Earthquake warning system

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An animation detailing how earthquake early warning systems work: When P-waves are detected, the readings are analyzed immediately, and, if needed, the warning information is distributed to advanced users and cell phones, radio, television, sirens, and PA systems/fire alarm systems before the arrival of S-waves.
Example of early warning issued by ShakeAlert[1]

An earthquake warning system or earthquake early warning system is a system of accelerometers, seismometers, communication, computers, and alarms that is devised for notifying adjoining regions of a substantial earthquake while it is in progress. This is not the same as earthquake prediction, which is currently incapable of producing decisive event warnings.

Time lag and wave projection[edit]

An earthquake is caused by the release of stored elastic strain energy during rapid sliding along a fault. The sliding starts at some location and progress away from the hypocenter in each direction along the fault surface. The speed of the progression of this fault tear is slower than, and distinct from the speed of the resultant pressure and shear waves, with the pressure wave traveling faster than the shear wave. The pressure waves generate an abrupt shock. The shear waves generate periodic motion (at about 1 Hz) that is the most destructive to structures, particularly buildings that have a similar resonant period. Typically these buildings are around eight floors in height. These waves will be strongest at the ends of the slippage, and may project destructive waves well beyond the fault failure. The intensity of such remote effects are highly dependent upon local soils conditions within the region and these effects are considered in constructing a model of the region that determines appropriate responses to specific events.

Transit safety[edit]

Such systems are currently implemented to determine appropriate real-time response to an event by the train operator in urban rail systems such as BART (Bay Area Rapid Transit). The appropriate response is dependent on the warning time, the local right-of-way conditions and the current speed of the train.

Warning time given by the earthquake warning system of the Earthquake Network project[2] during the May 2015 Nepal earthquake. The cross marker depicts the earthquake epicenter while the dot marker shows the detection location.


As of 2016, Japan and Taiwan have comprehensive, nationwide earthquake early warning systems. Other countries and regions have limited deployment of earthquake warning systems, including Mexico (the Mexican Seismic Alert System covers areas of central and southern Mexico including Mexico City and Oaxaca), limited regions of Romania (the Basarab bridge in Bucharest), and parts of the United States. The earliest automated earthquake pre-detection systems were installed in the 1990s; for instance, in California, the Calistoga fire station's system which automatically triggers a citywide siren to alert the entire area's residents of an earthquake.[3] Some California fire departments use their warning systems to automatically open overhead doors of fire stations before the earthquake can disable them. While many of these efforts are governmental, several private companies also manufacture earthquake early warning systems to protect infrastructure such as elevators, gas lines and fire stations.


In 2009, an early warning system called ShakeAlarm was installed and commissioned in Vancouver, British Columbia, Canada. It was placed to protect a piece of critical transportation infrastructure called the George Massey Tunnel, which connects the north and south banks of the Fraser River. In this application the system automatically closes the gates at the tunnel entrances if there is a dangerous seismic event inbound.[4] The success and the reliability of the system was such that as of 2015 there have been several additional installations on the west coast of Canada and the United States, and there are more being planned.


Japan's Earthquake Early Warning system was put to practical use in 2006. The system that warns the general public was installed on October 1, 2007.[5][6] It was modeled partly on the Urgent Earthquake Detection and Alarm System (UrEDAS) of Japan Railways, which was designed to enable automatic braking of bullet trains.[7]

Gravimetric data from the 2011 Tōhoku earthquake has been used to create a model for increased warning time compared to seismic models, as gravity fields travel at the speed of light, much faster than seismic waves.[8]


The Mexican Seismic Alert System, otherwise known as SASMEX, began operations in 1991 and began publicly issuing alerts in 1993. It is funded by the Mexico City government, with financial contributions from several states that receive the alert. Initially serving Mexico City with twelve sensors, the system now has 97 sensors and is designed to protect life and property in several central and southern Mexican states.

United States[edit]

The United States Geological Survey (USGS) began research and development of early warning system for the West Coast of the United States in August 2006. The system became demonstrable in August 2009.[9] In 2011, test users (mostly other seismologists) were able to access the system through the "UserDisplay" software.[10] In January 2012, "beta" users were able to access the alerts in California. In February 2015, "beta" users were able to access the alerts in Oregon and Washington.[11][12] In February 2016, the system moved from demonstrable to Production Prototype version 1.0 in California, providing alerts to "pilot" users. In April 2017, Production Prototype version 1.2 went live, expanding the prototype to Oregon and Washington "pilot" users.[11][13] In October 2018, version 2.0 went live, allowing the "sufficiently functional and tested" system to begin Phase 1 of alerting California, Oregon and Washington.[14]

