Greenland's glaciers flowing into the ocean are grounded
deeper below sea level than previously measured, allowing
intruding ocean water to badly undercut the glacier faces. That
process will raise sea levels around the world much faster than
currently estimated, according to a team of researchers led by
Eric Rignot of the University of California, Irvine (UCI), and
NASA's Jet Propulsion Laboratory, Pasadena, California.
The researchers battled rough waters and an onslaught of
icebergs for three summers to map the remote channels below
Greenland's marine-terminating glaciers for the first time.
Their results have been accepted for publication in the journal
Geophysical Research Letters and are
now available online.
"Measurements are challenging to obtain beneath hundreds of
meters of seawater in poorly charted, ice-infested fjords,"
Rignot wrote. He and co-authors Ian Fenty of JPL, Cilan Cai and
Yun Xu of UCI, and Chris Kemp of Terrasond Ltd., Seattle,
obtained and analyzed around-the-clock measurements of the
depth, salinity and temperature of channel waters and their
intersection with the coastal edge of Greenland's ice sheet.
The team found some glaciers perched on giant earthen sills,
protecting them from the punishing salt waters for now, while
others were being severely eroded out of sight beneath the
surface, meaning they could collapse and melt much sooner.
"Numerical ice sheet models do not take into account these
interactions and as a result underestimate how fast the glaciers
will respond to climate warming," said Rignot.
To see video, photos and a narrative of the August 2014
expedition:
http://news.uci.edu/greenland/
NASA uses the vantage point of space to
increase our understanding of our home
planet, improve lives and safeguard our
future. NASA develops new ways to observe
and study Earth's interconnected natural
systems with long-term data records. The
agency freely shares this unique knowledge
and works with institutions around the world
to gain new insights into how our planet is
changing.
For more information about NASA's Earth
science activities, visit:
http://www.nasa.gov/earth
Media Contact
Alan Buis
Jet Propulsion Laboratory, Pasadena,
California
818-354-0474
Alan.Buis@jpl.nasa.gov
Janet Wilson
University of California, Irvine
949-824-3969
janethw@uci.edu
2015-240
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