scholarly journals Lakes and subglacial hydrological networks around Dome C, East Antarctica

2003 ◽  
Vol 37 ◽  
pp. 252-256 ◽  
Author(s):  
Frédérique Rémy ◽  
Laurent Testut ◽  
Benoît Legrésy ◽  
Alessandro Forieri ◽  
Cesido Bianchi ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Flow Regime ◽  
Flow Dynamics ◽  
Ice Flow ◽  
Subglacial Lake ◽  
Radio Echo Sounding ◽  
Fine Structures ◽  
Satellite Radar ◽  
Subglacial Lakes ◽  
Satellite Radar Altimetry

AbstractPrecise topography from European Remote-sensing Satellite radar altimetry and high density of airborne radio-echo sounding in the area surrounding Dome C, Antarctica, show a link between surface features and subglacial lakes. In this paper, we extend the study to fine structures by computing a curvature-based coefficient (cy) related to surface undulations. These coefficient variations reveal many surface undulations, and some elongated features of this parameter seem to link known subglacial lakes. A population of high values of this coefficient, assumed to correspond to transitions between sliding and non-sliding flow regime, strengthen the appearance of a network which would link most of the lakes in the area. The existence of such a network impacts on ice-flow dynamics and on subglacial-lake studies.

scholarly journals Detecting and Searching for subglacial lakes through airborne radio-echo sounding in Princess Elizabeth Land (PEL), Antarctica

2020 ◽  
Vol 163 ◽  
pp. 04002
Author(s):  
Xiangbin Cui ◽  
Shinan Lang ◽  
Jingxue Guo ◽  
Bo Sun
Keyword(s):  
Remote Sensing ◽  
Ice Sheet ◽  
Extreme Environment ◽  
Ice Flow ◽  
Preliminary Results ◽  
Lake Vostok ◽  
Subglacial Lake ◽  
Radio Echo Sounding ◽  
Subglacial Lakes ◽  
Echo Sounding

Over 400 subglacial lakes were discovered in Antarctica through radio-echo sounding (RES) method and remote sensing. Subglacial lakes have significance in lubricating ice-bedrock interface and enhancing ice flow. Moreover, ancient lives may exist in the extreme environment. Since 2015, the “Snow Eagle 601” BT-67 airborne platform has been deployed and applied to map ice sheet and bedrock of Princess Elizabeth Land. One of great motivations of airborne surveys is to detect and search for subglacial lakes in the region. In this paper, we provided preliminary results of RES over both old and new discovered lakes, including Lake Vostok, a potential second large subglacial lake and other lakes beneath interior of the ice sheet in Antarctica.

scholarly journals Subglacial hydrological networks in Antarctica and their impact on ice flow

2004 ◽  
Vol 39 ◽  
pp. 67-72 ◽  
Author(s):  
Frédérique Remy ◽  
Benoît Legresy
Keyword(s):  
Remote Sensing ◽  
Ice Flow ◽  
Elevation Data ◽  
Antarctic Continent ◽  
Satellite Radar ◽  
Basal Melting ◽  
The Antarctic ◽  
Satellite Radar Altimetry ◽  
East West ◽  
Geothermal Flux

AbstractDeep beneath the thick ice cover of the Antarctic continent there exist subglacial hydrological networks, within which basal meltwater can flow. In this paper, we use surface elevation data from European Remote-sensing Satellite radar altimetry to map these subglacial hydrological networks for the whole continent. We observe a confused pattern of subglacial systems, linking regions where basal melting takes place. In some regions, channels can be followed over some hundreds of kilometres. Some of these meet the ice-sheet margin, suggesting that meltwater can be transported all the way to the ocean. We observe an east–west gradient in the distribution of hydrological networks that could be explained by the geothermal flux pattern.

scholarly journals Synthesizing multiple remote-sensing techniques for subglacial hydrologic mapping: application to a lake system beneath MacAyeal Ice Stream, West Antarctica

2010 ◽  
Vol 56 (196) ◽  
pp. 187-199 ◽  
Author(s):  
Helen Amanda Fricker ◽  
Ted Scambos ◽  
Sasha Carter ◽  
Curt Davis ◽  
Terry Haran ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Water Movement ◽  
Satellite Image ◽  
West Antarctica ◽  
Basal Resistance ◽  
Ice Stream ◽  
Radio Echo Sounding ◽  
Satellite Radar ◽  
Remote Sensing Techniques ◽  
Subglacial Lakes

AbstractWe present an analysis of the active hydrologic system of MacAyeal Ice Stream (MacIS), West Antarctica, from a synthesis of multiple remote-sensing techniques: satellite laser altimetry; satellite image differencing; and hydrologic potential mapping (using a satellite-derived DEM and a bedrock DEM from airborne radio-echo sounding). Combining these techniques augments the information provided by each one individually, and allows us to develop a protocol for studying subglacial hydrologic systems in a holistic manner. Our study reveals five large active subglacial lakes under MacIS, the largest of which undergoes volume changes of at least 1.0 km3. We discuss the hydrologic properties of this system and present evidence for links between the lakes. At least three of the lakes are co-located with sticky spots, i.e. regions of high local basal shear stress. We also find evidence for surface elevation changes due to ice-dynamic effects (not just water movement) caused by changes in basal resistance. Lastly, we show that satellite radar altimetry is of limited use for monitoring lake activity on fast-flowing ice streams with surfaces that undulate on ∼10 km length scales.

