,-60 -63,-60 -63.7,-60 -64.4,-60 -65.1,-60 -65.8,-60 -66.5,-60 -67.2,-60 -67.9,-60 -68.6,-60 -69.3,-60 -70,-62 -70,-64 -70,-66 -70,-68 -70,-70 -70,-72 -70,-74 -70,-76 -70,-78 -70,-80 -70,-80 -69.3,-80 -68.6,-80 -67.9,-80 -67.2,-80 -66.5,-80 -65.8,-80 -65.1,-80 -64.4,-80 -63.7,-80 -63))"] |
Cryptic Hydrology of the McMurdo Dry Valleys: Water Track Contributions to Water and Geochemical Budgets in Taylor Valley, Antarctica
|
1343649 |
2015-01-01 | Levy, Joseph |
Cryptic Hydrology of the McMurdo Dry Valleys: Water Track Contributions to Water and Geochemical Budgets in Taylor Valley, Antarctica |
The PIs propose to quantify the hillslope water, solute, and carbon budgets for Taylor Valley in the McMurdo Dry Valleys, using water tracks to investigate near-surface geological processes and challenge the paradigm that shallow groundwater is minimal or non-exixtant. Water tracks are linear zones of high soil moisture that route shallow groundwater downslope in permafrost dominated soils. Four hypotheses will be tested: 1) water tracks are important pathways for water and solute transport; 2) water tracks transport more dissolved silica than streams in Taylor Valley indicating they are the primary site of chemical weathering for cold desert soils and bedrock; 3) water tracks that drain highland terrains are dominated by humidity-separated brines while water tracks that drain lowland terrains are dominated by marine aerosols; 4) water tracks are the sites of the highest terrestrial soil carbon concentrations and the strongest CO2 fluxes in Taylor Valley and their carbon content increases with soil age, while carbon flux decreases with age. To test these hypotheses the PIs will carry out a suite of field measurements supported by modeling and remote sensing. They will install shallow permafrost wells in water tracks that span the range of geological, climatological, and topographic conditions in Taylor Valley. Multifrequency electromagnetic induction sounding of the upper ~1 m of the permafrost will create the first comprehensive map of soil moisture in Taylor Valley, and will permit direct quantification of water track discharge across the valley. The carbon contents of water track soils will be measured and linked to global carbon dynamics. Non-science majors at Oregon State University will be integrated into the proposed research through a new Global Environmental Change course focusing on the scientific method in Antarctica. Three undergraduate students, members of underrepresented minorities, will be entrained in the research, will contribute to all aspects of field and laboratory science, and will present results at national meetings. | ["POLYGON((162.852 -77.6111,162.9893 -77.6111,163.1266 -77.6111,163.2639 -77.6111,163.4012 -77.6111,163.5385 -77.6111,163.6758 -77.6111,163.8131 -77.6111,163.9504 -77.6111,164.0877 -77.6111,164.225 -77.6111,164.225 -77.65331,164.225 -77.69552,164.225 -77.73773,164.225 -77.77994,164.225 -77.82215,164.225 -77.86436,164.225 -77.90657,164.225 -77.94878,164.225 -77.99099,164.225 -78.0332,164.0877 -78.0332,163.9504 -78.0332,163.8131 -78.0332,163.6758 -78.0332,163.5385 -78.0332,163.4012 -78.0332,163.2639 -78.0332,163.1266 -78.0332,162.9893 -78.0332,162.852 -78.0332,162.852 -77.99099,162.852 -77.94878,162.852 -77.90657,162.852 -77.86436,162.852 -77.82215,162.852 -77.77994,162.852 -77.73773,162.852 -77.69552,162.852 -77.65331,162.852 -77.6111))"] |
Retrospective Analysis of Antarctic Tracking data (RAATD): International Crabeater and Weddell Seal Tracking Data Sets
|
1321782 |
2015-01-01 | Costa, Daniel Paul |
Retrospective Analysis of Antarctic Tracking data (RAATD): International Crabeater and Weddell Seal Tracking Data Sets |
Identifying the basic habitat requirements of Antarctic predators is fundamental to understanding how they will respond to the human-induced challenges of commercial fisheries and climate change. This understanding can only be achieved if the underlying linkages to physical processes are related to animal movements. As part of the international Retrospective Analysis of Antarctic Tracking Data (RAATD) organized by the SCAR Expert Group of Birds and Marine Mammals, this research will collate and synthesize tracking data from crabeater seals, Lobodon carcinophagus, and Weddell seals, Leptonychotes weddelli. These data will be combined with all available data from the Southern Ocean that has been collected by researchers from Norway, United Kingdom, Germany, Australia and the USA. These data will be analyzed using a common analytical approach and synthesized into a synoptic view of these two species across the Southern Ocean. The diving and movement patterns will be examined for each species. As well, the total home range and core habitat utilization patterns for each species and region will be determined. This study will develop global habitat maps for each species based on physical and biological attributes of their 'hot-spots' and then overlay all the species specific maps to identify multi-species areas of ecological significance. Broader impacts include support and training for a postdoctoral scholar, the production of a publicly available database and the participation in an international data synthesis effort. | ["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))"] |
Pre and Post Molt Biology of Emperor Penguins - Oden Trans - Ross / Amundsen Sea Cruise
|
1043454 |
2015-01-01 | Kooyman, Gerald |
Pre and post molt biology of emperor penguins - Oden trans - Ross / Amundsen Sea cruise |
The emperor penguin dives deeper and longer, fasts longer, and endures the harshest weather conditions of all diving birds. It spends about four and half months per annum deep in Antarctic pack ice away from shore and stations, and thus is largely unavailable for study. This time includes preparation for the molt, and travel to the colony to breed, a time period in which great swings in body weight occur. This study will fill an important gap in what we know about the biology of the annual cycle of the emperor by examining the molt-post molt period. The P.I. proposes to traverse the Amundsen and Bellingshausen seas on the Oden, to locate and tag emperor penguins during the molt season. The objectives are to (1) Place satellite tags on 20 adult post molt birds to determine their route, rate of travel, and diving behavior as they return back to their breeding colonies, (2) Obtain an index of body condition, (3) Collect guano to determine the type of food consumed by emperor penguins in the region, (4) Conduct shipboard surveys to sight and plot the location and abundance of adult and juvenile birds on the ship's track. The PI hypothesizes that bird dives will be shallow during the initial post-molt phase, and that food will consist primarily of krill; that there will be differential dispersal of birds from the Ross Sea vs. Marie Byrd Land, with Ross Sea birds traveling farther; and that the greatest adult mortality occurs during the molt and early post molt period. Broader impacts include training of a post doc, a graduate student, and an aquarium volunteer. The P.I. also will present findings through a website, through public lectures, and in collaboration with the Birch aquarium. | ["POLYGON((-172.642 -72.55,-170.9074 -72.55,-169.1728 -72.55,-167.4382 -72.55,-165.7036 -72.55,-163.969 -72.55,-162.2344 -72.55,-160.4998 -72.55,-158.7652 -72.55,-157.0306 -72.55,-155.296 -72.55,-155.296 -73.0743,-155.296 -73.5986,-155.296 -74.1229,-155.296 -74.6472,-155.296 -75.1715,-155.296 -75.6958,-155.296 -76.2201,-155.296 -76.7444,-155.296 -77.2687,-155.296 -77.793,-157.0306 -77.793,-158.7652 -77.793,-160.4998 -77.793,-162.2344 -77.793,-163.969 -77.793,-165.7036 -77.793,-167.4382 -77.793,-169.1728 -77.793,-170.9074 -77.793,-172.642 -77.793,-172.642 -77.2687,-172.642 -76.7444,-172.642 -76.2201,-172.642 -75.6958,-172.642 -75.1715,-172.642 -74.6472,-172.642 -74.1229,-172.642 -73.5986,-172.642 -73.0743,-172.642 -72.55))"] |
Annual Satellite Era Accumulation Patterns Over WAIS Divide: A Study Using Shallow Ice Cores, Near-Surface Radars and Satellites
|
0944653 |
2015-01-01 | Forster, Richard |
Collaborative Research: Annual satellite era accumulation patterns over WAIS Divide: A study using shallow ice cores, near-surface radars and satellites |
This award supports a project to broaden the knowledge of annual accumulation patterns over the West Antarctic Ice Sheet by processing existing near-surface radar data taken on the US ITASE traverse in 2000 and by gathering and validating new ultra/super-high-frequency (UHF) radar images of near surface layers (to depths of ~15 m), expanding abilities to monitor recent annual accumulation patterns from point source ice cores to radar lines. Shallow (15 m) ice cores will be collected in conjunction with UHF radar images to confirm that radar echoed returns correspond with annual layers, and/or sub-annual density changes in the near-surface snow, as determined from ice core stable isotopes. This project will additionally improve accumulation monitoring from space-borne instruments by comparing the spatial-radar-derived-annual accumulation time series to the passive microwave time series dating back over 3 decades and covering most of Antarctica. The intellectual merit of this project is that mapping the spatial and temporal variations in accumulation rates over the Antarctic ice sheet is essential for understanding ice sheet responses to climate forcing. Antarctic precipitation rate is projected to increase up to 20% in the coming century from the predicted warming. Accumulation is a key component for determining ice sheet mass balance and, hence, sea level rise, yet our ability to measure annual accumulation variability over the past 5 decades (satellite era) is mostly limited to point-source ice cores. Developing a radar and ice core derived annual accumulation dataset will provide validation data for space-born remote sensing algorithms, climate models and, additionally, establish accumulation trends. The broader impacts of the project are that it will advance discovery and understanding within the climatology, glaciology and remote sensing communities by verifying the use of UHF radars to monitor annual layers as determined by visual, chemical and isotopic analysis from corresponding shallow ice cores and will provide a dataset of annual to near-annual accumulation measurements over the past ~5 decades across WAIS divide from existing radar data and proposed radar data. By determining if temporal changes in the passive microwave signal are correlated with temporal changes in accumulation will help assess the utility of passive microwave remote sensing to monitor accumulation rates over ice sheets for future decades. The project will promote teaching, training and learning, and increase representation of underrepresented groups by becoming involved in the NASA History of Winter project and Thermochron Mission and by providing K-12 teachers with training to monitor snow accumulation and temperature here in the US, linking polar research to the student's backyard. The project will train both undergraduate and graduate students in polar research and will encouraging young investigators to become involved in careers in science. In particular, two REU students will participate in original research projects as part of this larger project, from development of a hypothesis to presentation and publication of the results. The support of a new, young woman scientist will help to increase gender diversity in polar research. | ["POLYGON((-119.4 -78.1,-118.46 -78.1,-117.52 -78.1,-116.58 -78.1,-115.64 -78.1,-114.7 -78.1,-113.76 -78.1,-112.82 -78.1,-111.88 -78.1,-110.94 -78.1,-110 -78.1,-110 -78.29,-110 -78.48,-110 -78.67,-110 -78.86,-110 -79.05,-110 -79.24,-110 -79.43,-110 -79.62,-110 -79.81,-110 -80,-110.94 -80,-111.88 -80,-112.82 -80,-113.76 -80,-114.7 -80,-115.64 -80,-116.58 -80,-117.52 -80,-118.46 -80,-119.4 -80,-119.4 -79.81,-119.4 -79.62,-119.4 -79.43,-119.4 -79.24,-119.4 -79.05,-119.4 -78.86,-119.4 -78.67,-119.4 -78.48,-119.4 -78.29,-119.4 -78.1))"] |
Stable Isotope Analyses of Pygoscelid Penguin remains from Active and Abandoned Colonies in Antarctica
|
0739575 |
2015-01-01 | Emslie, Steven; Patterson, William; Polito, Michael |
Stable Isotope Analyses of Pygoscelid Penguin remains from Active and Abandoned Colonies in Antarctica |
The research combines interdisciplinary study in geology, paleontology, and biology, using stable isotope and radiocarbon analyses, to examine how climate change and resource utilization have influenced population distribution, movement, and diet in penguins during the mid-to-late Holocene. Previous investigations have demonstrated that abandoned colonies contain well-preserved remains that can be used to examine differential responses of penguins to climate change in various sectors of Antarctica. As such, the research team will investigate abandoned and active pygoscelid penguin (Adelie, Chinstrap, and Gentoo) colonies in the Antarctic Peninsula and Ross Sea regions, and possibly Prydz Bay, in collaboration with Chinese scientists during four field seasons. Stable isotope analyses will be conducted on recovered penguin tissues and prey remains in guano to address hypotheses on penguin occupation history, population movement, and diet in relation to climate change since the late Pleistocene. The study will include one Ph.D., two Masters and 16 undergraduate students in advanced research over the project period. Students will be exposed to a variety of fields, the scientific method, and international scientific research. They will complete field and lab research for individual projects or Honor's theses for academic credit. The project also will include web-based outreach, lectures to middle school students, and the development of interactive exercises that highlight hypothesis-driven research and the ecology of Antarctica. Two undergraduate students in French and Spanish languages at UNCW will be hired to assist in translating the Web page postings for broader access to this information. | ["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))"] |
Abrupt Environmental Change in the Larsen Ice Shelf System (LARISSA) - Marine Ecosystems
|
0732983 |
2014-01-01 | Vernet, Maria |
Collaborative Research in IPY: Abrupt Environmental Change in the Larsen Ice Shelf System, a Multidisciplinary Approach -- Cryosphere and Oceans |
Collaborative Research in IPY: Abrupt Environmental Change in the Larsen Ice Shelf System, a Multidisciplinary Approach - Marine Ecosystems. A profound transformation in ecosystem structure and function is occurring in coastal waters of the western Weddell Sea, with the collapse of the Larsen B ice shelf. This transformation appears to be yielding a redistribution of energy flow between chemoautotrophic and photosynthetic production, and to be causing the rapid demise of the extraordinary seep ecosystem discovered beneath the ice shelf. This event provides an ideal opportunity to examine fundamental aspects of ecosystem transition associated with climate change. We propose to test the following hypotheses to elucidate the transformations occurring in marine ecosystems as a consequence of the Larsen B collapse: (1) The biogeographic isolation and sub-ice shelf setting of the Larsen B seep has led to novel habitat characteristics, chemoautotrophically dependent taxa and functional adaptations. (2) Benthic communities beneath the former Larsen B ice shelf are fundamentally different from assemblages at similar depths in the Weddell sea-ice zone, and resemble oligotrophic deep-sea communities. Larsen B assemblages are undergoing rapid change. (3) The previously dark, oligotrophic waters of the Larsen B embayment now support a thriving phototrophic community, with production rates and phytoplankton composition similar to other productive areas of the Weddell Sea. To document rapid changes occurring in the Larsen B ecosystem, we will use a remotely operated vehicle, shipboard samplers, and moored sediment traps. We will characterize microbial, macrofaunal and megafaunal components of the seep community; evaluate patterns of surface productivity, export flux, and benthic faunal composition in areas previously covered by the ice shelf, and compare these areas to the open sea-ice zone. These changes will be placed within the geological, glaciological and climatological context that led to ice-shelf retreat, through companion research projects funded in concert with this effort. Together these projects will help predict the likely consequences of ice-shelf collapse to marine ecosystems in other regions of Antarctica vulnerable to climate change. The research features international collaborators from Argentina, Belgium, Canada, Germany, Spain and the United Kingdom. The broader impacts include participation of a science writer; broadcast of science segments by members of the Jim Lehrer News Hour (Public Broadcasting System); material for summer courses in environmental change; mentoring of graduate students and postdoctoral fellows; and showcasing scientific activities and findings to students and public through podcasts. | ["POLYGON((-66 -62,-65.3 -62,-64.6 -62,-63.9 -62,-63.2 -62,-62.5 -62,-61.8 -62,-61.1 -62,-60.4 -62,-59.7 -62,-59 -62,-59 -62.8,-59 -63.6,-59 -64.4,-59 -65.2,-59 -66,-59 -66.8,-59 -67.6,-59 -68.4,-59 -69.2,-59 -70,-59.7 -70,-60.4 -70,-61.1 -70,-61.8 -70,-62.5 -70,-63.2 -70,-63.9 -70,-64.6 -70,-65.3 -70,-66 -70,-66 -69.2,-66 -68.4,-66 -67.6,-66 -66.8,-66 -66,-66 -65.2,-66 -64.4,-66 -63.6,-66 -62.8,-66 -62))"] |
Ocean-Ice Interaction in the Amundsen Sea Sector of West Antarctica
|
0732804 |
2014-01-01 | McPhee, Miles G. |
Collaborative Research; IPY: Ocean-Ice Interaction in the Amundsen Sea sector of West Antarctica |
The Office of Polar Programs, Antarctic Integrated and System Science Program has made this award to support an interdisciplinary study of the effects of the ocean on the stability of glacial ice in the most dynamic region the West Antarctic Ice Sheet, namely the Pine Island Glacier in the Amundsen Sea Embayment. The collaborative project builds on the knowledge gained by the highly successful West Antarctic Ice Sheet program and is being jointly sponsored with NASA. Recent observations indicate a significant ice loss, equivalent to 10% of the ongoing increase in sea-level rise, in this region. These changes are largest along the coast and propagate rapidly inland, indicating the critical impact of the ocean on ice sheet stability in the region. While a broad range of remote sensing and ground-based instrumentation is available to characterize changes of the ice surface and internal structure (deformation, ice motion, melt) and the shape of the underlying sediment and rock bed, instrumentation has yet to be successfully deployed for observing boundary layer processes of the ocean cavity which underlies the floating ice shelf and where rapid melting is apparently occurring. Innovative, mini ocean sensors that can be lowered through boreholes in the ice shelf (about 500 m thick) will be developed and deployed to automatically provide ocean profiling information over at least three years. Their data will be transmitted through a conducting cable frozen in the borehole to the surface where it will be further transmitted via satellite to a laboratory in the US. Geophysical and remote sensing methods (seismic, GPS, altimetry, stereo imaging, radar profiling) will be applied to map the geometry of the ice shelf, the shape of the sub ice-shelf cavity, the ice surface geometry and deformations within the glacial ice. To integrate the seismic, glaciological and oceanographic observations, a new 3-dimensional coupled ice-ocean model is being developed which will be the first of its kind. NASA is supporting satellite based research and the deployment of a robotic-camera system to explore the environment in the ocean cavity underlying the ice shelf and NSF is supporting all other aspects of this study. Broader impacts: This project is motivated by the potential societal impacts of rapid sea level rise and should result in critically needed improvements in characterizing and predicting the behavior of coupled ocean-ice systems. It is a contribution to the International Polar Year and was endorsed by the International Council for Science as a component of the 'Multidisciplinary Study of the Amundsen Sea Embayment' proposal #258 of the honeycomb of endorsed IPY activities. The research involves substantial international partnerships with the British Antarctic Survey and the University of Bristol in the UK. The investigators will partner with the previously funded 'Polar Palooza' education and outreach program in addition to undertaking a diverse set of outreach activities of their own. Eight graduate students and one undergraduate as well as one post doc will be integrated into this research project. | ["POINT(166.25 -77.42)"] |
