Powerboat-World.com
 
 
News Home Video Gallery Newsletters Features FishingBoating Photo Gallery Sail-World Australia Australian Cruising
Sail-World Australia Australian Cruising MarineBusiness-World

 

Sail-World.com : Under the ice sheet

Under the ice sheet

'The ICECAP team with the Basler aircraft used for the survey (Photo: Todor Iolovski)'    Australian Antarctic Division ©

An international team has shed new light on what lies beneath a large slice of the East Antarctic ice sheet. The research reveals a vast, smooth and deep bedrock basin, reaching more than a kilometre below sea level, bordered by rugged mountain ranges which are cut by broad valleys. Interpreting this buried landscape has brought new insights into the early development of the Antarctic ice sheet.

The research, by scientists including those from the Australian Antarctic Division and the Antarctic Climate and Ecosystems Cooperative Research Centre (ACECRC), was published today in the journal Nature. This important scientific paper illuminates a 20-million-year period of repeated growth and retreat of the ice sheet following initial Antarctic glaciation around 34 million years ago. It shows a geological connection with past climate changes, helps us understand how climate and the ice sheet interact, and connects the ice with changes in past and perhaps future sea level.

The paper is focused on a key geological feature in East Antarctica, the Aurora Subglacial Basin (ASB). This extends more than 1000 kilometres inland from Australia’s Casey Station and is overlain by some of the thickest ice in Antarctica, While scientists knew of its existence from Australian ground survey work in the 1970s, this project, called ICECAP, has provided the first detailed understanding of the early development of the ice sheet that now fills the basin.

'We're seeing what the ice sheet looked like at a time when Earth was much warmer than today,' said Duncan Young, research scientist at the University of Texas at Austin's Institute for Geophysics and lead author of the paper. 'Back then it was very dynamic, with significant surface melting. Today, the ice sheet is a bit more well behaved.'

However, satellites have recently detected thinning of the Aurora Basin’s major outlet glacier near the coast, raising concerns about this sector of Antarctica in a warming climate.

Accurate maps of regions like the ASB where the ice sheet rests on bedrock below sea-level are important for computer models predicting ice sheet changes and future sea level rise. One of the Australian authors, glaciologist Roland Warner, said the bedrock of this area had been poorly known until now. 'We knew more about the surface of Mars than about this part of our own planet.'

The new research shows the full extent of the basin, bounded on the East and West by sharp mountain ranges. 'The most exciting discovery is that these mountains are cut through by very wide, deep, smooth fjords sculpted by ice,' Dr Warner said.

'We know from sea sediment records that sea levels varied during this period (34-14 million years ago) and it is likely that these massive fjords were excavated by several episodes as the ice sheets advanced through the basin to the continental margins and retreated back to the high central subglacial mountains of East Antarctica.'

The paper, with authors from Australia, the UK and the US, is the first major product from the ICECAP project – a collaboration begun in 2007 aimed at exploring the little-known ice thickness and bedrock properties of East Antarctica.

In the Antarctic field seasons of 2008-9 and 2009-10 scientists flew 47,000 kilometres of survey lines from Casey. The area surveyed corresponds to a semicircle centred on Sydney and stretching from Hobart, out beyond Broken Hill and up to Brisbane. High resolution ice-penetrating radar was used to capture the rock surface under the ice sheet and layers within ice up to 4.5 km thick, providing insight into bedrock conditions and past ice flow.

ICECAP stands for Investigating the Cryospheric Evolution of the Central Antarctic Plate. The Australian authors on the Nature paper are glaciologists Jason Roberts, Roland Warner, Neal Young and Tas van Ommen, all from the Australian Antarctic Division and members of the ACE CRC Cryosphere Program.

The Basler aircraft used in the ICECAP project (Photo: Paul Hellerman) -  Australian Antarctic Division?nid=85288_©  

The ICECAP plane taking off (Photo: Jack Holt) -  Australian Antarctic Division?nid=85288_©  

Australian Antarctic Division Glaciologist Tas van Ommen with radar equipment onboard the Basler (Photo: Tas van Ommen) -  Australian Antarctic Division?nid=85288_©  

Australian Antartic Division website




by Australian Antarctic Division

  

Click on the FB Like link to post this story to your FB wall

http://www.powerboat-world.com/index.cfm?nid=85288

11:57 AM Wed 29 Jun 2011 GMT






Click here for printer friendly version
Click here to send us feedback or comments about this story.