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 Influence of tides and tidal current on Mertz Glacier, Antarctica

2004 ◽  
Vol 50 (170) ◽  
pp. 427-435 ◽  
Author(s):  
Benoît Legrésy ◽  
Anja Wendt ◽  
Ignazio Tabacco ◽  
Frédérique Rémy ◽  
Reinhard Dietrich
Keyword(s):  
Boundary Conditions ◽  
Tidal Current ◽  
Ice Flow ◽  
Radio Echo Sounding ◽  
Radar Imagery ◽  
Sea Level Variations ◽  
Induced Currents ◽  
Satellite Radar ◽  
Satellite Radar Altimetry

AbstractMertz Glacier, East Antarctica, is characterized by a 140 km long, 25 km wide floating ice tongue. In this paper, we combine a large number of remotely sensed datasets, including in situ global positioning system measurements, satellite radar altimetry, airborne radio-echo sounding and satellite synthetic aperture radar imagery and interferometry. These various datasets allow us to study the interaction of the ice tongue with the tides and currents. However, the inverse barometer effect needs to be applied to sea-level variations affecting the tongue. We find that the tide-induced currents exert a small lateral pressure on the tongue which, when integrated over the large surface of the tongue, induce a flexure of up to 2 m amplitude per day. Simple elastic modelling of the flexure confirms the observations and helps validate the boundary conditions necessary to explain different eastward and westward tongue deflections. In addition, the along-flow velocity of the tongue does vary daily from 1.9 to 6.8 md-1 depending on the tidal current. When the current pushes the tongue toward the eastern boundary of the fjord, the tongue is retarded by the drag and the velocity decreases. The accumulated stress is released, allowing the tongue to flow very rapidly when the current pushes the tongue westward. These forcing and boundary conditions on the floating ice flow are important and must be taken into account when studying glacier discharge and calving.

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 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 AN AUTOMATIC EXTRACTION METHOD FOR ANTARCTIC SUBGLACIAL LAKE BASED ON RADIO ECHO SOUNDING DATA

2021 ◽  
Vol XLIII-B3-2021 ◽  
pp. 521-526
Author(s):  
D. Wang ◽  
T. Feng ◽  
T. Hao ◽  
R. Li
Keyword(s):  
Automatic Extraction ◽  
Visual Interpretation ◽  
Subglacial Lake ◽  
The Past ◽  
Lake Region ◽  
Geometric Spreading ◽  
Radio Echo Sounding ◽  
Subglacial Lakes ◽  
Quantitative Indicators ◽  
Echo Sounding

Abstract. Detection of subglacial lakes and interpretation their hydrological connectivity is of great importance to understanding the mass balance of Antarctic ice sheet. Over the past five decades, a large number of Radio Echo Sounding (RES) data has been collected in Antarctica. However, the identification of subglacial lakes based on RES data mainly relies on visual interpretation due to the lack of quantitative indicators for subglacial lakes distinguishing. To solve this problem, an automatic subglacial lakes detection method based on the reflective characteristics of B-scan echogram is proposed in this paper. Firstly, the echo strength of the original radar echogram is corrected for the dielectric attenuation and geometric spreading in the ice. Secondly, the original radar echogram is binarized to preserve the bright subglacial lake region, and the thickness of bright pixels is measured along the direction of A-scan. Thirdly, the thickness, the variance of the thickness in the neighbourhood and the corrected echo strength are used to obtain the response value for the subglacial lake. Finally, a threshold for the response value is determined to detect subglacial lakes. It is found that the proposed method can determine the location of the subglacial lake in Antarctica's Gamburtsev Province (AGAP) region with high accuracy.

scholarly journals Investigating the stability of subglacial lakes with a full Stokes ice-sheet model

2008 ◽  
Vol 54 (185) ◽  
pp. 353-361 ◽  
Author(s):  
Frank Pattyn
Keyword(s):  
Ice Sheet ◽  
Drainage System ◽  
Potential Gradient ◽  
Surface Slope ◽  
Ice Flow ◽  
Subglacial Lake ◽  
Lake Drainage ◽  
Subglacial Lakes ◽  
The Impact ◽  
Subglacial Drainage

AbstractDespite the large amount of subglacial lakes present underneath the East Antarctic ice sheet and the melt processes involved, the hydrology beneath the ice sheet is poorly understood. Changes in subglacial potential gradients may lead to subglacial lake outbursts, discharging excess water through a subglacial drainage system underneath the ice sheet. Such processes can eventually lead to an increase in ice flow. In this paper, a full Stokes numerical ice-sheet model was employed which takes into account the ice flow over subglacial water bodies in hydrostatic equilibrium with the overlying ice. Sensitivity experiments were carried out for small perturbations in ice flow and basal melt rate as a function of ice thickness, general surface slope, ice viscosity and lake size, in order to investigate their influence on the subglacial potential gradient and the impact on subglacial lake drainage. Experiments clearly demonstrate that small changes in surface slope are sufficient to start and sustain episodic subglacial drainage events. Lake drainage can therefore be regarded as a common feature of the subglacial hydrological system and may influence, to a large extent, the present and future behavior of large ice sheets.

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