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 Reporter August 2015 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds

People & Company News

MN 100: Gencorp Insurance Group

The Company: Gencorp Insurance Group provides the Insurance and Surety needs of Marine Contractors, Vessel Operators and Shipyards throughout the country and Caribbean.

MN 100: Bordelon Marine

The Company: Founded in 1979, Bordelon Marine is a leading provider of Marine Transportation services operating in the Gulf of Mexico and around the world. The

MN 100: Bouchard Transportation

The Company: Bouchard Transportation’s history dates back to its incorporation in 1918 by founder, Capt. Fred Bouchard, the youngest tugboat captain in the Port of New York.

Technology

MN 100: ContainerTug B.V.

The Company: ContainerTug B.V. is a specialized Dutch naval design engineering and construction company with a strong focus on developing workboats and the evaluation

Exhaust Gas Scrubber Guide Updated

An updated version of the “Exhaust Gas Cleaning Systems Selection Guide” is now available, the U.S. Maritime Administration (MARAD) announced today.   Developed

Damen's Ship with Van der Velden FLEX Tunnel Commissioned

The first ship outfitted with the Van der Velden FLEX Tunnel was named Friday, August 14th in Duisburg. The Rhenus Duisburg, the new barge combination from shipping company Rhenus PartnerShip,

Environmental

Panama Canal Suspends Draft Restriction

The Panama Canal Authority (ACP) has lifted scheduled vessel draft restrictions brought on by lingering draught conditions in the region.   The ACP had previously set restrictions of 11.

Exhaust Gas Scrubber Guide Updated

An updated version of the “Exhaust Gas Cleaning Systems Selection Guide” is now available, the U.S. Maritime Administration (MARAD) announced today.   Developed

Tropical Storm Erika Heads for Florida

Tropical Storm Erika lashed Puerto Rico and the Virgin Islands with heavy rain and fierce winds on Friday, moving across the Caribbean and apparently heading for the Dominican Republic,

Arctic Operations

Wärtsilä Scrubbers for Finnlines Vessels

Finnlines, a Ro-Ro and passenger vessel operator with services in the North and Baltic Seas, has contracted Wärtsilä to supply three vessels with exhaust cleaning scrubber systems.

Yamal LNG Arctic Project in Doldrums

The massive $27 billion Yamal LNG liquefied-natural-gas venture in the Arctic Circle, a centerpiece of President Vladimir Putin’s plan for Russia has been squeezed by U.

US Navy Sub Completes Arctic Deployment

Fast-attack submarine USS Seawolf (SSN 21) returned to its homeport of Naval Base Kitsap-Bremerton August 21, following a six-month Arctic deployment during which

Ocean Observation

Tropical Storm Erika Heads for Florida

Tropical Storm Erika lashed Puerto Rico and the Virgin Islands with heavy rain and fierce winds on Friday, moving across the Caribbean and apparently heading for the Dominican Republic,

Russian-Chinese Naval Drills End

The second phase of the Russian-Chinese Joint Sea-2015 naval maneuvers has officially ended outside the port of Vladivostok in Russia’s Far East, says spokesman

Shipping Lines Cut CO2 Emissions

The container carriers have managed to reduce their combined CO2 emissions by around one third since 2009, according to a new report.   Average CO2 emissions

 
 
Maritime Careers / Shipboard Positions Maritime Contracts Maritime Security Maritime Standards Navigation Offshore Oil Pod Propulsion Shipbuilding / Vessel Construction 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: 0.6515 sec (2 req/sec)