| Subject: That is Scary. |
Author:
The Equalizer
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Date Posted: 11:17:37 03/23/02 Sat
Author Host/IP: 208.184.25.41
In reply to:
The Veeckster
's message, "We're Screwed! HUGE Ice shelf breaks off Antarctica." on 08:16:42 03/21/02 Thu
thanks for this Informative post Veeckster.
>We gotta get Bush out of office.
>
>March 19, 2002 | An enormous floating ice shelf in
>Antarctica that has existed since the last Ice Age
>12,000 years ago collapsed this month with staggering
>speed during one of the warmest summers on record
>there, scientists say.
>
>Scientists stopped short of blaming the collapse on
>global warming caused by human activity. But they
>noted that the ice shelf had persisted through
>previous climate changes well before civilization
>began altering the environment.
>
>"It's a profound event," said geologist Christina
>Hulbe of Portland State University. "This ice shelf
>has endured many climate oscillations over many
>thousands of years. Now it's gone."
>
>Satellite images show that a piece of the Larsen Ice
>Shelf collapsed during a five-week period that ended
>March 7. It splintered into a plume of drifting
>icebergs.
>
>The piece of ice that broke off was designated Larsen
>B, and was 650 feet thick and with a surface area of
>1,250 square miles, or about the size of Rhode Island.
>
>The Ice Shelf is on the Antarctic Peninsula and
>extends about 1,000 miles closer to the tip of South
>America than the rest of the Antarctic continent.
>
>In recent months, with the polar summer just
>beginning, temperatures were already creeping above
>freezing in the peninsula region. Scientists said
>there has also been a 50-year warming trend in the
>peninsula, which is considered a sensitive, early
>indicator of global climate change.
>
>"We're seeing a very rapid and profound response by
>the ice sheet to a warming that's been around for just
>a few decades," said Ted Scambos of the National Snow
>and Ice Data Center at the University of Colorado.
>
>Scambos was one of three U.S. researchers monitoring
>the Larsen Ice Sheet by satellite.
>
>"We can use this as sort of a guide for what's going
>to happen if the rest of the Antarctic should begin to
>warm because of climate change," he said.
>
>The Larsen Ice Shelf has been under careful
>observation since 1995, when its northernmost sector,
>known as Larsen A, collapsed in a similarly dramatic
>event.
>
>The entire Larsen Ice Shelf now is about 40 percent of
>its original size.
>
>"We knew what was left would collapse eventually, but
>the speed of it is staggering," said David Vaughan, a
>glaciologist at the British Antarctic Survey. "Hard to
>believe that 500 million billion tons of ice sheet has
>disintegrated in less than a month."
>
>Previous measurements showed the Antarctic Peninsula
>has warmed an average of more than 4 degrees
>Fahrenheit during the past half-century, a rate that
>is as much as five times faster than the global
>average.
>
>But the overall climate picture in Antarctica is
>anything but consistent. In fact, glaciers elsewhere
>on the continent are both thickening and thinning as
>temperatures show conflicting climate trends.
>
>In 1995, when Larsen A broke off, the summer melt had
>persisted for 80 days, about 20 days longer than
>average.
>
>As for Larsen B, satellite images show that virtual
>ponds of melted water were forming atop the ice in
>recent months. Later images showed the water was
>seeping into the ice sheet's interior, accelerating
>its demise.
>
>The next portion of the ice shelf is known as Larsen
>C. It is losing stability and could suffer the same
>fate in the coming years if the warming trend
>continues, researchers said.
>
>And even larger ice shelves elsewhere on the
>continent's coastline may be just a few summertime
>degrees away from the same fate.
>
>"Other ice shelves are closer to the breaking point
>than we previously thought," Scambos said. "Breakups
>in some other areas, such as the Ross Ice Shelf, could
>lead to increases in ice flow off the Antarctic and
>cause sea level to rise."
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