PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATIO
PASADENA, CALIFORNIA 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov
Contact: Mary A. Hardin
FOR IMMEDIATE RELEASE
February 7, 1997
NASA SENSORS PROVIDE SAFE PLATFORM FOR VOLCANO STUDIES
NASA scientists are developing and using a variety of
airborne and spaceborne remote-sensing tools to study potentially
dangerous volcanoes that could one day threaten populated areas
in the United States and around the world.
A number of domestic volcanoes are being studied, including
Mount St. Helens and Mount Rainier in Washington; Mount Shasta
and Lassen Peak in California; and Kilauea and Mauna Loa in
Hawaii. Using information collected with the Spaceborne Imaging
Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR), the
Airborne Synthetic Aperture Radar (AIRSAR), the Airborne Emission
Spectrometer (AES), the Thermal Infrared Multispectral Scanner
(TIMS), the airborne Laser Altimeter Facility, and the Shuttle
Laser Altimeter, scientists create three-dimensional "flyover"
video animation clips that help them study how the volcanoes are
changing.
"Imaging radar is a particularly useful tool for studying
volcanoes because the radar is able to see through the weather
and volcanic clouds. It's a good tool for mapping new volcanic
deposits because of the radar's sensitivity to texture such as
ash and different types of lava flows," said Dr. Jeffrey J.
Plaut, SIR-C experiment scientist at NASA's Jet Propulsion
Laboratory. "We are using radar data to study the dormant lava
domes in Long Valley, CA so we can understand how lava is placed
during eruptions. Understanding the eruptive process helps us
know where lava will flow and that has bearing on the hazards
that are posed to the nearby communities, including the Mammoth
Mountain ski areas."
"By combining the radar data with information from scanning
laser altimeters, we are now tracking changes at the summits of
Mount St. Helens and Mount Rainier that will document the impact
of erosion, climate and other factors on the topography and
stability of large volcanoes," said Dr. James B. Garvin, chief
scientist for the Shuttle Laser Altimeter at NASA's Goddard Space
Flight Center (GSFC), Greenbelt, MD. "These laser altimeters
also have successfully measured the flank topography of volcanoes
beneath their tree canopies. This is important because many of
the most dangerous volcanoes are heavily vegetated, and the
subtleties of their local relief must be known to accurately
predict the path of their flows."
In recent months, AIRSAR, AES and TIMS were part of a cadre
of scientific instruments onboard a NASA DC-8 aircraft that
captured images of the Manam volcano within hours of an eruption
on an island off the north coast of Papua New Guinea. "The
airborne instrument helps us map the topography from a safe
distance. The data over Manam were collected as a "target of
opportunity" and the topographic data set will serve as a
valuable baseline for studies about future changes to the
volcano," said Ellen O'Leary, the AIRSAR science coordinator at
JPL.
"We use the thermal infrared data to study volcanoes in
three ways. The first is to map ground temperatures, which we can
relate to geothermal phenomena. The second is to map variations
in the composition of lava flows and the third is to map the
sulfur dioxide in volcanic plumes," said Dr. Vincent J. Realmuto,
TIMS experiment scientist at JPL. "TIMS data are useful for
studying volcanoes because thermal infrared remote sensing is the
only practical means of obtaining virtually instantaneous maps of
dynamic phenomena such as the distribution of temperatures on the
ground or sulfur dioxide in a plume. Such data are of great use
in monitoring volcanoes, where changes in ground temperatures or
sulfur dioxide emission can signal impending activity."
JPL's Digital Image Animation Laboratory (DIAL) turns the
scientific data into three-dimensional video animations and other
images. "These visualizations can range from the simple, such as
the use of color to combine data sets, to the complex, such as
simulated flights through the data. The basic objectives of data
visualization are to give scientists new perspectives into
complex data sets and to permit them to communicate their
findings in a format that is both compelling and accessible,"
Realmuto said.
The DIAL is best known for visualizations of planetary data
sets of Venus and Mars, but visualizations have been produced for
a variety of volcanoes, such as Mount Rainier, the Long Valley
caldera in the Mammoth Mountains of California, Mauna Loa, Mount
Pinatubo and Taal in the Philippines, Mount Etna near Sicily, and
the trans-Mexican volcanic belt. The most recent addition to this
series is a simulated flight over Mount St. Helens that was
created by combining TIMS data with a high-resolution digital
elevation map.
AIRSAR is the airborne cousin of SIR-C/X-SAR that flew
twice on the space shuttle Endeavour in 1994. AIRSAR also uses
three radar wavelengths: L-band (24-cm), C-band (6-cm) and P-band
(68-cm) and can collect data in both vertical and horizontal
polarization. AIRSAR can also be used to collect three-
dimensional topographic data in its TOPSAR mode to create digital
elevation models.
TIMS collects image data in the thermal infrared portion of
the spectrum. TIMS operates at six channels between 8 and 12
micrometers. For comparison, visible light extends from 0.4 to
0.7 micrometers. TIMS is a precursor to the Advanced Spaceborne
Thermal Emission and Reflection Radiometer (ASTER) that is
scheduled to fly on the first Earth Observing System satellite
(EOS AM-1) in 1998.
AES is a spectrometer that operates between 2.3 and 15.4
micrometers, and is a precursor to the Tropospheric Emission
Spectrometer (TES). TES is scheduled for launch aboard the EOS
CHEM-1 platform in 2002.
The GSFC Laser Altimeter Facility sensors are routinely
flown aboard NASA Wallops Flight Facility aircraft such as the P-3
and T-39. The Shuttle Laser Altimeter (SLA) experiment flew on
STS-72, and a second flight of SLA is scheduled for July 1997
as part of STS-85.
JPL manages the SIR-C/X-SAR, AIRSAR and AES missions
for NASA's Office of Mission to Planet Earth, Washington D.C.
TIMS and the DC-8 aircraft are maintained and operated by NASA's
Ames Research Center, Moffet Field, CA. All of these instruments
are part of NASA's Mission to Planet Earth, a
coordinated research enterprise designed to study the Earth as a
total system.
For more information: http://www.geo.mtu.edu/eos/
#####
NOTE TO EDITORS: NASA television will feature show three-
dimensional images of a volcanic island called Manam in Papua,
New Guinea, a three-dimensional flyover of Mount St. Helens,
followed by views of Mount Pinatubo, the Kiluschevskoi volcano
and Mount Ranier today at at 9 a.m., noon, 3 p.m., 6 p.m., and 9
p.m. PST. NASA Television is broadcast on Spacenet 2,
transponder 5, channel 9, C-Band, located at 69 degrees West
longitude, with horizontal polarization. Frequency is on 3880.0
megahertz, with audio on 6.8 megahertz.
#9709 mah
2/7/97
