Missing Radioactivity In Ice Cores Bodes Ill For Part Of Asia

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. "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." "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. "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.

http://www.sciencedaily.com/releases/2008/11/081118122148.htm