MarineBusiness-World.com
 
 
News Home FishingBoating Photo Gallery Australian Cruising Sail-World Australia
Sail-World.com : Unknown mechanism which breaks up tabular icebergs at sea discovered
Unknown mechanism which breaks up tabular icebergs at sea discovered

'Operation Iceberg'    BBC    Click Here to view large photo

A previously unknown mechanism by which large tabular icebergs break up out at sea, as part of a study carried out on the Peterman Iceberg in Baffin Bay over the summer, has been discovered by an international team of scientists. Scientists observed that the gradual creation of a huge underwater ice foot produced so much buoyancy that it broke large chunks off the main iceberg thus causing the iceberg to slowly disintegrate. This discovery was captured on camera as a film crew followed the expedition for Operation Iceberg, a two part BBC Two series going out this week.

Scientists have long assumed the decay of icebergs was either caused by wave action physically splitting them apart, or by warmer sea water gradually melting them. The truth now appears to be an interesting combination of factors. During the arctic expedition, scientists found that warm surface water, aided by wave action, erodes a deep notch around the edge of the iceberg. This notch is at water level, and the unsupported ice above the notch quickly sloughs away. Over time this creates a large underwater 'ram' or ice foot sticking out which is protected by colder, deeper water. This underwater ram creates so much buoyant upwards pressure that it finds a weak point within the iceberg which then snaps off. This can be a sizeable chunk of ice. During filming for Operation Iceberg, camera crews and scientists were aboard the iceberg when a chunk of ice, 200m by 50m, broke off in this way.

Operation Iceberg - BAS scientist Dr Keith Nicholls -  BBC   Click Here to view large photo

Dr Keith Nicholls of the British Antarctic Survey was on the two week expedition. He argues that the notch is the key start to this process. In the programme he says: 'The reason this iceberg is breaking up really fast in front of us is all about what’s happening at the wave cut in the warm water layer right at the surface.'

Also on the expedition was one of the world leading experts on ice science, Prof Peter Wadhams of Cambridge University, who believes their observation of the process is unique: 'We have discovered a new mechanism. People don’t normally sit beside melting icebergs in a ship. Normally when they come across an iceberg they give it a wide berth. So in a way, we’re the first people to be doing it.'

Alon Stern of New York University was responsible for taking the temperature measurements of the sea water around the iceberg, including key data gathered by the BBC’s dive team. These readings confirmed that the deeper water measured -1.5 degrees Celsius, and was therefore able to protect the ice foot from melting.

Understanding the mechanism by which icebergs break up is important for shipping in the North Atlantic. It is also becoming clear that because of climate change, the number of tabular icebergs in Arctic seas is increasing. Keith Nicholls added: 'In recent years we’ve been seeing a lot more big tabular icebergs come off the Greenland ice sheet and they’re now ending up in Baffin Bay. That’s a change and the only reason that can change is because the climate around Greenland is changing.'

To watch the team in action, tune into Operation Iceberg, at 9pm on BBC Two on Tuesday 30th of October and Thursday first of November.

You can read Dr Keith Nicholls' blog here.

British Antartic Survey website


by British Antarctic survey/BBC Operation Iceberg

  

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

http://www.marinebusiness-world.com/index.cfm?nid=103439

10:21 AM Fri 2 Nov 2012GMT


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







Marine Business News





UK superyacht industry on the rise by British Marine Federation,




















Predictwind helps you pick the best time to depart by Richard Gladwell Sail-World.com/nz,










































Boat Shows - the engine powering the boating industry
'Honey, Let's Go Boating!' next best-seller for Finkelstein *Feature
2014 Brisbane Boat Show - Set to add new features
Collinson FX Market Commentary: July 19, 2014 - Step into Wonderland
European Commission to take UK to court over red diesel
Understanding the Ocean's role in Greenland Glacier melt
America's Cup: Updates on Team Australia withdraw
2016-2017 America's Cup - Team Australia withdraws
Collinson FX Market Commentary: July 18, 2014 - AUD moves up
Collinson FX Market Commentary: July 17, 2014 - KIWI takes hammering
Revealing report on Search for American yacht Nina released *Feature
ECOfishers and AMA to establish NSW Fisheries Taskforce
PredictWind's Weather Routing opens your navigation options - try it!
Collinson FX Market Commentary: July 16, 2014 - Oz confirms low rates
Cameron Appleton joins North Sails
National 4x4 Outdoors Show - Unprecedented exhibitors expected
New-to-New Zealand products at the Auckland On Water Boat Show
Auckland on the Water Boat Show: Two new Bavaria yachts on display
AYSS PacificNet/Tahiti voted a success!
Collinson FX Market Commentary: July 15, 2014 - Rising interest hits
July 2014 edition of Finnfare has been published   
Taiwan's first marina a Superior effort *Feature   
Vaavud launches generation 2 wind meter   
Research highlights marinas economic, social and environmental benefit   
Solar 1 Monte Carlo Cup 2014 - Monaco sunshine new fuel for motorboats   
Hamilton Island Audi Race Week 2014 - Accommodation options   
Rio cleaning up its act in the lead up to Olympic sailing test event *Feature   
Collinson FX Market Commentary: July 12, 2014 - KIWI heads to 90c   
National Squib Owners Association and Rondar Raceboats join forces   
Collinson FX Market Commentary: July 11, 2014 - Portugal bank defaults   
Sydney International Boat Show updates   
Portland’s new state-of-the-art boat ramp officially opened   
Collinson FX Market Commentary: July 10, 2014 - KIWI hits higher   
SECUMAR appoint new sales director   
Collinson FX Market Commentary: July 9, 2014 - New stat pushes ANZACs   
Your invitation to the Seawind 1160 LITE World launch   
APSNZ appoints Duthie Lidgard as new MD   
Abell Point Marina looking shipshape   
Oceanis 48 at the Sydney International Boat Show   
Bar Crusher's fully-enclosed fishing weapons   


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/FaceBook-icon.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 MBW
LocalAds   DE  ES  FR  IT