Ice flow velocities over Vostok Subglacial Lake, East Antarctica, determined by 10 years of GNSS observations

Richter, Andreas; Fedorov, Denis; Fritsche, Mathias; Попов, С. В.; Lipenkov, V. Ya.; Ekaykin, A. A.; Lukin, Valeriy; Matveev, Alexey Y; Grebnev, V.P.; Rosenau, Ralf; Dietrich, Reinhard

doi:10.3189/2013jog12j056

Cited by 21 publications

(36 citation statements)

References 33 publications

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“…The first type are observations performed on lightweight snowmobiles. With the help of such profiles Richter et al (2014a) have shown that the surface elevation around Vostok Station has been stable over the last decade, confirming the results of permanent GNSS observations (Richter et al, 2008(Richter et al, , 2014a. Such profiles acquired on snowmobiles provide accuracies of only a few centimetres (see also King et al, 2009;Siegfried et al, 2011) and are thus well suited for precise studies on local elevation and elevation changes.…”

Section: Kinematic Gnss Observationssupporting

confidence: 72%

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Schröder¹

2017

Preprint

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Ice-surface elevation profiles of more than 30 000 km in total length are derived from kinematic GNSS (GPS and the Russian GLONASS) observations on sledge convoy vehicles along traverses between Vostok Station and the East Antarctic coast. These profiles have accuracies between 4 and 9 cm. They are used to validate elevation data sets from both radar and laser satellite altimetry as well as four digital elevation models. A crossover analysis with three different processing versions of Envisat radar altimetry elevation profiles yields a clear preference for the relocation method over the direct method of slope correction and for threshold retrackers over functional fit algorithms. The validation of CryoSat-2 low-resolution mode and SARIn mode data sets documents the progress made from baseline B to C elevation products. ICESat laser altimetry data are demonstrated to be accurate to a few decimetres over a wide range of surface slopes. A crossover adjustment in the region of subglacial Lake Vostok combining ICESat elevation data with our GNSS profiles yields a new set of ICESat laser campaign biases and provides new, independent evidence for the stability of the ice-surface elevation above the lake. The evaluation of the digital elevation models reveals the benefits of combining laser and radar altimetry.Published by Copernicus Publications on behalf of the European Geosciences Union.

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Section: Kinematic Gnss Observationssupporting

confidence: 72%

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Schröder¹

2017

Preprint

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“…These might form subglacial lakes, analogous to terrestrial lakes such as Vostok in Antarctica (Siegert and Rigley, 1998;Siegert et al, 2001;Kwok et al, 2000;Bell et al, 2002;Studinger et al, 2004;Richter et al, 2013), that would infill with sediment, perhaps contributing to the explanation for the shallow, degraded character of Noachian highland craters (Craddock and Maxwell, 1993;Craddock et al, 1997;Craddock and Howard, 2002;Weiss and Head, 2014). We conclude that the Late Noachian icy highlands are unlikely to have ever had widespread wet bed conditions, although the presence of limited "lakes" in deep craters is a possibility given a supply limit of 4 5X.…”

Section: Results: Discussionmentioning

confidence: 90%

Glaciation in the Late Noachian Icy Highlands: Ice accumulation, distribution, flow rates, basal melting, and top-down melting rates and patterns

Fastook

Head

2015

Planetary and Space Science

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“…The abundance of subglacial water bodies underneath this portion of the ISIS may have considerably increased basal ice‐flow velocity (Bell, ). It has been demonstrated that subglacial lakes in Antarctica and development of subglacial meltwater drainage in Greenland control the increase in ice stream velocities (Shepherd et al ., ; Richter et al ., ). This relation implies that the retreat of the ISIS during deglaciation, illustrated by the deposition of proglacial sediments above subglacial sediments in Ballyhorsey and Killiney Bay, occurred in response to and along with high ice‐flow velocity (Rijsdijk et al ., ; Clerc et al ., ).…”

Section: Discussionmentioning

confidence: 99%

Sedimentological and deformational criteria for discriminating subglaciofluvial deposits from subaqueous ice‐contact fan deposits: A Pleistocene example (Ireland)

et al. 2014

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A pit located near Ballyhorsey, 28 km south of Dublin (eastern Ireland), displays subglacially deposited glaciofluvial sediments passing upwards into proglacial subaqueous ice‐contact fan deposits. The coexistence of these two different depositional environments at the same location will help with differentiation between two very similar and easily confused glacial lithofacies. The lowermost sediments show aggrading subglacial deposits indicating a constrained accommodation space, mainly controlled by the position of an overlying ice roof during ice‐bed decoupling. These sediments are characterized by vertically stacked tills with large lenses of tabular to channelized sorted sediments. The sorted sediments consist of fine‐grained laminated facies, cross‐laminated sand and channelized gravels, and are interpreted as subglaciofluvial sediments deposited within a subglacial de‐coupled space. The subglaciofluvial sequence is characterized by glaciotectonic deformation structures within discrete beds, triggered by fluid overpressure and shear stress during episodes of ice/bed recoupling (clastic dykes and folds). The upper deposits correspond to the deposition of successive hyperpycnal flows in a proximal proglacial lake, forming a thick sedimentary wedge erosively overlying the subglacial deposits. Gravel facies and large‐scale trough bedding sand are observed within this proximal wedge, while normally graded sand beds with developed bedforms are observed further downflow. The building of the prograding ice‐contact subaqueous fan implies an unrestricted accommodation space and is associated with deformation structures related to gravity destabilization during fan spreading (normal faults). This study facilitates the recognition of subglacial/submarginal depositional environments formed, in part, during localized ice/bed coupling episodes in the sedimentary record. The sedimentary sequence exposed in Ballyhorsey permits characterization of the temporal framework of meltwater production during deglaciation, the impact on the subglacial drainage system and the consequences on the Irish Sea Ice Stream flow mechanisms.

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Ice flow velocities over Vostok Subglacial Lake, East Antarctica, determined by 10 years of GNSS observations

Abstract: ABSTRACT. Repeated Global Navigation Satellite Systems (GNSS) observations

Cited by 21 publications

References 33 publications

Reply to referee comment from reviewer #1

Reply to referee comment from reviewer #1

Glaciation in the Late Noachian Icy Highlands: Ice accumulation, distribution, flow rates, basal melting, and top-down melting rates and patterns

Sedimentological and deformational criteria for discriminating subglaciofluvial deposits from subaqueous ice‐contact fan deposits: A Pleistocene example (Ireland)

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