Dating and Paleoenvironmental Studies on Ancient Ice in the Dry Valleys, Antarctica
|
0636731 |
2014-01-01 | Bender, Michael |
Collaborative Research: Dating and Paleoenvironmental Studies on Ancient Ice in the Dry Valleys, Antarctica |
This project studies ancient ice buried in the Dry Valleys of Antarctica. The ice, which may approach ten million years in age, will be dated using argon and uranium radioisotope techniques. High-risk work, if successful it will offer the first and perhaps only samples of the Earth's atmosphere from millions of years in the past. These samples could offer critically important tests of paleoclimate records and proxies, as well as a glimpse into the characteristics of a past world much like the predicted future, warmer Earth. The broader impacts are graduate student education, and potentially contributing to society's understanding of global climate change and sea level rise. | ["POLYGON((-180 -72.6,-176.887 -72.6,-173.774 -72.6,-170.661 -72.6,-167.548 -72.6,-164.435 -72.6,-161.322 -72.6,-158.209 -72.6,-155.096 -72.6,-151.983 -72.6,-148.87 -72.6,-148.87 -73.533,-148.87 -74.466,-148.87 -75.399,-148.87 -76.332,-148.87 -77.265,-148.87 -78.198,-148.87 -79.131,-148.87 -80.064,-148.87 -80.997,-148.87 -81.93,-151.983 -81.93,-155.096 -81.93,-158.209 -81.93,-161.322 -81.93,-164.435 -81.93,-167.548 -81.93,-170.661 -81.93,-173.774 -81.93,-176.887 -81.93,180 -81.93,174.335 -81.93,168.67 -81.93,163.005 -81.93,157.34 -81.93,151.675 -81.93,146.01 -81.93,140.345 -81.93,134.68 -81.93,129.015 -81.93,123.35 -81.93,123.35 -80.997,123.35 -80.064,123.35 -79.131,123.35 -78.198,123.35 -77.265,123.35 -76.332,123.35 -75.399,123.35 -74.466,123.35 -73.533,123.35 -72.6,129.015 -72.6,134.68 -72.6,140.345 -72.6,146.01 -72.6,151.675 -72.6,157.34 -72.6,163.005 -72.6,168.67 -72.6,174.335 -72.6,-180 -72.6))"] |
Exploring A 2 Million + Year Ice Climate Archive-Allan Hills Blue Ice Area (2MBIA)
|
0838849 |
2014-01-01 | Bender, Michael |
Collaborative Research: Exploring A 2 Million + Year Ice Climate Archive-Allan Hills Blue Ice Area (2MBIA) |
This award supports a project to generate an absolute timescale for the Allan Hills Blue Ice Area (BIA), and then to reconstruct details of past climate changes and greenhouse gas concentrations for certain time periods back to 2.5 Ma. Ice ages will be determined by applying emerging methods for absolute and relative dating of trapped air bubbles (based on Argon-40/Argon-38, delta-18O of O2, and the O2/N2 ratio). To demonstrate the potential of the Allan Hills BIAs as a paleoclimate archive trenches and ice cores will be collected for age intervals corresponding to 110-140 ka, 1 Ma, and 2.5 Ma. During the proposed two field seasons a total of 6x100 m and additional 15 m cores will be combined with trenching. The intellectual merit of the proposed activity is that the results of this work will extend the landmark work of EPICA and other deep ice coring efforts, which give records dating back to 0.8 Ma, and will complement work planned by IPICS to drill a continuous Antarctic ice core extending to 1.5 Ma. The results will help to advance understanding of major climate regimes and transitions that took place between 0-2.5 Ma, including the 40 kyr world and the mid-Pleistocene climate transition. A major long-term scientific goal is to provide a transformative approach to the collection of paleoclimate records by establishing an 'International Climate Park' in the Allan Hills BIA that would enable sampling of large quantities of known age ice as old as 2.5 Ma, by any interested American or foreign investigator. The broader impacts resulting from the proposed activity include training students who are well versed in advanced field, laboratory and numerical modeling methods combining geochemistry, glaciology, and paleoclimatology. We will include material relevant to our proposed research in our ongoing efforts in local education and in our outreach efforts for media. The University of Maine already has cyberinfrastructure, using state of the art web-based technology, which can provide a wide community of scientists with fast access to the results of our research. The work will contribute to the broad array of climate change studies that is informing worldwide understanding of natural and anthropogenic forced climate change, and the options for responding. This award has field work in Antarctica. | ["POLYGON((159.16667 -76.66667,159.19167 -76.66667,159.21667 -76.66667,159.24167 -76.66667,159.26667 -76.66667,159.29167 -76.66667,159.31667 -76.66667,159.34167 -76.66667,159.36667 -76.66667,159.39167 -76.66667,159.41667 -76.66667,159.41667 -76.673336,159.41667 -76.680002,159.41667 -76.686668,159.41667 -76.693334,159.41667 -76.7,159.41667 -76.706666,159.41667 -76.713332,159.41667 -76.719998,159.41667 -76.726664,159.41667 -76.73333,159.39167 -76.73333,159.36667 -76.73333,159.34167 -76.73333,159.31667 -76.73333,159.29167 -76.73333,159.26667 -76.73333,159.24167 -76.73333,159.21667 -76.73333,159.19167 -76.73333,159.16667 -76.73333,159.16667 -76.726664,159.16667 -76.719998,159.16667 -76.713332,159.16667 -76.706666,159.16667 -76.7,159.16667 -76.693334,159.16667 -76.686668,159.16667 -76.680002,159.16667 -76.673336,159.16667 -76.66667))"] |
Ammonia Oxidation Versus Heterotrophy in Crenarchaeota Populations from Marine Environments West of the Antarctic Peninsula
|
0838996 |
2014-01-01 | Hollibaugh, James T. |
Ammonia Oxidation Versus Heterotrophy in Crenarchaeota Populations from Marine Environments West of the Antarctic Peninsula |
Ammonia oxidation is the first step in the conversion of regenerated nitrogen to dinitrogen gas, a 3-step pathway mediated by 3 distinct guilds of bacteria and archaea. Ammonia oxidation and the overall process of nitrification-denitrification have received relatively little attention in polar oceans where the effects of climate change on biogeochemical rates are likely to be pronounced. Previous work on Ammonia Oxidizing Archaea (AOA) in the Palmer LTER study area West of the Antarctic Peninsula (WAP), has suggested strong vertical segregation of crenarchaeote metabolism, with the 'winter water' (WW, ~50-100 m depth range) dominated by non-AOA crenarchaeotes, while Crenarchaeota populations in the 'circumpolar deep water' (CDW), which lies immediately below the winter water (150-3500 m), are dominated by AOA. Analysis of a limited number of samples from the Arctic Ocean did not reveal a comparable vertical segregation of AOA, and suggested that AOA and Crenarchaeota abundance is much lower there than in the Antarctic. These findings led to 3 hypotheses that will be tested in this project: 1) the apparent low abundance of Crenarchaeota and AOA in Arctic Ocean samples may be due to spatial or temporal variability in populations; 2) the WW population of Crenarchaeota in the WAP is dominated by a heterotroph; 3) the WW population of Crenarchaeota in the WAP 'grows in' during spring and summer after this water mass forms. The study will contribute substantially to understanding an important aspect of the nitrogen cycle in the Palmer LTER (Long Term Ecological Research) study area by providing insights into the ecology and physiology of AOA. The natural segregation of crenarchaeote phenotypes in waters of the WAP, coupled with metagenomic studies in progress in the same area by others (A. Murray, H. Ducklow), offers the possibility of major breakthroughs in understanding of the metabolic capabilities of these organisms. This knowledge is needed to model how water column nitrification will respond to changes in polar ecosystems accompanying global climate change. The Principal Investigator will participate fully in the education and outreach efforts of the Palmer LTER, including making highlights of our findings available for posting to their project web site and participating in outreach (for example, Schoolyard LTER). The research also will involve undergraduates (including the field work if possible) and will support high school interns in the P.I.'s laboratory over the summer. | ["POLYGON((-79 -63,-77.5 -63,-76 -63,-74.5 -63,-73 -63,-71.5 -63,-70 -63,-68.5 -63,-67 -63,-65.5 -63,-64 -63,-64 -63.8,-64 -64.6,-64 -65.4,-64 -66.2,-64 -67,-64 -67.8,-64 -68.6,-64 -69.4,-64 -70.2,-64 -71,-65.5 -71,-67 -71,-68.5 -71,-70 -71,-71.5 -71,-73 -71,-74.5 -71,-76 -71,-77.5 -71,-79 -71,-79 -70.2,-79 -69.4,-79 -68.6,-79 -67.8,-79 -67,-79 -66.2,-79 -65.4,-79 -64.6,-79 -63.8,-79 -63))"] |
Validating contrasting terrestrial climate-sensitive Pliocene deposits through high resolution modeling of paleo-environments in the Transantarctic Mountains
|
1354231 |
2014-01-01 | Kowalewski, Douglas |
Validating contrasting terrestrial climate-sensitive Pliocene deposits through high resolution modeling of paleo-environments in the Transantarctic Mountains |
Intellectual Merit: Neogene sediment records recovered by ANDRILL suggest multiple events of open water conditions and elevated sea surface temperatures at times when terrestrial data from the McMurdo Dry Valleys indicate hyper arid, cold, desert conditions. Interpretation of the ANDRILL data suggests the West Antarctic Ice Sheet is highly sensitive to changes in Pliocene sea surface temperatures and this conclusion has been supported by recent Global Circulation Model results for the early to mid Pliocene. The PIs propose to model paleo-ice configurations and warm orbits associated with a WAIS collapse to assess potential climate change in East Antarctica. During such episodes of polar warmth they propose to answer: What is the limit of ablation along the East Antarctic Ice Sheet?; Are relict landforms in the Dry Valleys susceptible to modification from increase in maximum summertime temperatures?; and Is there sufficient increase in minimum wintertime temperatures to sustain a tundra environment in the Dry Valleys? Integration of depositional records and model outputs have the potential to test the performance of numerical models currently under development as part of ANDRILL; reconcile inconsistencies between marine and terrestrial paleoclimate records in high Southern Latitudes; and improve understanding of Antarctic climate and ice volume sensitivity to forcing for both the East Antarctic and West Antarctic Ice Sheets. Broader impacts: Results from this study have the potential to be used widely by the research community. Outreach to local elementary schools from other funded efforts will continue and be extended to homeschooled students. A Post Doc will be supported as part of this award. | ["POLYGON((-160 -70,-156 -70,-152 -70,-148 -70,-144 -70,-140 -70,-136 -70,-132 -70,-128 -70,-124 -70,-120 -70,-120 -71.5,-120 -73,-120 -74.5,-120 -76,-120 -77.5,-120 -79,-120 -80.5,-120 -82,-120 -83.5,-120 -85,-124 -85,-128 -85,-132 -85,-136 -85,-140 -85,-144 -85,-148 -85,-152 -85,-156 -85,-160 -85,-160 -83.5,-160 -82,-160 -80.5,-160 -79,-160 -77.5,-160 -76,-160 -74.5,-160 -73,-160 -71.5,-160 -70))"] |
Pleistocene East Antarctic Ice Sheet History as Recorded in Sediment Provenance and Chronology of High-elevation TAM Moraines
|
0944475 |
2014-01-01 | Kaplan, Michael |
Collaborative Research: Pleistocene East Antarctic Ice Sheet History as Recorded in Sediment Provenance and Chronology of High-elevation TAM Moraines |
Intellectual Merit: The proposed work will investigate changes in the compositional variation of glacial tills over time across two concentric sequences of Pleistocene moraines located adjacent to the heads of East Antarctic outlet glaciers in the Transantarctic Mountains (TAM). The chronologic framework for this work will be generated from cosmogenic exposure ages of boulders on prominent morainal ridges. The PIs hypothesize that variations in till composition may indicate a change in ice flow direction or a change in the composition of the original source area, while ages of the moraines provide a long-term terrestrial perspective on ice sheet dynamics. Both results are vital for modeling experiments that aim to reconstruct the East Antarctic Ice Sheet and assess its role in the global climate system and its potential impact on global sea level rise. The variation of till compositions through time also allows for a more accurate interpretation of sediment cores from the Ross Sea and the Southern Ocean. Additionally, till exposures at the head of some East Antarctic outlet glaciers have been shown to contain subglacial material derived from East Antarctic bedrock, providing a window through the ice to view East Antarctica's inaccessible bedrock. Till samples will be collected from two well-preserved sequences of moraine crests at Mt. Howe (head of Scott Glacier) and Mt. Achernar (between Beardmore and Nimrod Glaciers). Each size fraction in glacial till provides potentially valuable information, and the PIs will measure the petrography of the clast and sand fractions, quantitative X-ray diffraction on the crushed <2mm fraction, elemental abundance of the silt/clay fraction, and U/Pb of detrital zircons in the sand fraction. Data collection will rely on established methods previously used in this region and the PIs will also explore new methods to assess their efficacy. On the same moraines crests sampled for provenance studies, the PIs will sample for cosmogenic surface exposure analyses to provide a chronologic framework at the sites for provenance changes through time. Broader Impact: The proposed research involves graduate and undergraduate training in a diverse array of laboratory methods. Students and PIs will be make presentations to community and campus groups, as well as conduct interviews with local news outlets. The proposed work also establishes a new, potentially long-term, collaboration between scientists at IUPUI and LDEO and brings a new PI (Kaplan) into the field of Antarctic Earth Sciences. | ["POLYGON((-180 -84.1,-176.97 -84.1,-173.94 -84.1,-170.91 -84.1,-167.88 -84.1,-164.85 -84.1,-161.82 -84.1,-158.79 -84.1,-155.76 -84.1,-152.73 -84.1,-149.7 -84.1,-149.7 -84.43,-149.7 -84.76,-149.7 -85.09,-149.7 -85.42,-149.7 -85.75,-149.7 -86.08,-149.7 -86.41,-149.7 -86.74,-149.7 -87.07,-149.7 -87.4,-152.73 -87.4,-155.76 -87.4,-158.79 -87.4,-161.82 -87.4,-164.85 -87.4,-167.88 -87.4,-170.91 -87.4,-173.94 -87.4,-176.97 -87.4,180 -87.4,178.12 -87.4,176.24 -87.4,174.36 -87.4,172.48 -87.4,170.6 -87.4,168.72 -87.4,166.84 -87.4,164.96 -87.4,163.08 -87.4,161.2 -87.4,161.2 -87.07,161.2 -86.74,161.2 -86.41,161.2 -86.08,161.2 -85.75,161.2 -85.42,161.2 -85.09,161.2 -84.76,161.2 -84.43,161.2 -84.1,163.08 -84.1,164.96 -84.1,166.84 -84.1,168.72 -84.1,170.6 -84.1,172.48 -84.1,174.36 -84.1,176.24 -84.1,178.12 -84.1,-180 -84.1))"] |
Impact of Rising Oceanic Temperatures on the Embryonic Development of Antarctic Notothenioid Fishes
|
1019305 |
2014-01-01 | Grim, Jeffrey |
PostDoctoral Research Fellowship |
Survival of Antarctic notothenioid fishes in the context of global climate change will depend upon the impact of rising oceanic temperatures on their embryonic development, yet little is known regarding the molecular mechanisms underlying this complex suite of processes. Many notothenioids are characterized by secondary pelagicism, which enables them to exploit food sources in the water column and is supported in part by skeletal pedomorphism. Here the PI proposes to examine the hypothesis that reactive oxygen species (ROS) regulate notothenioid skeletal pedomorphism. The research objectives are : 1) To quantify and localize ROS production and identify the point(s) of origin of ROS production in embryonic Antarctic fishes that differ in skeletal phenotypes 2) To determine whether the time course of embryogenesis and the extent of osteological development in embryonic Antarctic fishes can be altered by changing the oxidative status of the animal during embryogenesis 3) To evaluate whether transgenic alteration of oxidative status can induce skeletal pedomorphism in a fish model. Broader Impacts will include teaching undergraduate lectures, recruiting undergraduate students to help with lab analyses (and possibly field work), lectures and demonstrations to high school students, and allowing secondary educators access to personal photos and videos of research animals for curriculum development. | [] |
Weddell seals as autonomous sensors of the winter oceanography of the Ross Sea
|
0838937 |
2014-01-01 | Costa, Daniel Paul |
Collaborative Research: Weddell seals as autonomous sensors of the winter oceanography of the Ross Sea |
Marine mammals of the Southern Ocean have evolved diverse life history patterns and foraging strategies to accommodate extreme fluctuations in the physical and biological environment. In light of ongoing climate change and the dramatic shifts in the extent and persistence of sea ice in the Ross Sea, it is critical to understand how Weddell seals, Leptonychotes weddellii, a key apex predator, select and utilize foraging habitats. Recent advances in satellite-linked animal-borne conductivity, temperature and depth (CTD) tags make it possible to simultaneously collect data on seal locations, their diving patterns, and the temperature and salinity profiles of the water columns they utilize. In other ecosystems, such data have revealed that marine predators selectively forage in areas where currents and fronts serve to locally concentrate prey resources, and that these conditions are required to sustain populations. Weddell seals will be studied in McMurdo Sound and at Terra Nova Bay, Ross Sea and will provide the first new data on Weddell seal winter diving behavior and habitat use in almost two decades. The relationship between an animal's diving behavior and physical habitat has enormous potential to enhance monitoring studies and to provide insight into how changes in ice conditions (due either to warming or the impact of large icebergs, such as B15) might impact individual time budgets and foraging success. The second thrust of this project is to use the profiles obtained from CTD seal tags to model the physical oceanography of this region. Current mathematical models of physical oceanographic processes in the Southern Ocean are directed at better understanding the role that it plays in global climate processes, and the linkages between physical and biological oceanographic processes. However, these efforts are limited by the scarcity of oceanographic data at high latitudes in the winter months; CTD tags deployed on animals will collect data at sufficient spatial and temporal resolution to improve data density. The project will contribute to two IPY endorsed initiatives: MEOP (Marine Mammals as Explorers of the Ocean Pole to Pole) and CAML (Census of Antarctic Marine Life). In addition, the highly visual nature of the data and analysis lends itself to public and educational display and outreach, particularly as they relate to global climate change, and we have collaborations with undergraduate and graduate training programs, the Seymour Marine Discovery Center, and the ARMADA program to foster these broader impacts. | ["POLYGON((162 -75,162.7 -75,163.4 -75,164.1 -75,164.8 -75,165.5 -75,166.2 -75,166.9 -75,167.6 -75,168.3 -75,169 -75,169 -75.3,169 -75.6,169 -75.9,169 -76.2,169 -76.5,169 -76.8,169 -77.1,169 -77.4,169 -77.7,169 -78,168.3 -78,167.6 -78,166.9 -78,166.2 -78,165.5 -78,164.8 -78,164.1 -78,163.4 -78,162.7 -78,162 -78,162 -77.7,162 -77.4,162 -77.1,162 -76.8,162 -76.5,162 -76.2,162 -75.9,162 -75.6,162 -75.3,162 -75))"] |
Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History
|
1043700 |
2014-01-01 | Harry, Dennis L. |
Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History |
Intellectual Merit: This research will place the subsidence history of the southern Victoria Land Basin into a quantitative geodynamic context and will assess the influence of flexure associated with late Neogene volcanic loading of the crust by the Erebus Volcanic Group. This will be done by extending geodynamic models of extension in the West Antarctic Rift System to include extensional hiatuses hypothesized to have occurred during the Late Paleogene and Miocene, and by developing a new geodynamic model of volcanic loading and associated lithosphere flexure. Finite element and finite difference modeling methods will be used. In the first phase of the project, a series of extensional geodynamic models will be developed to examine the effect that proposed extensional hiatuses have on the style of extension, with emphasis placed on developing a process based understanding of the change in rift style from diffuse during the Late Cretaceous to more focused during the Cenozoic. The models will test the hypotheses that extensional hiatuses led to the change in rifting style, and will place constraints on the timing and duration of the hiatuses. The second phase of the project will use the thermal and rheological properties of the previous models to constrain the flexural rigidity of the lithosphere in order to model the flexural response to volcanic loading to test the hypotheses that flexural subsidence contributed to cyclic changes between grounded and floating ice at the ANDRILL AND-1A site, complicating interpretations of the climatic record from this core, and that flexure contributes to the stress orientation at the AND-2B site, which is inconsistent with the expected regional extensional stress orientation. Broader impacts: The project will train an undergraduate student and an M.S. student. Outreach activities include a planned series of talks at regional high schools, junior colleges, and 4-year colleges that have geology programs. | ["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))"] |
Fate of Drilling Fluids during the South McMurdo Sound Project (SMS) of the Antarctic Geological Drilling Program (ANDRILL)
|
1043740 |
2014-01-01 | Lenczewski, Melissa |
Fate of Drilling Fluids during the South McMurdo Sound Project (SMS) of the Antarctic Geological Drilling Program (ANDRILL) |
The PI proposes to utilize computer models used by hydrogeologists to establish the fate and transport of contamination and determine the extent of drilling fluid contamination in the ANDRILL SMS core. For these models, previously collected logs of lithology, porosity, fracture density, fracture type, fracture orientation, drilling fluid loss, drilling fluid characteristics and temperature will be used as input parameters. In addition, biodegradation and sorption constants for the drilling fluid will be determined and incorporated into the models. Samples of drilling fluids used during coring as well as the return fluids were collected at the drill site using standard microbiological sampling techniques. Fluids will be tested at in situ temperatures under aerobic and anaerobic conditions to determine biodegradation constants. Sorption will be determined between the drilling fluids and core samples using standard isotherm methods. Geochemical and microbial fingerprints of the fluids and the changes during biodegradation will determine the potential impact of the drilling fluids on the isolated microbial communities and the geochemistry within various subsurface lithologic units beneath the southern McMurdo Sound in Antarctica. The results of this study could potentially provide guidelines on developing less detrimental methods for future exploration, if deemed necessary through this research. This proposed project will train a graduate student. The methods developed for analyses of samples in this project will serve as a guide for future studies of similar interest and will improve the understanding of ecological impacts of geologic drilling in Antarctica. The results of this study will be used as a reference for comparison with future studies examining newly developed, and improved, sample collection methods in future exploratory drilling projects in pristine environments. The PI is new to Antarctic research. | ["POLYGON((165 -77.5,165.3 -77.5,165.6 -77.5,165.9 -77.5,166.2 -77.5,166.5 -77.5,166.8 -77.5,167.1 -77.5,167.4 -77.5,167.7 -77.5,168 -77.5,168 -77.6,168 -77.7,168 -77.8,168 -77.9,168 -78,168 -78.1,168 -78.2,168 -78.3,168 -78.4,168 -78.5,167.7 -78.5,167.4 -78.5,167.1 -78.5,166.8 -78.5,166.5 -78.5,166.2 -78.5,165.9 -78.5,165.6 -78.5,165.3 -78.5,165 -78.5,165 -78.4,165 -78.3,165 -78.2,165 -78.1,165 -78,165 -77.9,165 -77.8,165 -77.7,165 -77.6,165 -77.5))"] |
Are the Dry Valleys Getting Wetter? A Preliminary Assessment of Wetness Across the McMurdo Dry Valleys Landscape
|
1045215 |
2014-01-01 | Gooseff, Michael N. |
EAGER: Are the Dry Valleys Getting Wetter? A Preliminary Assessment of Wetness Across the McMurdo Dry Valleys Landscape |
Intellectual Merit: Until recently, wetted soils in the Dry Valleys were generally only found adjacent to streams and lakes. Since the warm austral summer of 2002, numerous "wet spots" have been observed far from shorelines on relatively flat valley floor locations and as downslope fingers of flow on valley walls. The source of the water to wet these soils is unclear, as is the spatial and temporal pattern of occurrence from year to year. Their significance is potentially great as enhanced soil moisture may change the thermodynamics, hydrology, and erosion rate of surface soils, and facilitate transport of materials that had previously been stable. These changes to the soil active layer could significantly modify permafrost and ground ice stability within the Dry Valleys. The PIs seek to investigate these changes to address two competing hypotheses: that the source of water to these ?wet spots? is ground ice melt and that the source of this water is snowmelt. The PIs will document the spatiotemporal dynamics of these wet areas using high frequency remote sensing data from QuickBird and WorldView satellites to document the occurrence, dimensions, and growth of wet spots during the 2010-11 and 2011-12 austral summers. They will test their hypotheses by determining whether wet spots recur in the same locations in each season, and they will compare present to past distribution using archived imagery. They will also determine whether spatial snow accumulation patterns and temporal ablation patterns are coincident with wet spot formation. Broader impacts: One graduate student will be trained on this project. Findings will be reported at scientific meetings and published in peer reviewed journals. They will also develop a teaching module on remote sensing applications to hydrology for the Modular Curriculum for Hydrologic Advancement and an innovative prototype project designed to leverage public participation in mapping wet spots and snow patches across the Dry Valleys through the use of social media and mobile computing applications. | ["POLYGON((160 -77.25,160.5 -77.25,161 -77.25,161.5 -77.25,162 -77.25,162.5 -77.25,163 -77.25,163.5 -77.25,164 -77.25,164.5 -77.25,165 -77.25,165 -77.375,165 -77.5,165 -77.625,165 -77.75,165 -77.875,165 -78,165 -78.125,165 -78.25,165 -78.375,165 -78.5,164.5 -78.5,164 -78.5,163.5 -78.5,163 -78.5,162.5 -78.5,162 -78.5,161.5 -78.5,161 -78.5,160.5 -78.5,160 -78.5,160 -78.375,160 -78.25,160 -78.125,160 -78,160 -77.875,160 -77.75,160 -77.625,160 -77.5,160 -77.375,160 -77.25))"] |
Continued Research on the Jurassic Vertebrate Fauna from the Beardmore Glacier Region of Antarctica
|
1244253 |
2014-01-01 | Hammer, William R. |
Collaborative Research: Continued Research on the Jurassic Vertebrate Fauna from the Beardmore Glacier Region of Antarctica |
This proposal requests support for research on Early Jurassic vertebrate fauna of the Beardmore Glacier region of Antarctica. The project will support preparation and systematic and paleobiological research on four Antarctic dinosaurs, including two new species, collected in the Central Transantarctic Mountains. With the new material Cryolophosaurus will become one of the most complete Early Jurassic theropods known, and thus has the potential to become a keystone taxon for resolving the debated early evolutionary history of theropod dinosaurs, the group that gave rise to birds. Two new dinosaur specimens include a nearly complete articulated skeleton of a juvenile sauropodomorph, and the articulated hip region of another small individual. Both appear to be new taxa. The dinosaurs from the Hanson Formation represent some of the highest paleolatitude vertebrates known from the Jurassic. The PIs will generate CT datasets for Cryolophosaurus and the more complete new sauropodomorph species to mine for phylogenetic trait information, and to investigate their comparative neuroanatomy and feeding behavior. Histological datasets will be generated from multiple skeletal elements for all four Mt. Kirkpatrick taxa to understand patterns of growth in different clades of polar dinosaurs and compare them to relatives from lower paleolatitudes. This paleohistological study of a relatively diverse sample of sauropodomorph taxa from Antarctica may contribute to determining whether and how these dinosaurs responded to contemporary climatic extremes. The PIs have established a successful undergraduate training program as part of previous research. Summer interns from Augustana are trained at the Field Museum in specimen preparation, curation, molding/casting, and histological sampling. They also participate in existing Field Museum REU programs, including a course on phylogenetic systematics. Four undergraduate internships and student research projects will be supported through this proposal. The PIs will develop a traveling exhibit on Antarctic Mesozoic paleontology that they estimate will be seen by 2.5 million people over the five-year tour. | ["POLYGON((-165 -85,-164.5 -85,-164 -85,-163.5 -85,-163 -85,-162.5 -85,-162 -85,-161.5 -85,-161 -85,-160.5 -85,-160 -85,-160 -85.2,-160 -85.4,-160 -85.6,-160 -85.8,-160 -86,-160 -86.2,-160 -86.4,-160 -86.6,-160 -86.8,-160 -87,-160.5 -87,-161 -87,-161.5 -87,-162 -87,-162.5 -87,-163 -87,-163.5 -87,-164 -87,-164.5 -87,-165 -87,-165 -86.8,-165 -86.6,-165 -86.4,-165 -86.2,-165 -86,-165 -85.8,-165 -85.6,-165 -85.4,-165 -85.2,-165 -85))"] |
Major Ion Concentrations in 2004 South Pole Ice Core
|
0337933 |
2013-11-19 | Cole-Dai, Jihong |
Collaborative Research: Investigating Atmospheric Chemistry and Dynamics through Oxygen and Sulfur Isotopes in Volcanic Sulfate from South Pole Ice Cores |
A 180 m ice core drilled at South Pole in 2004/2005 was analyzed for concentrations of major ions at a depth resolution of approximately 2 cm. Measured ions are chloride, nitrate, sulfate, sodium, potassium, magnesium and calcium. The bottom of the core has been dated to 1830 years before 2004. | ["POINT(0 -90)"] |
Weddell seals as autonomous sensors of the winter oceanography of the Ross Sea
|
0838892 |
2013-01-01 | Burns, Jennifer |
Collaborative Research: Weddell seals as autonomous sensors of the winter oceanography of the Ross Sea |
Marine mammals of the Southern Ocean have evolved diverse life history patterns and foraging strategies to accommodate extreme fluctuations in the physical and biological environment. In light of ongoing climate change and the dramatic shifts in the extent and persistence of sea ice in the Ross Sea, it is critical to understand how Weddell seals, Leptonychotes weddellii, a key apex predator, select and utilize foraging habitats. Recent advances in satellite-linked animal-borne conductivity, temperature and depth (CTD) tags make it possible to simultaneously collect data on seal locations, their diving patterns, and the temperature and salinity profiles of the water columns they utilize. In other ecosystems, such data have revealed that marine predators selectively forage in areas where currents and fronts serve to locally concentrate prey resources, and that these conditions are required to sustain populations. Weddell seals will be studied in McMurdo Sound and at Terra Nova Bay, Ross Sea and will provide the first new data on Weddell seal winter diving behavior and habitat use in almost two decades. The relationship between an animal's diving behavior and physical habitat has enormous potential to enhance monitoring studies and to provide insight into how changes in ice conditions (due either to warming or the impact of large icebergs, such as B15) might impact individual time budgets and foraging success. The second thrust of this project is to use the profiles obtained from CTD seal tags to model the physical oceanography of this region. Current mathematical models of physical oceanographic processes in the Southern Ocean are directed at better understanding the role that it plays in global climate processes, and the linkages between physical and biological oceanographic processes. However, these efforts are limited by the scarcity of oceanographic data at high latitudes in the winter months; CTD tags deployed on animals will collect data at sufficient spatial and temporal resolution to improve data density. The project will contribute to two IPY endorsed initiatives: MEOP (Marine Mammals as Explorers of the Ocean Pole to Pole) and CAML (Census of Antarctic Marine Life). In addition, the highly visual nature of the data and analysis lends itself to public and educational display and outreach, particularly as they relate to global climate change, and we have collaborations with undergraduate and graduate training programs, the Seymour Marine Discovery Center, and the ARMADA program to foster these broader impacts. | ["POLYGON((162 -75,162.7 -75,163.4 -75,164.1 -75,164.8 -75,165.5 -75,166.2 -75,166.9 -75,167.6 -75,168.3 -75,169 -75,169 -75.3,169 -75.6,169 -75.9,169 -76.2,169 -76.5,169 -76.8,169 -77.1,169 -77.4,169 -77.7,169 -78,168.3 -78,167.6 -78,166.9 -78,166.2 -78,165.5 -78,164.8 -78,164.1 -78,163.4 -78,162.7 -78,162 -78,162 -77.7,162 -77.4,162 -77.1,162 -76.8,162 -76.5,162 -76.2,162 -75.9,162 -75.6,162 -75.3,162 -75))"] |
Photoheterotrophic Microbes in the West Antarctic Peninsula Marine Ecosystem
|
0838830 |
2013-01-01 | Cottrell, Matthew; Kirchman, David |
Photoheterotrophic Microbes in the West Antarctic Peninsula Marine Ecosystem |
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's 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. | ["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))"] |
The Role of Snow Patches on the Spatial Distribution of Soil Microbial Communities and Biogeochemical Cycling in the Antarctic Dry Valleys
|
0838850 |
2013-01-01 | Gooseff, Michael N. |
Collaborative Research: The Role of Snow Patches on the Spatial Distribution of Soil Microbial Communities and Biogeochemical Cycling in the Antarctic Dry Valleys |
Two models have been proposed to describe controls over microbial biogeography. One model proposes that microbes are ubiquitously distributed across the global environment, and that environmental conditions select for taxa physiologically adapted to local physical conditions. An alternative model predicts that dispersal is the important limitation to the distribution of microorganisms and that spatial heterogeneity of microbial communities is a result of both dispersal and local environmental limitations. According to both models, spatial heterogeneity of microbial communities may be especially pronounced in extreme ecosystems where the environmental selection for organisms with suitable physiology is most strongly manifest. We propose that Antarctic terrestrial environments are ideal places to examine microbial biogeography for 3 reasons: 1) the pristine nature and remoteness of Antarctica minimizes the prevalence of exotic species dispersed through human vectors; 2) the extreme conditions of Antarctic environments provide a strong environmental filter which limits the establishment of non-indigenous taxa; and 3) extreme heterogeneity in the terrestrial environment provides natural gradients of soil conditions (temperature, water and nutrient availability). In the proposed research we will investigate the influence of snow on the composition and spatial distribution of soil microbial communities and linked biogeochemical cycling in the McMurdo Dry Valleys. We will conduct fieldwork at the landscape scale (repeated remote sensing to characterize snow distribution), at the valley and patch scales (quantify snow patch ablation, microbial communities and biogeochemical cycling in subnivian soils). We hypothesize that snow patches play an important role in structuring the spatial distribution of soil microbial communities and their associated ecosystem functioning because of the physical and hydrological influences that snow patches have on the soil environment. The research will contribute to greater public awareness of the importance of polar research to fundamental questions of biology, ecology and hydrology through direct linkages with International Antarctic Institute public outreach activities, including dissemination of web-based learning units on environmental science and microbiology, targeted as resources for secondary and post-secondary educators. Three graduate students, one postdoctoral scholar and multiple undergraduates will participate in the research activities. | ["POLYGON((-163.3 -77.62,-163.202 -77.62,-163.104 -77.62,-163.006 -77.62,-162.908 -77.62,-162.81 -77.62,-162.712 -77.62,-162.614 -77.62,-162.516 -77.62,-162.418 -77.62,-162.32 -77.62,-162.32 -77.631,-162.32 -77.642,-162.32 -77.653,-162.32 -77.664,-162.32 -77.675,-162.32 -77.686,-162.32 -77.697,-162.32 -77.708,-162.32 -77.719,-162.32 -77.73,-162.418 -77.73,-162.516 -77.73,-162.614 -77.73,-162.712 -77.73,-162.81 -77.73,-162.908 -77.73,-163.006 -77.73,-163.104 -77.73,-163.202 -77.73,-163.3 -77.73,-163.3 -77.719,-163.3 -77.708,-163.3 -77.697,-163.3 -77.686,-163.3 -77.675,-163.3 -77.664,-163.3 -77.653,-163.3 -77.642,-163.3 -77.631,-163.3 -77.62))"] |
The Cellular Stress Response in Cold-adapted Organisms: Building Novel Mechanistic Links between Heat Stress, Cell Cycle Arrest and Apoptosis in Antarctic Fishes.
