Studies show rapid rate of Greenland ice melt
Many scientists are studying Greenland ice as it melts and flows into the sea. A recent study by Eric Rignot and Pannir Kanagaratnam suggests that the rate of Greenland ice melt has almost doubled in the last five years.
DB: This is Earth & Sky, with Isabella Velicogna of the University of Colorado.
JB: Her team has used satellite data to monitor changes in Greenland’s ice sheet.
Isabella Velicogna: The reason why people are very interested in the major sheets is because they are the biggest reservoir of fresh water on the planet.
DB: The data show Greenland ice turning to water at a rapid rate. Velicogna said to picture it this way. She said Los Angeles County, in one year, uses about a cubic kilometer of fresh water for drinking, sanitation, and agriculture. Her work shows that, on average, about 160 cubic kilometers of Greenland ice have melted each year since 2002. That’s 160 times the total water needs of Los Angeles flowing from Greenland into the ocean every year.
JB: All this fresh water melting from Greenland contributes to sea level rise. Velicogna’s team calculates a rise in sea level of about .4 millimeters – about one eighth of all sea level rise globally each year – due solely to Greenland ice. Other researchers agree. Eric Rignot and Pannir Kanagaratnam estimate a .5 millimeter increase per year in global sea level rise due to melting Greenland ice.
DB: Their works shows the rate of Greenland ice flowing to the Atlantic almost doubling in the last five years. Our thanks today to NASA: explore, discover, understand. We’re Block and Byrd for Earth & Sky.
Eric Rignot and Pannir Kanagaratnam presented their results at the 2006 AAAS meeting, held Feb. 16-20 in St. Louis.
The following images were provided by Rignot and Kanagaratnam:
An image of Petermann Glacier, north Greenland taken from helicopter in April 2002. (Image courtesy of E. Rignot)
Kangerdlugssuaq Gletscher, East Greenland showing ice-elevated surfaces hanging on rocks about 100 meters above the present-day ice level. They were were left by the rapid thinning of the glacier. (Image courtesy of Greenpeace/Morgan; University of Maine/Hamilton)
The calving front of Helheim Gletscher, southeast Greenland in May 2005 showing high calving activity associated with a rapid rate of melting. This glacier is now one of the fastest moving glaciers in the world. (Image courtesy of NASA Wallops/Sonntag)
The calving front of Kangerdlugssuaq Gletscher, east Greenland in May 2005 showing enormous calving activity. This glacier is now moving 14 kilometers/year or 38 meters/day or 126 feet/day; nearly three times faster than in the past. (Image courtesy of NASA Wallops/Sonntag (John Sonntag))
Additional Teacher Resources
NASA Earth Observatory: Vanishing Ice
Konrad Steffen arrived on the Greenland Ice Sheet for the 2002 summer fieldwork season and immediately observed that something significant was happening in the Arctic. Pools of water already spotted the ice surface, and melting was occurring where it never had before. “That year the melt was so early and so intense – it really jumped out at me. I’d never seen the seasonal melt occur that high on the ice sheet before, and it had never started so early in the spring,” said Steffen, principal scientist and interim director at the Cooperative Institute for Research in Environmental Sciences (CIRES) at the University of Colorado.
NASA Earth Observatory: The Melting Ice of Greenland
What might at first be mistaken for a series of images showing the approach of summer on the edge of the Greenland ice sheet in fact shows an increase in melting over the past several years. The three images above show the melting in June of 2001, 2002, and 2003. Since 2001, the amount of melting along the edges of Greenland’s ice cap has increased significantly.
