Earthquake Early Warning

Development and Uses

Earthquake early warning (EEW) detects and measures earthquakes fast enough that warning can be given before the strongest shaking arrives, providing seconds to minutes to prepare.

Earthquake early warning is being implemented in many locations around the world.  The 2011 Tohuku Earthquake demonstrated some of its advantages.  The earthquake was recognized as serious within 30 seconds of its initiation offshore.  Tokyo residents had ~30 seconds warning of approaching strong ground motion.  Cell phone alarms warned millions of people when large aftershocks were likely to soon rattle them.

On the west coast of the the US, with USGS funding, Cal Tech and UC Berkeley have developed and are testing an early prototype EEW system known as ShakeAlert in California.  In November, 2012, the Moore Foundation announced awarded grants to Cal Tech, UC Berkeley, and the University of Washington to develop and begin testing this prototype system.  The USGS will help coordinate these activities.


 ShakeAlert Beta Test











EEW in the News

On Monday morning (April 10) the Pacific Northwest Seismic Network (PNSN) was buzzing with activity, but not seismic activity. Network employees were sporting PNSN t-shirts and there were numerous outside officials wearing splashes of University of Washington purple. Reporters from The Seattle Times, KIRO News, the UW Office of News and Information, and more where crowded into the small lab room, surrounded by recording equipment. The lab room itself, with its old school, drum seismograms, was accessorized with extra monitors, a podium, and a clean, purple tablecloth covering the long table, normally cluttered with various earthquake demonstrations. 

What was the occasion? The Seismic Network hosted a press conference to announce the rollout of a new version of the earthquake early warning (EEW) system, ShakeAlert, which is now fully integrated across the entire West Coast of the United States. Speakers included the Dean of the UW College of the Environment, Lisa GraumlichDave Applegate and Doug Given from the United States Geological Survey, U.S. Representative Derek Kilmer, Washington State Seismologist, John VidaleMaximilian Dixon from the Washington State Emergency Management Division, and Dan Ervin, chair of RH2 Engineering.

John Vidale shows an example of the ShakeAlert interface during a test warning. Photo credit: Kyla Marzewski.

Previously the EEW system in the Pacific Northwest was detecting earthquakes and issuing warnings to a beta test group, but the warnings were not being utilized. Now, while the system is not yet ready to send alerts to the public, warnings issued to pilot users will be used to test earthquake response systems. Users include RH2 Engineering in Bothell, WA, which will use the alerts to secure municipal water and sewer systems, and the Eugene Water and Electricity Board in Oregon, where alerts will be used to lower canal water levels above a residential area and turn off turbines at a power plant.

While the release of the updated system marks a large step forward for West Coast earthquake early warning, there is still more work to be done to allow the system to reach its full potential. Both Applegate and Given emphasized that the system only has about half the funding needed in terms of annual support. The development of the system has so far been funded by a combination of public and private grants, including support from the Gordon and Betty Moore Foundation, Amazon Catalyst, and Puget Sound Energy.

“Federal investment in science matters,” said representative Derek Kilmer.

Kilmer believes that Monday’s press conference highlights the value of the EEW system. He hopes that Congress will realize the benefits of having an EEW system across the West Coast and respond. Additional funding will go towards installing new earthquake-recording stations, improving telecommunications between stations and network computers, continued testing of the system, and hiring new staff.

Currently, the system only includes 700 of the 1700 stations needed to cover all the hazards and populations on the West Coast. While the EEW system can move forward with the existing stations, earthquakes in some places, for example parts of Eastern Washington, will be detected less quickly than with the full station set or not at all. Unfortunately, installing new stations is not like “planting flowers” reported Given. Not only do new stations cost money, getting permits to put stations on private, state, and federally owned land is time consuming. 

Another critical component needed to expand the system to be able to issue public alerts is education. Receiving a warning on your cellphone is not useful unless you know what the alert means and how to respond. While there is no funding for education yet, reported Dixon, the ultimate goal of EEW education is for the public to be able to react to warnings with a practiced, automatic response.

Despite the fact that a fully-fledged West Coast EEW system still requires more time, work, and funding, all the press conference speakers emphasized the utility of having earthquake warnings.

“(The earthquake risk on the West Coast) cannot be overstated,” stressed Given.

The EEW system will save lives, preserve infrastructure, and mitigate the loss of productivity post-quake. The release of the West Coast integrated system marks a milestone in earthquake preparedness.

Other articles about the West Coast early warning system:

ShakeAlert earthquake warning system expands to Washington and Oregon, enters prototype testing

USGS Earthquake Early Warning Coordinator Doug Given speaking at the Pacific Northwest Seismic Network. (GeekWire Photo / Clare McGrane)

Nuts and Bolts

EEW is made possible by these contributing factors:
  • Less destructive P waves travel faster than the more destructive S waves, and so will arrive first at any given location.
  •  A dense seismic station network near the earthquake source can quickly detect seismic waves well before the more significant shaking will arrive at more distant population centers.
  •  Data transmission to PNSN, processing at PNSN, and distribution to the end user is very fast relative to seismic travel times.
The amount of warning time increases rapidly with one's distance from the epicenter, and there will be a minimum distance from the hypocenter of the earthquake within which early warning is not possible.


For specifics see USGS Fact Sheet 2014-3083.


EEW Costs and Benefits


A study prepared by the Pacific Earthquake Engineering Research Center (PEER) in the state of California explored the anticipated value of an earthquake early warning system through a series of interviews with organizations representing important sectors of the state's infrastructure and economy. The interviews focused on potential uses of EEW and perceived benefits to the public as well as their own empoyees and businesses.

Major points of the study were:

  • The capital cost to construct and launch a California EEW system is estimated to be $28 million, and the personnel and operating expenses are estimated at $17 million annually. 
  • It was unanimously perceived that the overall societal benefits of a statewide EEW system is very high - a few seconds of advance warning could possibly help millions to Drop, Cover, and Hold On before heavy shaking begins, as well as increase public preparedness for earthquakes and reduce anxiety.
  • Access and concrete use of an EEW system by different sectors of the state's infrastructure and economy could reduce organizational and economic disruptions, benefitting customers and communities by providing essential services related to safety, loss avoidance, and resumption of normal life. 
  • System reliability, design and development of delivery mechanisms, overcoming IT security and software issues, and appropriate training or edcuation of personnel must all be addressed before sectors can make full use of EEW.
  • Obtaining secure and consistent funding, providing equal access for both organizations and society as a whole, a realistic timeframe for implementing EEW, establishing practical and appropriate methods of delivery, and public earthquake education and awareness must all be considered.
  • Furthur study and technologic development is essential for launching a statewide EEW system in California and incorporating global standards.

For more detailed information, read the complete California Earthquake Early Warning System Benefit Study


EEW Workshops


UW's specific research objective is to develop the capability of issuing an alert tens of seconds after the onset of a large Cascadia Subduction Zone earthquake. The PNSN has hosted past workshops and will host another workshop in September 2016 at the University of Washington's Urban Horticulture Center reporting the progress of earthquake early warning and discussing beta testers for the system.


Video of the earthquake early warning system during the Tohoku Earthquake, March 11, 2011.