The University of Colorado at Boulder scientists said their finding might help explain the recently observed acceleration of glaciers in Greenland that contributes to the rise of global sea levels.

The study, led by Professor Robert Anderson of the Institute of Arctic and Alpine Research, found the amount of water passing through conduits inside and underneath the Kennicott glacier increases during seasonal melting, forcing water back into a honeycomb of passages inside the glacier.

That phenomenon, said Anderson, results in an increase in water pressure that causes the glacier to slide more rapidly down its bedrock valley.

The sliding eventually opens spaces in the glacier's bed to allow the accommodation of some of the excess water, helping to relieve the water pressure, the authors said.

"This phenomenon is also relevant to small glaciers around the world, because it may help to explain their non-steady rates of sliding," said Anderson.

The study that also included Suzanne Anderson and Timothy Bartholomaus appears in the journal Nature Geoscience.