Featured Research

from universities, journals, and other organizations

Missing Radioactivity In Ice Cores Bodes Ill For Part Of Asia

Date:
November 26, 2008
Source:
Ohio State University
Summary:
When glaciologists failed to find the expected radioactive signals in the latest core they drilled from a Himalayan ice field, they knew it meant trouble for their research. But those missing markers of radiation, remnants from atomic bomb tests a half-century ago, foretell much greater threat to the half-billion or more people living downstream of that vast mountain range.

Naimona'nyi's frozen ice cap lacks critical radioactive signal.
Credit: Photo courtesy and copyright Thomas Nash, 2007

When Ohio State glaciologists failed to find the expected radioactive signals in the latest core they drilled from a Himalayan ice field, they knew it meant trouble for their research.

But those missing markers of radiation, remnants from atomic bomb tests a half-century ago, foretell much greater threat to the half-billion or more people living downstream of that vast mountain range.

It may mean that future water supplies could fall far short of what’s needed to keep that population alive.

In a paper just published in Geophysical Research Letters, researchers from the Byrd Polar Research Center explain that levels of tritium, beta radioactivity emitters like strontium and cesium, and an isotope of chlorine are absent in all three cores taken from the Naimona’nyi glacier 19,849 feet (6,050 meters) high on the southern margin of the Tibetan Plateau.

“We’ve drilled 13 cores over the years from these high-mountain regions and found these signals in all but one – this one,” explained Lonnie Thompson, University Distinguished Professor of Earth Sciences at Ohio State.

The absence of radioactive signals in the top portion of these cores is a critical problem for determining the age of the ice in the cores. The signals, remnants of the 1962-63 Soviet Arctic nuclear blasts and the 1952-58 nuclear tests in the South Pacific, provide well-dated benchmarks to calibrate the core time scales.

“We rely on these time markers to date the upper part of the ice cores and without them, extracting the climate history they preserve becomes more challenging,” Thompson said.

“We drilled three cores through the ice to bedrock at Naimona’nyi in 2006,” said Natalie Kehrwald, a doctoral student at Ohio State and lead author on the paper. “When we analyzed the top 50 feet (15 meters) of each core, we found that the beta radioactivity signal was barely above normal background levels.”

Tritium, an isotope of hydrogen, and chlorine-36 were also both absent from the Naimona’nyi cores, she said. They were able, however, to find a small amount of a lead isotope, lead-210, which allowed them to date the top of the core.

“We were able to get a date of approximately 1944 A.D.,” Kehrwald said, “and that, coupled with the other missing signals, means that no new ice has accumulated on the surface of the glacier since 1944,” nearly a decade before the atomic tests.

While the loss of the radioactive horizons to calibrate the cores poses a challenge for Thompson’s research, he worries more about the possibility that other high-altitude glaciers in the region, like Naimona’nyi, are no longer accumulating ice and the impact that could have on water resources for the people living in these regions

“When you think about the millions of people over there who depend on the water locked in that ice, if they don’t have it available in the future, that will be a serious problem,” he said.

Seasonal runoff from glaciers like Naimona’nyi feeds the Indus, the Ganges and the Brahmaputra rivers in that part of the Asian subcontinent. In some places, for some months each year, those rivers are severely depleted now, the researchers said. The absence of new ice accumulating on the glaciers will only worsen that problem.

“The current models that predict river flow in the region have taken recent glacial ‘retreat’ into account,” said Kehrwald, “but they haven’t considered that some of these glaciers are actually thinning until now.

“If the thinning isn’t included, then whatever strategies people adopt in their efforts to adapt to reductions in river flow simply won’t work.”

Thompson fears that what’s happening to the Naimona’nyi glacier may be happening to many other high-altitude glaciers around the world. “I think that this has tremendous implications for future water supplies in the Andes, as well as the Himalayas, and for people living in those regions.”

The absence of the radioactive signals in the 2006 Naimona’nyi core also suggests that Thompson and his colleagues have been lucky with their previous expeditions to other ice fields.

“We have to wonder -- if we were to go back to previous drill sites, some drilled in the 1980s, and retrieved new cores -- would these radioactive signals be present today?” he asked.

“My guess is that they would be missing.” The researchers’ recent work has shown similar thinning on glaciers in Africa, South America and in Asia in the past few years.

Working on the project with Thompson and Kehrwald were professor of geography Ellen Mosley-Thompson, Mary Davis, and Yao Tandong, of the Institute for Tibetan Plateau Research with the Chinese Academy of Sciences.

The National Science Foundation and the Gary Comer Foundation supported parts of this research.


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. "Missing Radioactivity In Ice Cores Bodes Ill For Part Of Asia." ScienceDaily. ScienceDaily, 26 November 2008. <www.sciencedaily.com/releases/2008/11/081118122148.htm>.
Ohio State University. (2008, November 26). Missing Radioactivity In Ice Cores Bodes Ill For Part Of Asia. ScienceDaily. Retrieved July 26, 2014 from www.sciencedaily.com/releases/2008/11/081118122148.htm
Ohio State University. "Missing Radioactivity In Ice Cores Bodes Ill For Part Of Asia." ScienceDaily. www.sciencedaily.com/releases/2008/11/081118122148.htm (accessed July 26, 2014).

Share This




More Earth & Climate News

Saturday, July 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Virginia Governor Tours Tornado Aftermath

Virginia Governor Tours Tornado Aftermath

AP (July 25, 2014) Virginia Gov. Terry McAuliffe toured the Cherrystone Family Camping and RV Resort on the Chesapeake Bay today, a day after it was hit by a tornado. The storm claimed two lives and injured dozens of others. (July 25) Video provided by AP
Powered by NewsLook.com
Europe's Highest Train Turns 80 in French Pyrenees

Europe's Highest Train Turns 80 in French Pyrenees

AFP (July 25, 2014) Europe's highest train, the little train of Artouste in the French Pyrenees, celebrates its 80th birthday. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
Goma Cheese Brings Whiff of New Hope to DRC

Goma Cheese Brings Whiff of New Hope to DRC

Reuters - Business Video Online (July 24, 2014) The eastern region of the Democratic Republic of Congo, mainly known for conflict and instability, is an unlikely place for the production of fine cheese. But a farm in the village of Masisi, in North Kivu is slowly transforming perceptions of the area. Known simply as Goma cheese, the Congolese version of Dutch gouda has gained popularity through out the region. Ciara Sutton reports. Video provided by Reuters
Powered by NewsLook.com
Bill Gates: Health, Agriculture Key to Africa's Development

Bill Gates: Health, Agriculture Key to Africa's Development

AFP (July 24, 2014) Health and agriculture development are key if African countries are to overcome poverty and grow, US software billionaire Bill Gates said Thursday, as he received an honourary degree in Ethiopia. Duration: 00:36 Video provided by AFP
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