Showing 11145 items
1 March, 2017 by Rob Shore
Measurements of the Earth’s magnetic field collected by low-Earth-orbit satellites such as Swarm and CHAMP, as well as at ground observatories, are dominated by sources in the Earth’s interior. However…1 March, 2017 by Hugh Corr
We present a compilation of radio-echo sounding (RES) measurements of five radar systems (AWI, BAS, CReSIS, INGV and UTIG) around the EPICA Dome C (EDC) drill site, East Antarctica. The…1 March, 2017 by Dave Munday
The Southern Ocean plays a pivotal role in climate change by exchanging heat and carbon, and provides the primary window for the global deep ocean to communicate with the atmosphere.…1 March, 2017 by Claire Waluda, Helen Peat, Philip Trathan, Simeon Hill
Inter-annual variability in diet during crèche (December to February) over 22 years (1989–2010) was examined for gentoo penguins Pygoscelis papua breeding at Bird Island, South Georgia (54°00′S, 38°03′W). Overall, diets…1 March, 2017 by Fausto Ferraccioli, Hugh Corr, Tom Jordan
Unravelling the long-term evolution of the subglacial landscape of Antarctica is vital for understanding past ice sheet dynamics and stability, particularly in marine-based sectors of the ice sheet. Here, we…1 March, 2017 by Katrin Linse
Background Extreme environments prompt the evolution of characteristic adaptations. Yet questions remain about whether radiations in extreme environments originate from a single lineage that masters a key adaptive pathway, or…1 March, 2017 by David Barnes
The western Antarctic Peninsula (WAP) is a hotspot of rapid recent regional ‘climate change’. This has resulted in a 0.4°C rise in sea temperature in the last 50 years, five…1 March, 2017 by Adrian Jenkins, Andrew Orr, Hilmar Gudmundsson, Claus-Dieter Hillenbrand, John Turner, Thomas Bracegirdle
Over recent decades outlet glaciers of the Amundsen Sea Embayment (ASE), West Antarctica, have accelerated, thinned and retreated, and are now contributing approximately 10% to global sea level rise. All…Read more on Atmosphere-ocean-ice interactions in the Amundsen Sea Embayment, West Antarctica
1 March, 2017 by Andy Smith
Amplitude analysis of reflection seismic data reveals the presence of highly variable bed conditions under the main sticky spot and adjacent regions of the Kamb Ice Stream (KIS—formerly ice stream…Read more on Characteristics of the sticky spot of Kamb Ice Stream, West Antarctica
1 March, 2017 by Geraint Tarling, Helen Peat, Laura Gerrish, Peter Fretwell, Peter Ward, Simeon Hill, Sophie Fielding
Antarctic krill (Euphausia superba) and salps are major macroplankton contributors to Southern Ocean food webs and krill are also fished commercially. Managing this fishery sustainably, against a backdrop of rapid…1 March, 2017
The distribution of oceanic cephalopod species is not fully understood but seabirds, which feed on cephalopods and cover vast oceanic areas, might work as samplers and mappers of the occurrence…Read more on Using seabirds to map the distribution of elusive pelagic cephalopod species
1 March, 2017 by John Turner
The Antarctic sea ice extent has been slowly increasing contrary to expected trends due to global warming and results from coupled climate models. After a record high extent in 2012…1 March, 2017 by Dag Arne Lorentzen, Lisa Baddeley
A study is undertaken into parameters of the polar auroral and geomagnetic pulsations in the frequency range 1–4 mHz (Pc5∕Pi3) during quiet geomagnetic intervals preceding auroral substorms and non-substorm background variations.…1 March, 2017 by Louise Sime, Robert Mulvaney
In order to understand atmospheric methane (CH4) biogeochemistry now and in the future, we must apprehend its natural variability, without anthropogenic influence. Samples of ancient air trapped within ice cores…Read more on Atmospheric methane variability: Centennial-scale signals in the Last Glacial Period
1 March, 2017 by Geraint Tarling
Euphausiid crustaceans, commonly referred to as krill, are fast-moving, pelagic, exclusively marine, and found in all oceans generally below 50 m. While restricted to only 86 species in two families,…1 March, 2017 by John King
The record high temperature for regions south of 60°S latitude is a balmy 19.8°C (67.6°F), recorded 30 January 1982 at a research station on Signy Island.Read more on Evaluating highest temperature extremes for the Antarctic region
24 February, 2017 by Jean-Baptiste Sallee
Contrasting regional changes in Southern Ocean sea ice have occurred over the last 30 years with distinct regional effects on ecosystem structure and function. Quantifying how Antarctic predators respond to…24 February, 2017 by Andrew Orr
Atmospheric gravity waves yield substantial small-scale temperature fluctuations that can trigger the formation of polar stratospheric clouds (PSCs). This paper introduces a new satellite record of gravity wave activity in…22 February, 2017 by Andrew Clarke, Hugh Venables, Michael Meredith
An eight year time-series in the Western Antarctic Peninsula (WAP) with an approximately weekly sampling frequency was used to elucidate changes in virioplankton abundance and their drivers in this climatically-sensitive…22 February, 2017 by David Pearce, Peter Convey
Planococcus is a Gram-positive halotolerant bacterial genus in the phylum Firmicutes, commonly found in various habitats in Antarctica. Quorum quenching (QQ) is the disruption of bacterial cell-to-cell communication (known as…Read more on AidP, a novel N-Acyl Homoserine Lactonase gene from Antarctic Planococcus sp.