|
0944743 |
2013-01-01 | Buckley, Bradley |
The Cellular Stress Response in Cold-adapted Organisms: Building Novel Mechanistic Links between Heat Stress, Cell Cycle Arrest and Apoptosis in Antarctic Fishes. |
The research will investigate a novel mechanism by which cold-adapted fishes of the Southern Ocean sense and respond to elevated temperatures. It is hypothesized that sub-lethal heat stress may induce cell cycle arrest and/or programmed cell death through apoptosis. The study will use genome-enabled technologies to examine the environmental control over gene expression in Antarctic species and will build direct mechanistic links between the expression of a specific signaling pathway gene and heat-induced changes in cells. Prior results support the hypothesis that heat stress results in cell cycle arrest and, in some cases, programmed cell death in Antarctic fishes. If so, this represents a novel, modified version of the well-conserved cellular stress response found in essentially all other species and suggests that warming ocean temperatures may have profound cellular and physiological impacts on these extremely stenothermal species. The P.I. conducts outreach activities with the Oregon Museum of Science and Industry, will be involved in developing a science curriculum for the Native American Youth and Family Center (NAYA) Early College Academy in Portland, and supports the educational and professional development of both undergraduate and graduate students at Portland State University. | ["POINT(166.66667 -77.83333)"] |
Linkages among Mitochondrial Form, Function and Thermal Tolerance of Antarctic Notothenioid Fishes
|
0741301 |
2013-01-01 | O'Brien, Kristin |
Collaborative Research: Linkages among Mitochondrial Form, Function and Thermal Tolerance of Antarctic Notothenioid Fishes |
Antarctic notothenioid fishes have evolved in the Southern Ocean for 10-14 MY under an unusual set of circumstances. Their characteristics include the complete absence of the circulating oxygen-binding protein, hemoglobin (Hb) within the Channichthyid (Icefish) family of notothenioids. Moreover, some species within the 16 members of this family have also lost the ability to express the oxygen-binding and storage protein, myoglobin (Mb) in cardiac muscle. Our previous work has determined that the loss of Hb and/or Mb is correlated with significant increases in densities of mitochondria within oxidative tissues, and extensive remodeling of these vital organelles. To date, nothing is known about how modifications in mitochondrial architecture of icefishes affect organelle function, or more importantly, how they affect organismal-level physiology. Most critical for Antarctic fishes is that mitochondrial characteristics have been linked to how well ectotherms can withstand increases in temperature. This collaborative research project will address the hypothesis that the unusual mitochondrial architecture of Antarctic Channichthyids has led to changes in function that impact their ability to withstand elevations in temperature. Specifically, the research will (1) determine if the unusual mitochondrial architecture of icefishes affects function and contributes to organismal thermal sensitivity, (2) identify differences in organismal thermal tolerance between red- and white- blooded notothenioids, (3) identify molecular mechanisms regulating changes in mitochondrial structure in icefishes. The results may establish channichthyid icefishes as a sentinel taxon for signaling the impact of global warming on the Southern Ocean. Broad impacts of this project will be realized by participation of high school biology teachers in field work through cooperation with the ARMADA project at the University of Rhode Island, as well as graduate education. | ["POLYGON((-64.45 -63.29,-64.249 -63.29,-64.048 -63.29,-63.847 -63.29,-63.646 -63.29,-63.445 -63.29,-63.244 -63.29,-63.043 -63.29,-62.842 -63.29,-62.641 -63.29,-62.44 -63.29,-62.44 -63.371,-62.44 -63.452,-62.44 -63.533,-62.44 -63.614,-62.44 -63.695,-62.44 -63.776,-62.44 -63.857,-62.44 -63.938,-62.44 -64.019,-62.44 -64.1,-62.641 -64.1,-62.842 -64.1,-63.043 -64.1,-63.244 -64.1,-63.445 -64.1,-63.646 -64.1,-63.847 -64.1,-64.048 -64.1,-64.249 -64.1,-64.45 -64.1,-64.45 -64.019,-64.45 -63.938,-64.45 -63.857,-64.45 -63.776,-64.45 -63.695,-64.45 -63.614,-64.45 -63.533,-64.45 -63.452,-64.45 -63.371,-64.45 -63.29))"] |
Biogeochemistry of Cyanobactrial Mats and Hyporheic Zone Microbes in McMurdo Dry Valley Glacial Meltwater Streams
|
0739648 |
2013-01-01 | Cary, S. Craig |
Collaborative Research: Biogeochemistry of Cyanobactrial Mats and Hyporheic Zone Microbes in McMurdo Dry Valley Glacial Meltwater Streams |
The glacial streams of the McMurdo Dry Valleys have extensive cyanobacterial mats that are a probable source of fixed C and N to the Valleys. The research will examine the interplay between the microbial mats in the ephemeral glacial streams and the microbiota of the hyporheic soils (wetted soil zone) underlying and adjacent to those mats. It is hypothesized that the mats are important sources of organic carbon and fixed nitrogen for the soil communities of the hyporheic zone, and release dissolved organic carbon (DOC) and nitrogen (DON) that serves the entire Dry Valley ecosystem. Field efforts will entail both observational and experimental components. Direct comparisons will be made between the mats and microbial populations underlying naturally rehydrated and desiccated mat areas, and between mat areas in the melt streams of the Adams and Miers Glaciers in Miers Valley. Both physiological and phylogenetic indices of the soil microbiota will be examined. Observations will include estimates of rates of mat carbon and nitrogen fixation, soil respiration and leucine and thymidine uptake (as measures of protein & DNA synthesis, respectively) by soil bacteria, bacterial densities and their molecular ecology. Experimental manipulations will include experimental re-wetting of soils and observations of the time course of response of the microbial community. The research will integrate modern molecular genetic approaches (ARISA-DNA fingerprinting and ultra deep 16S rDNA microbial phylogenetic analysis) with geochemistry to study the diversity, ecology, and function of microbial communities that thrive in these extreme environments. The broader impacts of the project include research and educational opportunities for graduate students and a postdoctoral associate. The P.I.s will involve undergraduates as work-study students and in REU programs, and will participate in educational and outreach programs. | ["POINT(163 -77.5)"] |
US/Chinese Collaborative Study: Investigation of Bottom Water Formation in Prydz Bay, Antarctica
|
1043669 |
2012-01-01 | Yuan, Xiaojun |
US/Chinese Collaborative Study: Investigation of Bottom Water Formation in Prydz Bay, Antarctica |
Processess governing the formation of Antarctic bottom water (AABW) in the Indian Ocean sector of the Southern Ocean remain poorly described. As with AABW formation in more well studied regions of the Antarctic continent, global climate impacts of the source regions of this dense, cold water that help drive the global ocean thermohaline circulation are uncertain. A combination of (annual) continental shelf and slope moorings, seasonal (summer) hydrographic surveys on board the Chinese icebreaker M/V Xuelong, together with synthesis of historic and satellite data will be used to better constrain shelf processes and the atmosphere-ocean-ice interactions in the Prydz Bay region. Despite the seeming remoteness of the study site, changes in the formation rate of AABW could potentially have impact on northern hemisphere climate via effects on the global heat budget and through sea-level rise in the coming decades. The project additionally seeks to promote international collaboration between Chinese and US researchers. The data collected will be broadly disseminated to the oceanographic community through the National Oceanography Data Center and Chinese Arctic and Antarctic Data Center. | ["POLYGON((70 -64,71 -64,72 -64,73 -64,74 -64,75 -64,76 -64,77 -64,78 -64,79 -64,80 -64,80 -64.6,80 -65.2,80 -65.8,80 -66.4,80 -67,80 -67.6,80 -68.2,80 -68.8,80 -69.4,80 -70,79 -70,78 -70,77 -70,76 -70,75 -70,74 -70,73 -70,72 -70,71 -70,70 -70,70 -69.4,70 -68.8,70 -68.2,70 -67.6,70 -67,70 -66.4,70 -65.8,70 -65.2,70 -64.6,70 -64))"] |
Rift Mechanisms and Thermal Regime of the Lithosphere across Beardmore Glacier Region, Central Transantarctic Mountains, from Magnetotelluric Measurements
|
0838914 |
2012-01-01 | Wannamaker, Philip |
Rift Mechanisms and Thermal Regime of the Lithosphere across Beardmore Glacier Region, Central Transantarctic Mountains, from Magnetotelluric Measurements |
The investigators will examine competing hypotheses for the mechanism of extension and creation of the Transantarctic Mountains, and evolution of the thermal regimes of rifted West Antarctica and stable East Antarctica using magnetotelluric (MT) profiles. Surrounded almost entirely by ocean ridges, Antarctica is a special tectonic situation because of the need to make accommodation space for rifting in the Transantarctic region. In the MT method, temporal variations in the Earth's natural electromagnetic field are used as source fields to probe the electrical resistivity structure in the depth range of 1 to 200 km, or more. Geophysical methods, such as MT, are appropriate in Antarctica because of the predominance of thick ice cover over most of the Continent and the difficult operating environment. The proposed effort will consist of approximately 50 sites over a distance approaching 500 km with a 10 km average spacing, oriented normal to the Transantarctic Mountains (TAM), in the Beardmore glacier area. High quality MT soundings will be collected over thick ice sheets using a custom electrode preamp design, updated from previous Antarctic projects. Data acquisition will take place over two field seasons. The primary goals are three-fold: to establish the location of the deeper tectonic transition between East and West Antarctica that may be offset from the physiographic transition at the surface, using deep resistivity structure distinguish between modes of extensional upwelling and magmatism that may be vertically non-uniform, depth and magnitude of quasi-layered deep crustal low resistivity, particularly below West Antarctica, will be used to estimate crustal heat flux into the ice sheet base. | ["POLYGON((141.01732 -82.13,144.910279 -82.13,148.803238 -82.13,152.696197 -82.13,156.589156 -82.13,160.482115 -82.13,164.375074 -82.13,168.268033 -82.13,172.160992 -82.13,176.053951 -82.13,179.94691 -82.13,179.94691 -82.351835,179.94691 -82.57367,179.94691 -82.795505,179.94691 -83.01734,179.94691 -83.239175,179.94691 -83.46101,179.94691 -83.682845,179.94691 -83.90468,179.94691 -84.126515,179.94691 -84.34835,176.053951 -84.34835,172.160992 -84.34835,168.268033 -84.34835,164.375074 -84.34835,160.482115 -84.34835,156.589156 -84.34835,152.696197 -84.34835,148.803238 -84.34835,144.910279 -84.34835,141.01732 -84.34835,141.01732 -84.126515,141.01732 -83.90468,141.01732 -83.682845,141.01732 -83.46101,141.01732 -83.239175,141.01732 -83.01734,141.01732 -82.795505,141.01732 -82.57367,141.01732 -82.351835,141.01732 -82.13))"] |
Thermochronologic and modelling test for a Mesozoic West Antarctic Plateau
|
0739781 |
2012-01-01 | Blythe, Ann Elizabeth; Huerta, Audrey D. |
Collaborative Research: Thermochronologic and modelling test for a Mesozoic West Antarctic Plateau |
This project studies formation of the TransAntarctic Mountains (TAM) through numerical modeling based on cooling histories of apatite mineral grains. The TAM are the highest and longest rift-related mountain range in the world. Various models for their uplift have been proposed, the most provocative of which is that they are not uplifted, but instead are the eroded remnant of a plateau. This project evaluates that hypothesis by collecting apatites from around Byrd Glacier for fission track thermochronology. Results will be combined with a kinematic and thermal model to determine the TAM's structural evolution. The plateau model, if correct, implies that the Byrd Glacier originated not as a glacier-carved valley through the TAM, but as a river system flowing in the opposite direction. Given that the Byrd Glacier is a key drainage for the East Antarctic ice sheet, this result has important implications for ice sheet models and interpretation of both regional geology and sediment records. The main broader impacts are undergraduate research and a new collaboration between a primarily undergraduate and a research institution. Students will be involved in the field program, sample analyses, and numerical modeling. | ["POLYGON((155.77667 -79.793335,156.208836 -79.793335,156.641002 -79.793335,157.073168 -79.793335,157.505334 -79.793335,157.9375 -79.793335,158.369666 -79.793335,158.801832 -79.793335,159.233998 -79.793335,159.666164 -79.793335,160.09833 -79.793335,160.09833 -79.8578345,160.09833 -79.922334,160.09833 -79.9868335,160.09833 -80.051333,160.09833 -80.1158325,160.09833 -80.180332,160.09833 -80.2448315,160.09833 -80.309331,160.09833 -80.3738305,160.09833 -80.43833,159.666164 -80.43833,159.233998 -80.43833,158.801832 -80.43833,158.369666 -80.43833,157.9375 -80.43833,157.505334 -80.43833,157.073168 -80.43833,156.641002 -80.43833,156.208836 -80.43833,155.77667 -80.43833,155.77667 -80.3738305,155.77667 -80.309331,155.77667 -80.2448315,155.77667 -80.180332,155.77667 -80.1158325,155.77667 -80.051333,155.77667 -79.9868335,155.77667 -79.922334,155.77667 -79.8578345,155.77667 -79.793335))"] |
Atmosphere-Ocean-Ice Interaction in a Coastal Polynya
|
0739464 |
2012-01-01 | Cassano, John; Maslanik, Jim |
Collaborative Research: Atmosphere-Ocean-Ice Interaction in a Coastal Polynya |
Antarctic polynyas are the ice free zones often persisting in continental sea ice. Characterization of the lower atmosphere properties, air-sea surface heat fluxes and corresponding ocean depth profiles of Antarctic polynyas, especially during strong wind events, is needed for a more detailed understanding of the role of polynya in the production of latent-heat type sea ice and the formation, through brine rejection, of dense ocean bottom waters. Broader impacts: A key technological innovation, the use of instrumented uninhabited aircraft systems (UAS), will be employed to enable the persistent and safe observation of the interaction of light and strong katabatic wind fields with the Terra Nova Bay (Victoria Land, Antarctica) polynya waters during late winter and early summer time frames. The use of UAS observational platforms on the continent to date has to date been modest, but demonstration of their versatility and effectiveness in surveying and observing mode is a welcome development. The projects use of UAS platforms by University of Colorado and LDEO (Columbia) researchers is both high risk, and potentially transformative for the systematic data measurement tasks that many Antarctic science applications increasingly require. | ["POLYGON((160 -74.5,161.5 -74.5,163 -74.5,164.5 -74.5,166 -74.5,167.5 -74.5,169 -74.5,170.5 -74.5,172 -74.5,173.5 -74.5,175 -74.5,175 -74.9,175 -75.3,175 -75.7,175 -76.1,175 -76.5,175 -76.9,175 -77.3,175 -77.7,175 -78.1,175 -78.5,173.5 -78.5,172 -78.5,170.5 -78.5,169 -78.5,167.5 -78.5,166 -78.5,164.5 -78.5,163 -78.5,161.5 -78.5,160 -78.5,160 -78.1,160 -77.7,160 -77.3,160 -76.9,160 -76.5,160 -76.1,160 -75.7,160 -75.3,160 -74.9,160 -74.5))"] |
Do Crustacean Zooplankton Play a Pivotal Role in Structuring Heterotrophic Plankton Communities in the Ross Sea?
|
0542111 |
2011-01-01 | Lonsdale, Darcy |
Collaborative Research: Do Crustacean Zooplankton Play a Pivotal Role in Structuring Heterotrophic Plankton Communities in the Ross Sea? |
Recent studies of marine ecosystems show conflicting evidence for trophic cascades, and in particular the relative strength of the crustacean zooplankton-phytoplankton link. The Ross Sea is a natural laboratory for investigating this apparent conflict. It is a site of seasonally high abundances of phytoplankton, characterized by regions of distinct phytoplankton taxa; the southcentral polynya is strongly dominated by the colony-forming prymnesiophyte Phaeocystis antarctica, while coastal regions of this sea are typically dominated by diatoms or flagellate species. Recent studies indicate that, while the south-central polynya exhibits a massive phytoplankton bloom, the poor food quality of P. antarctica for many crustacean zooplankton prevents direct utilization of much of this phytoplankton bloom. Rather, evidence suggests that indirect utilization of this production may be the primary mechanism by which carbon and energy become available to those higher trophic levels. Specifically, we hypothesized that nano- and microzooplankton constitute an important food source for crustacean zooplankton (largely copepods and juvenile euphausiids) during the summer period in the Ross Sea where the phytoplankton assemblage is dominated by the prymnesiophyte. In turn, we also hypothesize that predation by copepods (and other Crustacea) controls and structures the species composition of these protistan assemblages. We occupied stations in the south-central Ross Sea Polynya (RSP) and Terra Nova Bay (TNB) during austral summer to test these hypotheses. We hypothesized that the diatom species that dominate the phytoplankton assemblage in TNB constitute a direct source of nutrition to herbivorous/omnivorous zooplankton (relative to the situation in the south-central RSP). That is, the contribution of heterotrophic protists to crustacean diets will be reduced in TNB. Our research addressed fundamental gaps in our knowledge of food web structure and trophic cascades. | ["POINT(-166.287 -76.5799)"] |
Free Drifting Icebergs as Proliferation Sites of Iron Enrichment, Organic Carbon Production and Export in the Southern Ocean
|
0636319 |
2011-01-01 | Shaw, Tim; Twining, Benjamin |
Collaborative Research: Free Drifting Icebergs as Proliferation Sites of Iron Enrichment, Organic Carbon Production and Export in the Southern Ocean |
Atmospheric warming has been associated with retreating glaciers, disintegrating ice shelves, and the increasing prevalence of icebergs in the Southern Ocean over the last decade. Our preliminary study of two icebergs in the NW Weddell Sea, an area of high iceberg concentration, showed significant delivery of terrestrial material accompanied by significant enhancement of phytoplankton and zooplankton/micronekton abundance, and primary production surrounding the icebergs. We hypothesize that nutrient enrichment by free-drifting icebergs will increase primary production and sedimentation of organic carbon, thus increasing the draw-down and sequestration of CO2 in the Southern Ocean and impacting the global carbon cycle. Our research addresses the following questions:1) What is the relationship between the physical dynamics of free-drifting icebergs and the Fe and nutrient distributions of the surrounding water column? 2) What is the relationship between Fe and nutrient distributions associated with free-drifting icebergs and the organic carbon dynamics of the ice-attached and surrounding pelagic communities (microbes, zooplankton, micronekton)? 3) What is impact on the export flux of particulate organic carbon from the mixed layer? An interdisciplinary approach is proposed to examine iceberg structure and dynamics, biogeochemical processes, and carbon cycling that includes measurement of trace element, nutrient and radionuclide distributions; organic carbon dynamics mediated by microbial, ice-attached and zooplankton communities; and particulate organic carbon export fluxes. Results from this project will further our understanding of the relationship between climate change and carbon sequestration in the Southern Ocean. Our findings will be incorporated into the Antarctic Research division of the Ocean Exploration Center (OEC) as part of the SIOExplorer: Digital Library Project. The OEC allows users to access content, which is classified to one of four levels: entry (grade K-6), student (grade 6-12), college, and research. Graduate students, undergraduates, teachers, and volunteers are important participants in the proposed field and laboratory work. For the K-12 level, a professional writer of children's books will participate in cruises to produce an account of the expedition and a daily interactive website. | ["POLYGON((-51.9201 -57.5061,-50.99447 -57.5061,-50.06884 -57.5061,-49.14321 -57.5061,-48.21758 -57.5061,-47.29195 -57.5061,-46.36632 -57.5061,-45.44069 -57.5061,-44.51506 -57.5061,-43.58943 -57.5061,-42.6638 -57.5061,-42.6638 -58.03449,-42.6638 -58.56288,-42.6638 -59.09127,-42.6638 -59.61966,-42.6638 -60.14805,-42.6638 -60.67644,-42.6638 -61.20483,-42.6638 -61.73322,-42.6638 -62.26161,-42.6638 -62.79,-43.58943 -62.79,-44.51506 -62.79,-45.44069 -62.79,-46.36632 -62.79,-47.29195 -62.79,-48.21758 -62.79,-49.14321 -62.79,-50.06884 -62.79,-50.99447 -62.79,-51.9201 -62.79,-51.9201 -62.26161,-51.9201 -61.73322,-51.9201 -61.20483,-51.9201 -60.67644,-51.9201 -60.14805,-51.9201 -59.61966,-51.9201 -59.09127,-51.9201 -58.56288,-51.9201 -58.03449,-51.9201 -57.5061))"] |
