Nepal would have benefitted from a seismic early-warning system: Experts

Nepal would have benefitted from a seismic early-warning system: Experts

Published 29 April 2015

 

As far back as the thirteenth century, Nepal experienced a major earthquake every seventy-five years or so, and just like the recent magnitude 7.8 quake, no one has been able to predict exactly when the next quake will strike. If forecasters are unable to anticipate quakes days or weeks ahead, then residents of earthquake prone areas may have to rely on early-warning systems which are able to provide a few seconds notice before an earthquake strikes. Earthquake early-warning systems have been deployed in a few seismic hot zones including Japan, Mexico, and California.

As far back as the thirteenth century, Nepal experienced a major earthquake every seventy-five years or so, and just like the recent magnitude 7.8 quake, no one has been able to predict exactly when the next quake will strike. “So far, the search for diagnostic precursors has been unsuccessful. Most geoscientists do not believe that there is a realistic prospect of accurate prediction in the foreseeable future, and the principal focus of research is on improving the forecasting of earthquakes,” according to the U.S. Geological Society (USGS).
Seismologists met in Nepal’s capital earlier this April, but were unable to predict that an earthquake would strike at the end of the month. Addressing an international conference on disaster risk reduction last month in Japan, Nepalese foreign minister Mahendra Bahadur Pandly, warned that a major earthquake in the Kathmandu valley would be devastating.
If forecasters are unable to anticipate quakes days or weeks ahead, then residents of earthquake prone areas may have to rely on early-warning systems which are able to provide a few seconds notice before an earthquake strikes.
Earthquake early-warning systems have been deployed in a few seismic hot zones including Japan, Mexico, and California. Japan’s early warning system has issued public alerts since 2007 to emergency and law enforcement agencies, some private industrial facilities, and public infrastructure projects. When the 2011 Tohoku quake struck, bullet trains, nuclear reactors, and critical factory operations shut down automatically.
During the 2014 Napa earthquake, California’s early warning system, dubbed ShakeAlert, gave the San Francisco Bay Area five to ten seconds notice before shaking began. “If Nepal had a seismic network that operated as the seismic stations in Northern California did in the Napa quake, people in Kathmandu would probably have had 15 to 20 seconds warning,” seismologist Peggy Hellweg, of the Berkeley Seismological Laboratory at the University of California, Berkeley, told Newsweek.
ShakeAlert detects earthquakes using the California Integrated Seismic Network of roughly 400 ground motion sensors which identify primary waves (P-waves) as they move through the Earth at almost twice the speed of the earthquakes’ destructive S-waves, which shake the ground. Once P waves reach a seismic station, the information is transmitted via communications lines to labs, where computers calculate the origin and magnitude of the pending earthquake. Developers of ShakeAlert hope that in the near future, residents of California will receive earthquake warning alerts on their mobile phones and radio stations. California’s ShakeAlert is not yet available to the entire state or region (see “California exploring ways to fund ShakeAlert earthquake early warning system,” HSNW, 10 April 2015; and “Earthquake early-warning system to be deployed in Washington, Oregon,” HSNW, 13 February 2015).
The USGS estimated last year that it would cost $38.3 million to set up an early-warning system for the entire U.S. west coast, with annual maintenance and operations totaling $16.1 million.