15 February, 2017 by Peter Convey
Iron supplied by glacial weathering results in pronounced hotspots of biological production in an otherwise iron-limited Southern Ocean Ecosystem. However, glacial iron inputs are thought to be dominated by icebergs.…9 February, 2017 by Adrian Jenkins, Pierre Dutrieux, Satoshi Kimura
The instability and accelerated melting of the Antarctic Ice Sheet are among the foremost elements of contemporary global climate change1, 2. The increased freshwater output from Antarctica is important in…Read more on Vigorous lateral export of the meltwater outflow from beneath an Antarctic ice shelf
8 February, 2017 by Emily Shuckburgh
The Intergovernmental Panel on Climate Change (IPCC) has accepted the invitation from the UNFCCC to provide a special report on the impacts of global warming of 1.5 °C above pre-industrial levels…1 February, 2017 by Kevin Hughes
1.Few reports exist that describe marine non-native species in the Southern Ocean and near-shore waters around the Antarctic continent. Nevertheless, Antarctica's isolated marine communities, which show high levels of endemism,…1 February, 2017 by Pranab Deb
This study investigates the impact of wind-induced sea ice drift on sea ice cover over the Indian Ocean sector of the Southern Ocean (IOS) in the contrasting Southern Annular Mode…1 February, 2017
Feeding ecology and isotopic niche of the wandering albatross Diomedea exulans were investigated in the poorly studied population on the Kerguelen Islands and compared to that on the Crozet Islands.…1 February, 2017 by Mark Clilverd
Electromagnetic ion cyclotron (EMIC) waves are potentially important drivers of the loss of energetic electrons from the radiation belts. Numerous theoretical calculations exist with conflicting predictions of one of the…Read more on Evidence of sub-MeV EMIC-driven electron precipitation
1 February, 2017 by Hilmar Gudmundsson, Jan De Rydt
Data showing velocity changes on the Brunt Ice Shelf (BIS), Antarctica, over the last 55 years are presented and analysed. During this period no large-scale calving events took place and…Read more on Five decades of strong temporal variability in the flow of Brunt Ice Shelf, Antarctica
1 February, 2017 by Mervyn Freeman, Rob Shore
We describe a method of producing high-resolution models of the Earth's combined external and induced magnetic field using the method of empirical orthogonal functions (EOFs) applied to the SuperMAG archive…1 February, 2017 by Melody Clark
The field of molecular ecology is transitioning from the use of small panels of classical genetic markers such as microsatellites to much larger panels of single nucleotide polymorphisms (SNPs) generated…1 February, 2017 by Dani Jones, Mark Hammond
This dataset is a multiyear mean Southern Ocean freshwater flux field that uses recently compiled measurements of ice sheet melting, iceberg calving, iceberg tracking, and river runoff. It has a…Read more on Freshwater flux from ice sheet melting and iceberg calving in the Southern Ocean
16 January, 2017 by Dave Munday
The Antarctic Circumpolar Current is the strongest current in the ocean and has a pivotal impact on ocean stratification, heat content, and carbon content. The circumpolar volume transport is relatively…Read more on Eddy saturation and frictional control of the Antarctic Circumpolar Current
13 January, 2017 by Kevin Hughes
Human footprint models allow visualization of human spatial pressure across the globe. Up until now, Antarctica has been omitted from global footprint models, due possibly to the lack of a…13 January, 2017 by Norman Ratcliffe
Tropical cyclones are renowned for their destructive nature and are an important feature of marine and coastal tropical ecosystems. Over the last 40 years, their intensity, frequency and tracks have…13 January, 2017 by Xin Yang
Atmospheric deposition is the most important pathway by which Hg reaches marine ecosystems, where it can be methylated and enter the base of food chain. The deposition, transport and chemical…Read more on Sensitivity model study of regional mercury dispersion in the atmosphere
12 January, 2017 by Jennifer Jackson
Since 1970, blue whales (Balaenoptera musculus) have been seen feeding in the waters off southern Chile during the summer and autumn (December to May). Investigation of the genetic, acoustic and…11 January, 2017 by Bianca Perren