Controls on Climate-Active Gases by Amundsen Sea Ice Biota
|
0836061 |
2011-01-01 | Dennett, Mark |
Collaborative Research: Controls on climate-active gases by Amundsen Sea ice biota |
Convincing evidence now confirms that polar regions are changing rapidly in response to human activities. Changes in sea ice extent and thickness will have profound implications for productivity, food webs and carbon fluxes at high latitudes, since sea ice biota are a significant source of biogenic matter for the ecosystem. While sea ice is often thought to be a barrier to gas exchange between the ocean and the atmosphere, it more likely functions as a source or sink for climate-active gases such as carbon dioxide and ozone-depleting organohalogens, due in part to activities of microbes embedded in the sea ice matrix. This project brings together experienced US and Swedish investigators to examine the controls by sea-ice biota on the production and degradation of key climate-active gases in the Pacific sector of the Southern Ocean. We hypothesize that 1) the physical properties of the sea-ice environment will determine the community structure and activities of the sea ice biota; 2) the productivity, biomass, physiological state and species composition of ice algae will determine the production of specific classes of organic carbon, including organohalogens; 3) heterotrophic co-metabolism within the ice will break down these compounds to some extent, depending on the microbial community structure and productivity, and 4) the sea ice to atmosphere fluxes of CO2 and organohalogens will be inversely related. This project will build close scientific collaborations between US and Swedish researchers and also train young scientists, including members of underrepresented groups. Dissemination of results will include the scientific literature, and public outreach venues including interactions with a PolarTrec teacher. | ["POLYGON((-170 -69,-163 -69,-156 -69,-149 -69,-142 -69,-135 -69,-128 -69,-121 -69,-114 -69,-107 -69,-100 -69,-100 -70,-100 -71,-100 -72,-100 -73,-100 -74,-100 -75,-100 -76,-100 -77,-100 -78,-100 -79,-107 -79,-114 -79,-121 -79,-128 -79,-135 -79,-142 -79,-149 -79,-156 -79,-163 -79,-170 -79,-170 -78,-170 -77,-170 -76,-170 -75,-170 -74,-170 -73,-170 -72,-170 -71,-170 -70,-170 -69))"] |
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))"] |
Development of Quantitative Weathering Indicators in Proximal Alluvial Sediments to Assess Glacial Activity in the Rock Record
|
0842639 |
2011-01-01 | Madden, Megan Elwood; Soreghan, Gerilyn |
Development of Quantitative Weathering Indicators in Proximal Alluvial Sediments to Assess Glacial Activity in the Rock Record |
The proposed research seeks to test the hypothesis that chemical and physical weathering in proximal alluvial systems will show systematic and measurable variations between glacial and nonglacial systems. To accomplish this, the investigation will attempt to quantify the natural variation of chemical and physical weathering in granitoid-sourced proximal alluvial sediments in end-member glacial and nonglacial systems, when other, 'non-climatic' factors (e.g. provenance, drainage basin area and relief, sample grain size, sediment facies) are controlled. If chemical weathering in the proposed hot-humid, hot-arid, hot semi-arid nonglacial systems and the cool-wet, cold semi-arid, and cold-arid glacial systems show systematic variations, then chemical indices may be used to help differentiate paleoclimatic conditions. Continued reliance on students provides a broader impact of this proposed research and firmly grounds this effort in its educational mission. | ["POLYGON((-163.12865 -77.41693,-163.06062 -77.41693,-162.99259 -77.41693,-162.92456 -77.41693,-162.85653 -77.41693,-162.7885 -77.41693,-162.72047 -77.41693,-162.65244 -77.41693,-162.58441 -77.41693,-162.51638 -77.41693,-162.44835 -77.41693,-162.44835 -77.445495,-162.44835 -77.47406,-162.44835 -77.502625,-162.44835 -77.53119,-162.44835 -77.559755,-162.44835 -77.58832,-162.44835 -77.616885,-162.44835 -77.64545,-162.44835 -77.674015,-162.44835 -77.70258,-162.51638 -77.70258,-162.58441 -77.70258,-162.65244 -77.70258,-162.72047 -77.70258,-162.7885 -77.70258,-162.85653 -77.70258,-162.92456 -77.70258,-162.99259 -77.70258,-163.06062 -77.70258,-163.12865 -77.70258,-163.12865 -77.674015,-163.12865 -77.64545,-163.12865 -77.616885,-163.12865 -77.58832,-163.12865 -77.559755,-163.12865 -77.53119,-163.12865 -77.502625,-163.12865 -77.47406,-163.12865 -77.445495,-163.12865 -77.41693))"] |
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))"] |
The Chemical Ecology of Shallow-water Marine Macroalgae and Invertebrates on the Antarctic Peninsula
|
0442769 |
2010-01-01 | McClintock, James; Amsler, Charles |
Collaborative Research: The Chemical Ecology of Shallow-water Marine Macroalgae and Invertebrates on the Antarctic Peninsula Collaborative Research: The Chemical Ecology of Shallow-water Marine Macroalgae and Invertebrates on the Antarctic Peninsula - continuing |
Mesoherbivores, and specifically amphipods, are a conspicuous and dominant component of the macroalgal community in Antarctica. Despite their high abundance, the functional ecology, and particularly the trophic relationships of Antarctic amphipods are poorly understood. This project will evaluate the importance of mesograzers (small invertebrate predators approximately 1 to 25 mm in body length) in western Antarctic Peninsula marine communities. This will be accomplished by examining the role of mesoherbivores in structuring macroalgal communities and by elucidating the ecological interactions of mesograzers with a dominant group of benthic macroinvertebrates, the marine sponges. Moreover, chemical studies will be conducted to gain a more thorough understanding of the chemical defenses that Antarctic Peninsula sponges direct towards crustacean mesograzers. Three sets of questions will be addressed concerning the importance of mesograzers, and amphipods in particular, in nearshore habitats of the western Antarctic Peninsula. First, the hypothesis that mesoherbivory is particularly heavy in western Antarctic Peninsula marine communities and has an important influence on algal community structure will be addressed. Initial studies will document which species of amphipods feed in whole or part on microalgae and macroalgae, the incidence and distribution of filamentous endophytes in dominant macroalgae, comparative night time patterns of amphipod abundances on macrophytes, and the role of chemical mediation in these relationships. Second, the broad hypothesis that mesograzers in general, and amphipods in particular, interact with and prey upon sponges to a greater extent than heretofore recognized in Antarctic communities will be tested. The functional basis of these associations will be considered by examining whether the sponges are used as prey, and if so, whether there is evidence that some sponges produce secondary metabolites that show efficacy against mesograzers such as amphipods. Third, the researchers will test the hypotheses that: 1) Antarctic algae and invertebrates biosynthesize secondary metabolites that deter feeding by amphipod predators; and 2) pigments found in three Antarctic sponges are tryptophan catabolites produced as defenses against crustacean predators that impact molting. Evaluation of these hypotheses will be based on isolation and characterization of the specific anti-feeding metabolites, on biosynthetic studies to establish the metabolic origin of the pigments, and on bioassays to establish the chemical defense roles of both groups of compounds. A variety of educational activities will be a major component of this project. Opportunities will be made to support graduate and undergraduate research, both through NSF programs as well as home university-based programs including a number of funded programs that enhance the representation of minorities in the sciences. Through their proven and highly successful interactive web program, the investigators will continue to involve a large numbers of teachers, K-12 students, and other members of the community at large in their scientific endeavors in Antarctica. Moreover, they will actively participate in outreach efforts by presenting numerous talks on their research to school and community groups. | ["POLYGON((-64.15 -64.78,-64.132 -64.78,-64.114 -64.78,-64.096 -64.78,-64.078 -64.78,-64.06 -64.78,-64.042 -64.78,-64.024 -64.78,-64.006 -64.78,-63.988 -64.78,-63.97 -64.78,-63.97 -64.784,-63.97 -64.788,-63.97 -64.792,-63.97 -64.796,-63.97 -64.8,-63.97 -64.804,-63.97 -64.808,-63.97 -64.812,-63.97 -64.816,-63.97 -64.82,-63.988 -64.82,-64.006 -64.82,-64.024 -64.82,-64.042 -64.82,-64.06 -64.82,-64.078 -64.82,-64.096 -64.82,-64.114 -64.82,-64.132 -64.82,-64.15 -64.82,-64.15 -64.816,-64.15 -64.812,-64.15 -64.808,-64.15 -64.804,-64.15 -64.8,-64.15 -64.796,-64.15 -64.792,-64.15 -64.788,-64.15 -64.784,-64.15 -64.78))"] |
The Chemical Ecology of Shallow-water Marine Macroalgae and Invertebrates on the Antarctic Peninsula
|
0442857 |
2010-01-01 | 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 |
Mesoherbivores, and specifically amphipods, are a conspicuous and dominant component of the macroalgal community in Antarctica. Despite their high abundance, the functional ecology, and particularly the trophic relationships of Antarctic amphipods are poorly understood. This project will evaluate the importance of mesograzers (small invertebrate predators approximately 1 to 25 mm in body length) in western Antarctic Peninsula marine communities. This will be accomplished by examining the role of mesoherbivores in structuring macroalgal communities and by elucidating the ecological interactions of mesograzers with a dominant group of benthic macroinvertebrates, the marine sponges. Moreover, chemical studies will be conducted to gain a more thorough understanding of the chemical defenses that Antarctic Peninsula sponges direct towards crustacean mesograzers. Three sets of questions will be addressed concerning the importance of mesograzers, and amphipods in particular, in nearshore habitats of the western Antarctic Peninsula. First, the hypothesis that mesoherbivory is particularly heavy in western Antarctic Peninsula marine communities and has an important influence on algal community structure will be addressed. Initial studies will document which species of amphipods feed in whole or part on microalgae and macroalgae, the incidence and distribution of filamentous endophytes in dominant macroalgae, comparative night time patterns of amphipod abundances on macrophytes, and the role of chemical mediation in these relationships. Second, the broad hypothesis that mesograzers in general, and amphipods in particular, interact with and prey upon sponges to a greater extent than heretofore recognized in Antarctic communities will be tested. The functional basis of these associations will be considered by examining whether the sponges are used as prey, and if so, whether there is evidence that some sponges produce secondary metabolites that show efficacy against mesograzers such as amphipods. Third, the researchers will test the hypotheses that: 1) Antarctic algae and invertebrates biosynthesize secondary metabolites that deter feeding by amphipod predators; and 2) pigments found in three Antarctic sponges are tryptophan catabolites produced as defenses against crustacean predators that impact molting. Evaluation of these hypotheses will be based on isolation and characterization of the specific anti-feeding metabolites, on biosynthetic studies to establish the metabolic origin of the pigments, and on bioassays to establish the chemical defense roles of both groups of compounds. A variety of educational activities will be a major component of this project. Opportunities will be made to support graduate and undergraduate research, both through NSF programs as well as home university-based programs including a number of funded programs that enhance the representation of minorities in the sciences. Through their proven and highly successful interactive web program, the investigators will continue to involve a large numbers of teachers, K-12 students, and other members of the community at large in their scientific endeavors in Antarctica. Moreover, they will actively participate in outreach efforts by presenting numerous talks on their research to school and community groups. | ["POLYGON((-65 -63,-64.8 -63,-64.6 -63,-64.4 -63,-64.2 -63,-64 -63,-63.8 -63,-63.6 -63,-63.4 -63,-63.2 -63,-63 -63,-63 -63.2,-63 -63.4,-63 -63.6,-63 -63.8,-63 -64,-63 -64.2,-63 -64.4,-63 -64.6,-63 -64.8,-63 -65,-63.2 -65,-63.4 -65,-63.6 -65,-63.8 -65,-64 -65,-64.2 -65,-64.4 -65,-64.6 -65,-64.8 -65,-65 -65,-65 -64.8,-65 -64.6,-65 -64.4,-65 -64.2,-65 -64,-65 -63.8,-65 -63.6,-65 -63.4,-65 -63.2,-65 -63))"] |
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))"] |
Free-Drifting Icebergs as Proliferating Dispersion Sites of Iron Enrichment, Organic Carbon Production and Export in the Southern Ocean
|
0636543 |
2010-01-01 | Murray, Alison |
Collaborative Research: Free Drifting Icebergs as Proliferation Sites of Iron Enrichment, Organic Carbon Production and Export in the Southern Ocean |
Atmospheric warming has been associated with retreating glaciers, disintegrating ice shelves, and the increasing prevalence of icebergs in the Southern Ocean over the last decade. Our preliminary study of two icebergs in the NW Weddell Sea, an area of high iceberg concentration, showed significant delivery of terrestrial material accompanied by significant enhancement of phytoplankton and zooplankton/micronekton abundance, and primary production surrounding the icebergs. We hypothesize that nutrient enrichment by free-drifting icebergs will increase primary production and sedimentation of organic carbon, thus increasing the draw-down and sequestration of CO2 in the Southern Ocean and impacting the global carbon cycle. Our research addresses the following questions: 1) What is the relationship between the physical dynamics of free-drifting icebergs and the Fe and nutrient distributions of the surrounding water column? 2) What is the relationship between Fe and nutrient distributions associated with free-drifting icebergs and the organic carbon dynamics of the ice-attached and surrounding pelagic communities (microbes, zooplankton, micronekton)? 3) What is impact on the export flux of particulate organic carbon from the mixed layer? An interdisciplinary approach is proposed to examine iceberg structure and dynamics, biogeochemical processes, and carbon cycling that includes measurement of trace element, nutrient and radionuclide distributions; organic carbon dynamics mediated by microbial, ice-attached and zooplankton communities; and particulate organic carbon export fluxes. Results from this project will further our understanding of the relationship between climate change and carbon sequestration in the Southern Ocean. Our findings will be incorporated into the Antarctic Research division of the Ocean Exploration Center (OEC) as part of the SIOExplorer: Digital Library Project. The OEC allows users to access content, which is classified to one of four levels: entry (grade K-6), student (grade 6-12), college, and research. Graduate students, undergraduates, teachers, and volunteers are important participants in the proposed field and laboratory work. For the K-12 level, a professional writer of children's books will participate in cruises to produce an account of the expedition and a daily interactive website. | ["POLYGON((-51.98403 -57.58068,-51.042765 -57.58068,-50.1015 -57.58068,-49.160235 -57.58068,-48.21897 -57.58068,-47.277705 -57.58068,-46.33644 -57.58068,-45.395175 -57.58068,-44.45391 -57.58068,-43.512645 -57.58068,-42.57138 -57.58068,-42.57138 -58.10845,-42.57138 -58.63622,-42.57138 -59.16399,-42.57138 -59.69176,-42.57138 -60.21953,-42.57138 -60.7473,-42.57138 -61.27507,-42.57138 -61.80284,-42.57138 -62.33061,-42.57138 -62.85838,-43.512645 -62.85838,-44.45391 -62.85838,-45.395175 -62.85838,-46.33644 -62.85838,-47.277705 -62.85838,-48.21897 -62.85838,-49.160235 -62.85838,-50.1015 -62.85838,-51.042765 -62.85838,-51.98403 -62.85838,-51.98403 -62.33061,-51.98403 -61.80284,-51.98403 -61.27507,-51.98403 -60.7473,-51.98403 -60.21953,-51.98403 -59.69176,-51.98403 -59.16399,-51.98403 -58.63622,-51.98403 -58.10845,-51.98403 -57.58068))"] |
Free-Drifting Icebergs as Proliferating Dispersion Sites of Iron Enrichment, Organic Carbon Production and Export in the Southern Ocean
|
0636723 |
2010-01-01 | Helly, John |
Collaborative Research: Free Drifting Icebergs as Proliferation Sites of Iron Enrichment, Organic Carbon Production and Export in the Southern Ocean |
Atmospheric warming has been associated with retreating glaciers, disintegrating ice shelves, and the increasing prevalence of icebergs in the Southern Ocean over the last decade. Our preliminary study of two icebergs in the NW Weddell Sea, an area of high iceberg concentration, showed significant delivery of terrestrial material accompanied by significant enhancement of phytoplankton and zooplankton/micronekton abundance, and primary production surrounding the icebergs. We hypothesize that nutrient enrichment by free-drifting icebergs will increase primary production and sedimentation of organic carbon, thus increasing the draw-down and sequestration of CO2 in the Southern Ocean and impacting the global carbon cycle. Our research addresses the following questions: 1) What is the relationship between the physical dynamics of free-drifting icebergs and the Fe and nutrient distributions of the surrounding water column? 2) What is the relationship between Fe and nutrient distributions associated with free-drifting icebergs and the organic carbon dynamics of the ice-attached and surrounding pelagic communities (microbes, zooplankton, micronekton)? 3) What is impact on the export flux of particulate organic carbon from the mixed layer? An interdisciplinary approach is proposed to examine iceberg structure and dynamics, biogeochemical processes, and carbon cycling that includes measurement of trace element, nutrient and radionuclide distributions; organic carbon dynamics mediated by microbial, ice-attached and zooplankton communities; and particulate organic carbon export fluxes. Results from this project will further our understanding of the relationship between climate change and carbon sequestration in the Southern Ocean. Our findings will be incorporated into the Antarctic Research division of the Ocean Exploration Center (OEC) as part of the SIOExplorer: Digital Library Project. The OEC allows users to access content, which is classified to one of four levels: entry (grade K-6), student (grade 6-12), college, and research. Graduate students, undergraduates, teachers, and volunteers are important participants in the proposed field and laboratory work. For the K-12 level, a professional writer of children's books will participate in cruises to produce an account of the expedition and a daily interactive website. | ["POLYGON((-55 -52,-53.5 -52,-52 -52,-50.5 -52,-49 -52,-47.5 -52,-46 -52,-44.5 -52,-43 -52,-41.5 -52,-40 -52,-40 -53.3,-40 -54.6,-40 -55.9,-40 -57.2,-40 -58.5,-40 -59.8,-40 -61.1,-40 -62.4,-40 -63.7,-40 -65,-41.5 -65,-43 -65,-44.5 -65,-46 -65,-47.5 -65,-49 -65,-50.5 -65,-52 -65,-53.5 -65,-55 -65,-55 -63.7,-55 -62.4,-55 -61.1,-55 -59.8,-55 -58.5,-55 -57.2,-55 -55.9,-55 -54.6,-55 -53.3,-55 -52))"] |
Free-drifting Icebergs as Proliferating Dispersion Sites of Iron Enrichment, Organic Carbon Production and Export in the Southern Ocean
|
0636730 |
2010-01-01 | Vernet, Maria |
Collaborative Reseach: Free-drifting Icebergs as Proliferating Dispersion Sites of Iron Enrichment, Organic Carbon Production and Export in the Southern Ocean. |
Atmospheric warming has been associated with retreating glaciers, disintegrating ice shelves, and the increasing prevalence of icebergs in the Southern Ocean over the last decade. Our preliminary study of two icebergs in the NW Weddell Sea, an area of high iceberg concentration, showed significant delivery of terrestrial material accompanied by significant enhancement of phytoplankton and zooplankton/micronekton abundance, and primary production surrounding the icebergs. We hypothesize that nutrient enrichment by free-drifting icebergs will increase primary production and sedimentation of organic carbon, thus increasing the draw-down and sequestration of CO2 in the Southern Ocean and impacting the global carbon cycle. Our research addresses the following questions: 1) What is the relationship between the physical dynamics of free-drifting icebergs and the Fe and nutrient distributions of the surrounding water column? 2) What is the relationship between Fe and nutrient distributions associated with free-drifting icebergs and the organic carbon dynamics of the ice-attached and surrounding pelagic communities (microbes, zooplankton, micronekton)? 3) What is impact on the export flux of particulate organic carbon from the mixed layer? An interdisciplinary approach is proposed to examine iceberg structure and dynamics, biogeochemical processes, and carbon cycling that includes measurement of trace element, nutrient and radionuclide distributions; organic carbon dynamics mediated by microbial, ice-attached and zooplankton communities; and particulate organic carbon export fluxes. Results from this project will further our understanding of the relationship between climate change and carbon sequestration in the Southern Ocean. Our findings will be incorporated into the Antarctic Research division of the Ocean Exploration Center (OEC) as part of the SIOExplorer: Digital Library Project. The OEC allows users to access content, which is classified to one of four levels: entry (grade K-6), student (grade 6-12), college, and research. Graduate students, undergraduates, teachers, and volunteers are important participants in the proposed field and laboratory work. For the K-12 level, a professional writer of children's books will participate in cruises to produce an account of the expedition and a daily interactive website. | ["POLYGON((-55 -52,-53.5 -52,-52 -52,-50.5 -52,-49 -52,-47.5 -52,-46 -52,-44.5 -52,-43 -52,-41.5 -52,-40 -52,-40 -53.3,-40 -54.6,-40 -55.9,-40 -57.2,-40 -58.5,-40 -59.8,-40 -61.1,-40 -62.4,-40 -63.7,-40 -65,-41.5 -65,-43 -65,-44.5 -65,-46 -65,-47.5 -65,-49 -65,-50.5 -65,-52 -65,-53.5 -65,-55 -65,-55 -63.7,-55 -62.4,-55 -61.1,-55 -59.8,-55 -58.5,-55 -57.2,-55 -55.9,-55 -54.6,-55 -53.3,-55 -52))"] |
