The movement of the giant Byrd Glacier in East Antarctica increased in speed as two lakes under the ice overflowed. Leigh Stearns and colleagues have been able to show that great floods under the Antarctic Ice sheet speed up the movement of ice towards the ocean.  As more ice melts into the ocean the higher the water levels rise. 

When flooding occurs an increase of 10% has been recorded in the speed of the ice flow.  Scientists have known about the existence of sub glacial lakes for many years.  There are over 150 lakes with the largest being the size of Lake Ontario in North America.  Warm spots in the underlying rock keep the lakes liquid despite being capped in some cases by several kilometres of ice.

In 2005 scientists discovered that the levels in the lakes could change rapidly and at times would fill and burst their rims under the ice sheet.  When this occurred the ice lifted up by several metres – something which can be seen by over-flying satellites that measure the height of the ice.  The flood water acts as a lubricant enabling the ice to move over the bedrock with ease. 

 This observation has been critical to our being able to understand future possible rises in sea levels.  Recent findings have provided direct evidence that active lake drainage systems can cause large and rapid changes in glacier dynamics.