ENVIRONMENT REPORT -April 5, 2002: Antarctic Ice Breaks Off
By Cynthia Kirk This is the VOA Special English ENVIRONMENT REPORT.
A huge piece of ice the size of a small country has broken off Antarctica. The event has created thousands of floating icebergs in the Weddell Sea. American and British scientists say it is the largest piece of ice that has broken off in thirty years.
Scientists say the ice broke off from the Larsen B Shelf area in a thirty-five day period that began January thirty- first. This area of ice was on the east side of the Antarctic Peninsula. The peninsula is the Antarctic area that is closest to southern Argentina and Chile. It is surrounded on three sides by seas that keep temperatures more moderate.
Larsen B is one of many ice shelves on Antarctica. The shelves are huge pieces of ice that float in the water. They are floating extensions of the ice sheets covering the Antarctic continent. The ice shelves block the ice sheets from moving off the land into the water.
The part of Larsen B that broke off was two-hundred meters thick and covered about two-thousand square kilometers. Scientists say the ice shelf probably has existed since before the end of the last major ice age twelve thousand years ago.
Scientists say the break up of the Larsen B shelf will
not raise sea levels because the ice was already floating in the water. Sea levels would rise only if the land ice behind it now began to flow more quickly into the sea.
Scientists say warming temperatures during the Antarctic summers probably caused the ice to break. Temperatures have risen two-point-five degrees Celsius in the Antarctic Peninsula during the past fifty years. That is much faster than climate warming worldwide or even in other parts of Antarctica.
Some studies have suggested other areas of Antarctica might be cooling. A recent study reported that the ice in West Antarctica is thickening, not melting.
The Larsen Ice Shelf has been under careful observation since Nineteen-Ninety-Five. That is when a piece of ice in the northern part of the ice shelf, known as Larsen A, broke off in a similar event. Scientists say the southern part of the ice shelf, Larsen C, could also break apart if the warming continues in Antarctica.
Some scientists say the separation of the ice shelves is linked to the climate warming caused by human activity. But, other scientists say the break was probably caused by a natural warming event.
This VOA Special English ENVIRONMENT REPORT was written by Cynthia Kirk.
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Satellite images: January 31 ... (Photos - NASA) ... and March 7 |