scholarly journals Subglacial hydrological connectivity within the Byrd Glacier catchment, East Antarctica

2014 ◽  
Vol 60 (220) ◽  
pp. 345-352 ◽  
Author(s):  
A.P. Wright ◽  
D.A. Young ◽  
J.L. Bamber ◽  
J.A. Dowdeswell ◽  
A.J. Payne ◽  
...  
Keyword(s):  
East Antarctica ◽  
Laser Altimetry ◽  
Ice Cloud ◽  
Ice Surface ◽  
New Radio ◽  
Radio Echo Sounding ◽  
Hydraulic Gradients ◽  
Height Change ◽  
Subglacial Lakes ◽  
Along Track

AbstractIce, Cloud and land Elevation Satellite (ICESat) repeat-track laser altimetry has identified 17 sites within the Byrd Glacier catchment, East Antarctica, where rapid ice-surface height changes have occurred, which have been interpreted as evidence for ‘active’ subglacial lakes. Here we present evidence from a new radio-echo sounding (RES) survey at 11 of these locations to understand the bed conditions associated with the proposed hydrological activity. At none of the sites examined did we find evidence in support of substantial pooled basal water. In the majority of cases, along-track RES bed reflection amplitudes either side of the locations of surface height change are indistinguishable from those within the features. These results indicate that, in most cases, hypothesized ‘active’ lakes are not discrete radar targets and are therefore much smaller than the areas of surface height change. In addition, we have identified three new relatively large subglacial lakes upstream of the region where most ‘active’ subglacial lakes are found, in an area where the hydraulic gradient is significantly lower. Our results suggest that substantial and long-lasting basal water storage in the Byrd Glacier catchment occurs only under low hydraulic gradients, while coast-proximal sites of hydraulic activity likely involve small or temporary accumulations of basal water.

scholarly journals Determining basal ice-sheet conditions in the Dome C region of East Antarctica using satellite radar altimetry and airborne radio-echo sounding

1998 ◽  
Vol 44 (146) ◽  
pp. 1-8 ◽  
Author(s):  
Martin J. Siegert ◽  
Jeffrey K. Ridley
Keyword(s):  
Ice Sheet ◽  
East Antarctica ◽  
Radar Altimetry ◽  
Sheet Surface ◽  
Ice Surface ◽  
Radio Echo Sounding ◽  
Satellite Radar ◽  
Subglacial Lakes ◽  
Water Saturated ◽  
Satellite Radar Altimetry

AbstractLarge subglacial lakes manifest themselves as flat regions on the ice surface. ERS-1 satellite radar altimetry of the Dome C region of East Antarctica was analyzed to correlate unusually flat areas on the ice surface with known locations of subglacial lakes identified from airborne radio-echo sounding (RES) data. The mean length of subglacial lakes which have an expression in the ice-sheet surface was ~8.3 km, whilst those that did not exhibit a surface morphological manifestation had a mean length of ~3.3 km. Thus, lakes up to about 4 km in length arc unlikely to be detected from satellite radar altimetry of the ice surface. Given that the spacing of radio-echo flight tracks within the SPRI-NSF-TUD Antarctic database is 50-100 km in many areas, a number of subglacial lakes probably lie undetected beneath the ice sheet. RES information from two large, flat surface regions within Dome C, and a further flat area located at 80° S, 127° E, indicates the absence of subglacial lakes beneath the ice-surface features. However, these areas are characterised by relatively strong radio-echo returns which may indicate the presence of water-saturated basal sediments. We suggest that (1) blankets of water-saturated basal sediments may cause similar surface morphological features to those produced by subglacial lakes; and (2) misidentification of subglacial lakes from satellite altimeter observations of the ice-sheet surface is possible without the support of RES information relating to the ice-sheet base. Furthermore, our study indicates a lack of subglacial lake signals from RES data over relatively thick regions of East Antarctica such as the Adventure Subglacial Trough. We conclude that subglacial water produced in such regions may be transported by a basal hydrological system, driven by overburden pressure, to less thick regions of the ice sheet where subglacial lakes have been identified.

scholarly journals Active lakes of Recovery Ice Stream, East Antarctica: a bedrock-controlled subglacial hydrological system

2014 ◽  
Vol 60 (223) ◽  
pp. 1015-1030 ◽  
Author(s):  
Helen Amanda Fricker ◽  
Sasha P. Carter ◽  
Robin E. Bell ◽  
Ted Scambos
Keyword(s):  
East Antarctica ◽  
Water Model ◽  
Laser Altimetry ◽  
Main Trunk ◽  
Image Differencing ◽  
Ice Stream ◽  
Hydrologic Connections ◽  
Radio Echo Sounding ◽  
Hydrological System ◽  
Subglacial Lakes

