Satellite images taken by the National Snow and Ice Data Center (NSIDC) at the University of Colorado show that the vast Wilkins Ice Shelf in Antarctica has begun to disintegrate under the influence of global warming. A massive iceberg, covering an area of 414 square kilometers, located in one corner of the ice shelf, recently broke apart. Scientists indicate that this was caused by an iceberg 41 kilometers long and 2.4 kilometers wide breaking off from the southwestern leading edge of the ice shelf on February 28th.
The largest collapse since 2002
The Wilkins Ice Shelf is a vast, perennial ice sheet covering 12,950 square kilometers, located in the southwestern Antarctic Peninsula, approximately 1,609 kilometers from South America. Due to recent ice breakup, including larger-scale cracks in 2002 and 1995, the remaining portion of the ice sheet is currently supported only by a thin ice column located between two islands.
Scientists noticed the satellite images within hours of the ice shelf breaking apart and immediately ordered satellite cameras to turn around, even circling overhead to capture rare photos and images. According to scientists involved in the filming, giant ice blocks the size of small houses were scattered everywhere, resembling a bomb explosion.
"If the ice shelf continues to retreat, this last support will also disintegrate, and we could lose half of the entire ice shelf in the coming years," NSIDC Chief Scientist Scarpos said in a statement. He pointed out that the ice shelf was filled with water at the cracks and was breaking and disintegrating. British Antarctic Survey scientist Warfen, who participated in the investigation, said that this disintegration was similar to the effect of hammering reinforced glass.
Scientists worry this is the key to the massive collapse.
Scientists fear that the remaining parts of the Wilkin Ice Shelf may also break apart in the future. Werfen predicts the Wilkin Ice Shelf will collapse in fifteen years, but it should remain intact until next year as the Antarctic summer ends and the cold season approaches. Although the recently fractured portion represents only 4% of the entire ice shelf, it is a crucial part that could trigger further disintegration.
Scientists are not worried that the ice shelf collapse will cause sea levels to rise, but they believe it is a sign of worsening global warming, indicating a turning point in the climate system. The western Antarctic Peninsula has experienced the most dramatic warming on Earth in the past half-century, averaging 0.5 degrees Celsius per decade.
Updated date:2008/03/27 04:09
[Compiled by Luo Yanjie from foreign news reports from Washington on the 26th]
