February 11, 2009

Ancient 70-foot rise in sea level found

U.S. scientists say they have found proof that Earth's sea level was more than 70 feet (21 meters) higher 400,000 years ago than it is now.

Storrs Olson, a zoologist at the Smithsonian's National Museum of Natural History, and geologist Paul Hearty of the Bald Head Island Conservancy said they discovered sedimentary and fossil evidence in the walls of a limestone quarry in Bermuda that documents the rise in sea level during an interglacial period of the Middle Pleistocene.

Although Hearty and colleagues published preliminary evidence of the sea-level rise nearly a decade ago, they said the new fossil find provides unequivocal evidence of the timing and extent of the event.

The scientists said such a rise in sea level would have ramifications well beyond geology and climate modeling.

These findings are incredibly important and have major relevance because of their potential predictive value since this sea-level rise took place during the interglacial period most similar to the present one now in progress, Olaon said. It thus becomes essential that the full extent and duration of this event be more widely recognized and acknowledged.

The findings are reported in the journal Quaternary Science Reviews.