Powerboat-World.com
 
 
News Home Video Gallery Newsletters FishingBoating Features 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





























Fort Lauderdale International Boat Show - 13 things to See and do by Fort Lauderdale International Boat Show,






























Yamaha inspires students to succeed by Yamaha Motor Australia,








Swan celebrates sales success *Feature
4x4 Outdoors Show and Fishing and Boating Expo on the horizon
Polar research: Six priorities for Antarctic science
Stealth i14 out of China
Bivalves' ability to clean chemicals from waterways
Brisbane Boat Show 2014 - New boat engines set to rev up interest
Two rescued in tow from 13km offshore
Enhancing boating safety in the Mallacoota region
National 4x4 Outdoors Show and Fishing and Boating Expo - 4WD heaven
Yanmar selected for big torque at low revs
Sydney Boat Show display winners recognised *Feature
China Yachting Conference lines up the speakers
2014 National 4x4 Outdoors Show: Popularity of caravanning and camping
2015 Sydney Inte'l Boat Show - Boating Industry commences planning
Last chance to join 2014 Multihull Solutions Whitsunday Rendezvous
Dangerous conditions for boaters from this evening
Pacific Boating membership offers hassle-free boating *Feature
Marine15 expands trade, networking and B2B opportunities *Feature
2014 Auckland on the Water Boatshow - Huge prize packs up for grabs
4X4 Outdoors Show and Fishing and Boating Expo wows water lovers
John Wilson has sights set on second P1 SuperStock title   
Torquay Grand Prix - Pertemps tops table on penultimate day   
Plain sailing for yachts with river cargo ship ban in Shanghai   
Dangerous conditions for boaters from this afternoon   
Sydney Int'l Boat Show - Stellar results for Multihull Solutions   
NSW Environment Minister awards 'Fish Friendly' Marina Accreditations   
Refurbished Protector project 'better than buying new'   
Gold Coast International Marine Expo - High-Diver Steve Black is back   
4x4 Outdoors Show, Fishing and Boating Expo - Campfire cooking corner   
See the heat with FLIR ONE *Feature   
John Temple to retire, Will Sangster appointed General Manager   
Multihull Central launches Aquila range at SIBS *Feature   
If all else fails read the instructions!!   
If all else fails read the instructions!!   
Sun shines on recreational boating at Sydney International Boat Show   
Phuket Yacht Show: new kid on the block taking on PIMEX? *Feature   
2014 Offshore Superboat Championships - The boats are back!   
Sydney International Boat Show - Days 3 & 4 *Feature   
Kirby Marine launch 13metre Naiad Tender   
Shellfish reefs in Port Phillip Bay to be rejuvenated   


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