AbstractA connected system of active subglacial lakes was revealed beneath Recovery Ice Stream, East Antarctica, by ICESat laser altimetry. Here we combine repeat-track analysis of ICESat (2003–09), Operation IceBridge laser altimetry and radio-echo sounding (2011 and 2012), and MODIS image differencing (2009–2011) to learn more about the lake activity history, the surface and bedrock topographic setting of the lakes and the constraints on water flow through the system. We extend the lake activity time series to 2012 for the three lower lakes and capture two major lake drainages. One lake underwent a large deflation between 2009 and 2011 while another lake, which had been continuously filling between 2003 and 2010, started to drain after 2011. Most of the active lakes are located in a ~ 1000 km long bedrock trough under the main trunk of Recovery Ice Stream, whose base is ~ 1500– 2000 m below present-day sea level. The hydrologic system beneath Recovery Ice Stream is controlled by this unusually pronounced bedrock topography, in contrast to most Antarctic systems studied to date, which are controlled by the ice surface topography. Hydrologic connections among the lakes appear to be direct and responsive, and we reproduce the lake activity using a simple subglacial water model. We discuss potential causes of non-steady hydrologic behavior in major Antarctic catchments.

scholarly journals Determining basal ice-sheet conditions in the Dome C region of East Antarctica using satellite radar altimetry and airborne radio-echo sounding

1998 ◽  
Vol 44 (146) ◽  
pp. 1-8 ◽  
Author(s):  
Martin J. Siegert ◽  
Jeffrey K. Ridley
Keyword(s):  
Ice Sheet ◽  
East Antarctica ◽  
Radar Altimetry ◽  
Sheet Surface ◽  
Ice Surface ◽  
Radio Echo Sounding ◽  
Satellite Radar ◽  
Subglacial Lakes ◽  
Water Saturated ◽  
Satellite Radar Altimetry

AbstractLarge subglacial lakes manifest themselves as flat regions on the ice surface. ERS-1 satellite radar altimetry of the Dome C region of East Antarctica was analyzed to correlate unusually flat areas on the ice surface with known locations of subglacial lakes identified from airborne radio-echo sounding (RES) data. The mean length of subglacial lakes which have an expression in the ice-sheet surface was ~8.3 km, whilst those that did not exhibit a surface morphological manifestation had a mean length of ~3.3 km. Thus, lakes up to about 4 km in length arc unlikely to be detected from satellite radar altimetry of the ice surface. Given that the spacing of radio-echo flight tracks within the SPRI-NSF-TUD Antarctic database is 50-100 km in many areas, a number of subglacial lakes probably lie undetected beneath the ice sheet. RES information from two large, flat surface regions within Dome C, and a further flat area located at 80° S, 127° E, indicates the absence of subglacial lakes beneath the ice-surface features. However, these areas are characterised by relatively strong radio-echo returns which may indicate the presence of water-saturated basal sediments. We suggest that (1) blankets of water-saturated basal sediments may cause similar surface morphological features to those produced by subglacial lakes; and (2) misidentification of subglacial lakes from satellite altimeter observations of the ice-sheet surface is possible without the support of RES information relating to the ice-sheet base. Furthermore, our study indicates a lack of subglacial lake signals from RES data over relatively thick regions of East Antarctica such as the Adventure Subglacial Trough. We conclude that subglacial water produced in such regions may be transported by a basal hydrological system, driven by overburden pressure, to less thick regions of the ice sheet where subglacial lakes have been identified.

scholarly journals Forty-seven new subglacial lakes in the 0–110° E sector of East Antarctica

2007 ◽  
Vol 53 (181) ◽  
pp. 289-297 ◽  
Author(s):  
Sergey V. Popov ◽  
Valery N. Masolov
Keyword(s):  
Heat Flux ◽  
Scientific Work ◽  
East Antarctica ◽  
Lake Area ◽  
Geothermal Heat ◽  
Subglacial Lake ◽  
Deep Faults ◽  
Radio Echo Sounding ◽  
Subglacial Lakes ◽  
Echo Sounding

AbstractDuring the summer field seasons of 1987–91, studies of central East Antarctica by airborne radio-echo sounding commenced. This scientific work continued in the 1990s in the Vostok Subglacial Lake area and along the traverse route from Mirny, and led to the discovery of 16 new subglacial water cavities in the areas of Domes Fuji and Argus and the Prince Charles Mountains. Twenty-nine subglacial water cavities were revealed in the area near Vostok, along with a feature we believe to be a subglacial river. Two subglacial lakes were discovered along the Mirny–Vostok traverse route. These are located 50 km north of Komsomolskaya station and under Pionerskaya station. We find high geothermal heat flux in the vicinity of the largest of the subglacial lakes, and suggest this may be due to their location over deep faults where additional mantle heat is available.

