Please select your home edition
Edition
Vaikobi 2024 December

New discovery from Antarctica’s ‘ghost mountains’

by British Antarctic Survey and Lamont-Doherty Observ on 7 Mar 2011
AGAP team British Antarctic Survey http://www.antarctica.ac.uk
The discovery of numerous large ice structures within Antarctica’s Dome A region, the site of the buried ‘ghost mountains’, reveals new understanding about ice sheet growth and movement that is essential for predicting how the ice sheet may change as the Earth’s climate warms.

Reporting this week in the journal Science a six-nation group of scientists studying the Gamburtsev Subglacial Mountains describe how these remarkable structures form. Typically ice sheets grow when layers of snow are deposited on the surface, but the researchers found startling new evidence of growth at the base. Widespread re-freezing of large volumes of water to the underside of the ice sheet modifies its structure. In some places this process can account for up to half the ice sheet’s thickness, and the growth caused by refreezing may be comparable to that occurring at the surface.


The enigmatic Gamburtsev Subglacial Mountains lie buried beneath as much as 3 km (two and a half miles) of ice. An international team mounted an ambitious field campaign to investigate the ice sheet and what lies beneath during the International Polar Year (2007-09).

Lead Author, Dr Robin Bell of Columbia University’s Lamont-Doherty Earth Observatory says, 'We usually think of ice sheets like cakes - one layer at a time added from the top. This is like someone injected a layer of frosting at the bottom - a really thick layer. Water has always been known to be important to ice sheet dynamics, but mostly as a lubricant. As ice sheets change, we want to predict how they will change. Our results show that models must include water beneath.'

Co-Author Dr Fausto Ferraccioli, from British Antarctic Survey says, 'This International Polar Year study provides a unique view on the interactions between subglacial water and ice sheet structure in East Antarctica. Understanding these interactions is critical for the search for the oldest ice and also to better comprehend subglacial environments and ice sheet dynamics. Incorporating these processes into models will enable more accurate predictions of ice sheet response to global warming and its impact on future sea-level rise'.

The refrozen structures form because the vast Antarctic ice sheet acts like blanket trapping geothermal heat from the Earth beneath. This heat, combined with the great pressure from the overlying ice allows ice to melt at the base. When under the ice this water can be pushed uphill, towards mountain ridges where the ice sheet is thinner. This thinner and colder ice refreezes the water, creating the spectacular structures observed close to the base of the ice sheet.

The researchers theorize that this process explains the re-frozen structures appearing at the heads of valleys beneath the ice sheet. This new ice at the base pushes older ice closer to the surface, making the ancient layered record of climate embedded in the ice easier for researchers to reach.

Bell continues, 'When we first saw these [refrozen] ice structures in the field, we thought they looked like beehives and were worried they were an error in the data. As they were seen on many lines, it became clear that they were real. We did not think that water moving through ancient river valleys beneath more than one mile of ice would alter the basic structure of the ice sheet.'

The refrozen ice accounts for up to 24% of the area of the ice sheet base around Dome A, the top of the East Antarctic ice sheet. The scientists suggest that this process has been going on since East Antarctica became encased in a large ice sheet 32 million years ago. Researchers now will now look into how refreezing affects the margins of the Antarctic and Greenland ice sheets, where the most rapid change is occurring.


AGAP © British Antarctic Survey http://www.antarctica.ac.uk
AGAP © British Antarctic Survey
British Antarctic Survey website
Boat Books Australia FOOTERJeanneau Sun Odyssey 350North Sails Loft 57 Podcast

Related Articles

Lightweight Wind Barrier
The Henri-Lloyd Breeze Jacket combines lightweight, waterproof performance with modern design The Henri-Lloyd Breeze Jacket combines lightweight, waterproof performance with modern design, making it the ideal choice for warm-weather sailing and everyday on-water activities.
Posted on 24 May
“Foil4TheGulf” sets Southern Hemisphere record
With over 200 entrants the Black Foils and Live Ocean's event “Foil4TheGulf” raises awareness With over 200 entrants the Black Foils and Live Ocean's event “Foil4TheGulf” to raise awareness for the Hauraki Gulf / Tikapa Moana Marine Protection Bill has become New Zealand's largest ever foiling event by entries.
Posted on 24 May
Tasar Training Made Easy
Hybrid in-person and webinar events in the Victorian Tasar fleet In 2024, the Victorian Tasar fleet expressed strong interest in ongoing training opportunities, ranging from on-the-water sessions to classroom and online formats.
Posted on 24 May
Help shape the future of sailing in Queensland
Help shape the future of sailing in Queensland Ocean Crusaders is conducting the Queensland Yachting Participation Survey to gather insights from sailors across all levels—keelboat, sports boat, and multihull divisions.
Posted on 24 May
Copa del Rey MAPFRE surpasses 100 entries
Still almost two months to go until the start The Copa del Rey MAPFRE continues to exceed expectations — and this year, it's doing so well in advance.
Posted on 23 May
Tasar Australian Nationals preview
51st edition will be held at Wallaroo in January 2026 It won't be long before Tasar sailors around Australia embark on their next Nationals regatta at Wallaroo Sailing club in South Australia. Located on the west coast of SA's stunning Yorke Peninsula, the venue boasts azure blue waters.
Posted on 23 May
America's Cup: Big changes in crew line-up
Women and Youth crews to sail in AC75 in the next Cup - Final Draft of AC38 Protocol Historic changes are proposed in the Final Draft of the Protocol released by the America's Cup Defender. For the first time a Female and Youth crew members will be part of the six-crew lineup on board the all-electric AC75s.
Posted on 23 May
America's Cup: The Blitz of Statements
Various parties associated with the America's Cup released statements calling for more transparency Various parties associated with the America's Cup released statements calling for more transparency in the America's Cup. Emirates Team New Zealand responded by releasing what is tagged as the Final Draft of the Protocol.
Posted on 23 May
IMA Maxi Europeans overall
Bella Mente successfully defends her IMA European Championship title The 20 remaining yachts competing in the IMA Maxi European Championship, organised by the Circolo del Remo e della Vela Italia in conjunction with the International Maxi Association, took part in a final coastal race today in a 8-14 knot southwesterly.
Posted on 22 May
Cape Horn Hall of Fame nominations close by 30 May
Public nominations open for just a little longer The International Association of Cape Horners (IACH) is calling for nominations for new inductees to the Cape Horn Hall of Fame.
Posted on 22 May