Aging in Weddell Seals: Proximate Mechanisms of Age-Related Changes in Adaptations to Breath-Hold Hunting in an Extreme Environment
|
0649609 |
2010-01-01 | Horning, Markus |
Collaborative Research: Aging in Weddell Seals: Proximate Mechanisms of Age-Related Changes in Adaptations to Breath-Hold Hunting in an Extreme Environment |
The primary objectives of this research are to investigate the proximate effects of aging on diving capability in the Weddell Seal and to describe mechanisms by which aging may influence foraging ecology, through physiology and behavior. This model pinniped species has been the focus of three decades of research in McMurdo Sound, Antarctica. Compared to the knowledge of pinniped diving physiology and ecology during early development and young adulthood, little is known about individuals nearing the upper limit of their normal reproductive age range. Evolutionary aging theories predict that elderly diving seals should exhibit senescence. This should be exacerbated by surges in the generation of oxygen free radicals via hypoxia-reoxygenation during breath-hold diving and hunting, which are implicated in age-related damage to cellular mitochondria. Surprisingly, limited observations of non-threatened pinniped populations indicate that senescence does not occur to a level where reproductive output is affected. The ability of pinnipeds to avoid apparent senescence raises two major questions: what specific physiological and morphological changes occur with advancing age in pinnipeds; and what subtle adjustments are made by these animals to cope with such changes? This investigation will focus on specific, functional physiological and behavioral changes relating to dive capability with advancing age. Data will be compared between Weddell seals in the peak, and near the end, of their reproductive age range. The investigators will quantify age-related changes in general health and body condition, combined with fine scale assessments of external and internal ability to do work in the form of diving. Specifically, patterns of muscle morphology, oxidant status and oxygen storage with age will be examined. The effects of age on skeletal muscular function and exercise performance will also be examined. The investigators hypothesize that senescence does occur in Weddell seals at the level of small-scale, proximate physiological effects and performance, but that behavioral plasticity allows for a given degree of compensation. Broader impacts include the training of students and outreach activities including interviews and articles written for the popular media. This study should also establish diving seals as a novel model for the study of cardiovascular and muscular physiology of aging and develop a foundation for similar research on other species. Advancement of the understanding of aging by medical science has been impressive in recent years but basic mammalian aging is an area of study the still requires considerable effort. The development of new models for the study of aging has tremendous potential benefits to society at large. | ["POLYGON((165.975 -77.54,166.0631 -77.54,166.1512 -77.54,166.2393 -77.54,166.3274 -77.54,166.4155 -77.54,166.5036 -77.54,166.5917 -77.54,166.6798 -77.54,166.7679 -77.54,166.856 -77.54,166.856 -77.5709,166.856 -77.6018,166.856 -77.6327,166.856 -77.6636,166.856 -77.6945,166.856 -77.7254,166.856 -77.7563,166.856 -77.7872,166.856 -77.8181,166.856 -77.849,166.7679 -77.849,166.6798 -77.849,166.5917 -77.849,166.5036 -77.849,166.4155 -77.849,166.3274 -77.849,166.2393 -77.849,166.1512 -77.849,166.0631 -77.849,165.975 -77.849,165.975 -77.8181,165.975 -77.7872,165.975 -77.7563,165.975 -77.7254,165.975 -77.6945,165.975 -77.6636,165.975 -77.6327,165.975 -77.6018,165.975 -77.5709,165.975 -77.54))"] |
Ice Nucleation by Marine Psychrophiles
|
0801392 |
2010-01-01 | Swanson, Brian |
Ice Nucleation by Marine Psychrophiles |
The primary objective of this research is to investigate polar marine psychrophilic bacteria for their potential to nucleate ice using a combination of microbiological, molecular biological and atmospheric science approaches in the laboratory. Very little is known about how psychrophiles interact and cope with ice or their adaptations to conditions of extreme cold and salinity. This work will involve a series of laboratory experiments using a novel freeze-tube technique for assaying freezing spectra which will provide quantitative information on: (i) the temperature-dependent freezing rates for heterogeneously frozen droplets containing sea-ice bacteria, (ii) the proportional occurrence of ice-nucleation activity versus anti-freeze activity among sea-ice bacterial isolates and (iii) the temperature-dependent freezing rates of bacteria with ice-nucleation activity grown at a range of temperatures and salinities. The compound(s) responsible for the observed activity will be identified, which is an essential step towards the development of an in-situ bacterial ice-nucleation detection assay that can be applied in the field to Antarctic water and cloud samples. One of the goals of this work is to better understand survival and cold adaptation processes of polar marine bacteria confronted with freezing conditions in sea ice. Since sea ice strongly impacts polar, as well as the global climates, this research is of significant interest because it will also provide data for accessing the importance of bacterial ice nucleation in the formation of sea ice. These measurements of ice-nucleation rates will be the first high-resolution measurements for psychrophilic marine bacteria. Another goal is to better understand the impact of bacterial ice initiation processes in polar clouds by making high-resolution measurements of nucleation rates for cloud bacteria found over Arctic and Antarctic regions. Initial measurements indicate these bacteria nucleate ice at warmer temperatures and the effect in polar regions may be quite important, since ice can strongly impact cloud dynamics, cloud radiative properties, precipitation formation, and cloud chemistry. If these initial measurements are confirmed, the data collected here will be important for improving the understanding of polar cloud processes and models. A third goal is to better understand the molecular basis of marine bacterial ice nucleation by characterizing the ice-nucleation compound and comparing it with those of known plant-derived ice-nucleating bacteria, which are the only ice-nucleating bacteria examined in detail to date. The proposed activity will support the beginning academic career of a post-doctoral researcher and will serve as the basis for several undergraduate student laboratory projects. Results from this research will be widely published in various scientific journals and outreach venues. | ["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))"] |
Controls on Climate-Active Gases by Amundsen Sea Ice Biota
|
0836112 |
2010-01-01 | Smith, Walker O. |
Collaborative Research: Controls on climate-active gases by Amundsen Sea ice biota |
Convincing evidence now confirms that polar regions are changing rapidly in response to human activities. Changes in sea ice extent and thickness will have profound implications for productivity, food webs and carbon fluxes at high latitudes, since sea ice biota are a significant source of biogenic matter for the ecosystem. While sea ice is often thought to be a barrier to gas exchange between the ocean and the atmosphere, it more likely functions as a source or sink for climate-active gases such as carbon dioxide and ozone-depleting organohalogens, due in part to activities of microbes embedded in the sea ice matrix. This project brings together experienced US and Swedish investigators to examine the controls by sea-ice biota on the production and degradation of key climate-active gases in the Pacific sector of the Southern Ocean. We hypothesize that 1) the physical properties of the sea-ice environment will determine the community structure and activities of the sea ice biota; 2) the productivity, biomass, physiological state and species composition of ice algae will determine the production of specific classes of organic carbon, including organohalogens; 3) heterotrophic co-metabolism within the ice will break down these compounds to some extent, depending on the microbial community structure and productivity, and 4) the sea ice to atmosphere fluxes of CO2 and organohalogens will be inversely related. This project will build close scientific collaborations between US and Swedish researchers and also train young scientists, including members of underrepresented groups. Dissemination of results will include the scientific literature, and public outreach venues including interactions with a PolarTrec teacher. | ["POLYGON((-170 -69,-163 -69,-156 -69,-149 -69,-142 -69,-135 -69,-128 -69,-121 -69,-114 -69,-107 -69,-100 -69,-100 -70,-100 -71,-100 -72,-100 -73,-100 -74,-100 -75,-100 -76,-100 -77,-100 -78,-100 -79,-107 -79,-114 -79,-121 -79,-128 -79,-135 -79,-142 -79,-149 -79,-156 -79,-163 -79,-170 -79,-170 -78,-170 -77,-170 -76,-170 -75,-170 -74,-170 -73,-170 -72,-170 -71,-170 -70,-170 -69))"] |
PENGUIn - A High-Latitude Window to Geospace Dynamics
|
0840398 |
2010-01-01 | Frey, Harald; Mende, Stephen |
Collaborative Research: PENGUIn - A High-Latitude Window to Geospace Dynamics |
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The PENGUIn team will continue investigating in depth a multi-scale electrodynamic system that comprises space environment of Planet Earth (geospace). Several science topics important to the space physics and aeronomy are outlines in this proposal that can be broadly categorized as the following objectives: (a) to study reconnection and waves in the southern cusp region; (b) to investigate unraveling global geomagnetic substorm signatures; (c) to understand the dayside wave-particle interactions; and (d) to observe and investigate various polar cap phenomena and neutral atmosphere dynamics. Cutting-edge science on these critical topics will be accomplished by acquiring multi-instrument data from a distributed network of autonomous observatories in Antarctica, built and deployed with the matured technological achievements. In the last several years, advances in power supply systems and Iridium data transmission for the Automatic Geophysical Observatories (AGOs) have proven effective for providing real-time geophysical data reliably. Five AGOs that span from the auroral zone to deep in the polar cap will be maintained providing a wealth of data for science analyses. Additional instrumentation as GPS-based receivers measuring total electron content in the ionosphere will be deployed at AGOs. These scientific investigations will be enriched by complementary measurements from manned stations in the Antarctic, from magnetically conjugate regions in the Arctic, and from a fleet of magnetospheric and ionospheric spacecraft. Continued reliance on students provides a broader impact to this proposed research and firmly grounds this effort in its educational mission. | ["POLYGON((-180 -75,-144 -75,-108 -75,-72 -75,-36 -75,0 -75,36 -75,72 -75,108 -75,144 -75,180 -75,180 -76.5,180 -78,180 -79.5,180 -81,180 -82.5,180 -84,180 -85.5,180 -87,180 -88.5,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -88.5,-180 -87,-180 -85.5,-180 -84,-180 -82.5,-180 -81,-180 -79.5,-180 -78,-180 -76.5,-180 -75))"] |
Antarctic Subglacial Lake Classification Inventory
|
9911617 9319379 |
2009-02-06 | Blankenship, Donald D.; Holt, John W.; Carter, Sasha P. |
Continuation of Activities for the Support Office for Aerogeophysical Research (SOAR) |
This data set is an Antarctic radar-based subglacial lake classification collection, which focuses on the radar reflection properties of each given lake. The Subglacial lakes are separated into four categories specified by radar reflection properties. Additional information includes: latitude, longitude, length (in kilometers), hydro-potential (in meters), bed elevation (in meters above WGS84), and ice thickness (in meters). Source data used to compile this data set were collected between 1998 and 2001. Data are available via FTP as a Microsoft Excel Spreadsheet (XLS), and Tagged Image File Format (TIF). | ["POLYGON((-160 -70,-142.5 -70,-125 -70,-107.5 -70,-90 -70,-72.5 -70,-55 -70,-37.5 -70,-20 -70,-2.5 -70,15 -70,15 -72,15 -74,15 -76,15 -78,15 -80,15 -82,15 -84,15 -86,15 -88,15 -90,-2.5 -90,-20 -90,-37.5 -90,-55 -90,-72.5 -90,-90 -90,-107.5 -90,-125 -90,-142.5 -90,-160 -90,-160 -88,-160 -86,-160 -84,-160 -82,-160 -80,-160 -78,-160 -76,-160 -74,-160 -72,-160 -70))"] |
The Aerobic Dive Limit: Oxygen Transport and Depletion in Emperor Penguins
|
0538594 |
2009-01-01 | Ponganis, Paul |
The Aerobic Dive Limit: Oxygen Transport and Depletion in Emperor Penguins |
The research will examine blood and muscle oxygen store depletion in relation to the documented aerobic dive limit (ADL, onset of post-dive blood lactate accumulation) in diving of emperor penguins. The intellectual merits of this proposal involve its evaluation of the physiological basis of the ADL concept. The ADL is probably the most commonly-used, but rarely measured, factor to interpret and model the behavior and foraging ecology of diving animals. Based on prior studies, and on recent investigations of respiratory and blood oxygen depletion during dives of emperor penguins, it is hypothesized that the ADL is a result of the depletion of myoglobin (Mb)-bound oxygen and increased glycolysis in the primary locomotory muscles. This project will accurately define the physiological mechanisms underlying the ADL through 1) evaluation of the rate and magnitude of muscle oxygen depletion during dives in relation to the previously measured ADL, 2) characterization of the hemoglobin-oxygen dissociation curve in blood of emperor penguins and comparison of that curve to those of other diving and non-diving species, 3) application of the emperor hemoglogin-oxygen dissociation curve to previously collected oxygen and hemoglobin data in order to estimate the rate and magnitude of blood oxygen depletion during dives, and 4) measurement of muscle phosphoocreatine and glycogen concentrations in order to estimate their potential contributions to muscle energy metabolism during diving. The project also continues the census and monitoring of the emperor colonies in the Ross Sea, which is especially important in light of both fisheries activity and the movement of iceberg B15-A. Broader impacts of the project include: 1) technological development of microprocessor-based, 'backpack' near-infrared spectrophotometer, which will be applicable not only to other species, but also to other fields (i.e., exercise physiology), 2) collaboration with the Department of Anesthesia at the U.S. Naval Hospital in San Diego in the training of anesthesia residents in research techniques, 3) the training and thesis research of two graduate students in these techniques and in Antarctic field research, and 4) a better understanding of the ADL concept and its use in the fields of diving behavior and physiology. In addition the annual census of emperor penguin colonies in the Ross Sea, in conjunction with the continued evaluation of previously developed remote cameras to monitor colony status, will form the basis of a new educational web site, and allow development of an educational outreach program to school children through SeaWorld of San Diego. | ["POLYGON((165.983 -77.683,166.0164 -77.683,166.0498 -77.683,166.0832 -77.683,166.1166 -77.683,166.15 -77.683,166.1834 -77.683,166.2168 -77.683,166.2502 -77.683,166.2836 -77.683,166.317 -77.683,166.317 -77.6897,166.317 -77.6964,166.317 -77.7031,166.317 -77.7098,166.317 -77.7165,166.317 -77.7232,166.317 -77.7299,166.317 -77.7366,166.317 -77.7433,166.317 -77.75,166.2836 -77.75,166.2502 -77.75,166.2168 -77.75,166.1834 -77.75,166.15 -77.75,166.1166 -77.75,166.0832 -77.75,166.0498 -77.75,166.0164 -77.75,165.983 -77.75,165.983 -77.7433,165.983 -77.7366,165.983 -77.7299,165.983 -77.7232,165.983 -77.7165,165.983 -77.7098,165.983 -77.7031,165.983 -77.6964,165.983 -77.6897,165.983 -77.683))"] |
Triple-dating (Pb-FT-He) of Antarctic Detritus and the Origin of the Gamburtsev Mountains
|
0817163 |
2009-01-01 | Gehrels, George; Reiners, Peter |
Collaborative Research: SGER: Triple-dating (Pb-FT-He) of Antarctic Detritus and the Origin of the Gamburtsev Mountains |
This Small Grant for Exploratory Research investigates the origin and evolution of the Gamburtsev subglacial mountains (GSM). These mountains are considered the nucleation point for Antarctica's largest ice sheets; however, being of indeterminate age, they may postdate ice sheet formation. As well, their formation could reflect tectonic events during the breakup of Gondwana. The project studies GSM-derived detrital zircon and apatite crystals from Prydz Bay obtained by the Ocean Drilling Program. Analytical work includes triple-dating thermochronometry by U/Pb, fission track, and (U/Th)/He methods. The combined technique offers insight into both high and low temperature processes, and is potentially sensitive to both the orogenic events and the subsequent cooling and exhumation due to erosion. In terms of broader impacts, this project supports research for a postdoctoral fellow. | ["POLYGON((72 -66,72.3 -66,72.6 -66,72.9 -66,73.2 -66,73.5 -66,73.8 -66,74.1 -66,74.4 -66,74.7 -66,75 -66,75 -66.3,75 -66.6,75 -66.9,75 -67.2,75 -67.5,75 -67.8,75 -68.1,75 -68.4,75 -68.7,75 -69,74.7 -69,74.4 -69,74.1 -69,73.8 -69,73.5 -69,73.2 -69,72.9 -69,72.6 -69,72.3 -69,72 -69,72 -68.7,72 -68.4,72 -68.1,72 -67.8,72 -67.5,72 -67.2,72 -66.9,72 -66.6,72 -66.3,72 -66))"] |
Triple-dating (Pb-FT-He) of Antarctic Detritus and the Origin of the Gamburtsev Mountains
|
0816934 |
2009-01-01 | Thomson, Stuart |
Collaborative Research: SGER: Triple-dating (Pb-FT-He) of Antarctic Detritus and the Origin of the Gamburtsev Mountains |
This Small Grant for Exploratory Research investigates the origin and evolution of the Gamburtsev subglacial mountains (GSM). These mountains are considered the nucleation point for Antarctica's largest ice sheets; however, being of indeterminate age, they may postdate ice sheet formation. As well, their formation could reflect tectonic events during the breakup of Gondwana. The project studies GSM-derived detrital zircon and apatite crystals from Prydz Bay obtained by the Ocean Drilling Program. Analytical work includes triple-dating thermochronometry by U/Pb, fission track, and (U/Th)/He methods. The combined technique offers insight into both high and low temperature processes, and is potentially sensitive to both the orogenic events and the subsequent cooling and exhumation due to erosion. In terms of broader impacts, this project supports research for a postdoctoral fellow. | ["POLYGON((65 -66,72.9 -66,80.8 -66,88.7 -66,96.6 -66,104.5 -66,112.4 -66,120.3 -66,128.2 -66,136.1 -66,144 -66,144 -66.3,144 -66.6,144 -66.9,144 -67.2,144 -67.5,144 -67.8,144 -68.1,144 -68.4,144 -68.7,144 -69,136.1 -69,128.2 -69,120.3 -69,112.4 -69,104.5 -69,96.6 -69,88.7 -69,80.8 -69,72.9 -69,65 -69,65 -68.7,65 -68.4,65 -68.1,65 -67.8,65 -67.5,65 -67.2,65 -66.9,65 -66.6,65 -66.3,65 -66))"] |
Small Grants for Exploratory Research - Oceanographic Research in the Amundsen and Ross Seas
|
0741380 |
2009-01-01 | Smith, Walker O. |
Small Grants for Exploratory Research - Oceanographic Research in the Amundsen and Ross Seas: |
