How fast and how much glacial melting?
Greenland glacier. (Photo by SKW)
Ian Howat: If you open up a glaciology textbook – the textbooks we all learned from – it says these glaciers should change on timescales of decades to centuries or even millennia. And suddenly, we’re finding that you can have big changes in the dynamics of these huge glaciers in weeks or less.
That’s Ian Howat, author of a 2007 study related to how fast Greenland’s glaciers release mass to the sea…
...And so, how much these glaciers might contribute to sea level rise in this century. Between 2000 and 2005, it seemed that Greenland’s glaciers were releasing mass at a very fast rate, both through melting and through direct discharge of ice into the sea. This is still happening. The rate hasn’t slowed down, said Howat.
But two of the largest glaciers are now releasing mass more slowly, he said. So, the rate of discharge isn’t steady, and the dynamics of these ice sheets now are known to change quickly.
Ian Howat: It’s a bit of a humbling. It’s a bit of a realization that we haven’t been observing these changes very long. And I think it’s just the nature of the scientific beast.
Howat said this variability makes it tough for scientists to predict how much Greenland’s glaciers will contribute to sea level rise in this century. Our thanks today to NASA : explore, discover, understand.
Our thanks to:
Dr. Ian Howat
Research Associate, Polar Science Center
Applied Physics Laboratory
University of Washington
Seattle, WA
and
National Snow and Ice Data Center
Boulder, CO
