Featured Research

from universities, journals, and other organizations

Arctic ice at low point compared to recent geologic history

Date:
June 3, 2010
Source:
Ohio State University
Summary:
Less ice covers the Arctic today than at any time in recent geologic history. That's the conclusion of an international group of researchers, who have compiled the first comprehensive history of Arctic ice.

Pack ice near the Arctic island Spitsbergen/Svalbard.
Credit: iStockphoto/Michel De Nijs

Less ice covers the Arctic today than at any time in recent geologic history.

That's the conclusion of an international group of researchers, who have compiled the first comprehensive history of Arctic ice.

For decades, scientists have strived to collect sediment cores from the difficult-to-access Arctic Ocean floor, to discover what the Arctic was like in the past. Their most recent goal: to bring a long-term perspective to the ice loss we see today.

Now, in an upcoming issue of Quarternary Science Reviews, a team led by Ohio State University has re-examined the data from past and ongoing studies -- nearly 300 in all -- and combined them to form a big-picture view of the pole's climate history stretching back millions of years.

"The ice loss that we see today -- the ice loss that started in the early 20th Century and sped up during the last 30 years -- appears to be unmatched over at least the last few thousand years," said Leonid Polyak, a research scientist at Byrd Polar Research Center at Ohio State University. Polyak is lead author of the paper and a preceding report that he and his coauthors prepared for the U.S. Climate Change Science Program.

Satellites can provide detailed measures of how much ice is covering the pole right now, but sediment cores are like fossils of the ocean's history, he explained.

"Sediment cores are essentially a record of sediments that settled at the sea floor, layer by layer, and they record the conditions of the ocean system during the time they settled. When we look carefully at various chemical and biological components of the sediment, and how the sediment is distributed -- then, with certain skills and luck, we can reconstruct the conditions at the time the sediment was deposited."

For example, scientists can search for a biochemical marker that is tied to certain species of algae that live only in ice. If that marker is present in the sediment, then that location was likely covered in ice at the time. Scientists call such markers "proxies" for the thing they actually want to measure -- in this case, the geographic extent of the ice in the past.

While knowing the loss of surface area of the ice is important, Polyak says that this work can't yet reveal an even more important fact: how the total volume of ice -- thickness as well as surface area -- has changed over time.

"Underneath the surface, the ice can be thick or thin. The newest satellite techniques and field observations allow us to see that the volume of ice is shrinking much faster than its area today. The picture is very troubling. We are losing ice very fast," he said.

"Maybe sometime down the road we'll develop proxies for the ice thickness. Right now, just looking at ice extent is very difficult."

To review and combine the data from hundreds of studies, he and his cohorts had to combine information on many different proxies as well as modern observations. They searched for patterns in the proxy data that fit together like pieces of a puzzle.

Their conclusion: the current extent of Arctic ice is at its lowest point for at least the last few thousand years.

As scientists pull more sediment cores from the Arctic, Polyak and his collaborators want to understand more details of the past ice extent and to push this knowledge further back in time.

During the summer of 2011, they hope to draw cores from beneath the Chukchi Sea, just north of the Bering Strait between Alaska and Siberia. The currents emanating from the northern Pacific Ocean bring heat that may play an important role in melting the ice across the Arctic, so Polyak expects that the history of this location will prove very important. He hopes to drill cores that date back thousands of years at the Chukchi Sea margin, providing a detailed history of interaction between oceanic currents and ice.

"Later on in this cruise, when we venture into the more central Arctic Ocean, we will aim at harvesting cores that go back even farther," he said. "If we could go as far back as a million years, that would be perfect."

Polyak's coauthors on the report hailed from Penn State University, University of Colorado, University of Massachusetts, the U.S. Geological Survey, Old Dominion University, the Geological Survey of Canada, University of Copenhagen, the Cooperative Institute for Research in Environmental Sciences, Stockholm University, McGill University, James Madison University, and the British Antarctic Survey.

This research was funded by the US Geological Survey and the National Science Foundation.


Story Source:

The above story is based on materials provided by Ohio State University. The original article was written by Pam Frost Gorder. Note: Materials may be edited for content and length.


Journal Reference:

  1. Leonid Polyak, Richard B. Alley, John T. Andrews, Julie Brigham-Grette, Thomas M. Cronin, Dennis A. Darby, Arthur S. Dyke, Joan J. Fitzpatrick, Svend Funder, Marika Holland, Anne E. Jennings, Gifford H. Miller, Matt O'Regan, James Savelle, Mark Serreze, Kristen St. John, James W.C. White, Eric Wolff. History of sea ice in the Arctic. Quarternary Science Reviews, 2010; DOI: 10.1016/j.quascirev.2010.02.010

Cite This Page:

Ohio State University. "Arctic ice at low point compared to recent geologic history." ScienceDaily. ScienceDaily, 3 June 2010. <www.sciencedaily.com/releases/2010/06/100602193423.htm>.
Ohio State University. (2010, June 3). Arctic ice at low point compared to recent geologic history. ScienceDaily. Retrieved September 15, 2014 from www.sciencedaily.com/releases/2010/06/100602193423.htm
Ohio State University. "Arctic ice at low point compared to recent geologic history." ScienceDaily. www.sciencedaily.com/releases/2010/06/100602193423.htm (accessed September 15, 2014).

Share This



More Earth & Climate News

Monday, September 15, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Conservationists Face Uphill PR Battle With New Shark Rules

Conservationists Face Uphill PR Battle With New Shark Rules

Newsy (Sep. 14, 2014) — New conservation measures for shark fishing face an uphill PR battle in the fight to slow shark extinction. Video provided by Newsy
Powered by NewsLook.com
Pakistan's 'killer Mountain' Fails to Draw Tourists After Attack

Pakistan's 'killer Mountain' Fails to Draw Tourists After Attack

AFP (Sep. 12, 2014) — In June 2013, 10 foreign mountaineers and their guide were murdered on Nanga Parbat, an iconic peak that stands at 8,126m tall in northern Pakisan. Duration: 02:34 Video provided by AFP
Powered by NewsLook.com
Solar Storm To Hit This Weekend, Scientists Not Worried

Solar Storm To Hit This Weekend, Scientists Not Worried

Newsy (Sep. 11, 2014) — Two solar flares which erupted in our direction this week will arrive this weekend. The resulting solar storm will be powerful but not dangerous. Video provided by Newsy
Powered by NewsLook.com
The Ozone Layer Is Recovering, But It's Not All Good News

The Ozone Layer Is Recovering, But It's Not All Good News

Newsy (Sep. 11, 2014) — The Ozone layer is recovering thickness! Hooray! But in helping its recovery, we may have also helped put more greenhouse gases out there. Hooray? Video provided by Newsy
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:
from the past week

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