MUCH of the West Antarctic ice sheet has collapsed in the past 750 000 years.
Another collapse could raise global sea level by 5 to 6 metres.
Reed Scherer of Uppsala University in Sweden found radioactive isotopes and
fossils of open-ocean algae under ice far from the coast, suggesting the ice
collapsed (Science, vol 281, p 82). 鈥淚t鈥檚 hard to explain open water
that far south without significant destruction of the interior ice,鈥� he
says.
He thinks the thaw occurred about 400 000 years ago during an unusually long
and warm interglacial period. That could be ominous for the future, because
other studies suggest that the current interglacial period may last for another
several thousand years. If so, says Scherer, 鈥渢here鈥檚 a strong possibility that
the West Antarctic ice sheet might not survive.鈥�
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