This Echo is READ ONLY !   NO Un-Authorized Messages Please!
 ~~~~~~~~~~~~~~~~~~~~~~~~   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

David E. Steitz
Headquarters, Washington            April 11, 2003
(Phone: 202/358-1730)

Alan Buis
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/354-0474)

RELEASE: 03-138

PERIL IN PERU? NASA TAKES A LOOK AT MENACING GLACIER

An Earth-monitoring instrument aboard NASA's Terra satellite is
keeping a close eye on a potential glacial disaster-in-the-making in
Peru's spectacular, snow-capped Cordillera Blanca (White Mountains),
the highest range of the Peruvian Andes.

Data from NASA's Advanced Spaceborne Thermal Emission and Reflection 
Radiometer (ASTER) is assisting Peruvian government officials and 
geologists in monitoring a glacier that feeds Lake Palcacocha,
located high above the city of Huaraz, 270 kilometers (168 miles)
north of Lima. An ominous crack has developed in the glacier. Should
the large glacier chunk break off and fall into the lake, the ensuing
flood could hurtle down the Cojup Valley into the Rio Santa Valley
below, reaching Huaraz and its population of 60,000 in less than 15
minutes. 

"Remote sensing instruments like ASTER can serve a vital role in
mountain hazard management and disaster mapping by providing rapid
access to data, even in regions not easily accessible by humans,"
explained Dr. Michael Abrams, associate ASTER team leader at NASA's
Jet Propulsion Laboratory, Pasadena, Calif.

"ASTER's unique vantage point from space gives scientists another
tool with which to see early signs of potential glacial flood-burst
events and to monitor changes in glacial behavior over time. In
Huaraz, Peruvian authorities and scientists will incorporate ASTER
data along with data from ground-based monitoring techniques to
better assess current conditions and take steps necessary to reduce
risks to human lives and property," Abrams said. 

Comparison images of the area and more information are available at:

http://photojournal.jpl.nasa.gov/catalog/PIA03899

Huaraz can be seen in the images' left-center, with Lake Palcacocha
in the images' upper right corners at the head of a valley, below the
snow and glacier cap. The left image was acquired on November 5,
2001; the right on April 8, 2003.

Glacial flood-bursts, known by Peruvians as "aluviones," occur
periodically when water is released abruptly from a previously
ice-damned lake alongside, within or above a glacier. The release can
be caused by various triggering events. These flood-bursts typically
arrive with little or no warning, carrying liquid mud, large rock
boulders and blocks of ice. 

The Rio Santa Valley is no stranger to such disasters. Since 1702,
floods caused by glaciological conditions have repeatedly caused
death and destruction in the region. One particularly devastating
event in 1941 destroyed approximately one-third of Huaraz, killing an
estimated 5,000 to 7,000 people. Since then, the Peruvian government
has emphasized control of the water level in Lake Palcacocha and
other lakes in the region that pose similar threats. The efforts
appear to have worked; since 1972, no destructive floods resulting
from the breakout of glacial lakes have occurred. Nevertheless,
officials are still monitoring the current situation closely.

ASTER's broad spectral coverage and high spectral resolution is
ideally suited for monitoring dynamic conditions and changes in
Earth's landscape over time, including glacial advances and retreats.
Its 14 spectral bands measure from the visible to the thermal
infrared wavelength region, and it can "see" at a resolution of 15 to
90 meters (about 50 to 300 feet). 

ASTER provides scientists in numerous disciplines critical
information used for surface mapping and monitoring of dynamic
conditions and changes over time. Example applications include
monitoring glacial advances and retreats and potentially active
volcanoes; identifying crop stress; determining cloud morphology and
physical properties; evaluating wetlands; monitoring thermal
pollution and coral reef degradation; mapping surface temperatures of
soils and geology; and measuring surface heat balance. It can also
image the same area as frequently as every other day in response to
urgent priorities.

ASTER is one of five Earth-observing instruments launched December
18, 1999, on NASA's Terra satellite. Japan's Ministry of Economy,
Trade and Industry built the instrument. A joint U.S./Japan science
team is responsible for validation and calibration of the instrument
and the data products.

The Terra satellite is part of NASA's Earth Science Enterprise, a
program dedicated to understanding the Earth as an integrated system
and applying Earth System Science to improve prediction of climate,
weather and natural hazards using the unique vantage point of space.

-end-

 - END OF FILE -
==========

@Message posted automagically by IMTHINGS POST 1.30
---