Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Highs and lows: height changes in the ice sheets mapped

20.08.2014

Researchers from the Alfred Wegener Institute in Germany have used satellite data to map elevation and elevation changes in both Greenland and Antarctica.

The new maps are the most complete published to date, from a single satellite mission. They also show the ice sheets are losing volume at an unprecedented rate of about 500 cubic kilometres per year. The results are published today in The Cryosphere, an open access journal of the European Geosciences Union (EGU).


New elevation models of Greenland and Antarctica derived from CryoSat-2. Areas in red are higher than areas in blue. Helm et al., The Cryosphere, 2014

“The new elevation maps are snapshots of the current state of the ice sheets,” says lead-author Veit Helm of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), in Bremerhaven, Germany. The snapshots 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 – about the size of Spain.”

Satellite altimetry missions measure height by bouncing radar or laser pulses off the surface of the ice sheets and surrounding water. The team derived the maps, which show how height differs across each of the ice sheets, using just over a year’s worth of data collected in 2012 by the altimeter on board the European Space Agency satellite CryoSat-2. These 'digital elevation models’ incorporate a total of 7.5 million elevation measurements for Greenland and 61 million for Antarctica.

In addition to showing the highs and lows of the ice sheets at present, the study also highlights 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. The researchers say it’s important to understand how ice thickness across Greenland and Antarctica has changed to model ice movements, and find out just how much ice sheets contribute to sea level rise.

The team derived the elevation change maps using a staggering 200 million data points for Antarctica and 14.3 million for Greenland collected by CryoSat-2 over the three-year period. The maps published in The Cryosphere reveal that Greenland alone is reducing in volume by about 375 cubic kilometres per year.

The two ice sheets combined are thinning at a rate of 500 cubic kilometres per year, the highest rate observed since altimetry satellite records began about 20 years ago. The researchers say the ice-sheets annual contribution to sea level rise doubled since 2009.

“Since 2009, the volume loss in Greenland has increased by a factor of about 2, and in the West Antarctic Ice Sheet by a factor of 3,” says AWI glaciologist Angelika Humbert, another of the study’s authors. Both the West Antarctic Ice Sheet and the Antarctic Peninsula, on the far west of the continent, are rapidly losing volume. By contrast, East Antarctica is gaining volume, though at a moderate rate that doesn’t compensate the losses on the other side of the continent.

The areas where the researchers detected the largest elevation changes were Jakobshavn Isbrae (Jakobshavn Glacier) in Greenland – recently found to be moving ice into the ocean faster than any other ice-sheet glacier – and Pine Island Glacier (PIG) in Antarctica. The new study confirms that PIG, like other glaciers in the West Antarctic, has been thinning rapidly in recent years.

The researchers highlight the role of CryoSat-2 and its radar altimeter (also known as SIRAL) in producing the height maps, particularly in regions where the surface slopes steeply and elevation changes are more pronounced. “These areas can be difficult to measure, but SIRAL enabled us to continuously observe the surface of the ice sheets with high precision and dense coverage, better than any previous system,” says Helm.

Please mention the name of the publication (The Cryosphere) if reporting on this story and, if reporting online, include a link to the paper (TBA) or to the journal website (http://www.the-cryosphere.net).

*More information*
This research, funded by the German Ministry of Economics and Technology, is presented in the paper ‘Elevation and elevation change of Greenland and Antarctica derived from CryoSat-2’ to appear in the EGU open access journal The Cryosphere on 20 August 2014.

The scientific article is available online, free of charge, from the publication date onwards, at http://www.the-cryosphere.net/recent_papers.html. *A pre-print version of the paper and accompanying images are available for download at http://www.egu.eu/news/120/highs-and-lows-height-changes-in-the-ice-sheets-mappe....*

The team is composed of Veit Helm, Angelika Humbert and Heinrich Miller from the Glaciology Section of the Alfred Wegener Institute, the Helmholtz Centre for Polar and Marine Research in Bremerhaven, Germany.

The *European Geosciences Union (www.egu.eu)* is Europe’s premier geosciences union, dedicated to the pursuit of excellence in the Earth, planetary, and space sciences for the benefit of humanity, worldwide. It is a non-profit interdisciplinary learned association of scientists founded in 2002. The EGU has a current portfolio of 16 diverse scientific journals, which use an innovative open access format, and organises a number of topical meetings, and education and outreach activities. Its annual General Assembly is the largest and most prominent European geosciences event, attracting over 11,000 scientists from all over the world. The meeting’s sessions cover a wide range of topics, including volcanology, planetary exploration, the Earth’s internal structure and atmosphere, climate, energy, and resources. The EGU 2015 General Assembly is taking place in Vienna, Austria, from 12 to 17 April 2015. For information regarding the press centre at the meeting and media registration, please check http://media.egu.eu closer to the time of the conference.

If you wish to receive our press releases via email, please use the Press Release Subscription Form at http://www.egu.eu/news/subscribe/. Subscribed journalists and other members of the media receive EGU press releases under embargo (if applicable) 24 hours in advance of public dissemination.

Weitere Informationen:

http://www.egu.eu/news/120/highs-and-lows-height-changes-in-the-ice-sheets-mappe...
http://www.the-cryosphere.net/

Dr. Bárbara Ferreira | European Geosciences Union

Further reports about: AWI Antarctic Antarctica CryoSat-2 EGU Geosciences Greenland Polar satellite

More articles from Earth Sciences:

nachricht Climate change weakens Walker circulation
20.10.2017 | MARUM - Zentrum für Marine Umweltwissenschaften an der Universität Bremen

nachricht Shallow soils promote savannas in South America
20.10.2017 | Senckenberg Forschungsinstitut und Naturmuseen

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>