Glaciers can shrink “in a geologic instant”

June 22nd, 2009 - 12:24 pm ICT by ANI  

Washington, June 22 (ANI): A new research by scientists has revealed that modern glaciers in deep ocean water can undergo periods of rapid retreat, where they can shrink even more quickly than has recently been observed.

According to new findings by paleoclimatologists at the University at Buffalo (UB), US, modern glaciers, such as those making up the Greenland and Antarctic ice sheets, are capable of undergoing periods of rapid shrinkage or retreat.

The research describes fieldwork demonstrating that a prehistoric glacier in the Canadian Arctic rapidly retreated in just a few hundred years.

The UB team studied the rates of retreat of the prehistoric tidewater glacier, of similar size and geometry to contemporary ones, as way to get a longer-term view of how fast these glaciers can literally disappear.

The researchers used a special dating tool at UB to study rock samples they extracted from a large fjord that drained the ice sheet that covered the North American Arctic during the past Ice Age.

The samples provided the researchers with climate data over a period from 20,000 years ago to about 5,000 years ago, a period when significant warming occurred.

“Even though the ice sheet retreat was ongoing throughout that whole period, the lion’s share of the retreat occurred in a geologic instant - probably within as little as a few hundred years,” said Jason Briner, assistant professor of geology in the UB College of Arts and Sciences and lead author on the research paper.

The proof of such rapid retreat of ice sheets provides one of the few explicit confirmations that this phenomenon occurs.

Should the same conditions recur today, which the UB scientists say is very possible, they would result in sharply rising global sea levels, which would threaten coastal populations.

“A lot of glaciers in Antarctica and Greenland are characteristic of the one we studied in the Canadian Arctic,” said Jason Briner, assistant professor of geology in the UB College of Arts and Sciences and lead author on the research paper.

“Based on our findings, they, too, could retreat in a geologic instant,” he added.

The new findings will allow scientists to more accurately predict how global warming will affect ice sheets and the potential for rising sea levels in the future, by developing more robust climate and ice sheet models.

Briner said the findings are especially relevant to the Jakobshavn Isbrae, Greenland’s largest and fastest moving tidewater glacier, which is retreating under conditions similar to those he studied in the Canadian Arctic. (ANI)

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