Record Decline of Greenland & Antarctic Ice Sheets

By George Backwell
Wednesday, August 20, 2014
Arctic scene: File photo

Researchers from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), have for the first time extensively mapped Greenland’s and Antarctica’s ice sheets with the help of the ESA satellite CryoSat-2 and have thus been able to prove that the ice crusts of both regions momentarily decline at an unprecedented rate.

In total the ice sheets are losing around 500 cubic kilometres of ice per year. This ice mass corresponds to a layer that is about 600 metres thick and would stretch out over the entire metropolitan area of Hamburg, Germany's second largest city.

“The new elevation maps are snapshots of the current state of the ice sheets. The elevations are very accurate, to just a few metres in height, and cover close to 16 million km2 of the area of the ice sheets. This is 500,000 square kilometres more than any previous elevation model from altimetry”, says lead-author Dr. Veit Helm, glaciologist at the Alfred Wegener Institute in Bremerhaven.

For the new digital maps, the AWI scientists had evaluated all data by the CryoSat-2 altimeter SIRAL. Satellite altimeter measure the height of an ice sheet by sending radar or laser pulses in the direction of the earth. These signals are then reflected by the surface of the glaciers or the surrounding waters and are subsequently retrieved by the satellite. This way the scientists were able to precisely determine the elevation of single glaciers and to develop detailed maps.

On the basis of further CrysoSat-2 the scientists also documented how the elevation has changed over the 2011–2014 period. Ice sheets gain mass through snowfall and lose it due to melting and accelerating glaciers, which carry ice from the interior of the ice sheet to the ocean. “We need to understand where and to which extent the ice thickness across the glaciers has changed. Only then can we can analyse the drivers of these changes and find out how much ice sheets contribute to global sea level rise”, says Veit Helm.

The team derived the elevation change maps using over 200 million SIRAL data points for Antarctica and around 14.3 million data points for Greenland. The results reveal that Greenland alone is reducing in volume by about 375 cubic kilometres per year.

“When we compare the current data with those from the ICESat satellite from the year 2009, the volume loss in Greenland has doubled since then. The loss of the West Antarctic Ice Sheet has in the same time span increased by a factor of 3. Combined the two ice sheets are thinning at a rate of 500 cubic kilometres per year. That is the highest speed observed since altimetry satellite records began about 20 years ago,” says AWI glaciologist Prof. Dr. Angelika Humbert, another of the study’s authors.

The areas where the researchers detected the largest elevation changes were Jakobshavn Isbrae (Jakobshavn Glacier) in West Greenland and Pine Island Glacier in West Antarctica. Since February 2014 scientists know that the Jakobshavn Isbrae is moving ice into the ocean at a record rate of up to 46 meters a day. The Pine Island Glacier hit the headlines in July 2013. Back then AWI scientists reported that a table iceberg as large as the area of Hamburg had broken off the tip of its ice shelf.

But whereas both the West Antarctic Ice Sheet and the Antarctic Peninsula, on the far west of the continent, are rapidly losing volume, East Antarctica is gaining volume – though at a moderate rate that doesn’t compensate the losses on the other side of the continent.

The maps and results of this study are published in 'The Cryosphere', an open access journal of the European Geosciences Union (EGU).

Source: Alfred Wegener Institute
 

Maritime Today


The Maritime Industry's original and most viewed E-News Service

Maritime Reporter February 2016 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds

People & Company News

SunEdison Restrained from 'Unusual' Asset Transfers

Solar company SunEdison Inc said a U.S. court has restrained the company from making any unusual asset transfers until a hearing in a lawsuit brought on by investors

Maersk to Scrap Ships at India's Alang Beaches, NGO Dismayed

Maersk Line said on Friday it had chosen four shipbreaking yards along India's Alang beaches to handle an increase in vessels that need to be scrapped, to the dismay

Teknotherm Marine Moves HVAC Arm to Bergen

Maritime heating, ventilation and air conditioning (HVAC) firm Teknotherm Marine has established a new subsidiary is established with the name Teknotherm Marine HVAC AS.

Technology

Sentinel Launches New Rudder Feedback Unit

Sentinel, a Beier Radio company, has designed and manufactured a new Rudder Feedback Unit (RFU) with many new features, including watertight components and connections

Innovative Equipment Will Help Unload Listing Ship

Following Smit Salvage’s salvage of the stricken ship Modern Express in the Gulf of Biscay, another Rotterdam company has now become involved in the rescue operations.

Sea IT, Veritas Tankers Ink Long-term Software Deal

Sea IT has entered a long term ICT agreement with Veritas Tankers. The agreement comprises installation of BlueCORE Generation 4, an ICT platform specifically developed for the marine industry,

Environmental

Brazil's CEEE to sell stakes in Wind Farms, Dams

Brazil's Companhia Estadual de Energia Elétrica (CEEE), a power utility controlled by the state of Rio Grande do Sul, will sell assets including stakes in wind farms,

Submarine Tourism in Turkey's Waters

The first tourist submarine in Turkey is waiting to be sent on a voyage that will reveal the wonders of the undersea world of the Mediterranea.   The first submarine

Cautious Optimism on Pacific NorthWest LNG Report

Canadian Environmental Assessment Agency (CEAA)  has ruled that Pacific NorthWest LNG’s project in British Columbia would likely harm harbour porpoises and contribute to climate change,

Arctic Operations

Helsinki, Tyumen State Universities to form Arctic station

Within the framework of the international project Reeh, Tyumen State University in cooperation with the University of Helsinki are planning to create a unique Arctic observation stations.

U.S. Okays ConocoPhillips Alaska LNG Exports

The U.S. Department of Energy approved ConocoPhillips' application to export about 40 billion cubic feet of natural gas from its Kenai liquefied natural gas export

IOCs Stress on OSV Fuel Management Performance

Growing insistence by international oil companies (IOCs) that oilfield contract vessels (OSVs) are fitted with fuel monitoring systems has prompted an upsurge in

Ocean Observation

UK to Double NATO Naval Deployments in 2016

Britain is doubling its naval deployments to North Atlantic Treaty Organization (NATO) in a move aimed a showing enemies that "we are ready to respond to any threat",

CMA-CGM and Cosco Alliance in the Offing?

The newly-formed shipping giant China Cosco Shipping Corporation and CMA CGM met recently in Shanghai to discuss the possibility of a new French-Asian alliance, say local Chinese media.

Bangladesh, Thailand Plans Direct Coastal Shipping

Bangladesh and Thailand are planning to launch direct coastal shipping, connecting the Chittagong Port in the Bay of Bengal with the Ranong Port in the East of

 
 
Maritime Contracts Maritime Standards Naval Architecture Navigation Offshore Oil Pod Propulsion Port Authority Ship Electronics Sonar Winch
rss | archive | history | articles | privacy | contributors | top maritime news | about us | copyright | maritime magazines
maritime security news | shipbuilding news | maritime industry | shipping news | maritime reporting | workboats news | ship design | maritime business

Time taken: 0.0852 sec (12 req/sec)