scholarly journals Ice-Sheet flow in the Vicinity of Southern Victoria Land, Antarctica: Implications for Glacial Chronology

1979 ◽  
Vol 24 (90) ◽  
pp. 483
Author(s):  
David J. Drewry
Keyword(s):  
Ice Sheet ◽  
East Antarctica ◽  
Small Surface ◽  
The North ◽  
Ice Surface ◽  
Glacial Chronology ◽  
Victoria Land ◽  
Dry Valley ◽  
Radio Echo Sounding ◽  
Taylor Glacier

Abstract Systematic radio echo-sounding during three seasons since 1971–72 has produced data on the configuration of the ice sheet in East Antarctica. In the sector extending inland from southern Victoria Land, the ice sheet exhibits a large ridge which drives ice towards David Glacier in the north and Mulock and Byrd Glaciers to the south. Within 100 km of the McMurdo dry-valley region soundings along ten sub-parallel lines (c. 10 km apart) provides detail on ice surface and flow patterns at the ridge tip. A small surface dome lies just inland of Taylor Glacier. The surface drops by 100 m or more before rising to join the major ridge in East Antarctica.

scholarly journals A revised inventory of Antarctic subglacial lakes

2005 ◽  
Vol 17 (3) ◽  
pp. 453-460 ◽  
Author(s):  
MARTIN J. SIEGERT ◽  
SASHA CARTER ◽  
IGNAZIO TABACCO ◽  
SERGEY POPOV ◽  
DONALD D. BLANKENSHIP
Keyword(s):  
East Antarctica ◽  
Large Lake ◽  
Dome A ◽  
Lake Vostok ◽  
The Third ◽  
The Us ◽  
Radio Echo Sounding ◽  
Subglacial Lakes ◽  
Lake Type ◽  
Echo Sounding

The locations and details of 145 Antarctic subglacial lakes are presented. The inventory is based on a former catalogue of lake-type features, which has been subsequently reanalysed, and on the results from three additional datasets. The first is from Italian radio-echo sounding (RES) of the Dome C region of East Antarctica, from which 14 new lakes are identified. These data also show that, in a number of occasions, multiple lake-type reflectors thought previously to be individual lakes are in fact reflections from the same relatively large lake. This reduces the former total of lake-type reflectors by six, but also adds a significant level of information to these particular lakes. The second dataset is from a Russian survey of the Dome A and Dome F regions of East Antarctica, which provides evidence of 18 new lakes and extends the coverage of the inventory considerably. The third dataset comprises three airborne RES surveys undertaken by the US in East Antarctica over the last five years, from which forty three new lakes have been identified. Reference to information on Lake Vostok, from Italian and US surveys taken in the last few years, is now included.

Ice-Sheet flow in the Vicinity of Southern Victoria Land, Antarctica: Implications for Glacial Chronology

1979 ◽  
Vol 24 (90) ◽  
pp. 483-483
Author(s):  
David J. Drewry
Keyword(s):  
Ice Sheet ◽  
East Antarctica ◽  
Small Surface ◽  
The North ◽  
Ice Surface ◽  
Glacial Chronology ◽  
Victoria Land ◽  
Dry Valley ◽  
Radio Echo Sounding ◽  
Taylor Glacier

AbstractSystematic radio echo-sounding during three seasons since 1971–72 has produced data on the configuration of the ice sheet in East Antarctica. In the sector extending inland from southern Victoria Land, the ice sheet exhibits a large ridge which drives ice towards David Glacier in the north and Mulock and Byrd Glaciers to the south. Within 100 km of the McMurdo dry-valley region soundings along ten sub-parallel lines (c. 10 km apart) provides detail on ice surface and flow patterns at the ridge tip. A small surface dome lies just inland of Taylor Glacier. The surface drops by 100 m or more before rising to join the major ridge in East Antarctica.

scholarly journals Assessing the subglacial lake coverage of Antarctica

2016 ◽  
Vol 57 (72) ◽  
pp. 109-117 ◽  
Author(s):  
Sebastian Goeller ◽  
Daniel Steinhage ◽  
Malte Thoma ◽  
Klaus Grosfeld
Keyword(s):  
Remote Sensing ◽  
East Antarctica ◽  
Ice Dynamics ◽  
Potential Equation ◽  
Subglacial Lake ◽  
Covered Area ◽  
Radio Echo Sounding ◽  
Dronning Maud Land ◽  
Subglacial Lakes ◽  
The Antarctic

