Saint-Hubert, March 21, 2001- Images produced by RADARSAT-1, Canada’s
renowned Earth Observation satellite is helping a team of scientists answer
crucial questions about the rate and extent of global climate change in
Antarctica. This initiative, the second since 1997, was a joint project of
the Canadian Space Agency and NASA.

Early analyses show that in just three years the Amery Ice Shelf has
advanced five kilometres, while the Shirase Glacier, located in the Indian
Ocean sector of the continent, has retreated twelve kilometres. Scientists
are seeking to understand whether this variability is due to the forces of
external climate on the great ice sheet or due to natural and episodic
instabilities that arise from the forces that control complex glacier flow.
The new velocity measurements from this second completed mission will help
answer these questions.

“The Antarctic Ice Sheet moves slowly and surely under the force of its own
enormous weight,” says Principal Scientist Dr. Kenneth C. Jezek of The Ohio
State University’s Byrd Polar Research Center. “This mission gives us the
first, overall snapshot of how the ice moves and important new insight into
how and why the ice sheet is changing. Moreover, by measuring the extent
and velocity of the moving ice and estimating its thickness, we can estimate
how much ice may be lost into the ocean from Earth’s largest storehouse of
freshwater. These calculations are important for understanding Antarctica’s
contribution to the present rate of sea level rise of about two millimeters
a year.”

For this mission, the Canadian Space Agency’s RADARSAT-1 satellite trained
its imaging radar on the outer half of the continent twice during each of
three consecutive 24-day periods, ending last Nov. 14. “This was a
challenging mission for our professionals who had to accurately navigate the
satellite, controlling the 800 kilometre orbit, while periodically firing
the spacecraft’s onboard thrusters so as to position the satellite within a
few hundred meters of its nominal track on each orbit,” said Rolf Mamen,
Director General of Space Operations at the Canadian Space Agency. Precise
navigation and data from the six passes make it possible to create detailed
topographic maps and to measure the speed of the moving glaciers.

The two scientific missions supported by RADARSAT-1 have produced a new
baseline dataset for the scientific community-one that will prove invaluable
in monitoring the state of the Antarctic ice cap. And although RADARSAT-1 is
being exploited by the Canadian Space Agency beyond its nominal lifetime,
this same leading-edge technology continues to produce outstanding imagery
is also being brought to bear on studies of polar ice in Canada’s Arctic
region.

RADARSAT-2, currently under construction for the Canadian Space Agency by
MacDonald Dettwiler and Associates of British Columbia and scheduled for
launch in 2003, will contribute to expanding the vast data archive already
captured by RADARSAT-1. These unique Earth Observation spacecraft, and the
team of highly skilled Canadian Space Agency professionals operating them,
are performing an important service, providing key data for clients in the
fields of mapping, geology, oceanography, ice surveillance, agriculture,
natural resources exploration, supporting disaster and relief efforts
worldwide and helping scientists improve their understanding and measure the
effects of global warming on our planet Earth.

About the Antarctic Mapping Missions

Building on the success of the first complete mapping of the continent in
1997, RADARSAT-1 was again deployed in November, 2000 to support a second
Antarctic Mapping Mission. This follow-on initiative was a joint project of
the Canadian Space Agency and NASA. The science team includes members from
the Byrd Polar Research Center at The Ohio State University, NASA’s Jet
Propulsion Laboratory, the Alaska SAR Facility at the University of Alaska,
Fairbanks, and the Vexcel Corporation. The mission is part of NASA’s Earth
Science Enterprise, a long-term research program dedicated to studying how
human-induced and natural changes affect our global environment.

About the Canadian Space Agency

Established in 1989 and situated in Saint-Hubert, Quebec, the Canadian Space
Agency (CSA) coordinates all aspects of the Canadian Space Program. Through
its Space Knowledge, Applications and Industry Development business line,
the CSA delivers services involving: Earth and the Environment; Space
Science; Human Presence in Space; Satellite Communications; Generic Space
Technologies; Space Qualification Services and Awareness. The Canadian Space
Agency is at the forefront of the development and application of space
knowledge for the benefit of Canadians and humanity.

For more information:

B-Roll will be broadcast on NASA TV, March 22 between 16:30-21:00 (GE-2.,
transponder 9C, C-Band, 85 degrees West longitude; frequency 3888.0 MHz,
polarization vertical, audio monaural at 6.8 MHz)

The mission: http://www-bprc.mps.ohio-state.edu/radarsat

The images: http://www.jpl.nasa.gov/pictures/antarctica/

The Canadian Space Agency and RADARSAT-1: http://www.space.gc.ca

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André Leclair

Senior Communications Advisor

Canadian Space Agency

(450) 926-4370

andre.leclair@space.gc.ca