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 October 2014 Digital Edition
FREE Maritime Reporter Subscription
Latest Maritime News    rss feeds

People & Company News

NAVCENT Commander Recognizes Journey of Hope Sailors

Commander, U.S. Naval Forces Central Command, U.S. 5th Fleet, Combined Maritime Forces, Vice Adm. John. W. Miller, recognized the accomplishments of three special-needs sailors from the Kuwaiti ship,

NYK Holds 8th Environmental Management Conference

NYK welcomed about 60 environmental supervisors from 47 NYK Group companies to the group’s annual Environmental Management Conference in Tokyo. NYK holds this

W&O, LESER Partner to Deliver Safety Relief Valves

W&O, a global supplier to the marine and upstream oil and gas markets for pipe, valves and fittings, valve automation and engineered solutions, has partnered with

Technology

World’s First LNG-Ready Ultra Large Container Ship Named

The race is on in global maritime circles to be the “world’s first” in every aspect of environmental friendliness, particularly in regards to the incorporation of LNG as fuel onboard commercial ships.

Wärtsilä Integrated Solutions for Maersk's AHTS Vessels

A new series of six Anchor Handling Tug Supply vessels to be built at the Kleven Verft AS in Norway for the Danish based Maersk Supply Service A/S - part of the A.

ClassNK Approves Niigata Dual-fuel Engine Design

Classification society ClassNK has granted approval to the design of the new 28AHX-DF dual-fuel engine developed by Niigata Power Systems Co., Ltd. The new engine

Environmental

World’s First LNG-Ready Ultra Large Container Ship Named

The race is on in global maritime circles to be the “world’s first” in every aspect of environmental friendliness, particularly in regards to the incorporation of LNG as fuel onboard commercial ships.

NAVCENT Commander Recognizes Journey of Hope Sailors

Commander, U.S. Naval Forces Central Command, U.S. 5th Fleet, Combined Maritime Forces, Vice Adm. John. W. Miller, recognized the accomplishments of three special-needs sailors from the Kuwaiti ship,

MSC Approves SOLAS Amendments

SOLAS amendments to make IGF Code mandatory approved by Maritime Safety Committee   The International Maritime Organization’s (IMO) Maritime Safety Committee (MSC),

Arctic Operations

MSC Approves SOLAS Amendments

SOLAS amendments to make IGF Code mandatory approved by Maritime Safety Committee   The International Maritime Organization’s (IMO) Maritime Safety Committee (MSC),

Production Begins on Sovcomflot’s New MPSV

Arctech Helsinki Shipyard started production of the new icebreaking multipurpose supply vessel   The production of the icebreaking multipurpose supply vessel

Strategy Can Maximize UKCS potential

Companies operating in the North Sea require a cultural shift to make the most of the its potential, according to a new report from Deloitte, the business advisory firm.

Ocean Observation

Thickness of Antarctic Sea Ice Surpass Expectations

Antarctica's ice paradox has yet another puzzling layer. Not only is the amount of sea ice increasing each year, but an underwater robot now shows the ice is

Everett College to Launch New Research Boat

Everett Community College’s Ocean Research College Academy (ORCA) will launch its new research vesel on November 22 with a celebration at 11 a.m. at the Port of Everett.

IMO Steps Up Safety in Polar Waters

United Nations’ International Maritime Organization (IMO) has adopted global, binding regulations to enhance safety of navigation in polar waters. After several years’ intense negotiations,

 
 
Maritime Careers / Shipboard Positions Maritime Standards Navigation Offshore Oil Salvage Ship Electronics Ship Repair Shipbuilding / Vessel Construction Sonar Winch
rss | archive | history | articles | privacy | terms and conditions | 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: 0.4898 sec (2 req/sec)