Diatoms, combined with a multiproxy study of lake sediments (organic matter, N, δ15N, δ13C, biogenic silica, grain size, Cladocera and chironomids, Alnus pollen) from Lone Spruce Pond, Alaska detail the…1 January, 2017 by Martin Collins, Mark Belchier, Susan Gregory
This research is the first to investigate deepwater demersal fish distribution and community structure around South Georgia and Shag Rocks. Analysis of catch data from a trawl survey conducted in…1 January, 2017 by Lloyd Peck, Michael Thorne, Melody Clark, Simon Morley
Understanding species' responses to environmental change underpins our abilities to make predictions on future biodiversity under any range of scenarios. In spite of the huge biodiversity in most ecosystems, a…1 January, 2017 by Claus-Dieter Hillenbrand, Teal Riley
Marine sedimentary rocks drilled on the southeastern margin of the South Orkney microcontinent in Antarctica (Ocean Drilling Program Leg 113 Site 696) were deposited between ∼36.5 Ma to 33.6 Ma,…Read more on Widespread Antarctic glaciation during the Late Eocene
1 January, 2017 by Richard Phillips
Fisheries bycatch is a major threat to seabird populations, and understanding sex- and age-biases in bycatch rates is important for assessing population-level impacts. We analysed 44 studies to provide the…Read more on Global patterns of sex- and age-specific variation in seabird bycatch
1 January, 2017 by Lloyd Peck
We present the results of our eighth annual horizon scan of emerging issues likely to affect global biological diversity, the environment, and conservation efforts in the future. The potential effects…Read more on A 2017 Horizon Scan of Emerging Issues for Global Conservation and Biological Diversity
1 January, 2017 by Chester Sands
Marine systems have traditionally been thought of as “open” with few barriers to gene flow. In particular, many marine organisms in the Southern Ocean purportedly possess circumpolar distributions that have…1 January, 2017 by Kevin Hughes
Generally, Antarctica is considered to be an untouched area of the planet; however, the region's ecosystems have been subject to increased human pressure for at least the past half-century. This…1 January, 2017 by Lloyd Peck
There is an increasing use of marine species as paleoclimate recorders for the marine realm. These archives provide novel baseline records of past oceanographic variability in regions devoid of instrumental…1 January, 2017 by Thomas Bracegirdle
Polar lows are intense, small-scale cyclones in the high latitudes. Typically, polar lows are initiated through baroclinic processes, but they sometimes evolve into a post-baroclinic mature stage where air-sea interaction…Read more on Sensitivity of an apparently hurricane-like polar low to sea surface temperature
1 January, 2017 by Rowan Whittle
Fossils of the Late Ordovician Soom Shale Lagerstätte are characterized by exceptional preservation of their soft tissues in clay minerals. The low-diversity community lived in an unusual cold-water setting, dominated…1 January, 2017 by Melody Clark, Tejaswi Yarra, Victoria Sleight
Bivalves have evolved a range of complex shell forming mechanisms that are reflected by their incredible diversity in shell mineralogy and microstructures. A suite of proteins exported to the shell…Read more on Insights from the shell proteome: biomineralization to adaptation
1 January, 2017 by Fausto Ferraccioli, Philip Leat, Tom Jordan
Gondwana breakup changed the global continental configuration, leading to opening of major oceanic gateways, shifts in the climate system and significant impacts on the biosphere, hydrosphere and cryosphere. Although of…1 January, 2017 by Philip Leat, Teal Riley
The continental margin of Gondwana preserves a record of long-lived magmatism from the Andean Cordillera to Australia. The crustal blocks of West Antarctica form part of this margin, with Palaeozoic–Mesozoic…1 January, 2017 by Lloyd Peck
The scarcity of long instrumental series from the Southern Ocean limits our understanding of key climate and environmental feedbacks within the Antarctic system. We present an assessment for the Antarctic…1 January, 2017 by John Turner
We present projected changes in the speed and meridional location of the Subtropical Jet (STJ) during winter using output of the Coupled Model Intercomparison Project Phase 5 (CMIP5) models. We…1 January, 2017 by Philip Trathan, Peter Fretwell
