Earthquakes warningImproving earthquake early warning systems
Earthquake early warning systems may provide the public with crucial seconds to prepare for severe shaking. For California, a new study suggests upgrading current technology and relocating some seismic stations would improve the warning time, particularly in areas poorly served by the existing network — south of San Francisco Bay Area to north Los Angeles and north of the San Francisco Bay Area.
Earthquake early warning systems may provide the public with crucial seconds to prepare for severe shaking. For California, a new study suggests upgrading current technology and relocating some seismic stations would improve the warning time, particularly in areas poorly served by the existing network — south of San Francisco Bay Area to north Los Angeles and north of the San Francisco Bay Area.
An SSA release reports that a separate case study focuses on the utility of low cost sensors to create a high-density, effective network that can be used for issuing early warnings in Taiwan. Both studies appear in the November/December 2013 issue of the journal Seismological Research Letters (SRL) (the California early warning system study here; the low-cost sensors study here).
“We know where most active faults are in California, and we can smartly place seismic stations to optimize the network,” said Serdar Kuyuk, assistant professor of civil engineering at Sakarya University in Turkey, who conducted the California study while he was a post-doctoral fellow at University of California (UC), Berkeley. Richard Allen, director of the Berkeley Seismological Laboratory, is the co-author of this study.
Japan started to build its EEW system after the 1995 Kobe earthquake and performed well during the 2011 magnitude 9 Tohoku-Oki earthquake. While the U.S. Geological Survey(USGS)/Caltech Southern California Seismic and TriNet Network in Southern California was upgraded in response to the 1994 Northridge quake, the United States is lagging behind Japan and other countries in developing a fully functional warning system.
“We should not wait until another major quake before improving the early warning system,” said Kuyuk.
Noting California recently passed a law which calls for the creation of a statewide earthquake early warning (EEW) system (see “California mulls costly earthquake early-warning system,” HSNW, 19 September 2013). Kuyuk says, “the study is timely and highlights for policymakers where to deploy stations for optimal coverage.” The approach maximizes the warning time and reduces the size of “blind zones” where no warning is possible, while also taking into account budgetary constraints.
Earthquake early warning systems detect the initiation of an earthquake and issue warning alerts of possible forthcoming ground shaking. Seismic stations detect the energy from the compressional P-wave first, followed by the shear and surface waves, which cause the intense shaking and most damage.
