Arctic Science Journeys Radio
Arctic lakes shrink, disappear 3:00:00

INTRO:  Lakes and ponds across the Arctic are beginning to shrink, and 
some have disappeared altogether, as a warmer global climate dries out the 
northern landscape. As Doug Schneider reports in this weekÕs Arctic Science 
Journeys Radio, scientists say the loss of surface freshwater across the 
Arctic portends a dramatic ecological shift that could have long-term 
impacts on everything from subsistence to weather, to ocean circulation.

STORY:  Geography professor Laurence Smith from the University of 
California Los Angeles knew something strange was happening across the 
Arctic when he noticed Siberian rivers were carrying far more freshwater 
than usual.

All that freshwater had to be coming from somewhere. To solve the mystery, 
Smith compared satellite images of nearly 11,000 Siberian lakes in the early 
1970s with images taken between 1997 and 2004. 

In all, Smith says 1,170 lakes became smaller, shrinking a total of 359 
square miles. And in just 30 years, one-hundred-twenty-five lakes had 
completely disappeared, and are now covered by vegetation. 

SMITH: "In the earth sciences world, this is a very rapid, dynamic change."

Smith, together with scientists from the State University of New York and 
the University of Alaska Fairbanks, published their research in a recent issue 
of the journal Science. They say the lakes drained away after the frozen 
ground beneath them, called permafrost, thawed. UAF researcher Larry 
Hinzman.

HINZMAN: "Lakes in the southern region of permafrost are relatively thin. 
They are just lakes perched atop the permafrost, and if the permafrost thaws 
completely through, then they start to drain."

Interestingly, lakes in northern Siberia actually gained in size. Smith says 
thatÕs because the permafrost beneath them is thicker and slower to thaw.  In 
time, he says those lakes will shrink as well.

Lakes in Alaska also are shrinking as the underlying permafrost thaws. 
Researchers have documented lake declines in the Yukon Flats, the Seward 
Peninsula, and the Copper River region. And studies done two years ago by 
Canadian scientists found lakes there also have disappeared. Laurence Smith 
of UCLA says if the trend continues, the Arctic landscape will look very 
different in coming decades.

SMITH: "With the river discharges that we have spoken of and now this 
study; the long-term impact is a shift from above ground storage of water to 
below ground storage of water." 

That shift would likely have cascading impacts on wildlife, the environment, 
the weather, and even Arctic Ocean circulation. Migratory birds, fish, and 
other wildlife important to AlaskaÕs Native subsistence users likely will be 
the first the feel the pinch as marshy habitat dries up. And with drier soils, 
Hinzman says the danger of forest fires will increase.

HINZMAN:"We get around Fairbanks something like 3,000 lightening 
strikes a day, but most donÕt amount to anything. But if we have a lot drier 
soils, then we are going to see a lot more forest fires and more severe forest 
fires."
 
And there may be other impacts: So much freshwater running off the land 
into the Arctic Ocean could alter the ocean food web, as well as change 
ocean circulation patterns that drive weather.

If youÕd like to learn more about the ArcticÕs disappearing lakes, come to 
our web site at asjradio.org.  This is Arctic Science Journeys Radio, a 
production of the University of Alaska Fairbanks School of Fisheries and 
Ocean Sciences.  IÕm Doug Schneider.


Websites:


National Science Foundation: Community-wide Arctic Hydrology Analysis 
and Monitoring Program
http://arcticchamp.sr.unh.edu/

UAF News Release: Disappearing arctic lakes linked to climate change
http://www.uaf.edu/news/headlines/20050525155245.html

Thanks to:

Dr. Laurence Smith
Associate Professor
UCLA Department of Geography
1255 Bunche Hall, Box 951524 
Los Angeles, CA 90095-1524
Email: lsmith@geog.ucla.edu
Phone: 310-825-3154
Faculty Profile: http://lena.sscnet.ucla.edu/

Dr. Larry Hinzman
Research Professor of Water Resources 
Water and Environmental Research Center 
Institute of Northern Engineering
University of Alaska Fairbanks
Phone: 907- 474-7331
Email: ffldh@uaf.edu
Faculty Profile: http://www.uaf.edu/water/faculty/hinzman/hinzman.html


Photo cutlines/credits:

ArcticLakes,jpg
Arctic lakes are disappearing as the permafrost beneath them thaws, 
according to a new study on the impacts of climate warming on the far north. 
Courtesy Karen Frey, UCLA 

 LarrySmith.jpg
Larry Smith compared satellite photos of northern Siberia taken in the 1970s 
with images taken recently to discover that Arctic lakes were drying up as 
Arctic temperatures rise. Courtesy Larry Smith, UCLA

LarryHinzman3.jpg
Larry Hinzman says the loss of freshwater in the Arctic could alter wildlife 
habitat, increase the danger of forest fires, and change weather patterns. 
Courtesy Larry Hinzman, UAF

Download PDF:

Science_Arctic_Lakes.doc
Science, June 3, 2005, Disappearing Arctic lakes