The research will examine the relative importance of the physical and chemical controls on phytoplankton dynamics and carbon flux in continental margin regions of the Southern Ocean, and elucidate mechanisms by which plankton populations and carbon export might be altered by climate change. We specifically will address (1) how the phytoplankton on the continental margins of the southern Ocean respond to spatial and temporal changes in temperature, light, iron supply, and carbon dioxide levels, (2) how these factors initiate changes in phytoplankton assemblage structure, and (3) how carbon export and the efficiency of the biological pump are impacted by the biomass and composition of the phytoplankton. Two regions of study (the Amundsen and Ross Seas) will be investigated, one well studied (Ross Sea) and one poorly described (Amundsen Sea). It is hypothesized that each region will have markedly different physical forcing, giving rise to distinct chemical conditions and therefore biological responses. As such, the comparison of the two may give us insights into the mechanisms of how Antarctic continental margins will respond under changing environmental conditions. Broader impacts include participation by an international graduate student from Brazil, outreach via seminars to the general public, collaboration with the teachers-in-residence on the cruise, development of a cruise web site and interactive email exchanges with local middle school students while at sea. | ["POLYGON((-160 -65,-154 -65,-148 -65,-142 -65,-136 -65,-130 -65,-124 -65,-118 -65,-112 -65,-106 -65,-100 -65,-100 -66.1,-100 -67.2,-100 -68.3,-100 -69.4,-100 -70.5,-100 -71.6,-100 -72.7,-100 -73.8,-100 -74.9,-100 -76,-106 -76,-112 -76,-118 -76,-124 -76,-130 -76,-136 -76,-142 -76,-148 -76,-154 -76,-160 -76,-160 -74.9,-160 -73.8,-160 -72.7,-160 -71.6,-160 -70.5,-160 -69.4,-160 -68.3,-160 -67.2,-160 -66.1,-160 -65))"] |
Landform Evolution in the Dry Valleys and its implications for Miocene-Pliocene Climate Change in Antarctica
|
0739452 |
2009-01-01 | Mukhopadhyay, Sujoy |
Landform Evolution in the Dry Valleys and its implications for Miocene-Pliocene Climate Change in Antarctica |
This project seeks to answer a simple question: how old are potholes and related geomorphic features found in the uplands of the McMurdo Dry Valleys, Antarctica? Some research suggests that they are over ten million years old and date the growth of the East Antarctic Ice Sheet, the world's largest. However, some evidence suggests that these are young, erosional features that continuing to evolve to this day. This project uses cosmogenic nuclide dating to determine the age of the pothole floors. The results are important for determining the ice sheet?s history and interpreting the O-isotope record from the marine sediment cores, key records of global climate. Broader impacts include K12 outreach and incorporation of outcomes into university courses. | ["POLYGON((161 -76,161.2 -76,161.4 -76,161.6 -76,161.8 -76,162 -76,162.2 -76,162.4 -76,162.6 -76,162.8 -76,163 -76,163 -76.2,163 -76.4,163 -76.6,163 -76.8,163 -77,163 -77.2,163 -77.4,163 -77.6,163 -77.8,163 -78,162.8 -78,162.6 -78,162.4 -78,162.2 -78,162 -78,161.8 -78,161.6 -78,161.4 -78,161.2 -78,161 -78,161 -77.8,161 -77.6,161 -77.4,161 -77.2,161 -77,161 -76.8,161 -76.6,161 -76.4,161 -76.2,161 -76))"] |
Periglacial Landscape Evolution in Antarctic Lava Flows and Glacial Tills
|
0636629 |
2009-01-01 | Soule, S. Adam; Kurz, Mark D. |
Periglacial Landscape Evolution in Antarctic Lava Flows and Glacial Tills |
This project uses cosmogenic nuclide dating and LIDAR studies of surface roughness to understand weathering and landscape evolution in the Dry Valleys of Antarctica. The work focuses on two processes: cryoturbation of frozen soils and the development of patterned, frozen ground on ancient lava flows. The approach includes innovative uses of He3 profiling. Results will also be applied to understanding the glacial history of the Dry Valleys. There are potential applications to understanding the history of the East Antarctic Ice Sheet and the formation of Martian landscapes. The broader impacts include graduate student education. As well, the work may contribute to our understanding of the history of the Antarctic ice sheets, which is important to modeling their behavior during global climate change. | ["POLYGON((160.7 -77.8,161.06 -77.8,161.42 -77.8,161.78 -77.8,162.14 -77.8,162.5 -77.8,162.86 -77.8,163.22 -77.8,163.58 -77.8,163.94 -77.8,164.3 -77.8,164.3 -77.86,164.3 -77.92,164.3 -77.98,164.3 -78.04,164.3 -78.1,164.3 -78.16,164.3 -78.22,164.3 -78.28,164.3 -78.34,164.3 -78.4,163.94 -78.4,163.58 -78.4,163.22 -78.4,162.86 -78.4,162.5 -78.4,162.14 -78.4,161.78 -78.4,161.42 -78.4,161.06 -78.4,160.7 -78.4,160.7 -78.34,160.7 -78.28,160.7 -78.22,160.7 -78.16,160.7 -78.1,160.7 -78.04,160.7 -77.98,160.7 -77.92,160.7 -77.86,160.7 -77.8))"] |
Solar activity during the last millennium, estimated from cosmogenic in-situ C14 in South Pole and GISP2 ice cores
|
0538683 |
2009-01-01 | Lal, Devendra |
Solar Activity during the Last Millennium, Estimated from Cosmogenic in-situ 14C in South Pole and GISP2 Ice Cores |
The principal aim of this research is to determine the precise manner in which solar activity has varied in the past 1000 years. During this period, four periods of very low solar activity have been identified: Wolf (1305-1345 AD), Spoerer (1418-1540 AD), Maunder (1645-1715), and one period of high solar activity (1100-1250 A.D.) have been deduced based on available historical records of sunspot numbers and aurora. Our proposal aims to study the solar activity during the past 1000 years in detail using a new method, based on studies of polar ice, as developed earlier (Earth and Planetary Science Letters, 234, 335-349, 2005). The method is based on the fact that greater solar activity leads to production of greater magnetic fields in the heliosphere, which reduces the primary cosmic ray flux in the near Earth environment, and vice-versa. Consequently if one can measure the primary cosmic ray flux in the near Earth space, it becomes a direct measure of the solar activity. Lal et al. (Earth and Planetary Science Letters, 234, 335-349, 2005) concluded that the best way of measuring the primary cosmic ray flux would be to measure the concentration of cosmogenic in-situ produced 14C in polar ice sheets, which was discovered by Lal et al. (Nature 346, 350-352, 1990). Following this idea Lal et al. (op. cit.) measured cosmogenic in-situ produced in 19 samples from the GISP 2 core covering time range of 375-31,250 yrs B.P. Their studies showed that there were two periods of very low solar activity in this time bracket (during 8500-9500 B.P and 27,000-32,000 B.P.), and one high solar activity period during 12,000-16,000 yrs B.P. In order to provide an independent check on the veracity of the new method, we decided to apply it to the historical period, < 1000 yrs B.P. The inferred Solar activities based on the study of cosmogenic in-situ produced 14C in South Pole ice samples clearly establish that there was a period of high Solar activity during 1100-1250 A.D., and a period of very low solar activity during 1416-1534 A.D, designated as the Spoerer Minimum. These results however do not confirm the proposed dates for the Dalton and the Maunder Minimum periods, predicted to be 1795-1825 A.D. and 1654-1714 A.D. respectively. Instead, our studies show that there was a long duration period of low solar activity during 1750-1860 A.D. These results make it quite clear that we should carry out more studies to fully establish the temporal behavior of the Solar activity in the past 1000 yrs. | ["POINT(-180 -90)"] |
Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till
|
0538195 |
2009-01-01 | Marone, Chris; Anandakrishnan, Sridhar |
Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till |
This award supports a project to conduct laboratory experiments and numerical modeling to determine the constitutive properties of subglacial till under dynamic stressing and to test the hypothesis that granular properties of till are sufficient, when coupled elastically to a large ice stream, to reproduce the field observations of triggered slip and subglacial seismicity. Testing will be carried out in a servo-controlled biaxial shear device under controlled temperature and stress conditions, which will allow both sliding and microstructural processes to be studied in detail. The main focus of the work will be on laboratory measurements. In addition, we will construct continuum models to evaluate whether our results can predict complex ice sheet motions and observed characteristics of subglacial seismicity. In terms of broader impacts, the proposed work will encourage interactions between the rock-mechanics and glaciology communities and will bring together members of different scientific backgrounds and vocabularies, but similar problems and data. The project will train undergraduate and graduate students at Penn State University and the scientists involved plan to give presentations to grade school classes, scout groups, and at community open houses. Results will be presented at professional meetings and will be published in a timely manner. The work will result in a better understanding of glacial motion and the physics of earthquake slip, which is essential for understanding ice sheet dynamics and earthquake hazard. | [] |
Differential Expression of Oxygen-binding Proteins in Antarctic Fishes Affects Nitric Oxide-mediated Pathways of Angiogenesis and Mitochondrial Biogenesis
|
0437887 |
2009-01-01 | Sidell, Bruce |
Collaborative Research: Differential Expression of Oxygen-binding Proteins in Antarctic Fishes Affects Nitric Oxide-mediated Pathways of Angiogenesis and Mitochondrial Biogenesis. |
The polar ocean presently surrounding Antarctica is the coldest, most thermally stable marine environment on earth. Because oxygen solubility in seawater is inversely proportional to temperature, the cold Antarctic seas are an exceptionally oxygen-rich aquatic habitat. Eight families of a single perciform suborder, the Notothenioidei, dominate the present fish fauna surrounding Antarctica. Notothenioids account for approximately 35% of fish species and 90% of fish biomass south of the Antarctic Polar Front. Radiation of closely related notothenioid species thus has occurred rapidly and under a very unusual set of conditions: relative oceanographic isolation from other faunas due to circumpolar currents and deep ocean trenches surrounding the continent, chronically, severely cold water temperatures, very high oxygen availability, very low levels of niche competition in a Southern Ocean depauperate of species subsequent to a dramatic crash in species diversity of fishes that occurred sometime between the mid-Tertiary and present. These features make Antarctic notothenioid fishes an uniquely attractive group for the study of physiological and biochemical adaptations to cold body temperature. Few distinctive features of Antarctic fishes are as unique as the pattern of expression of oxygen-binding proteins in one notothenioid family, the Channichthyidae (Antarctic icefishes). All channichthyid icefishes lack the circulating oxygen-binding protein, hemoglobin (Hb); the intracellular oxygen-binding protein, myoglobin (Mb) is not uniformly expressed in species of this family. Both proteins are normally considered essential for adequate delivery of oxygen to aerobically poised tissues of animals. To compensate for the absence of Hb, icefishes have developed large hearts, rapidly circulate a large blood volume and possess elaborate vasculature of larger lumenal diameter than is seen in red-blooded fishes. Loss of Mb expression in oxidative muscles correlates with dramatic elevation in density of mitochondria within the cell, although each individual organelle is less densely packed with respiratory proteins. Within the framework of oxygen movement, the adaptive significance of greater vascular density and mitochondrial populations is understandable but mechanisms underlying development of these characteristics remain unknown. The answer may lie in another major function of both Hb and Mb, degradation of the ubiquitous bioactive compound, nitric oxide (NO). The research will test the hypothesis that loss of hemoprotein expression in icefishes has resulted in an increase in levels of NO that mediate modification of vascular systems and expansion of mitochondrial populations in oxidative tissues. The objectives of the proposal are to quantify the vascular density of retinas in +Hb and -Hb notothenioid species, to characterize NOS isoforms and catalytic activity in retina and cardiac muscle of Antarctic notothenioid fishes, to evaluate level of expression of downstream factors implicat ed in angiogenesis (in retinal tissue) and mitochondrial biogenesis (in cardiac muscle), and to determine whether inhibition of NOS in vivo results in regression of angiogenic and mitochondrial biogenic responses in icefishes. Broader impacts range from basic biology, through training of young scientists, to enhanced understanding of clinically relevant biomedical processes. | ["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))"] |
Biodiversity, Buoyancy and Morphological Studies of Non-Antarctic Notothenioid Fishes
|
0436190 |
2009-01-01 | Eastman, Joseph |
Biodiversity, Buoyancy and Morphological Studies of Non-Antarctic Notothenioid Fishes |
Patterns of biodiversity, as revealed by basic research in organismal biology, may be derived from ecological and evolutionary processes expressed in unique settings, such as Antarctica. The polar regions and their faunas are commanding increased attention as declining species diversity, environmental change, commercial fisheries, and resource management are now being viewed in a global context. Commercial fishing is known to have a direct and pervasive effect on marine biodiversity, and occurs in the Southern Ocean as far south as the Ross Sea. The nature of fish biodiversity in the Antarctic is different than in all other ocean shelf areas. Waters of the Antarctic continental shelf are ice covered for most of the year and water temperatures are nearly constant at -1.5 C. In these waters components of the phyletically derived Antarctic clade of Notothenioids dominate fish diversity. In some regions, including the southwestern Ross Sea, Notothenioids are overwhelmingly dominant in terms of number of species, abundance, and biomass. Such dominance by a single taxonomic group is unique among shelf faunas of the world. In the absence of competition from a taxonomically diverse fauna, Notothenioids underwent a habitat or depth related diversification keyed to the utilization of unfilled niches in the water column, especially pelagic or partially pelagic zooplanktivory and piscivory. This has been accomplished in the absence of a swim bladder for buoyancy control. They also may form a special type of adaptive radiation known as a species flock, which is an assemblage of a disproportionately high number of related species that have evolved rapidly within a defined area where most species are endemic. Diversification in buoyancy is the hallmark of the notothenioid radiation. Buoyancy is the feature of notothenioid biology that determines whether a species lives on the substrate, in the water column or both. Buoyancy also influences other key aspects of life history including swimming, feeding and reproduction and thus has implications for the role of the species in the ecosystem. With similarities to classic evolutionary hot spots, the Antarctic shelf and its Notothenioid radiation merit further exploration. The 2004 'International Collaborative Expedition to collect and study Fish Indigenous to Sub-Antarctic Habitats,' or, 'ICEFISH,' provided a platform for collection of notothenioid fishes from sub-Antarctic waters between South America and Africa, which will be examined in this project. This study will determine buoyancy for samples of all notothenioid species captured during the ICEFISH cruise. This essential aspect of the biology is known for only 19% of the notothenioid fauna. Also, the gross and microscopic anatomy of brains and sense organs of the phyletically basal families Bovichtidae, Eleginopidae, and of the non-Antarctic species of the primarily Antarctic family Nototheniidae will be examined. The fish biodiversity and endemicity in poorly known localities along the ICEFISH cruise track, seamounts and deep trenches will be quantified. Broader impacts include improved information for comprehending and conserving biodiversity, a scientific and societal priority. | ["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))"] |
What Limits Denitrification and Bacterial Growth in Lake Bonney, Taylor Valley, Antarctica?
|
0230276 |
2009-01-01 | Ward, Bess |
Collaborative Research: What Limits Denitrification and Bacterial Growth in Lake Bonney, Taylor Valley, Antarctica? |
Denitrification is the main process by which fixed nitrogen is lost from ecosystems and the regulation of this process may directly affect primary production and carbon cycling over short and long time scales. Previous investigations of the role of bioactive metals in regulating denitrification in bacteria from permanently ice-covered Lake Bonney in the Taylor Valley of East Antarctica indicated that denitrifying bacteria can be negatively affected by metals such as copper, iron, cadmium, lead, chromium, nickel, silver and zinc; and that there is a distinct difference in denitrifying activity between the east and west lobes of the lake. Low iron concentrations were found to exacerbate the potential toxicity of the other metals, while silver has the potential to specifically inhibit denitrification because of its ability to interfere with copper binding in redox proteins, such as nitrite reductase and nitrous oxide reductase. High silver concentrations might prevent the functioning of nitrous oxide reductase in the same way that simple copper limitation does, thereby causing the buildup of nitrous oxide and resulting in a nonfunctional nitrogen cycle. Other factors, such as oxygen concentration, are likely also to affect bacterial activity in Lake Bonney. This project will investigate silver toxicity, general metal toxicity and oxygen concentration to determine their effect on denitrification in the lake by using a suite of 'sentinel' strains of denitrifying bacteria (isolated from the lake) incubated in Lake Bonney water and subjected to various treatments. The physiological responses of these strains to changes in metal and oxygen concentration will be quantified by flow cytometric detection of single cell molecular probes whose sensitivity and interpretation have been optimized for the sentinel strains. Understanding the relationships between metals and denitrification is expected to enhance our understanding of not only Lake Bonney's unusual nitrogen cycle, but more generally, of the potential role of metals in the regulation of microbial nitrogen transformations. The broader impacts of this work include not only a better understanding of regional biogeochemistry and global perspectives on these processes; but also the training of graduate students and a substantial outreach effort for school children. | ["POLYGON((162 -77.2,162.16 -77.2,162.32 -77.2,162.48 -77.2,162.64 -77.2,162.8 -77.2,162.96 -77.2,163.12 -77.2,163.28 -77.2,163.44 -77.2,163.6 -77.2,163.6 -77.26,163.6 -77.32,163.6 -77.38,163.6 -77.44,163.6 -77.5,163.6 -77.56,163.6 -77.62,163.6 -77.68,163.6 -77.74,163.6 -77.8,163.44 -77.8,163.28 -77.8,163.12 -77.8,162.96 -77.8,162.8 -77.8,162.64 -77.8,162.48 -77.8,162.32 -77.8,162.16 -77.8,162 -77.8,162 -77.74,162 -77.68,162 -77.62,162 -77.56,162 -77.5,162 -77.44,162 -77.38,162 -77.32,162 -77.26,162 -77.2))"] |
Long-term Data Collection at Select Antarctic Peninsula Visitor Sites
|
0230069 |
2009-01-01 | Naveen, Ronald |
Long-term Data Collection at Select Antarctic Peninsula Visitor Sites |
The Antarctic Site Inventory Project has collected biological data and site-descriptive information in the Antarctic Peninsula region since 1994. This research effort has provided data on those sites which are visited by tourists on shipboard expeditions in the region. The aim is to obtain data on the population status of several key species of Antarctic seabirds, which might be affected by the cumulative impact resulting from visits to the sites. This project will continue the effort by focusing on two heavily-visited Antarctic Peninsula sites: Paulet Island, in the northwestern Weddell Sea and Petermann Island, in the Lemaire Channel near Anvers Island. These sites were selected because both rank among the ten most visited sites in Antarctica each year in terms of numbers of visitors and zodiac landings; both are diverse in species composition, and both are sensitive to potential environmental disruptions from visitors. These data collected focus on two important biological parameters for penguins and blue-eyed shags: (1) breeding population size (number of occupied nests) and (2) breeding success (number of chicks per occupied nests). A long-term data program will be supported, with studies at the two sites over a five-year period. The main focus will be at Petermann Island, selected for intensive study due to its visitor status and location in the region near Palmer Station. This will allow for comparative data with the Palmer Long Term Ecological Research program. Demographic data will be collected in accordance with Standard Methods established by the Convention for the Conservation of Antarctic Marine Living Resources Ecosystem Monitoring Program and thus will be comparable with similar data sets being collected by other international Antarctic Treaty nation research programs. While separating human-induced change from change resulting from a combination of environmental factors will be difficult, this work will provide a first step to identify potential impacts. These long-term data sets will contribute to a better understanding of biological processes in the entire region and will contribute valuable information to be used by the Antarctic Treaty Parties as they address issues in environmental stewardship in Antarctica. | ["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))"] |
