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Sea level rises the fastest in 350 years

April 6, 2011 Comments off

walesonline



The San Rafael Glacier in the Northern Patagonian Ice Field

The San Rafael Glacier in the Northern Patagonian Ice Field

MELTING mountain glaciers are contributing to the fastest sea level rise in 350 years, according to research by Welsh scientists.

The team from Aberystwyth University, the University of Exeter and Stockholm University undertook a survey of the 270 largest outlet glaciers of the south and north Patagonian icefields of South America.

They mapped changes in the position of the glaciers since the Little Ice Age, which was the last time in the recent past when they were much larger.

The team calculated the volume of ice lost by the glaciers as they have retreated and thinned over the past 350 years and compared these volume losses to rates of change over the last 30 years.

They found that the rate at which the glaciers are losing volume over the past 30 years is between 10 and 100 times faster than the 350- year long-term average.

The study, which has been published in the journal Nature Geoscience, concludes the mountain glaciers have rapidly increased their melt rate in recent years and consequently their contribution to global sea level.

Lead author, Professor Neil Glasser of Aberystwyth University, said the work was based on a longer timescale than any earlier glacier research conducted.

The second author Dr Stephan Harrison of the University of Exeter, said: “The work is significant because it is the first time anyone has made a direct estimate of the sea-level contribution from glaciers since the peak of the Industrial Revolution.”

Pace of polar ice melt ‘accelerating rapidly’: study

March 10, 2011 Comments off

 

(AFP)

WASHINGTON — The pace at which the Greenland and Antarctic ice sheets are melting is “accelerating rapidly” and raising the global sea level, according to findings of a study financed by NASA and published Tuesday.

The findings suggest that the ice sheets — more so than ice loss from Earth’s mountain glaciers and ice caps — have become “the dominant contributor to global sea level rise, much sooner than model forecasts have predicted.”

This study, the longest to date examining changes to polar ice sheet mass, combined two decades of monthly satellite measurements with regional atmospheric climate model data to study changes in mass.

“That ice sheets will dominate future sea level rise is not surprising — they hold a lot more ice mass than mountain glaciers,” said lead author Eric Rignot, jointly of NASA’s Jet Propulsion Laboratory and the University of California, Irvine.

“What is surprising is this increased contribution by the ice sheets is already happening,” he said.

Under the current trends, he said, sea level is likely to be “significantly higher” than levels projected by Read more…

UA climate research: Big stretch of US coast at risk of rising seas

February 23, 2011 Comments off

azstarnet.com

If global temperatures continue to rise and polar ice continues to melt, 9 percent of the land in our coastal cities and towns will be beneath sea level by the end of the century, University of Arizona researchers say.

Climate researchers Jeremy Weiss and Jonathan Overpeck, along with Ben Strauss of Climate Central in Princeton, N.J., mapped the U.S. coastline, using elevations provided by the U.S. Geological Survey. They applied the most recent predictions of a sea level rise of 1 meter (3.28 feet) by 2100 to produce a map that predicts big trouble for 20 cities with more than 300,000 people and for 160 smaller municipalities.

Weiss is a senior researcher in geosciences. Overpeck is a professor of geosciences and atmospheric sciences and co-director of the UA’s Institute of the Environment.

The report was published last week in Climatic Change Letters.

The biggest impact will be felt in low-lying, heavily populated places such as New Orleans, Miami Beach and Virginia Beach, the report says.

Subsequent centuries will bring even higher sea levels that could completely submerge Read more…