Intensified ice sheet movements do not affect rising sea levels

Jul 08, 2008

Meltwater is rapidly increasing the tempo of glacial movements on the rim of the Greenland ice sheet. Over the long term, however, this process is interrupted as meltwater drains away via broad channels, as a result of which ice movement decreases once again. Ultimately, this is not a cause of accelerated sea level rise.

These are the findings presented by researchers from Utrecht University in the 4 July issue of the scientific journal Science.

Scientists from around the world are closely monitoring the Greenland ice sheet, as accelerated glacial melting is believed to cause rising sea level. The theory is that increased volumes of meltwater accelerate the movement of ice to warmer low-lying areas and, consequently, even more intensified glacial melting. Utrecht University researchers, however, insist that this is not how the process actually works in the long term.

GPS measurements

Since the early 1990s, Utrecht University scientists have tracked the movement of the West Greenland ice sheet using GPS measurements. During warmer weather, the ice appears to move – over the course of a few days – as much as four times faster, because the meltwater acts as lubricant between the ice and the subsoil.

As a result, the ice sheet moves more rapidly to lower and warmer areas. It seems, however, that over time larger channels form in the ice that are able to drain off the increased volumes of meltwater.

As a result, the water pressure on the ground once again decreases, as does the tempo of the ice movement. Over the long term, therefore, the feedback mechanism between the glacial melting and ice sheet movement contributes little to rising sea levels.

Citation: R.S.W. van de Wal, W. Boot, M.R. van den Broeke, C.J.P.P. Smeets, C.H. Reijmer, J.J.A. Donker, J. Oerlemans. Large and Rapid Melt-Induced Velocity Changes in the Ablation Zone of the Greenland Ice Sheet. Science, 4 July 2008.

Source: Utrecht University

Explore further: NASA gets two last looks at Tropical Cyclone Jack

add to favorites email to friend print save as pdf

Related Stories

Recommended for you

NASA gets two last looks at Tropical Cyclone Jack

13 hours ago

Tropical Cyclone Jack lost its credentials today, April 22, as it no longer qualified as a tropical cyclone. However, before it weakened, NASA's TRMM satellite took a "second look" at the storm yesterday.

Krypton used to accurately date ancient Antarctic ice

Apr 21, 2014

A team of scientists has successfully identified the age of 120,000-year-old Antarctic ice using radiometric krypton dating – a new technique that may allow them to locate and date ice that is more than ...

Taking the pulse of mountain formation in the Andes

Apr 21, 2014

Scientists have long been trying to understand how the Andes and other broad, high-elevation mountain ranges were formed. New research by Carmala Garzione, a professor of earth and environmental sciences ...

User comments : 3

Adjust slider to filter visible comments by rank

Display comments: newest first

Amy_Steri
1 / 5 (1) Jul 08, 2008
"It seems, however, that over time larger channels form in the ice that are able to drain off the increased volumes of meltwater..."

I suppose these "researchers" assume that these "increased volumes of meltwater" just dissapear, and never make it to the sea.
NotParker
2.3 / 5 (3) Jul 08, 2008
The sea level has not risen in the last 2 years. In fact, it is going down.

http://sealevel.c...obal.jpg

It is now lower than it was 5 years ago.

(blue line)
samweiss
5 / 5 (1) Jul 08, 2008
The headline of this article is misleading. Furthermore, this research has been reported in quite a few media outlets, and it is noticeable how different all the headlines are!

More news stories

Florida is 'Ground Zero' for sea level rise

Warm sunshine and sandy beaches make south Florida and its crown city, Miami, a haven for tourists, but the area is increasingly endangered by sea level rise, experts said Tuesday.

NASA gets two last looks at Tropical Cyclone Jack

Tropical Cyclone Jack lost its credentials today, April 22, as it no longer qualified as a tropical cyclone. However, before it weakened, NASA's TRMM satellite took a "second look" at the storm yesterday.

UV-radiation data to help ecological research

Many research projects study the effects of temperature and precipitation on the global distribution of plant and animal species. However, an important component of climate research, the UV-B radiation, is ...

Mantis shrimp stronger than airplanes

(Phys.org) —Inspired by the fist-like club of a mantis shrimp, a team of researchers led by University of California, Riverside, in collaboration with University of Southern California and Purdue University, ...

Volitional control from optical signals

(Medical Xpress)—In their quest to build better BMIs, or brain-machine-interfaces, researchers have recently begun to look closer at the sub-threshold activity of neurons. The reason for this trend is that ...