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NASA-funded
researchers have created the first complete map of the speed and
direction of ice flow in Antarctica. The map, which shows glaciers
flowing thousands of miles from the continent’s deep interior to its
coast, will be critical for tracking future sea-level increases from
climate change. The team created the map using integrated radar
observations from a consortium of international satellites.
“This
is like seeing a map of all the oceans’ currents for the first time.
It’s a game changer for glaciology,” said Eric Rignot of NASA’s Jet
Propulsion Laboratory in Pasadena, Calif., and the University of
California (UC), Irvine. Rignot is lead author of a paper about the ice
flow published online Thursday in Science Express. “We are seeing
amazing flows from the heart of the continent that had never been
described before.”
Rignot
and UC Irvine scientists Jeremie Mouginot and Bernd Scheuchl used
billions of data points captured by European, Japanese and Canadian
satellites to weed out cloud cover, solar glare and land features
masking the glaciers. With the aid of NASA technology, the team
painstakingly pieced together the shape and velocity of glacial
formations, including the previously uncharted East Antarctica, which
comprises 77% of the continent.
Like
viewers of a completed jigsaw puzzle, the scientists were surprised
when they stood back and took in the full picture. They discovered a new
ridge splitting the 5.4 million-square-mile (14
million-square-kilometer) landmass from east to west.
The
team also found unnamed formations moving up to 800 feet (244 meters)
annually across immense plains sloping toward the Antarctic Ocean and in
a different manner than past models of ice migration.
“The
map points out something fundamentally new: that ice moves by slipping
along the ground it rests on,” said Thomas Wagner, NASA’s cryospheric
program scientist in Washington. “That’s critical knowledge for
predicting future sea level rise. It means that if we lose ice at the
coasts from the warming ocean, we open the tap to massive amounts of ice
in the interior.”
The
work was conducted in conjunction with the International Polar Year
(IPY) (2007-2008). Collaborators worked under the IPY Space Task Group,
which included NASA; the European Space Agency (ESA); Canadian Space
Agency (CSA); Japan Aerospace Exploration Agency; the Alaska Satellite
Facility in Fairbanks; and MacDonald, Dettwiler and Associates of
Richmond, British Columbia, Canada. The map builds on partial charts of
Antarctic ice flow created by NASA, CSA and ESA using different
techniques. “To our knowledge, this is the first time that a tightly
knit collaboration of civilian space agencies has worked together to
create such a huge dataset of this type,” said Yves Crevier of CSA. “It
is a dataset of lasting scientific value in assessing the extent and
rate of change in polar regions.”