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))"] |
Occupation History and Diet of Adelie Penguins in the Ross Sea Region
|
0125098 |
2009-01-01 | Emslie, Steven |
Occupation History and Diet of Adelie Penguins in the Ross Sea Region |
This project will build on previous studies to investigate the occupation history and diet of Adelie penguins (Pygoscelis adeliae) in the Ross Sea region, Antarctica, with excavations of abandoned and active penguin colonies. Numerous active and abandoned colonies exist on the Victoria Land coast, from Cape Adare to Marble Point will be sampled. Some of these sites have been radiocarbon-dated and indicate a long occupation history for Adelie penguins extending to 13,000 years before present (B. P.). The material recovered from excavations, as demonstrated from previous investigations, will include penguin bones, tissue, and eggshell fragments as well as abundant remains of prey (fish bones, otoliths, squid beaks) preserved in ornithogenic (formed from bird guano) soils. These organic remains will be quantified and subjected to radiocarbon analyses to obtain a colonization history of penguins in this region. Identification of prey remains in the sediments will allow assessment of penguin diet. Other data (ancient DNA) from these sites will be analyzed through collaboration with New Zealand scientists. Past climatic conditions will be interpreted from published ice-core and marine-sediment records. These data will be used to test the hypothesis that Adelie penguins respond to climate change, past and present, in a predictable manner. In addition, the hypothesis that Adelie penguins alter their diet in accordance with climate, sea-ice conditions, and other marine environmental variables along a latitudinal gradient will be tested. Graduate and undergraduate students will be involved in this project and a project Web site will be developed to report results and maintain educational interaction between the PI and students at local middle and high schools in Wilmington, NC. | ["POLYGON((-50 -60,-29 -60,-8 -60,13 -60,34 -60,55 -60,76 -60,97 -60,118 -60,139 -60,160 -60,160 -63,160 -66,160 -69,160 -72,160 -75,160 -78,160 -81,160 -84,160 -87,160 -90,139 -90,118 -90,97 -90,76 -90,55 -90,34 -90,13 -90,-8 -90,-29 -90,-50 -90,-50 -87,-50 -84,-50 -81,-50 -78,-50 -75,-50 -72,-50 -69,-50 -66,-50 -63,-50 -60))"] |
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))"] |
Snow and Firn Permeability: Characteristics of Snow Megadunes and their Potential Effects on Ice Core Interpretation
|
0125276 |
2007-11-01 | Albert, Mary R.; Courville, Zoe; Cathles, Mac |
Collaborative Research: Characteristics of Snow Megadunes and Their Potential Effect on Ice Core Interpretation |
This data set contains firn physical properties measured in two meter snow pits and from deeper, 12- to 30-meter firn cores. The physical properties measured in the snow pits include density, permeability and microstructure (grain size and pore size). The physical properties measured on firn cores include density, permeability, diffusivity and microstructure. Data are available in Microsoft Excel format and ADOBE PDF and are available via FTP. | ["POLYGON((124.0218 -80.5304,124.22264 -80.5304,124.42348 -80.5304,124.62432 -80.5304,124.82516 -80.5304,125.026 -80.5304,125.22684 -80.5304,125.42768 -80.5304,125.62852 -80.5304,125.82936 -80.5304,126.0302 -80.5304,126.0302 -80.55538,126.0302 -80.58036,126.0302 -80.60534,126.0302 -80.63032,126.0302 -80.6553,126.0302 -80.68028,126.0302 -80.70526,126.0302 -80.73024,126.0302 -80.75522,126.0302 -80.7802,125.82936 -80.7802,125.62852 -80.7802,125.42768 -80.7802,125.22684 -80.7802,125.026 -80.7802,124.82516 -80.7802,124.62432 -80.7802,124.42348 -80.7802,124.22264 -80.7802,124.0218 -80.7802,124.0218 -80.75522,124.0218 -80.73024,124.0218 -80.70526,124.0218 -80.68028,124.0218 -80.6553,124.0218 -80.63032,124.0218 -80.60534,124.0218 -80.58036,124.0218 -80.55538,124.0218 -80.5304))"] |
AWS Data: Characteristics of Snow Megadunes and Their Potential Effect on Ice Core Interpretation
|
0225992 0125570 |
2006-10-05 | Fahnestock, Mark; Scambos, Ted; Haran, Terry; Bauer, Rob |
Collaborative Research: Characteristics of Snow Megadunes and Their Potential Effect on Ice Core Interpretation |
The Antarctic megadune research was conducted during two field seasons, one in November 2002 and the other during the period of December 2003 through January 2004. The megadune field site is located on the East Antarctic Plateau, southeast of Vostok station. The objectives of this multi-facetted research are 1) to determine the physical characteristics of the firn across the dunes including typical climate indicators such as stable isotopes and major chemical species and 2) to install instruments to measure the time variation of near-surface wind and temperature with depth, to test and refine hypotheses for megadune formation. It is important to improve our current understanding of the megadunes because of their extreme nature, their broad extent, and their potential impact on the climate record. Megadunes are a manifestation of an extreme terrestrial climate and may provide insight on the past terrestrial climate or on processes active on other planets. Snow megadunes are undulating variations in accumulation and surface texture with wavelengths of 2 to 5 km and amplitudes up to 5 meters. The features cover 500,000 km<sup>2</sup> of the East Antarctic plateau, occurring in areas of moderate regional slope and low accumulation on the flanks of the ice sheet between 2500 and 3800 meters elevation. Landsat images and aerial photography indicate the dunes consist of alternating surfaces of glaze and rough sastrugi, with gradational boundaries. This pattern is oriented perpendicular to the mean wind direction, as modeled in katabatic wind studies. Glazed surfaces cover the leeward faces and troughs; rough sastrugi cover the windward faces and crests. The megadune pattern is crossed by smooth to eroded wind-parallel longitudinal dunes. Wind-eroded longitudinal dunes form spectacular 1-meter-high sastrugi in nearby areas. This data set contains automated weather station (AWS) data from two sites. The Mac site was oriented on the rough sastrugi-covered windward face and the Zoe site was on the glazed leeward face. The AWSs collected data throughout the year from 16 January 2004 to 17 November 2004. Investigators received data from the two field sites via the ARGOS Satellite System (http://www.argosinc.com/). Data are provided in space-delimited ASCII text format and are available via FTP. | ["POLYGON((124.4345 -80.77546,124.443718 -80.77546,124.452936 -80.77546,124.462154 -80.77546,124.471372 -80.77546,124.48059 -80.77546,124.489808 -80.77546,124.499026 -80.77546,124.508244 -80.77546,124.517462 -80.77546,124.52668 -80.77546,124.52668 -80.776922,124.52668 -80.778384,124.52668 -80.779846,124.52668 -80.781308,124.52668 -80.78277,124.52668 -80.784232,124.52668 -80.785694,124.52668 -80.787156,124.52668 -80.788618,124.52668 -80.79008,124.517462 -80.79008,124.508244 -80.79008,124.499026 -80.79008,124.489808 -80.79008,124.48059 -80.79008,124.471372 -80.79008,124.462154 -80.79008,124.452936 -80.79008,124.443718 -80.79008,124.4345 -80.79008,124.4345 -80.788618,124.4345 -80.787156,124.4345 -80.785694,124.4345 -80.784232,124.4345 -80.78277,124.4345 -80.781308,124.4345 -80.779846,124.4345 -80.778384,124.4345 -80.776922,124.4345 -80.77546))"] |
GPR and GPS Data: Characteristics of Snow Megadunes and their Potential Effects on Ice Core Interpretation
|
0125276 |
2006-06-10 | Scambos, Ted; Bauer, Rob |
Collaborative Research: Characteristics of Snow Megadunes and Their Potential Effect on Ice Core Interpretation |
The Antarctic megadune research was conducted during two field seasons, one in November 2002 and the other in December 2003 through January 2004. The megadune field site is located on the East Antarctic Plateau, southeast of Vostok station. The objectives of this multi-facetted research are to determine the physical characteristics of the firn across the dunes including typical climate indicators such as stable isotopes and major chemical species and to install instruments to measure the time variation of near-surface wind and temperature with depth, to test and refine hypotheses for megadune formation. It is important to improve our current understanding of the megadunes because of their extreme nature, their broad extent, and their potential impact on the climate record. Megadunes are a manifestation of an extreme terrestrial climate and may provide insight on past terrestrial climate or on processes active on other planets. Snow megadunes are undulating variations in accumulation and surface texture with wavelengths of 2 to 5 km and amplitudes up to 5 meters. The features cover 500,000 km<sup>2</sup> of the East Antarctic plateau, occurring in areas of moderate regional slope and low accumulation on the flanks of the ice sheet between 2500 and 3800 meters elevation. Landsat images and aerial photography indicate the dunes consist of alternating surfaces of glaze and rough sastrugi, with gradational boundaries. This pattern is oriented perpendicular to the mean wind direction, as modeled in katabatic wind studies. Glaze surfaces cover the leeward faces and troughs; rough sastrugi cover the windward faces and crests. The megadune pattern is crossed by smooth to eroded wind-parallel longitudinal dunes. Wind-eroded longitudinal dunes form spectacular 1-meter-high sastrugi in nearby areas. This data set contains ground penetrating radar (GPR) data showing surface morphology and internal layering structure along with global positioning system (GPS) data collected within an area of 60 km<sup>2</sup>. GPS data are provided in space-delimited ASCII text Microsoft Excel formats, while GPR data are in JPEG format. Data are available via FTP. | ["POLYGON((124.0218 -80.5304,124.22264 -80.5304,124.42348 -80.5304,124.62432 -80.5304,124.82516 -80.5304,125.026 -80.5304,125.22684 -80.5304,125.42768 -80.5304,125.62852 -80.5304,125.82936 -80.5304,126.0302 -80.5304,126.0302 -80.55538,126.0302 -80.58036,126.0302 -80.60534,126.0302 -80.63032,126.0302 -80.6553,126.0302 -80.68028,126.0302 -80.70526,126.0302 -80.73024,126.0302 -80.75522,126.0302 -80.7802,125.82936 -80.7802,125.62852 -80.7802,125.42768 -80.7802,125.22684 -80.7802,125.026 -80.7802,124.82516 -80.7802,124.62432 -80.7802,124.42348 -80.7802,124.22264 -80.7802,124.0218 -80.7802,124.0218 -80.75522,124.0218 -80.73024,124.0218 -80.70526,124.0218 -80.68028,124.0218 -80.6553,124.0218 -80.63032,124.0218 -80.60534,124.0218 -80.58036,124.0218 -80.55538,124.0218 -80.5304))"] |
Ross Ice Drainage System (RIDS) Glaciochemical Analysis
|
9316564 |
2005-05-09 | Mayewski, Paul A.; Kreutz, Karl; Twickler, Mark; Whitlow, Sallie; Meeker, Loren D. |
Ross Ice Drainage System (RIDS) Late Holocene Climate Variability |
The Ross Ice Drainage System (RIDS) project provides a high-resolution record of atmospheric chemical deposition taken from several ice cores and snow pits located at sites within or immediately adjacent to the Ross Ice Drainage System. Three sites were visited during a 1995 traverse in inland West Antarctica. The traverse was 158 km, trending 26° from Byrd Surface Camp. The core from site A (78°44'S, 116°20'W) is 148 m deep, the core from site B (79°27.66'S, 118°02.68'W) is 60 m deep, and the core from site C (80°00.85'S, 119°33.73'W) is 60 m deep. Glaciochemical analysis focuses on the major ions deposited from the antarctic atmosphere, including Na (sodium), NH4 (ammonium), K (potassium), Mg (magnesium), Ca (calcium), Cl (chloride), NO3 (nitrate), and SO4 (sulfate). Chemical analysis also includes methanesulfonic acid (MSA) and nssSO4 (non-sea salt sulfate). The data are available by FTP in ASCII text format and Excel files. | ["POINT(-118.045 -79.461)", "POINT(-116.333 -78.733)", "POINT(-119.562 -80.014)"] |
Antarctic Aerogeophysics Data
|
9911617 9120464 9319369 9319379 |
2004-07-13 | Blankenship, Donald D.; Morse, David L.; Holt, John W.; Dalziel, Ian W. |
Continuation of Activities for the Support Office for Aerogeophysical Research (SOAR) |
The data that the Support Office for Aerogeophysical Research (SOAR) provides include various aerogeophysical measurements taken in the West Antarctic Ice Shelf (WAIS) from 1994 to 2001. The instruments used in experiments include ice-penetrating radar, laser altimetry and magnetics, and an integrated aerogeophysical platform that includes airborne gravity with carrier-phase GPS to support kinematic differential positioning. SOAR is a part of the University of Texas Institute for Geophysics (UTIG) and provides several types of data associated with various campaigns over the years. This material is based on work supported by the National Science Foundation under Grants: OPP-9120464, 9319369, 9319379, and 9911617. | ["POLYGON((-90 -68.73,-72 -68.73,-54 -68.73,-36 -68.73,-18 -68.73,0 -68.73,18 -68.73,36 -68.73,54 -68.73,72 -68.73,90 -68.73,90 -69.357,90 -69.984,90 -70.611,90 -71.238,90 -71.865,90 -72.492,90 -73.119,90 -73.746,90 -74.373,90 -75,72 -75,54 -75,36 -75,18 -75,0 -75,-18 -75,-36 -75,-54 -75,-72 -75,-90 -75,-90 -74.373,-90 -73.746,-90 -73.119,-90 -72.492,-90 -71.865,-90 -71.238,-90 -70.611,-90 -69.984,-90 -69.357,-90 -68.73))"] |
Ice Thickness and Surface Elevation, Southeastern Ross Embayment, West Antarctica
|
8919147 |
2004-03-17 | Blankenship, Donald D.; Finn, C. A.; Morse, David L.; Bell, R. E.; Peters, M. E.; Kempf, Scott D.; Hodge, S. M.; Behrendt, J. C.; Brozena, J. M.; Studinger, Michael S. |
Corridor Aerogeophysics of the Southeastern Ross Transect Zone (CASERTZ), Antarctica |
Ice surface elevation and ice thickness data are available for a portion of the West Antarctic Ice Sheet. The investigators utilized a laser altimeter and ice-penetrating radar mounted to a Twin Otter aircraft to survey the ice sheet. Ice surface elevations and ice thickness data, derived from laser altimetry and radar sounding results, are available in ASCII format via ftp. These data are a result of the Corridor Aerogeophysics of the Southeastern Ross Transect Zone (CASERTZ) experiments of the 1990s. The CASERTZ geophysical surveys were aimed at understanding geological controls on ice streams of the West Antarctic Ice Sheet, ultimately to help assess the potential for ice sheet collapse. Blankenship et al. (2001) used ice surface elevations and ice thicknesses (reported here) to calculate driving stresses across the ice sheet and thus to identify regions of rapid basal movement by ice streams. | ["POLYGON((-134 -80,-131 -80,-128 -80,-125 -80,-122 -80,-119 -80,-116 -80,-113 -80,-110 -80,-107 -80,-104 -80,-104 -80.4,-104 -80.8,-104 -81.2,-104 -81.6,-104 -82,-104 -82.4,-104 -82.8,-104 -83.2,-104 -83.6,-104 -84,-107 -84,-110 -84,-113 -84,-116 -84,-119 -84,-122 -84,-125 -84,-128 -84,-131 -84,-134 -84,-134 -83.6,-134 -83.2,-134 -82.8,-134 -82.4,-134 -82,-134 -81.6,-134 -81.2,-134 -80.8,-134 -80.4,-134 -80))"] |
Central West Antarctic Glaciochemistry from Ice Cores
|
None | 2003-10-16 | Reusch, David | No project link provided | Glaciochemical and accumulation rate records developed from four ice cores in central West Antarctica are used to reconstruct former atmospheric circulation patterns in this region for the last 40 years with extended records (150-250 years) at two sites. The sites lie on a 200 km traverse from 82 degrees 22 minutes south, 119 degrees 17 minutes west to 81 degrees 22 minutes south, 107 degrees 17 minutes west, gaining elevation from 950 to 1930 m. The glaciochemical records represent the major ionic species present in Antarctic snow: sodium, potassium, magnesium, calcium, chloride, nitrate, and sulfate. | ["POLYGON((-120 -80,-118.5 -80,-117 -80,-115.5 -80,-114 -80,-112.5 -80,-111 -80,-109.5 -80,-108 -80,-106.5 -80,-105 -80,-105 -80.5,-105 -81,-105 -81.5,-105 -82,-105 -82.5,-105 -83,-105 -83.5,-105 -84,-105 -84.5,-105 -85,-106.5 -85,-108 -85,-109.5 -85,-111 -85,-112.5 -85,-114 -85,-115.5 -85,-117 -85,-118.5 -85,-120 -85,-120 -84.5,-120 -84,-120 -83.5,-120 -83,-120 -82.5,-120 -82,-120 -81.5,-120 -81,-120 -80.5,-120 -80))"] |
Antarctic Oscillation (AO) Time Series Data since 1948 from JISAO
|
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/ | [] |
Ice Velocity Data from Ice Stream C, West Antarctica
|
9222121 9318121 |
2001-12-01 | Anandakrishnan, Sridhar |
Microearthquake Monitoring of Ice Stream C, West Antarctica: A Sensor for Sticky Spots |
Ice velocity data from ice stream C, including the body of the ice stream and its area of onset, are available. The investigator calculated velocities from precise ice displacement measurements made with a geodetic-quality Global Positioning System (GPS). These ice displacement measurements accompanied seismic experiments aimed at understanding controls on the flow of ice streams in west Antarctica. An understanding of ice stream flow is essential to predicting the response of the West Antarctic Ice Sheet to future climate change. Data are available in ASCII format via ftp. | ["POLYGON((-121.644 -82.2764,-121.4814 -82.2764,-121.3188 -82.2764,-121.1562 -82.2764,-120.9936 -82.2764,-120.831 -82.2764,-120.6684 -82.2764,-120.5058 -82.2764,-120.3432 -82.2764,-120.1806 -82.2764,-120.018 -82.2764,-120.018 -82.28496,-120.018 -82.29352,-120.018 -82.30208,-120.018 -82.31064,-120.018 -82.3192,-120.018 -82.32776,-120.018 -82.33632,-120.018 -82.34488,-120.018 -82.35344,-120.018 -82.362,-120.1806 -82.362,-120.3432 -82.362,-120.5058 -82.362,-120.6684 -82.362,-120.831 -82.362,-120.9936 -82.362,-121.1562 -82.362,-121.3188 -82.362,-121.4814 -82.362,-121.644 -82.362,-121.644 -82.35344,-121.644 -82.34488,-121.644 -82.33632,-121.644 -82.32776,-121.644 -82.3192,-121.644 -82.31064,-121.644 -82.30208,-121.644 -82.29352,-121.644 -82.28496,-121.644 -82.2764))", "POLYGON((-152.598 -81.8039,-149.8369 -81.8039,-147.0758 -81.8039,-144.3147 -81.8039,-141.5536 -81.8039,-138.7925 -81.8039,-136.0314 -81.8039,-133.2703 -81.8039,-130.5092 -81.8039,-127.7481 -81.8039,-124.987 -81.8039,-124.987 -81.90464,-124.987 -82.00538,-124.987 -82.10612,-124.987 -82.20686,-124.987 -82.3076,-124.987 -82.40834,-124.987 -82.50908,-124.987 -82.60982,-124.987 -82.71056,-124.987 -82.8113,-127.7481 -82.8113,-130.5092 -82.8113,-133.2703 -82.8113,-136.0314 -82.8113,-138.7925 -82.8113,-141.5536 -82.8113,-144.3147 -82.8113,-147.0758 -82.8113,-149.8369 -82.8113,-152.598 -82.8113,-152.598 -82.71056,-152.598 -82.60982,-152.598 -82.50908,-152.598 -82.40834,-152.598 -82.3076,-152.598 -82.20686,-152.598 -82.10612,-152.598 -82.00538,-152.598 -81.90464,-152.598 -81.8039))"] |
Siple Dome Glaciology and Ice Stream History 1994, 1996
|
9316338 |
1999-01-01 | Jacobel, Robert |
Siple Dome Glaciology and Ice Stream History |
The Siple Dome Glaciology and Ice Stream History project was part of Western Divide West Antarctic Ice Cores (WAISCORES), an NSF-funded project to understand the influence of the West Antarctic ice sheet on climate and sea level change. WAISCORES researchers acquired and analyzed ice cores from the Siple Dome, in the Siple Coast region, West Antarctica. This project supported glaciological studies of Siple Dome and its surroundings between Ice Streams C and D, via two major goals. First, it sought to characterize the dynamic environment and ice stratigraphy of Siple Dome and its surroundings, with the specific mission of assessing Siple Dome as a potential deep core site; and second, to determine whether the configuration of ice stream flow in the region has changed over time. Both goals are relevant to understanding the dynamics of the West Antarctic Ice Sheet (WAIS), its history, and potential future behavior. This project was a collaboration between Saint Olaf College, the University of Washington, and the National Snow and Ice Data Center at the University of Colorado. It included studies of satellite imagery and acquisition and analysis of field data from GPS, firn cores and snow pits, and ground-based ice-penetrating radar. Data in this collection were obtained during two Antarctic field seasons in 1994–95 and 1996–97. The data set is available via FTP as Microsoft Excel Spreadsheet (.xls) and ASCII tab delimited (.txt) files. Related notes are available as a Microsoft Word (.doc) or text (.txt) file. Related images and charts are available as Graphics Interchange Format (.gif) and Joint Photographic Experts Group (.jpg) files. | ["POLYGON((-155 -81,-154 -81,-153 -81,-152 -81,-151 -81,-150 -81,-149 -81,-148 -81,-147 -81,-146 -81,-145 -81,-145 -81.2,-145 -81.4,-145 -81.6,-145 -81.8,-145 -82,-145 -82.2,-145 -82.4,-145 -82.6,-145 -82.8,-145 -83,-146 -83,-147 -83,-148 -83,-149 -83,-150 -83,-151 -83,-152 -83,-153 -83,-154 -83,-155 -83,-155 -82.8,-155 -82.6,-155 -82.4,-155 -82.2,-155 -82,-155 -81.8,-155 -81.6,-155 -81.4,-155 -81.2,-155 -81))"] |