scholarly journals Potential technological solution for sampling the bottom sediments of the subglacial lake Vostok: relevance and formulation of investigation goals

2021 ◽  
Vol 252 ◽  
pp. 779-787
Author(s):  
Aleksey Bolshunov ◽  
Nikolay Vasiliev ◽  
Igor Timofeev ◽  
Sergey Ignatiev ◽  
Dmitriy Vasiliev ◽  
...  
Keyword(s):  
Environmental Safety ◽  
Climatic Conditions ◽  
Natural Phenomenon ◽  
Bottom Surface ◽  
Large Area ◽  
Lake Vostok ◽  
Subglacial Lake ◽  
Vostok Station ◽  
Environmentally Safe ◽  
Subglacial Lakes

The subglacial Lake Vostok in Antarctic is a unique natural phenomenon, its comprehensive study involves sampling of water and bottom surface rocks. For further study of the lake, it is necessary to drill a new access well and develop environmentally safe technologies for its exploration. This article discusses existing and potential technologies for sampling bottom surface rocks of subglacial lakes. All these technologies meet environmental safety requirements and are conducive for sampling. The authors have proposed an alternative technology, using a walking device, which, due to its mobility, enables selective sampling of rocks across a large area from a single access well. The principal issues, related to the implementation of the proposed technology, are investigated within this article. This report is prepared by a team of specialists with many years of experience in drilling at the Vostok Station in Antarctic and in experimental work on the design of equipment and non-standard means of mechanization for complicated mining, geological and climatic conditions.

scholarly journals Antarctic subglacial lake exploration: first results and future plans

2016 ◽  
Vol 374 (2059) ◽  
pp. 20140466 ◽  
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.

scholarly journals Basal melting over Subglacial Lake Ellsworth and its catchment: insights from englacial layering

2020 ◽  
Vol 61 (81) ◽  
pp. 198-205
Author(s):  
Neil Ross ◽  
Martin Siegert
Keyword(s):  
High Resolution ◽  
West Antarctica ◽  
Microbial Life ◽  
Lake Vostok ◽  
Subglacial Lake ◽  
Lake Outlet ◽  
Hydrological System ◽  
Subglacial Lakes ◽  
Basal Melting ◽  
Insight Into

AbstractDeep-water ‘stable’ subglacial lakes likely contain microbial life adapted in isolation to extreme environmental conditions. How water is supplied into a subglacial lake, and how water outflows, is important for understanding these conditions. Isochronal radio-echo layers have been used to infer where melting occurs above Lake Vostok and Lake Concordia in East Antarctica but have not been used more widely. We examine englacial layers above and around Lake Ellsworth, West Antarctica, to establish where the ice sheet is ‘drawn down’ towards the bed and, thus, experiences melting. Layer drawdown is focused over and around the northwest parts of the lake as ice, flowing obliquely to the lake axis becomes afloat. Drawdown can be explained by a combination of basal melting and the Weertman effect, at the transition from grounded to floating ice. We evaluate the importance of these processes on englacial layering over Lake Ellsworth and discuss implications for water circulation and sediment deposition. We report evidence of a second subglacial lake near the head of the hydrological catchment and present a new high-resolution bed DEM and hydropotential model of the lake outlet zone. These observations provide insight into the connectivity between Lake Ellsworth and the wider subglacial hydrological system.

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 Basal melting over Subglacial Lake Ellsworth and its catchment: insights from englacial layering

2020 ◽  
Author(s):  
Neil Ross ◽  
Martin Siegert
Keyword(s):  
High Resolution ◽  
West Antarctica ◽  
Microbial Life ◽  
Lake Vostok ◽  
Subglacial Lake ◽  
Lake Outlet ◽  
Hydrological System ◽  
Subglacial Lakes ◽  
Basal Melting ◽  
Insight Into

<p>Deep-water ‘stable’ subglacial lakes likely contain microbial life adapted in isolation to extreme environmental conditions. How water is supplied into a subglacial lake, and how water outflows, is important for understanding these conditions. Isochronal radio-echo layers have been used to infer where melting occurs above Lake Vostok and Lake Concordia in East Antarctica but have not been used more widely. We examine englacial layers above and around Lake Ellsworth, West Antarctica, to establish where the ice sheet is ‘drawn down’ towards the bed and, thus, experiences melting. Layer drawdown is focused over and around the NW parts of the lake as ice, flowing obliquely to the lake axis, becomes afloat. Drawdown can be explained by a combination of basal melting and the Weertman effect, at the transition from grounded to floating ice. We evaluate the importance of these processes on englacial layering over Lake Ellsworth and discuss implications for water circulation and sediment deposition. We report evidence of a second subglacial lake near the head of the hydrological catchment and present a new high-resolution bed DEM and hydropotential model of the lake outlet zone. These observations provide insight into the connectivity between Lake Ellsworth and the wider subglacial hydrological system.</p>

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

2005 ◽  
Vol 29 (2) ◽  
pp. 156-170 ◽  
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.

