FROM: NASA
WASHINGTON -- The space-based technology that lets GPS-equipped
motorists constantly update their precise location will undergo a
major test of its ability to rapidly pinpoint the location and
magnitude of strong earthquakes across the western United States.
Results from the new Real-time Earthquake Analysis for Disaster
(READI) Mitigation Network soon could be used to assist prompt
disaster response and more accurate tsunami warnings.
The new research network builds on decades of technology development
supported by the National Science Foundation, the Department of
Defense, NASA, and the U.S. Geological Survey (USGS). The network
uses real-time GPS measurements from nearly 500 stations throughout
California, Oregon and Washington. When a large earthquake is
detected, GPS data are used to automatically calculate its vital
characteristics including location, magnitude and details about the
fault rupture.
"With the READI network we are enabling continued development of
real-time GPS technologies to advance national and international
early warning disaster systems," said Craig Dobson, natural hazards
program manager in the Earth Science Division at NASA Headquarters in
Washington. "This prototype system is a significant step towards
realizing the goal of providing Pacific basin-wide natural hazards
capability around the Pacific 'Ring of Fire.'"
Accurate and rapid identification of earthquakes of magnitude 6.0 and
stronger is critical for disaster response and mitigation efforts,
especially for tsunamis. Calculating the strength of a tsunami
requires detailed knowledge of the size of the earthquake and
associated ground movements. Acquiring this type of data for very
large earthquakes is a challenge for traditional seismological
instruments that measure ground shaking.
High-precision, second-by-second measurements of ground displacements
using GPS have been shown to reduce the time needed to characterize
large earthquakes and to increase the accuracy of subsequent tsunami
predictions. After the capabilities of the network have been fully
demonstrated, it is intended to be used by appropriate natural hazard
monitoring agencies. USGS and the National Oceanic and Atmospheric
Administration are responsible for detecting and issuing warnings on
earthquakes and tsunamis, respectively.
"By using GPS to measure ground deformation from large earthquakes, we
can reduce the time needed to locate and characterize the damage from
large seismic events to several minutes," said Yehuda Bock, director
of Scripps Institution of Oceanography's Orbit and Permanent Array
Center in La Jolla, Calif. "We now are poised to fully test the
prototype system this year."
The READI network is a collaboration of many institutions including
Scripps at the University of California in San Diego; Central
Washington University in Ellensburg; the University of Nevada in
Reno; California Institute of Technology/Jet Propulsion Laboratory
(JPL) in Pasadena; UNAVCO in Boulder, Colo.; and the University of
California at Berkeley.
NASA, NSF, USGS, and other federal, state, and local partners support
the GPS stations in the network, including the EarthScope Plate
Boundary Observatory, the Pacific Northwest Geodetic Array, the Bay
Area Regional Deformation Array and the California Real-Time Network.
"The relatively small investments in GPS-based natural hazards systems
have revolutionized the way we view the Earth and allowed us to
develop this prototype system with great potential benefits for the
infrastructure and population in earthquake-prone states in the
western United States," said Frank Webb, Earth Science Advanced
Mission Concepts program manager at JPL.
The READI network is the outgrowth of nearly 25 years of U.S.
government research efforts to develop the capabilities and
applications of GPS technology. The GPS satellite system was created
by the Department of Defense for military and ultimately civil
positioning needs. NASA leveraged this investment by supporting
development of a global GPS signal receiving network to improve the
accuracy and utility of GPS positioning information. Today that
capability provides real-time, pinpoint positioning and timing for a
wide variety of uses from agriculture to Earth exploration.
"Conventional seismic networks have consistently struggled to rapidly
identify the true size of great earthquakes during the last decade,"
said Timothy Melbourne, director of the Central Washington
University's Pacific Northwest Geodetic Array. "This GPS system is
more likely to provide accurate and rapid estimates of the location
and amount of fault slip to fire, utility, medical and other
first-response teams."
The GPS earthquake detection capability was first demonstrated by
NASA-supported research on a major 2004 Sumatra quake conducted by
Geoffrey Blewitt and colleagues at the University of Nevada in Reno.
