Researchers say they have discovered a large reservoir of melt water that sits under the Greenland ice sheet all year round. The scientists say the water is stored in the air space between particles of ice, similar to the way that fruit juice stays liquid in a slush drink. The aquifer, which covers an area the size of Ireland, could yield important clues to sea level rise.
The research is published in the journal, Nature Geoscience. The melting of the Greenland ice sheet has been a significant contributor to a rise in sea levels over the past 100 years.
According to the latest report from the Intergovernmental Panel on Climate Change, the ice sheet lost 34 billion tonnes of ice per year between 1992 and 2001 – but this increased to 215 billion tonnes between 2002 and 2011
Scientists still have many unanswered questions about the direction and speed and ultimate destination of this melted water. This new research finds that a significant amount is stored in partially compacted snow called firn.
In the spring of 2011, researchers drilled deep into this slushy layer and to their surprise, found liquid water flowing back to the surface even though air temperatures were -15 degrees C.
As this was well before the onset of the summer melt, the team concluded the water had persisted in a liquid state through the Greenland winter.
"This discovery was a surprise," said Prof Rick Forster from the University of Utah.
"Instead of the water being stored in the air space between subsurface rock particles, the water is stored in the air space between the ice particles, like the juice in a snow cone."