MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
Contact: Diane Ainsworth
FOR IMMEDIATE RELEASE
September 3, 1999
NEW NASA OCEAN RADAR WATCHES FOR BREAKUP OF GIANT ICEBERG
A NASA satellite instrument is keeping an eye on an iceberg
the size of Rhode Island, the first time this space technology
has been used to track a potential threat to international
NASA's new orbiting SeaWinds radar instrument, flying aboard
the QuikScat satellite, will monitor Iceberg B10A, which snapped
off Antarctica seven years ago and has since drifted into a
Iceberg B10A, which measures about 38 by 77 kilometers
(about 24 miles by 48 miles), was spotted by the Instrument
during its first pass over Antarctica, demonstrating SeaWinds'
all-weather and day-night observational capabilities. The
massive iceberg extends about 90 meters (300 feet) above water
and may reach as deep as 300 meters (1,000 feet) below the
ocean's surface. It is breaking up into smaller pieces that
could pose a threat to commercial, cruise and fishing ships if
the pieces are blown back into the shipping lane by high winds.
"Although the iceberg isn't posing a threat to ships in the
area right now, pieces of B10A could be blown back into the
shipping lane and become a danger to ships using the Antarctic's
Drake Passage," said Dr. David Long, a member of the SeaWinds
science team from Utah's Brigham Young University, Provo, UT.
Long said that the SeaWinds instrument will be able to help
scientists at the National Ice Center, Suitland, MD, track pieces
of the iceberg down to 4 kilometers (about 2.5 miles) in size.
B10A, which took hundreds of thousands of years to form,
broke off the end of the Thwaites glacier of Antarctica in 1992
and has been drifting in the ocean ever since, driven by ocean
currents and wind. In 1995, the iceberg broke in half, but was
being tracked on a regular basis. Although conventional methods
of tracking sea-surface ice -- using ships' radar, shipping
reports, optical images from satellites and microwave sensor data
-- are usually sufficient for tracking large pieces of ice,
icebergs can sometimes disappear in the poor visibility of dark,
cloudy Antarctic winters.
"That happened earlier this year, when we lost track of
B10A's exact whereabouts," Long said. "Even though a ship was
dispatched to the iceberg's last known position, we were unable
to find it until we started receiving data from the SeaWinds
instrument in July."
Scientists were surprised at its location when they found
B10A, but it was clearly identified as a very large iceberg that
posed a considerable threat to ships in the area. A check with
the Naval Ice Center confirmed the iceberg's identity and has
enabled scientists to continue tracking its journey through the
Drake Passage. When it was rediscovered earlier this month
heading northeast between Tierra del Fuego at the southern tip of
South America and the Antarctic Peninsula, the National Ice
Center issued an iceberg navigation warning to the Argentine
Ironically, the iceberg that took many millennia to form is
expected to break up within about three months because it is
drifting into warmer waters, Long said. "We will be able to
watch the iceberg's breakup for the first time with daily radar
observations and better understand the effects of ocean winds and
climate on melting polar ice," Long said. "The polar regions
play a central role in regulating global climate, and it is
important to accurately record and monitor the extent and surface
conditions of Earth's major ice masses."
More information about the SeaWinds mission and observations
is available at the following URLs:
The orbiting SeaWinds radar instrument, launched on the
QuikScat satellite on June 19, is managed for NASA's Office of
Earth Science, Washington, DC, by NASA's Jet Propulsion
Laboratory, Pasadena, CA. JPL also built the SeaWinds radar
instrument and is providing ground science processing systems.
NASA's Goddard Space Flight Center, Greenbelt, MD, managed
development of the satellite, designed and built by Ball
Aerospace & Technologies Corp., Boulder, CO. The National
Oceanic and Atmospheric Administration has contributed support to
ground systems processing and related activities.
NASA's Earth Science Enterprise is a long-term research and
technology program designed to examine Earth's land, oceans,
atmosphere, ice and life as a total integrated system.
JPL is a division of the California Institute of Technology,