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
Additional Teacher Resources
National Snow and Ice Data Center (NSIDC): Education Center
The Education Center section of the National Snow and Ice Data Center provides information useful to educators on the topics of sea ice, glaciers, snow, climate change, and more.
NASA: Arctic Ice Meltdown Continues with Significantly Reduced Winter Ice Cover
A new study shows that in the last two years sea ice is shrinking on the surface of Arctic waters to record low levels. Using satellite data, scientists have observed this phenomenon. This article includes photographs of the sea ice and an interactive graph.
NOAA: How Does Arctic Sea Ice Form and Decay?
Sea ice occupies about 7% of the area of the world ocean, and is of enormous importance climatically because it reflects most of the solar radiation that falls on it, affecting the average temperature of the earth. This site explores the “life Cycle” of Arctic sea ice.
NOAA: Arctic and Antarctic Activity Book
This activity book designed for young learners contains a wealth of information about life in the arctic and Antarctic. It includes coloring pages with accompanying species text, word searches, connect the dots, mazes, Mad Libs and more.
NOAA: Arctic Change
This website sponsored by NOAA provides information on the present state of Arctic ecosystems and climate in historical context. It includes a link to the Arctic Report Card 2007: An annual update of changing conditions.
Andrill Project Iceberg: Education and Outreach
Learn how eight educators from the United States, Italy, Germany, and New Zealand are working with the scientists in Antarctica to see how conditions on Earth have changed over millions of years. Teachers and scientists provide video journals and photographs.
