California, USA: Satellites in orbit will soon help scientists and first responders on the ground more accurately pinpoint the location and severity of earthquakes in the Western United States. NASA’s Real-Time Earthquake Analysis for Disaster (READI) network, set to begin real-world testing this year, uses GPS to measure movement along fault lines in California, Oregon and Washington.
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 programme manager in the Earth Science Division at NASA Headquarters in Washington. “This prototype system is a significant step towards realising 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 characterise large earthquakes and to increase the accuracy of subsequent tsunami predictions. After the capabilities of the network have been fully demonstrated, it is intended for use by appropriate natural hazard monitoring agencies. The 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 characterise the damage from large seismic events to several minutes,” said Yehuda Bock, director of the 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 in Pasadena; UNAVCO in Boulder, Colo.; and the University of California at Berkeley.
NASA, National Science Foundation (NSF), the US Geological Survey (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.