Oceans to fall, not rise, over millions of years

By Alister Doyle, Environment Correspondent

OSLO (Reuters) - Sea levels are set to fall over millions of years, making the current rise blamed on climate change a brief interruption of an ancient geological trend, scientists said on Thursday.

They said oceans were getting deeper and sea levels had fallen by about 170 meters (560 ft) since the Cretaceous period 80 million years ago when dinosaurs lived. Previously, the little-understood fall had been estimated at 40 to 250 meters.

"The ocean floor has got on average older and gone down and so the sea level has also fallen," said Bernhard Steinberger at the Geological Survey of Norway, one of five authors of a report in the journal Science.

"The trend will continue," he told Reuters.

A computer model based on improved understanding of shifts of continent-sized tectonic plates in the earth's crust projects more deepening of the ocean floor and a further sea level decline of 120 meters in 80 million years' time.

If sea levels were to fall that much now, Russia would be connected to Alaska by land over what is now the Bering Strait, Britain would be part of mainland Europe and Australia and Papua island would be the same landmass.

The study aids understanding of sea levels by showing that geology has played a big role alongside ice ages, which can suck vast amounts of water from the oceans onto land.

DOWN NOT UP