Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Iceland Rises as Its Glaciers Melt From Climate Change

30.01.2015

The Earth’s crust under Iceland is rebounding as global warming melts the island’s great ice caps, according to a new study accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union.

The paper is the first to show the current fast uplift of the Icelandic crust is a result of accelerated melting of the island’s glaciers and coincides with the onset of warming that began about 30 years ago, according the study’s authors.


This global positioning satellite receiver is part of Iceland’s network of 62 such receivers that geoscientists are using to detect movements of the Icelandic crust that are as small as one millimeter per year. Langjökull glacier is in the background.

Credit: Richard A. Bennett/ University of Arizona Department of Geosciences.

Usage restrictions: This photo of a GPS receiver in Iceland by Richard A. Bennett may only be used to illustrate a story about the research described in the accompanying news release, “Iceland rises as its glaciers melt from climate change.” Please make sure to credit the photo as requested. Do not post this image independent of the story.

Some sites in south-central Iceland are moving upward as much as 35 millimeters (1.4 inches) per year – a speed that surprised the researchers.

“Our research makes the connection between recent accelerated uplift and the accelerated melting of the Icelandic ice caps,” said Kathleen Compton, a geosciences doctoral candidate at the University of Arizona in Tucson, and lead author of the new paper.

This global positioning satellite receiver is part of Iceland’s network of 62 such receivers that geoscientists are using to detect movements of the Icelandic crust that are as small as one millimeter per year. Langjökull glacier is in the background. Credit: Richard A. Bennett/ University of Arizona Department of Geosciences.

Geologists have long known that as glaciers melt and become lighter, the Earth rebounds as the weight of the ice decreases.

Whether the current rebound geologists detect is related to past deglaciation or modern ice loss has been an open question until now, said co-author Richard Bennett, a University of Arizona associate professor of geosciences.

“Iceland is the first place we can say accelerated uplift means accelerated ice mass loss,” Bennett said.

To figure out how fast the crust was moving upward, the team used a network of 62 global positioning satellite receivers fastened to rocks throughout Iceland. By tracking the position of the GPS receivers year after year, the scientists “watch” the rocks move and can calculate how far they have traveled – a technique called geodesy.

The new work shows that, at least for Iceland, the land’s current accelerating uplift is directly related to the thinning of glaciers and to global warming.

“What we’re observing is a climatically induced change in the Earth’s surface,” Bennett said.

He added there is geological evidence that during the past deglaciation roughly 12,000 years ago, volcanic activity in some regions of Iceland increased thirtyfold.

Others have estimated the Icelandic crust’s rebound from warming-induced ice loss could increase the frequency of volcanic eruptions such as the 2010 eruption of Eyjafjallajökull, which had negative economic consequences worldwide.

Some of Iceland’s GPS receivers have been in place since 1995. Bennett, Sigrun Hreinsdóttir of GNS Science in Avalon, New Zealand, and colleagues had installed 20 GPS receivers in Iceland in 2006 and 2009, thus boosting the coverage of the nation’s geodesy network. In central and southern Iceland, where five of the largest ice caps are located, the receivers are 30 kilometers (18 miles) or less apart on average.

The team primarily used the geodesy network to track geological activity such as earthquakes and volcanic eruptions.

In 2013, Bennett noticed one of the long-running stations in the center of the country was showing that site was rebounding at an accelerated rate. He wondered about it, so he and his colleagues checked the nearby stations to see if they had recorded the same changes.

“The striking answer was, yes, they all do,” he said. “We wondered what in the world could be causing this?”

The team began systematically analyzing years of signals from the entire network and found the fastest uplift was the region between several large ice caps. The rate of uplift slowed the farther the receiver was from the ice cap region.

Other researchers had been measuring ice loss and observed a notable uptick in the rate of melting since 1995. Temperature records for Iceland, some of which go back to the 1800s, show temperatures increasing since 1980.

To determine whether the same rate of ice loss year after year could cause such an acceleration in uplift, Compton tested that idea using mathematical models. The answer was no: The glaciers had to be melting faster and faster every year to be causing more and more uplift.

Compton found the onset of rising temperatures and the loss of ice corresponded tightly with her estimates of when uplift began.

“I was surprised how well everything lined up,” she said.

Bennett said, “There’s no way to explain that accelerated uplift unless the glacier is disappearing at an accelerated rate.”

Estimating ice loss is laborious and difficult, he said. “Our hope is we can use current GPS measurements of uplift to more easily quantify ice loss.”

The team’s next step is to analyze the uplift data to reveal the seasonal variation as the ice caps grow during the winter snow season and melt during the summer.

The National Science Foundation and the Icelandic Center for Research funded the research.

###

The American Geophysical Union is dedicated to advancing the Earth and space sciences for the benefit of humanity through its scholarly publications, conferences, and outreach programs. AGU is a not-for-profit, professional, scientific organization representing more than 62,000 members in 144 countries. Join our conversation on Facebook, Twitter, YouTube, and other social media channels.

Notes for Journalists

Journalists and public information officers (PIOs) of educational and scientific institutions who have registered with AGU can download a PDF copy of this article by clicking on this link:
http://onlinelibrary.wiley.com/doi/10.1002/2014GL062446/abstract?campaign=wlytk-41855.5282060185

Or, you may order a copy of the final paper by emailing your request to Nanci Bompey at nbompey@agu.org. Please provide your name, the name of your publication, and your phone number.

Neither the paper nor this press release is under embargo.
Title
“Climate driven vertical acceleration of Icelandic crust measured by CGPS geodesy”

Authors:
Kathleen Compton: Department of Geosciences, University of Arizona, Tucson, Arizona USA;

Richard A. Bennett: Department of Geosciences, University of Arizona, Tucson, Arizona USA;

Sigrun Hreinsdóttir: University of Iceland, now at GNS Science in Avalon, New Zealand.

Contact information for the authors:
Kathleen Compton: kcompton@email.arizona.edu

Richard Bennett: +1 (520) 621-2324, rb0@email.arizona.edu


AGU Contact:
Nanci Bompey
+1 (202) 777-7524
nbompey@agu.org

University of Arizona Contact:
Mari N. Jensen
+1 (520) 626-9635
mnjensen@email.arizona.edu

Peter Weiss | American Geophysical Union
Further information:
http://news.agu.org/press-release/iceland-rises-as-its-glaciers-melt-from-climate-change/

More articles from Earth Sciences:

nachricht Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie

nachricht Modeling magma to find copper
13.01.2017 | Université de Genève

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>