scholarly journals Probe technologies for clean sampling and measurement of subglacial lakes

2016 ◽  
Vol 374 (2059) ◽  
pp. 20150267 ◽  
Author(s):  
Matt Mowlem ◽  
Kevin Saw ◽  
Robin Brown ◽  
Edward Waugh ◽  
Christopher L. Cardwell ◽  
...  
Keyword(s):  
Lessons Learned ◽  
Hot Water ◽  
Lake Vostok ◽  
Subglacial Lake ◽  
Field Season ◽  
Electrical Conducting ◽  
Subglacial Lakes ◽  
Subglacial Lake Whillans ◽  
Negatively Buoyant ◽  
Sediment Corer

It is 4 years since the subglacial lake community published its plans for accessing, sampling, measuring and studying the pristine, and hitherto enigmatic and very different, Antarctic subglacial lakes, Vostok, Whillans and Ellsworth. This paper summarizes the contrasting probe technologies designed for each of these subglacial environments and briefly updates how these designs changed or were used differently when compared to previously published plans. A detailed update on the final engineering design and technical aspects of the probe for Subglacial Lake Ellsworth is presented. This probe is designed for clean access, is negatively buoyant (350 kg), 5.2 m long, 200 mm in diameter, approximately cylindrical and consists of five major units: (i) an upper power and communications unit attached to an optical and electrical conducting tether, (ii)–(iv) three water and particle samplers, and (v) a sensors, imaging and instrumentation pack tipped with a miniature sediment corer. To date, only in Subglacial Lake Whillans have instruments been successfully deployed. Probe technologies for Subglacial Lake Vostok (2014/15) and Lake Ellsworth (2012/13) were not deployed for technical reasons, in the case of Lake Ellsworth because hot-water drilling was unable to access the lake during the field season window. Lessons learned and opportunities for probe technologies in future subglacial access missions are discussed.

scholarly journals Characterization of subglacial Lake Vostok as seen from physical and isotope properties of accreted ice

2016 ◽  
Vol 374 (2059) ◽  
pp. 20140303 ◽  
Author(s):  
Vladimir Ya. Lipenkov ◽  
Alexey A. Ekaykin ◽  
Ekaterina V. Polyakova ◽  
Dominique Raynaud
Keyword(s):  
Lake Water ◽  
Hydrological Regime ◽  
Gas Content ◽  
Deep Drilling ◽  
Lake Vostok ◽  
Subglacial Lake ◽  
Direct Sampling ◽  
Vostok Station ◽  
Different Depths

Deep drilling at the Vostok Station has reached the surface of subglacial Lake Vostok (LV) twice—in February 2012 and January 2015. As a result, three replicate cores from boreholes 5G-1, 5G-2 and 5G-3 became available for detailed and revalidation analyses of the 230 m thickness of the accreted ice, down to its contact with water at 3769 m below the surface. The study reveals that the concentration of gases in the lake water beneath Vostok is unexpectedly low. A clear signature of the melt water in the surface layer of the lake, which is subject to refreezing on the icy ceiling of LV, has been discerned in the three different properties of the accreted ice: the ice texture, the isotopic and the gas content of the ice. These sets of data indicate in concert that poor mixing of the melt (and hydrothermal) water with the resident lake water and pronounced spatial and/or temporal variability of local hydrological conditions are likely to be the characteristics of the southern end of the lake. The latter implies that the surface water may be not representative enough to study LV's behaviour, and that direct sampling of the lake at different depths is needed in order to move ahead with our understanding of the lake's hydrological regime.

scholarly journals New large subglacial lake in Princess Elizabeth Land, East Antarctica, detected by airborne geophysical observations

2021 ◽  
Author(s):  
Lin Li ◽  
Aiguo Zhao ◽  
Tiantian Feng ◽  
Xiangbin Cui ◽  
Lu An ◽  
...  
Keyword(s):  
Ground Truth ◽  
East Antarctica ◽  
Gravity Modeling ◽  
Lake Vostok ◽  
Subglacial Lake ◽  
Innovative Method ◽  
Abstract Knowledge ◽  
Subglacial Lakes ◽  
Global Sea Level ◽  
The Stability

Abstract. Knowledge of subglacial lakes is important for understanding the stability of the Antarctica Ice Sheet (AIS) and its contribution to the global sea-level change. We designed an intensified airborne campaign to collect geophysical data in Princess Elizabeth Land (PEL), East Antarctica, during the 2015–2019 CHINARE expeditions. We developed an innovative method to build a set of evidence of a newly detected subglacial lake, Lake Zhongshan. Adaptive RES data analysis allowed us to detect the lake surface and extent. We quantified the lake depth and volume via gravity modeling. Another dataset collected at Lake Vostok provided the ground truth. The results revealed that Lake Zhongshan, located at 73°26'53"S, 80°30'39"E and ~3,603 m below surface, has an area of 328 ± 1 km2, making it the only one in PEL and the fifth largest in Antarctica. These findings are important for understanding subglacial hydrodynamics in PEL, as well as the stability of the AIS.

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