Worldwide Use of Earthquake Early Warning

A statewide earthquake early warning system (EEWS) is being developed for California under the leadership of the California Office of Emergency Services (CalOES). There is a proven capability of these systems to provide vital alerts to businesses and citizens, giving them up to several minutes of warning to enable protecting critical systems, securing transport and permitting preparedness response. In the recent 2017 Mexico earthquakes, citizens were given zero to 20 seconds warning depending on their location to get to safety.

However, EEWS are not new. In fact, some have been active for decades. Japan has had a nationwide system since 2007; Taiwan since 2001. Mexico deployed their system, SASMEX, in the 1990s which has since been expanded. Systems have also been deployed in Chile, Canada and China and they are planned for Europe. All of these systems have elements in common, including sensors, connecting communications links, central processing computers and notification networks, and they have some differences, principally the elements of the software that need to be tailored to the geology of the region.

Most of these systems are local or regional; only the Taiwan and Japan systems are effectively nationwide. But 11 European and Mediterranean countries are planning a multinational system. Starting in 2006 the European Commission funded work on the Seismic Early Warning for Europe (SAFER), designed to alert citizens about seismic risk.

Earthquake Early Warning – An Overview

Like earthquakes, hurricanes can be very destructive, but at least citizens can get some warning of their approach and intensity. Earthquakes, however, are unpredictable. While detailed prediction is still an inexact science, early warning of earthquakes is possible and systems are being deployed across the globe. This ability to provide early warning is based on the fact that the energy from an earthquake is released through different kinds of motion that create different waves of energy moving through the earth. Fortunately for us, the most destructive waves are slower than some others, and the early sensing of these faster waves enables early warning of the arrival of the more destructive ones.

Much of the early work on Earthquake Early Warning Systems (EEWS) began in Japan and, as a result, that country has the most advanced network operating in the world. However, Earthquake Early Warning (EEW) is still a young science; the Japanese system was first used only 10 years ago in 2007. It is used to provide early warning on earthquakes and associated tsunamis, important for an island nation.

There are four key elements of any large scale Earthquake Early Warning system:

  • The sensor network
  • Processing and analysis system
  • The alerting and notification system
  • Public education and coordination with key public and private organizations

All of these components must work in unison to maximize the public trust in the network. Numerous false warnings or malfunction of equipment will make it difficult to gain support for the network.