LAKES BENEATH THE ICE SHEET: The Occurrence, Analysis, and Future Exploration of Lake Vostok and Other Antarctic Subglacial Lakes

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.

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Recent advances in understanding Antarctic subglacial lakes and hydrology

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2014.0306 ◽

2016 ◽

Vol 374 (2059) ◽

pp. 20140306 ◽

Cited By ~ 43

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).

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Reviewing the origin of subglacial Lake Vostok and its sensitivity to ice sheet changes

Progress in Physical Geography Earth and Environment ◽

10.1191/0309133305pp441ra ◽

2005 ◽

Vol 29 (2) ◽

pp. 156-170 ◽

Cited By ~ 8

Author(s):

Martin J. Siegert

Keyword(s):

Ice Sheet ◽

Extreme Environment ◽

Ice Cover ◽

Ice Growth ◽

Lake Vostok ◽

Subglacial Lake ◽

Ice Surface ◽

Ice Flows ◽

Subglacial Lakes ◽

Ice Water

The history of Lake Vostok, the huge East Antarctic subglacial lake, is critical to the unique biota expected in this extreme environment. One theory is that the lake existed prior to the mid-Miocene glaciation of the continent at around 15 million years ago, survived the subsequent period of ice growth intact, and then remained relatively stable beneath its thick ice cover to the present day. The alternative is that the lake was formed by subglacial water flow into an existing and/or glacially eroded trough after the ice sheet reached its present configuration. Here, the onset of persistent ice cover in Antarctica is reviewed and a simple model for continental ice growth discussed. This information is used to argue against the preglacial origin of subglacial lakes. Lake Vostok is large because ice flows essentially perpendicular to the trough’s long axis, permitting the slopes of the ice surface and the ice-water interface to be low. During the onset of glaciation ice flow across Lake Vostok would have been more akin to flow across an ice marginal trough such as the Astrolabe Subglacial Basin, which holds the thickest ice in Antarctica: 4776 m where the bed is over 2 km below the sea level. Hence, regardless of whether Lake Vostok was a lake prior to glaciation, its trough is likely to have been occupied by grounded ice during the period of ice growth. Although the lake is stable today, its size and extent will be affected by ice sheet changes that occur over glacial-interglacial cycles. Such changes are reviewed and the potential consequences for the lake’s volume are discussed.

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Subglacial water-sheet floods, drumlins and ice-sheet lobes

Journal of Glaciology ◽

10.3189/s0022143000001702 ◽

1999 ◽

Vol 45 (150) ◽

pp. 201-213 ◽

Cited By ~ 3

Author(s):

E.M. Shoemaker

Keyword(s):

New York ◽

Lake Michigan ◽

New York State ◽

Ice Sheet ◽

Lake Ontario ◽

High Water ◽

Green Bay ◽

Subglacial Lake ◽

Western Lake ◽

Subglacial Lakes

AbstractThe effect of subglacial lakes upon ice-sheet topography and the velocity patterns of subglacial water-sheet floods is investigated. A subglacial lake in the combined Michigan–Green Bay basin, Great Lakes, North America, leads to: (1) an ice-sheet lobe in the lee of Lake Michigan; (2) a change in orientations of flood velocities across the site of a supraglacial trough aligned closely with Green Bay, in agreement with drumlin orientations; (3) low water velocities in the lee of Lake Michigan where drumlins are absent; and (4) drumlinization occurring in regions of predicted high water velocities. The extraordinary divergence of drumlin orientations near Lake Ontario is explained by the presence of subglacial lakes in the Ontario and Erie basins, along with ice-sheet displacements of up to 30 km in eastern Lake Ontario. The megagrooves on the islands in western Lake Erie are likely to be the product of the late stage of a water-sheet flood when outflow from eastern Lake Ontario was dammed by displaced ice and instead flowed westward along the Erie basin. The Finger Lakes of northern New York state, northeastern U.S.A., occur in a region of likely ice-sheet grounding where water sheets became channelized. Green Bay and Grand Traverse Bay are probably the products of erosion along paths of strongly convergent water-sheet flow.