Detecting and predicting how populations respond to environmental variability are crucial challenges for their conservation. Knowledge about the abundance and distribution of the emperor penguin is far from complete despite…Read more on Looking for new emperor penguin colonies? Filling the gaps
1 January, 2017 by Richard Horne
Extreme space weather due to coronal mass ejections has the potential to cause considerable disruption to the global economy by damaging the transformers required to operate electricity transmission infrastructure. However,…1 January, 2017 by Elaine Fitzcharles, Huw Griffiths
Many Antarctic marine invertebrates are considered to be highly stenothermal, subjected to loss of functionality at increased temperatures and so at high risk of mortality in a rapidly warming environment.…Read more on First report of Laternula elliptica in the Antarctic intertidal zone
1 January, 2017 by Alex Burton-Johnson
The internal structure and emplacement mechanisms of composite plutons are investigated using new field data from the composite Late Miocene granitic intrusion of Mt Kinabalu in northern Borneo. The pluton…1 January, 2017 by Adrian Jenkins, Povl Abrahamsen
Pine Island Glacier (PIG) terminates in a rapidly melting ice shelf, and ocean circulation and temperature are implicated in the retreat and growing contribution to sea level rise of PIG…Read more on Mechanisms driving variability in the ocean forcing of Pine Island Glacier
1 January, 2017 by Andrew Clarke, Hugh Venables, Michael Meredith
The rapid warming of the West Antarctic Peninsula region has led to reduced sea ice cover and enhanced glacial melt water input. This has potential implications for marine ecosystems, notably…1 January, 2017 by Gareth Chisham
Many empirical models and climatologies of high-latitude ionospheric processes, such as convection, have been developed over the last 40 years. One common feature in the development of these models is…1 January, 2017 by Alex Brisbourne, Andy Smith, David Vaughan, Ed King, Sebastian Rosier
Although 90% of Antarctica's discharge occurs via its fast-flowing ice streams, our ability to project future ice sheet response has been limited by poor observational constraints on the ice-bed conditions…Read more on Bed conditions of Pine Island Glacier, West Antarctica
1 January, 2017 by Mark Clilverd
A detailed comparison is undertaken of the energetic electron spectra and fluxes of two precipitation events that were observed in 18/19 January 2013. A novel but powerful technique of combining…15 December, 2016 by Andrew Gray, Kevin Hughes
Antarctic Treaty Consultative Parties are entitled to participate in consensus-based governance of the continent through the annual Antarctic Treaty Consultative Meetings. To acquire consultative status, an interested Party must demonstrate…6 December, 2016 by Jonathan Watkins, Philip Trathan, Simeon Hill, Sophie Fielding
This paper explains the management of the Antarctic krill (Euphausia superba) fishery in the Atlantic sector of the Southern Ocean, and current knowledge about the state of the regional krill…1 December, 2016 by Eugene Murphy
Climate change has significant implications for biodiversity and ecosystems. With slow progress towards reducing greenhouse gas emissions, climate engineering (or ‘geoengineering’) is receiving increasing attention for its potential to limit…1 December, 2016 by Peter Convey
Antarctic ice-free inland sites provide a unique perspective on the strategies coevolving organisms have developed for survival at the limits of life. Here, we provide the first combined description of…1 December, 2016 by Ben Robinson, Chester Sands, David Barnes, James Smith, Oliver Hogg
Aim High-latitude biodiversity distributions can preserve signals of the timing and geography of past glaciations, and as such ground truth ice-sheet models. Discrete polar archipelagos offer the fewest confounding factors…Read more on Biodiversity signature of the Last Glacial Maximum at South Georgia, Southern Ocean
1 December, 2016 by Kelly Hogan, Robert Larter
Detailed bathymetric and sub-bottom acoustic observations in Bourgeois Fjord (Marguerite Bay, Antarctic Peninsula) provide evidence on sedimentary processes and glacier dynamics during the last glacial cycle. Submarine landforms observed in…1 December, 2016 by Sandra McInnes, Sandra McInnes
