Featured Research

from universities, journals, and other organizations

Arctic Submarine Uncovers Evidence Of Giant, Ancient Ice Sheets

Date:
March 27, 2001
Source:
Ohio State University
Summary:
A scientific expedition on a submarine in the Arctic has found the footprints of ancient floating ice sheets -- possibly the largest masses of ice ever to cover the earth's oceans.

COLUMBUS, Ohio - A scientific expedition on a submarine in the Arctic has found the footprints of ancient floating ice sheets -- possibly the largest masses of ice ever to cover the earth's oceans.

Studying the formation and demise of these ancient ice sheets may help scientists better understand Earth's climate changes and, in particular, predict whether the melting of today's polar ice could lead to catastrophic floods in the future.

Leonid Polyak, research scientist at Byrd Polar Research Center at Ohio State, and his colleagues obtained sonar images of the Arctic Ocean floor through a unique collaboration between the U.S. Navy and civilian scientists -- the Science Ice Exercises (SCICEX) program.

The results appear in the March 22 issue of the journal Nature. Polyak's collaborators, Margo Edwards of the University of Hawaii and Bernard Coakley of Tulane University, were chief scientists on the 1999 SCICEX mission, which took place aboard the nuclear submarine USS Hawkbill.

Within two separate, somewhat elevated regions of the Arctic Ocean floor -- the Lomonosov Ridge near the North Pole and the Chukchi Borderland near Alaska -- SCICEX images showed numerous features carved into the seafloor, including matching sets of parallel grooves and ridges. Sometime in the past, Polyak said, the bottom of a very massive floating ice sheet scraped across the seafloor in both areas -- almost 1 km below the water surface at the Lomonosov Ridge and more than 700 meters below the water surface at the Chukchi Borderland.

The sonar images clearly showed objects resembling rocks and other debris that may have once been dragged along the seafloor beneath the grounded ice.

"The results were just fantastic. We had hoped to find these seafloor features, but we hadn't expected to get such beautiful images," Polyak said.

"Such amazingly coherent sets of streamlined grooves and ridges could only be made by one thing - sliding ice," Polyak continued. And only a large ice sheet could carve such a broad sets of parallel features. Free-floating icebergs, he explained, carve random patterns into the seafloor.

The finding may bolster a theory held by some scientists: that one giant ice sheet covered the entire Arctic periodically during the ice ages that occurred between 10,000 and 1.5 million years ago.

But Polyak thinks that the same features might have been carved by several large ice sheets instead of one. To find out for sure, he and his colleagues must determine whether the features formed at the same time in different regions of the Arctic Ocean. That's why the researchers have applied for funding to return to the Arctic on an icebreaker to take core samples from the seafloor.

"Even if there were two or more ice sheets instead of one, they were still giant structures of several hundred kilometers in length -- comparable to vast floating ice sheets observed today around Antarctica," said Polyak.

The researchers sought evidence of the ancient floating ice sheets in part to gather clues about the future of the West Antarctic Ice Sheet.

Unlike the ice in East Antarctica, the ice in West Antarctica is considered unstable because a large portion of it is floating. For years, scientists have debated whether a warming of earth's climate would cause the ice sheet in West Antarctica to collapse, which would cause sea levels to rise fast, possibly as high as 20 feet all over the world.

Polyak, a former biologist, says these findings also hold implications for other areas of science. For instance, he wonders how prehistoric life in the Arctic Ocean could have survived if the entire area was covered with an ice cap of several hundred meters in thickness.

This question is related to a recently proposed theory called "snowball Earth," Polyak said. The theory holds that ice completely covered the Earth's oceans at some time between 550 and 750 million years ago, drastically affecting the evolution of primitive life.

"Who knows - maybe clarifying the history of floating ice sheets in the Arctic Ocean will even help us understand the evolution of ice-bound planets, such as Jupiter's moon Europa," he said.


Story Source:

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


Cite This Page:

Ohio State University. "Arctic Submarine Uncovers Evidence Of Giant, Ancient Ice Sheets." ScienceDaily. ScienceDaily, 27 March 2001. <www.sciencedaily.com/releases/2001/03/010322075843.htm>.
Ohio State University. (2001, March 27). Arctic Submarine Uncovers Evidence Of Giant, Ancient Ice Sheets. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2001/03/010322075843.htm
Ohio State University. "Arctic Submarine Uncovers Evidence Of Giant, Ancient Ice Sheets." ScienceDaily. www.sciencedaily.com/releases/2001/03/010322075843.htm (accessed July 31, 2014).

Share This




More Earth & Climate News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Big Waves In Arctic Ocean Threaten Polar Ice

Big Waves In Arctic Ocean Threaten Polar Ice

Newsy (July 30, 2014) Big waves in parts of the Arctic Ocean are unprecedented, mainly because they used to be covered in ice. Video provided by Newsy
Powered by NewsLook.com
Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
Powered by NewsLook.com
Amid Drought, UCLA Sees Only Water

Amid Drought, UCLA Sees Only Water

AP (July 30, 2014) A ruptured 93-year-old water main left the UCLA campus awash in 8 million gallons of water in the middle of California's worst drought in decades. (July 30) Video provided by AP
Powered by NewsLook.com
In Virginia, the Rise of a New Space Coast

In Virginia, the Rise of a New Space Coast

AP (July 30, 2014) Every summer, tourists make the pilgrimage to Chincoteague Island, Va. to see wild ponies cross the Assateague Channel. But, it's the rockets sending to supplies to the International Space Station that are making this a year-round destination. (July 30) Video provided by AP
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