Even though ShakeAlert could alert the public beginning in October 2018, the messages themselves could not be distributed until the various private and public distribution partners had completed mobile apps and made changes to various emergency alerting systems. The first publicly available alerting system was the ShakeAlertLA app, released on New Year's Eve 2018 (although it only alerted for shaking in the Los Angeles area).[15] On October 17, 2019, Cal OES announced a statewide rollout of the alert distribution system in California, using mobile apps and the Wireless Emergency Alerts (WEA) system.[16][17][18] California refers to their system as the California Earthquake Early Warning System. On March 11, 2021, a statewide alert distribution system was rolled out in Oregon.[19] It is expected a similar rollout will happen in Washington on May 4, 2021.[20]

Global systems[edit]

Earthquake Network[edit]

In January 2013, Francesco Finazzi of the University of Bergamo started the Earthquake Network research project which aims at developing and maintaining a crowdsourced earthquake warning system based on smartphone networks.[2][21] Smartphones are used to detect the ground shaking induced by an earthquake and a warning is issued as soon as an earthquake is detected. People living at a further distance from the epicenter and the detection point may be alerted before they are reached by the damaging waves of the earthquake. People can take part in the project by installing the Android application "Earthquake Network" on their smart phones. The app requires the phone to receive the alerts.


In February 2016, the Berkeley Seismological Laboratory at University of California, Berkeley (UC Berkeley) released the MyShake mobile app. The app uses accelerometers in phones to record shaking and relay that information back to the laboratory. It is planned that the information will be used to issue early warnings in the future.[22] UC Berkeley released a Japanese-language version of the app in May 2016.[23] By December 2016, the app had captured nearly 400 earthquakes worldwide.[24]

Android Earthquake Alerts System[edit]

On August 11, 2020, Google announced that its Android operating system would begin using accelerometers in devices to detect earthquakes (and send the information to the company's "earthquake detection server"). As millions of phones operate on Android, this may result in the world's largest earthquake detection network. At first the system will not provide alert following a seismic event, but instead will be able to offer fast, accurate information on the earthquake via Google Search. In the future, it is expected the system will be able to provide early earthquake warnings for multiple states (in the United States) and many countries.[25] The system is also able to interface with USGS's ShakeAlert and forward that system's warnings to Android users on the West Coast of the United States.


On August 11, 2020, Linux Foundation, IBM and Grillo announced the first fully open-source earthquake early-warning system, featuring instructions for a low-cost seismometer, cloud-hosted detection system, dashboard and mobile app[26] . This project is supported by USAID, the Clinton Foundation and Arrow Electronics. Smartphone-based earthquake early-warning systems are dependent on a dense network of users near the earthquake rupture zone, whereas OpenEEW has focused instead on providing affordable devices that can be deployed in remote regions close to where earthquakes can begin. All components of this system are open source and available on the project's GitHub repositories.

Social media[edit]

Social networking sites such as Twitter and Facebook play a significant role during natural disasters.[27] The United States Geological Survey (USGS) has investigated collaboration with the social networking site Twitter to allow for more rapid construction of ShakeMaps.[28][29]

See also[edit]