Zoogeographical studies on Tardigrada are limited by the extent of our knowledge on tardigrade taxonomy and faunistics. In this paper we analyse the relationships between the tardigrade fauna of North,…1 December, 2016 by Eugene Murphy, Rachel Cavanagh, Susie Grant
Valuation of biodiversity and ecosystem services (ES) is widely recognized as a useful, though often controversial, approach to conservation and management. However, its use in the marine environment, hence evidence…1 December, 2016 by Sandra McInnes, Sandra McInnes
Antarctica is an ice-dominated continent and all its terrestrial and freshwater habitats are fragmented, which leads to genetic divergence and, eventually, speciation. Acutuncus antarcticus is the most common Antarctic tardigrade…1 December, 2016 by Sandra McInnes, Sandra McInnes
This paper is the third monograph of the series that describes the global records of limno-terrestrial water bears (Tardigrada). Here, we provide a comprehensive list of non-marine tardigrades recorded from…Read more on Annotated zoogeography of non-marine Tardigrada. Part III: North America and Greenland
1 December, 2016 by David Vaughan, Jane Francis, John Hall, Steve Colwell, Tim Stockings
The Antarctic Roadmap Challenges (ARC) project identified critical requirements to deliver high priority Antarctic research in the 21st century. The ARC project addressed the challenges of enabling technologies, facilitating access,…Read more on Delivering 21st century Antarctic and Southern Ocean science
1 December, 2016 by Eugene Murphy, Nadine Johnston, Rachel Cavanagh, Susie Grant
The determinants of the structure, functioning and resilience of pelagic ecosystems across most of the polar regions are not well known. Improved understanding is essential for assessing the value of…1 December, 2016 by Rachel Cavanagh
Meeting the ever-increasing needs of the Earth’s human population without excessively reducing biological diversity is one of the greatest challenges facing humanity, suggesting that new approaches to biodiversity conservation are…Read more on Biodiversity in the Anthropocene: prospects and policy
1 December, 2016 by Keith Nicholls
Calving of glacial ice into the ocean from the Greenland Ice Sheet is an important component of global sea level rise. The calving process itself is relatively poorly observed, understood,…Read more on An Intensive Observation of Calving at Helheim Glacier, East Greenland
1 December, 2016 by Adrian Jenkins, Hilmar Gudmundsson, James Smith
Mass loss from the Antarctic Ice Sheet is driven by changes at the marine margins. In the Amundsen Sea, thinning of the ice shelves has allowed the outlet glaciers to…Read more on Decadal Ocean Forcing and Antarctic Ice Sheet Response: Lessons from the Amundsen Sea
1 December, 2016 by Constantino Listowski, Thomas Lachlan-Cope
Observations of clouds over the Antarctic Peninsula during summer 2010 and 2011 are presented here. The peninsula is up to 2500 m high and acts as a barrier to weather systems…Read more on The microphysics of clouds over the Antarctic Peninsula – Part 1: Observations
1 December, 2016 by Keith Nicholls
Petermann Gletscher in North Greenland features the second largest floating ice shelf in the Northern Hemisphere. This paper describes the history of its exploration and presents new ocean and glacier…1 December, 2016 by Bianca Perren, Claire Allen, Dominic Hodgson, Louise Sime, Stephen Roberts, Thomas Bracegirdle
Latitudinal shifts in the Southern Ocean westerly wind jet could drive changes in the glacial to interglacial ocean CO2 inventory. However, whilst CMIP5 model results feature consistent future-warming jet shifts,…1 December, 2016 by Adrian Jenkins, Satoshi Kimura
Ice shelves around Antarctica are vulnerable to an increase in ocean-driven melting, with the melt rate depending on ocean temperature and the strength of flow inside the ice-shelf cavities. We…Read more on Ocean mixing beneath Pine Island Glacier ice shelf, West Antarctica
25 November, 2016 by Mai Mai Lam
We review recent research articles that present observations of the large-scale day-to-day dynamic tropospheric response to changes in the downward current density Jz of the global atmospheric electric circuit (GEC).…22 November, 2016