Power Boat News















You scratched my seagrass! by Steven Katona, Newport, RI


Join us on Boating Safety Day on 28 September by Roads and Maritime Services,






Dangerous conditions forecast for NSW boaters by Roads and Maritime Services,










Abbot Point onshore disposal by Great Barrier Reef Marine Park Authority,










Great Barrier Reef plan released for comment by Queensland Minister for Environment,










Brisbane Boat Show begins *Feature by Jeni Bone,














Brisbane Boat Show starts Friday - biggest in 10 years! *Feature
Marine Auctions adds new recruits
Ministerial advisory group launched by united marine industry sector
2014 Auckland on Water Boat Show: Coming up at the end of September
Australian research sheds light on ocean garbage gyres *Feature
Round the World racer joins Southern Pacific Inflatables
2014 Gold Coast Int'l Marine Expo - Quintrex factory opens its doors
Mediterranean Grand Prix - Pons and Chris win the titles
18 anti-piracy weapons for ships to fight pirates
Skysol Frame Large: A new shading solution for sunroofs
Mediterranean Grand Prix 2014 - Wins for Victory and Chaudron
Mediterranean Grand Prix, UIM-ABP Tour: Pons claims Runabout GP1 win
Mediterranean Grand Prix - Al Zaffain and Bin Hendi win race 1
Court judgement a stark reminder about towing safety
Australian Offshore Superboat 2014 - Superboats ready for Redcliffe
Southport Yacht Club’s annual Sail Past and Blessing of Fleet Ceremony
Gosport Grand Prix of the Sea finale to decide P1 champions
Camper & Nicholsons Yachts presents the Sagitta 42
GT15 and GT30 European Championships - Jelf takes to the podium twice
Marine Rescue crew saves cruiser in trouble in rough conditions
XCAT Series gets set to conquer another continent in 2015   
Dangerous conditions for boaters on most of NSW coast   
2014 Mandurah Boat Show - Third largest boat show in Australia   
2014 Gold Coast International Marine Expo - Eye on the big picture   
Mediterranean Grand Prix - Powerboat racing heavyweights head to Ibiza   
Mediterranean Grand Prix - World Aquabike stars all set   
Antarctic sea-level rising faster than global rate   
Powerboat champions gear up for Honda RYA Youth RIB National final   
Andrew Scott joins Superior as General Manager *Feature   
2014 Gold Coast International Marine Expo - Fastest Jet Ski ever built   
Best Birthday Party ever at Southport Yacht Club! *Feature   
‘Hall of Fame’ status for Empire Marina *Feature   
Girl power all set for Nottingham powerboat racing action   
Cowes to Torquay Race 2014 - Intense activity in preparation   
Fort Lauderdale International Boat Show - 13 things to See and do   
Australian Offshore Superboat Champ - 15 Superboats in Coffs Harbour   
European première for Belize 54 Daybridge at Cannes Yachting Festival   
‘Fish Friendly’ accreditation for Sanctuary Cove Marina   
Plethora of Powerboat racing action this weekend   
Vicsail Boat show Open Day at Rushcutters Bay   


For this week's complete news stories select    Last 7 Days
   Search All News
For last month's complete news stories select    Last 30 Days
   Archive News







Sail-World.com  


















Switch Default Region to:

Social Media

Asia

Australia

Canada

Europe

New Zealand

United Kingdom


http://www.sail-world.com/event_images/image/Twitter_logo_small.png   http://www.sail-world.com/event_images/image/RSS-Icon.png

United States

Cruising Northern

Cruising Southern

MarineBusiness World

PowerBoat World

FishingBoating World

 

Contact

Commercial

News

Search

Contact Us

Advertisers Information

Submit news/events

Search Stories/Text

Feedback

Advertisers Directory

Newsletter Archive

Photo Gallery

 

Banner Advertising Details

Newsletter Subscribe

Video Gallery

Policies

 

 

 

Privacy Policy

 

 


Cookie Policy

 

 



This site and its contents are © Copyright TetraMedia and/or the original author, photographer etc. All Rights Reserved.  Photographs are copyright by law.  If you wish to use or buy a photograph contact the photographer directly.
XLXL NEW PBW
LocalAds   DE  ES  FR  IT