  1. ^ Burkett, Erin R.; Given, Douglas D.; Jones, Lucile M. (February 2017). "ShakeAlert—An earthquake early warning system for the United States west coast". ShakeAlert: an earthquake early warning system for the United States West Coast. Fact Sheet 2014–3083. U.S. Geological Survey. p. 4. doi:10.3133/fs20143083. ISSN 2327-6932.
  2. ^ a b Finazzi, Francesco; Fassò, Alessandro (2016). "A statistical approach to crowdsourced smartphone-based earthquake early warning systems". Stochastic Environmental Research and Risk Assessment. 31 (7): 1649–1658. arXiv:1512.01026. doi:10.1007/s00477-016-1240-8.
  3. ^ Podger, Pamela (July 2001). "Calistoga to get an earful of nation's first quake siren". napanet. Archived from the original on 2014-02-23. Retrieved 2012-10-28.
  4. ^ Zaicenco, Anton; Weir-Jones, Iain (September 2012). "Lessons Learned from Operating an On-site Earthquake Early Warning System" (PDF). Proceedings, World Conference on Earthquake Engineering. 15th (2012): 10. Retrieved September 28, 2012.
  5. ^ "What is an Earthquake Early Warning?". Japan Meteorological Agency. Retrieved on 2008-06-29.
  6. ^ "Overview of the Earthquake Early Warning System" (in Japanese). Japan Meteorological Agency. Archived from the original on 2008-03-12. Retrieved 2008-06-29.
  7. ^ Kumagai, Jean (June 2007). "A BriefHistory of Earthquake Warnings". IEEE Spectrum. Retrieved 2009-05-09.[permanent dead link]
  8. ^ Lognonné, Philippe; Clévédé, Eric; Bernard, Pascal; Whiting, Bernard; Harms, Jan; Chassande-Mottin, Eric; Ampuero, Jean Paul; Barsuglia, Matteo; Juhel, Kévin; Montagner, Jean-Paul (2016-11-22). "Prompt gravity signal induced by the 2011 Tohoku-Oki earthquake". Nature Communications. 7: 13349. Bibcode:2016NatCo...713349M. doi:10.1038/ncomms13349. PMC 5121411. PMID 27874858.
  9. ^ "News". USGS. Retrieved April 3, 2021.
  10. ^ Allen, Richard. "Highlights of the Berkeley contributions to ShakeAlert". Berkeley Seismo Lab: Richard Allen. Berkeley Seismo Lab. February 2011: ShakeAlert starts providing warnings to test users
  11. ^ a b Revised Technical Implementation Plan for the ShakeAlert System—An Earthquake Early Warning System for the West Coast of the United States (Report). U.S. Geological Survey. 2018. Open-File Report 2018–1155. Retrieved April 3, 2021.
  12. ^ Hickey, Hannah (February 11, 2015). "Earthquake early warning begins testing in Pacific Northwest". UW News. University of Washington. Retrieved April 3, 2021.
  13. ^ Hickey, Hannah (April 10, 2017). "USGS, partners launch a unified, West Coast-wide earthquake early warning system". UW News. University of Washington. Retrieved April 3, 2021.
  14. ^ "ShakeAlert Phase 1: Version 2.0 Went Live in October 2018". 2018.
  15. ^ Lin II, Rong-Gong (January 2, 2019). "Long-awaited earthquake early warning app for L.A. can now be downloaded". Los Angeles Times. Los Angeles. Retrieved April 3, 2021.
  16. ^ Snibbe, Kurt (2019-10-15). "California's earthquake early warning system is now statewide". Mercury News. Retrieved 2019-12-31.
  17. ^ Calma, Justine (2019-10-17). "California's earthquake warning app: how it works and what comes next". The Verge. Retrieved 2019-12-31. CS1 maint: discouraged parameter (link)
  18. ^ "Wireless Emergency Alerts". Retrieved 2019-12-31. CS1 maint: discouraged parameter (link)
  19. ^ Walsh, Lucy (March 5, 2021). "Oregon Rolls Out Public Alerting for Earthquakes on March 11, 2021". PNSN blog. Pacific Northwest Seismic Network. Retrieved April 3, 2021.
  20. ^ "ShakeAlert comes to Washington on May 4". Washington Military Department. March 29, 2021. Retrieved April 3, 2021.
  21. ^ Finazzi, Francesco (2016). "The Earthquake Network Project: Toward a Crowdsourced Smartphone‐Based Earthquake Early Warning System". Bulletin of the Seismological Society of America. 106 (3): 1088–1099. arXiv:1512.01026. Bibcode:2016BuSSA.106.1088F. doi:10.1785/0120150354. Retrieved 10 June 2016.
  22. ^ Sanders, Robert (February 12, 2016). "New app turns smartphones into worldwide seismic network". Berkeley News. UC Berkeley. Retrieved April 4, 2021. UC Berkeley scientists today are releasing a free Android app that taps a smartphone’s ability to record ground shaking from an earthquake, with the goal of creating a worldwide seismic detection network that could eventually warn users of impending jolts from nearby quakes.
  23. ^ Sanders, Robert (May 21, 2016). "Japanese-language MyShake app crowdsources earthquake shaking". Berkeley News. UC Berkeley. Retrieved April 4, 2021.
  24. ^ Sanders, Robert (December 14, 2016). "Quake-detection app captured nearly 400 temblors worldwide". Berkeley News. UC Berkeley. Retrieved April 4, 2021.
  25. ^ Stogaitis, Marc (August 11, 2020). "Earthquake detection and early alerts, now on your Android phone". Google blog. Google. Retrieved April 4, 2021.
  26. ^ Foundation, Linux (August 11, 2020). "IBM Announce New Earthquake Early-Warning Open Source Project". Linux Foundation Blog. Linux Foundation. Retrieved August 11, 2020.
  27. ^ Dragović, Nataša; Vasiljević, Ðorđije; Stankov, Uglješa; Vujičić, Miroslav (20 August 2019). "Go social for your own safety! Review of social networks use on natural disasters – case studies from worldwide". Open Geosciences. 11 (1): 352–366. doi:10.1515/geo-2019-0028.
  28. ^ Mahalia Miller, Lynne Burks, and Reza Bosagh Zadeh Rapid Estimate of Ground Shaking Intensity by Combining Simple Earthquake Characteristics with Tweets, Tenth U.S. National Conference on Earthquake Engineering
  29. ^ Zadeh, Reza (May 2, 2014). "Using Twitter to measure earthquake impact in almost real time". Twitter Engineering.

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