The British Antarctic Survey VLF database from Halley (L = 4.3) and Faraday (L = 2.3) stations, Antarctica, has been searched for clear examples of whistler-triggered emissions (WTEs). Dominant events…Read more on Numerical simulation of whistler-triggered VLF emissions observed in Antarctica
10 November, 2016 by Michael Thorne
The Antarctic nematode Panagrolaimus sp. DAW1 is one of the only organisms known to survive extensive intracellular freezing throughout its tissues. Although the physiological mechanisms of this extreme adaptation are…1 November, 2016
Iceberg calving and increased ice discharge from ice-shelf tributary glaciers contribute significant amounts to global sea-level rise (SLR) from the Antarctic Peninsula (AP). Owing to ongoing ice dynamical changes (collapse…1 November, 2016 by Katrin Linse
The Antarctic marine environment is a diverse ecosystem currently experiencing some of the fastest rates of climatic change. The documentation and management of these changes requires accurate estimates of species…Read more on DNA barcoding uncovers cryptic diversity in 50% of deep-sea Antarctic polychaetes
1 November, 2016 by Richard Phillips
Many marine predators migrate between breeding and non-breeding areas to target resources that are seasonal but spatio-temporally predictable, and so are vulnerable to climate-induced changes in prey phenology and abundance.…1 November, 2016 by Richard Phillips
The Arctic is a highly seasonal environment with a harsh climate and extensive sea ice cover during the winter. Consequently, most Arctic-breeding seabirds migrate south to reach more benign environmental…1 November, 2016 by Melody Clark, Victoria Sleight
The Antarctic clam Laternula elliptica lives almost permanently below 0 °C and therefore is a valuable and tractable model to study the mechanisms of biomineralisation in cold water. The present study…Read more on An Antarctic molluscan biomineralisation tool-kit
1 November, 2016
Summary 1.Heterozygosity–fitness correlations (HFCs) have been widely used to explore the impact of inbreeding on individual fitness. Initially, most studies used small panels of microsatellites, but more recently with the…Read more on inbreedR : an R package for the analysis of inbreeding based on genetic markers
1 November, 2016 by Anna Jones, David Newnham
The sub-millimetre is an understudied region of the Earth's atmospheric electromagnetic spectrum. Prior technological gaps and relatively high opacity due to the prevalence of rotational water vapour lines at these…28 October, 2016 by Adrian Jenkins, Povl Abrahamsen, Keith Nicholls
We present subannual observations (2009–2014) of a major West Antarctic glacier (Pine Island Glacier) and the neighboring ocean. Ongoing glacier retreat and accelerated ice flow were likely triggered a few…Read more on Sensitivity of Pine Island Glacier to observed ocean forcing
26 October, 2016 by Claire Waluda, Derren Fox, Jennifer Jackson, Michael Dunn, Stacey Adlard
We report long-term changes in population size of three species of sympatrically breeding pygoscelid penguins: Adélie (Pygoscelis adeliae), chinstrap (Pygoscelis antarctica) and gentoo (Pygoscelis papua ellsworthii) over a 38 year…24 October, 2016 by Peter Convey
Most climate and environmental change models predict significant increases in temperature and precipitation by the end of the 21st Century, for which the current functional output of certain symbioses may…16 October, 2016 by Richard Horne
Magnetosonic waves and electromagnetic ion cyclotron (EMIC) waves are important for electron acceleration and loss from the radiation belts. It is generally understood that these waves are generated by unstable…16 October, 2016 by Paul Holland
Previous work have shown that sea ice variability in the South Pacific is associated with extratropical atmospheric anomalies linked to the Southern Oscillation (SO). Over a 32 year period (1982–2013), our…Read more on Linked trends in the South Pacific sea ice edge and Southern Oscillation Index
15 October, 2016 by Fausto Ferraccioli, Tom Jordan
The relative roles of climate and tectonics in mountain building have been widely debated. Central to this debate is the process of flexural uplift in response to valley incision. Here…Read more on Erosion-driven uplift in the Gamburtsev Subglacial Mountains of East Antarctica