Featured Research

from universities, journals, and other organizations

Ice-loss moves the Earth 250 miles down

Date:
May 11, 2014
Source:
Newcastle University
Summary:
Scientists have revealed that Earth's mantle under Antarctica is at a lower viscosity and moving at such a rapid rate it is changing the shape of the land at a rate that can be recorded by GPS. They have explained for the first time why the upward motion of Earth's crust in the Northern Antarctic Peninsula is currently taking place so quickly.

Antarctic iceberg. Scientists have shown for the first time how the mantle below Earth's crust in the Antarctic Peninsula is flowing much faster than expected, probably due to subtle changes in temperature or chemical composition.
Credit: Goinyk Volodymyr / Fotolia

An international research team led by Newcastle University, UK, reveal Earth's mantle under Antarctica is at a lower viscosity and moving at such a rapid rate it is changing the shape of the land at a rate that can be recorded by GPS.

Related Articles


At the surface, Antarctica is a motionless and frozen landscape. Yet hundreds of miles down the Earth is moving at a rapid rate, new research has shown.

The study, led by Newcastle University, UK, and published this week in Earth and Planetary Science Letters, explains for the first time why the upward motion of Earth's crust in the Northern Antarctic Peninsula is currently taking place so quickly.

Previous studies have shown Earth is 'rebounding' due to the overlying ice sheet shrinking in response to climate change. This movement of the land was understood to be due to an instantaneous, elastic response followed by a very slow uplift over thousands of years.

But GPS data collected by the international research team, involving experts from Newcastle University, UK; Durham University; DTU, Denmark; University of Tasmania, Australia; Hamilton College, New York; the University of Colorado and the University of Toulouse, France, has revealed that the land in this region is actually rising at a phenomenal rate of 15mm a year -- much greater than can be accounted for by the present-day elastic response alone.

And they have shown for the first time how the mantle below Earth's crust in the Antarctic Peninsula is flowing much faster than expected, probably due to subtle changes in temperature or chemical composition.

This means it can flow more easily and so responds much more quickly to the lightening load hundreds of miles above it, changing the shape of the land.

Lead researcher, PhD student Grace Nield, based in the School of Civil Engineering and Geosciences at Newcastle University, explains: "You would expect this rebound to happen over thousands of years and instead we have been able to measure it in just over a decade. You can almost see it happening which is just incredible.

"Because the mantle is 'runnier' below the Northern Antarctic Peninsula it responds much more quickly to what's happening on the surface. So as the glaciers thin and the load in that localised area reduces, the mantle pushes up the crust.

"At the moment we have only studied the vertical deformation so the next step is to look at horizontal motion caused by the ice unloading to get more of a 3-D picture of how Earth is deforming, and to use other geophysical data to understand the mechanism of the flow."

Since 1995 several ice shelves in the Northern Antarctic Peninsula have collapsed and triggered ice-mass unloading, causing the solid Earth to 'bounce back'.

"Think of it a bit like a stretched piece of elastic," says Nield, whose project is funded by the Natural Environment Research Council (NERC).

"The ice is pressing down on the Earth and as this weight reduces the crust bounces back. But what we found when we compared the ice loss to the uplift was that they didn't tally -- something else had to be happening to be pushing the solid Earth up at such a phenomenal rate.

"Collating data from seven GPS stations situated across the Northern Peninsula, the team found the rebound was so fast that the upper mantle viscosity -- or resistance to flow -- had to be at least ten times lower than previously thought for the region and much lower than the rest of Antarctica.

Professor Peter Clarke, Professor of Geophysical Geodesy at Newcastle University and one of the authors of the paper, adds: "Seeing this sort of deformation of the Earth at such a rate is unprecedented in Antarctica. What is particularly interesting here is that we can actually see the impact that glacier thinning is having on the rocks 250 miles down."


Story Source:

The above story is based on materials provided by Newcastle University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Grace A. Nield, Valentina R. Barletta, Andrea Bordoni, Matt A. King, Pippa L. Whitehouse, Peter J. Clarke, Eugene Domack, Ted A. Scambos, Etienne Berthier. Rapid bedrock uplift in the Antarctic Peninsula explained by viscoelastic response to recent ice unloading. Earth and Planetary Science Letters, 2014; 397: 32 DOI: 10.1016/j.epsl.2014.04.019

Cite This Page:

Newcastle University. "Ice-loss moves the Earth 250 miles down." ScienceDaily. ScienceDaily, 11 May 2014. <www.sciencedaily.com/releases/2014/05/140511214811.htm>.
Newcastle University. (2014, May 11). Ice-loss moves the Earth 250 miles down. ScienceDaily. Retrieved January 27, 2015 from www.sciencedaily.com/releases/2014/05/140511214811.htm
Newcastle University. "Ice-loss moves the Earth 250 miles down." ScienceDaily. www.sciencedaily.com/releases/2014/05/140511214811.htm (accessed January 27, 2015).

Share This


More From ScienceDaily



More Earth & Climate News

Tuesday, January 27, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Obama's Wildlife Plan Renews Alaska Drilling Debate

Obama's Wildlife Plan Renews Alaska Drilling Debate

Newsy (Jan. 26, 2015) President Obama&apos;s proposal aims to protect more land in the Arctic National Wildlife Refuge, but so far, all that&apos;s materialized is a war of words. Video provided by Newsy
Powered by NewsLook.com
Florida Might Legalize Black Bear Hunting

Florida Might Legalize Black Bear Hunting

Newsy (Jan. 24, 2015) A string of black bear attacks has Florida officials considering lifting the ban on hunting the animals to control their population. Video provided by Newsy
Powered by NewsLook.com
Dramatic Footage Shows Coast Guard Rescue Off Scottish Coast

Dramatic Footage Shows Coast Guard Rescue Off Scottish Coast

Reuters - News Video Online (Jan. 23, 2015) Footage just released by the UK Coast Guard shows a dramatic helicopter rescue off the Scottish coast, where five men were plucked to safety after their fishing boat sank on Saturday. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Stunning Wingsuit Proximity Flying in Norway

Stunning Wingsuit Proximity Flying in Norway

Rumble (Jan. 23, 2015) A collection of amazing shots from flights made in the Aurland Valley in Norway. How incredible is that? Credit to &apos;BASEjumper&apos;. Video provided by Rumble
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

    Health News

    Environment News

    Technology News



    Save/Print:
    Share:

    Free Subscriptions


    Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

    Get Social & Mobile


    Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

    Have Feedback?


    Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
    Mobile: iPhone Android Web
    Follow: Facebook Twitter Google+
    Subscribe: RSS Feeds Email Newsletters
    Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins