Scientists from the University and the Centre for Geodynamics in Norway have made the first comprehensive model of the Earth's sea level rising and falling over the last 140 million years, resolving a long-standing controversy over sea level fluctuations through geological history.

The group, led by Associate Professor Dietmar Müller from the School of Geosciences at the University of Sydney, has reconstructed the volumes of ancient ocean basins from the Cretaceous period until the present, in an article published in the journal Science on the 7 March 2008.

"A global sea level rise of a metre, driven by slowly melting ice sheets, would have disastrous effects on at least 60 million people in coastal areas worldwide. But even larger sea level fluctuations have occurred in the ancient past, in 'hothouse' climates, when neither humans nor inland ice caps existed," explains Associate Professor Müller.

"Our goal was to understand these changes, as sea level fluctuations have been a driving force in the evolution of animals and plants, in climate change and biogeography," says Associate Professor Müller.

"By creating a detailed set of digital maps of ancient ocean basins we were able to show that cycles of mid-ocean ridge creation, evolution and destruction have profoundly effected shifting coastlines and inland seas through time."