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DYNAMICS OF ICE SHEET SURFACE OVER SUBGLACIAL LAKES IN ANTARCTICA

Journal Ice and Snow ◽

10.15356/2076-6734-2012-4-97-103 ◽

2015 ◽

Vol 52 (4) ◽

pp. 97

Author(s):

V. M. Kotlyakov ◽

L. N. Vasiliev ◽

A. B. Kachalin ◽

M. Yu. Moskalevsky ◽

A. S. Tyuflin

Keyword(s):

Ice Sheet ◽

Sheet Surface ◽

Subglacial Lakes

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Prospects for metazoan life in sub-glacial Antarctic lakes: the most extreme life on Earth?

International Journal of Astrobiology ◽

10.1017/s1473550418000356 ◽

2019 ◽

Vol 18 (05) ◽

pp. 416-419 ◽

Cited By ~ 1

Author(s):

Sven Thatje ◽

Alastair Brown ◽

Claus-Dieter Hillenbrand

Keyword(s):

Hydrothermal Vents ◽

Pure Water ◽

Hydrothermal Activity ◽

Microbial Life ◽

Lake Vostok ◽

Physico Chemical ◽

Physiological Adaptations ◽

Subglacial Lakes ◽

Life On Earth ◽

Harsh Conditions

AbstractAbout 400 subglacial lakes are known from Antarctica. The question of whether life unique of subglacial lakes exists has been paramount since their discovery. Despite frequent evidence of microbial life mostly from accretion ice, subglacial lakes are characterized by physiologically hostile conditions to metazoan life, as we know it. Pure water (salinity ≤0.4–1.2%), extreme cold (−3°C), high hydrostatic pressure, areas of limited or no oxygen availability and permanent darkness altogether require physiological adaptations to these harsh conditions. The record of gene sequences including some associated with hydrothermal vents does foster the idea of metazoan life in Lake Vostok. Here, we synthesize the physico-chemical environment surrounding sub-glacial lakes and potential sites of hydrothermal activity and advocate that the physico-chemical stability found at these sites may be the most likely sites for metazoan life to exist. The unique conditions presented by Lake Vostok may also offer an outlook on life to be expected in extra-terrestrial subglacial environments, such as on Jupiter's moon Europa or Saturn's moon Enceladus.

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Antarctic subglacial lakes drain through sediment-floored canals: theory and model testing on real and idealized domains

The Cryosphere ◽

10.5194/tc-11-381-2017 ◽

2017 ◽

Vol 11 (1) ◽

pp. 381-405 ◽

Cited By ~ 19

Author(s):

Sasha P. Carter ◽

Helen A. Fricker ◽

Matthew R. Siegfried

Keyword(s):

Distributed System ◽

Process Model ◽

Ice Sheet ◽

Drainage System ◽

Drainage Water ◽

Process Models ◽

Altimeter Data ◽

Laser Altimeter ◽

Ice Stream ◽

Subglacial Lakes

Abstract. Over the past decade, satellite observations of ice surface height have revealed that active subglacial lake systems are widespread under the Antarctic Ice Sheet, including the ice streams. For some of these systems, additional observations of ice-stream motion have shown that lake activity can affect ice-stream dynamics. Despite all this new information, we still have insufficient understanding of the lake-drainage process to incorporate it into ice-sheet models. Process models for drainage of ice-dammed lakes based on conventional R-channels incised into the base of the ice through melting are unable to reproduce the timing and magnitude of drainage from Antarctic subglacial lakes estimated from satellite altimetry given the low hydraulic gradients along which such lakes drain. We have developed an alternative process model, in which channels are mechanically eroded into the underlying deformable subglacial sediment. When applied to the known active lakes of the Whillans–Mercer ice-stream system, the model successfully reproduced both the inferred magnitudes and recurrence intervals of lake-volume changes, derived from Ice, Cloud and land Elevation Satellite (ICESat) laser altimeter data for the period 2003–2009. Water pressures in our model changed as the flood evolved: during drainage, water pressures initially increased as water flowed out of the lake primarily via a distributed system, then decreased as the channelized system grew, establishing a pressure gradient that drew water away from the distributed system. This evolution of the drainage system can result in the observed internal variability of ice flow over time. If we are correct that active subglacial lakes drain through canals in the sediment, this mechanism also implies that active lakes are typically located in regions underlain by thick subglacial sediment, which may explain why they are not readily observed using radio-echo-sounding techniques.