ABSTRACTLakes beneath the Antarctic Ice Sheet are known to decrease traction at the ice base and therefore can have a great impact on ice dynamics. However, the total extent of Antarctic subglacial lakes is still unknown. We address this issue by combining modeling and remote-sensing strategies to predict potential lake locations using the general hydraulic potential equation. We are able to reproduce the majority of known lakes, as well as predict the existence of many new and so far undetected potential lakes. To validate our predictions, we analyzed ice-penetrating radar profiles from radio-echo sounding flights acquired over 1994–2013 in Dronning Maud Land, East Antarctica, and this led to the identification of 31 new subglacial lakes. Based on these findings, we estimate the total number of Antarctic subglacial lakes to be ~1300, a factor of three higher than the total number of lakes discovered to date. We estimate that only ~30% of all Antarctic subglacial lakes and ~65% of the total estimated lake-covered area have been discovered, and that lakes account for 0.6% of the Antarctic ice/bed interface.

scholarly journals Recent advances in understanding Antarctic subglacial lakes and hydrology

2016 ◽  
Vol 374 (2059) ◽  
pp. 20140306 ◽  
Author(s):  
Martin J. Siegert ◽  
Neil Ross ◽  
Anne M. Le Brocq
Keyword(s):  
Large Scale ◽  
Ice Sheet ◽  
Satellite Observation ◽  
Hydrological Processes ◽  
Lake Vostok ◽  
Ice Surface ◽  
Recent Advances ◽  
Radio Echo Sounding ◽  
Subglacial Lakes ◽  
Bodies Of Water

It is now well documented that over 400 subglacial lakes exist across the bed of the Antarctic Ice Sheet. They comprise a variety of sizes and volumes (from the approx. 250 km long Lake Vostok to bodies of water less than 1 km in length), relate to a number of discrete topographic settings (from those contained within valleys to lakes that reside in broad flat terrain) and exhibit a range of dynamic behaviours (from ‘active’ lakes that periodically outburst some or all of their water to those isolated hydrologically for millions of years). Here we critique recent advances in our understanding of subglacial lakes, in particular since the last inventory in 2012. We show that within 3 years our knowledge of the hydrological processes at the ice-sheet base has advanced considerably. We describe evidence for further ‘active’ subglacial lakes, based on satellite observation of ice-surface changes, and discuss why detection of many ‘active’ lakes is not resolved in traditional radio-echo sounding methods. We go on to review evidence for large-scale subglacial water flow in Antarctica, including the discovery of ancient channels developed by former hydrological processes. We end by predicting areas where future discoveries may be possible, including the detection, measurement and significance of groundwater (i.e. water held beneath the ice-bed interface).

scholarly journals Bed topography of Princess Elizabeth Land in East Antarctica

2020 ◽  
Author(s):  
Xiangbin Cui ◽  
Hafeez Jeofry ◽  
Jamin S. Greenbaum ◽  
Jingxue Guo ◽  
Lin Li ◽  
...  
Keyword(s):  
Gravity Data ◽  
Mass Conservation ◽  
East Antarctica ◽  
Ice Thickness ◽  
Surface Model ◽  
Hydraulic Pressure ◽  
Satellite Gravity ◽  
Free Zone ◽  
Ice Surface ◽  
Radio Echo Sounding

Abstract. We present a topographic digital elevation model (DEM) for Princess Elizabeth Land (PEL), East Antarctica – the last remaining region in Antarctica to be surveyed by airborne radio-echo sounding (RES) techniques. The DEM covers an area of ~900,000 km2 and was established from new RES data collected by the ICECAP-2 consortium, led by the Polar Research Institute of China, from four campaigns since 2015. Previously, the region (along with Recovery basin elsewhere in East Antarctica) was characterised by an inversion using low resolution satellite gravity data across a large (>200 km wide) data-free zone to generate the Bedmap2 topographic product. We use the mass conservation (MC) method to produce an ice thickness grid across faster-flowing (>30 m yr-1) regions of the ice sheet and streamline diffusion in slower-flowing areas. The resulting ice thickness model is integrated with an ice surface model to build the bed DEM. With the revised bed DEM, we are able to model the flow of subglacial water and assess where the hydraulic pressure, and hydrological routing, is most sensitive to small ice-surface gradient changes. Together with BedMachine Antarctica, and Bedmap2, this new PEL bed DEM completes the first order measurement of subglacial continental Antarctica – an international mission that began around 70 years ago. The ice thickness and bed elevation DEMs of PEL (resolved horizontally at 500 m relative to ice surface elevations obtained from a combination of European Remote Sensing Satellite 1 radar (ERS-1) and Ice, Cloud and Land Elevation Satellite (ICESat) laser satellite altimetry datasets) are accessible from https://doi.org/10.5281/zenodo.3666088 (Cui et 38al., 2020).

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