New research on fossilised corals from Tahiti, conducted by researchers from the 21st Century Ocean Institute, shows that the behaviour of ice sheets is much more volatile and dynamic than previously thought. This work, led by Alex Thomas and Gideon Henderson, was featured on the front cover of Science magazine in May 2009.
Analysis of Tahitian corals suggests that ice sheets can change rapidly over just hundreds of years, giving rise to associated sea level rises of several metres. It also shows that a natural warming mechanism (northern hemisphere summer insolation) previously thought to be responsible for ending ice ages may not be the sole factor of influence. The timing of sea level changes shows that this natural warming mechanism could not have caused the deglaciation that brought the penultimate ice age to an end around 137,000 years ago, and so there may still be unidentified natural phenomena driving the fluctuation in Earth’s ice coverings.