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Ice motion over Lake Vostok, Antarctica: constraints on inferences regarding the accreted ice

Journal of Glaciology ◽

10.3189/172756500781832710 ◽

2000 ◽

Vol 46 (155) ◽

pp. 689-694 ◽

Cited By ~ 39

Author(s):

R. Kwok ◽

M.J. Siegert ◽

F. D. Carsey

Keyword(s):

Ice Core ◽

Ice Sheet ◽

Maximum Velocity ◽

Sar Interferometry ◽

Surface Velocity ◽

Parabolic Profile ◽

Lake Vostok ◽

The North ◽

Regional Flow ◽

Overlapping Data

AbstractIce motion over Lake Vostok, Antarctica, is measured using repeat-pass synthetic-aperture radar (SAR) interferometry. The coverage of the lake and the components of the vector field are resolved using 10 overlapping data takes from ascending and descending look directions. Seventy-day temporal baselines provide the sensitivity required to observe the range of ice motion (0–6 m a−1) over the lake and the adjacent ice sheet. It is remarkable that the scattering field remained coherent over these time separations. This is critical for interferometric analysis and can be attributed to the low surface accumulation and low air temperature at this elevation. The regional flow of the ice sheet around Lake Vostok is from west to east, perpendicular to the surface elevation contours. As the ice flows past the grounding line, a southward component of motion develops that is correlated with the north–south surface slope along the length of the lake. The surface velocity increases slowly from the northern tip of the lake and then more rapidly south of 77° S. At Vostok station, the ice motion is 4.2 m a−1. Across the lake and away from boundary effects, the down-lake flow pattern takes on a parabolic profile with maximum velocity close to the center line of the lake. The overall influence of the subglacial lake is the addition of a down-lake motion component to the prevailing west–east motion of the ice sheet. As a result, we estimate 10% of the mass flowing onto the lake is diverted south. Reconstructions based on the Vostok ice core indicate that the ice was grounded up-glacier from the core site approximately 5000 years ago. This suggests a minimum freezing rate of 40 mm a−1 for the subglacial accretion ice, 10 times greater than that inferred from thermodynamic modeling of the upper 2 km of the ice core.

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A revised inventory of Antarctic subglacial lakes

Antarctic Science ◽

10.1017/s0954102005002889 ◽

2005 ◽

Vol 17 (3) ◽

pp. 453-460 ◽

Cited By ~ 201

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.

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Antarctic subglacial lake exploration: first results and future plans

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2014.0466 ◽

2016 ◽

Vol 374 (2059) ◽

pp. 20140466 ◽

Cited By ~ 15

Author(s):

Martin J. Siegert ◽

John C. Priscu ◽

Irina A. Alekhina ◽

Jemma L. Wadham ◽

W. Berry Lyons

Keyword(s):

Lake Water ◽

Ice Core ◽

Hot Water ◽

Microbial Life ◽

Lake Vostok ◽

Subglacial Lake ◽

Coastal Margin ◽

First Results ◽

Scientific Results ◽

Subglacial Lakes

After more than a decade of planning, three attempts were made in 2012–2013 to access, measure in situ properties and directly sample subglacial Antarctic lake environments. First, Russian scientists drilled into the top of Lake Vostok, allowing lake water to infiltrate, and freeze within, the lower part of the ice-core borehole, from which further coring would recover a frozen sample of surface lake water. Second, UK engineers tried unsuccessfully to deploy a clean-access hot-water drill, to sample the water column and sediments of subglacial Lake Ellsworth. Third, a US mission successfully drilled cleanly into subglacial Lake Whillans, a shallow hydraulically active lake at the coastal margin of West Antarctica, obtaining samples that would later be used to prove the existence of microbial life and active biogeochemical cycling beneath the ice sheet. This article summarizes the results of these programmes in terms of the scientific results obtained, the operational knowledge gained and the engineering challenges revealed, to collate what is known about Antarctic subglacial environments and how to explore them in future. While results from Lake Whillans testify to subglacial lakes as being viable biological habitats, the engineering challenges to explore deeper more isolated lakes where unique microorganisms and climate records may be found, as exemplified in the Lake Ellsworth and Vostok missions, are considerable. Through international cooperation, and by using equipment and knowledge of the existing subglacial lake exploration programmes, it is possible that such environments could be explored thoroughly, and at numerous sites, in the near future.

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