An earthquake early warning (EEW) system is a system of

accelerometer An accelerometer is a device that measures the proper acceleration of an object. Proper acceleration is the acceleration (the rate of change (mathematics), rate of change of velocity) of the object relative to an observer who is in free fall (tha ...

seismometer A seismometer is an instrument that responds to ground displacement and shaking such as caused by quakes, volcanic eruptions, and explosions. They are usually combined with a timing device and a recording device to form a seismograph. The out ...

s, communication, computers, and alarms that is devised for rapidly notifying adjoining regions of a substantial

earthquake An earthquakealso called a quake, tremor, or tembloris the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they ...

once one begins. This is not the same as

earthquake prediction Earthquake prediction is a branch of the science of geophysics, primarily seismology, concerned with the specification of the time, location, and magnitude of future earthquakes within stated limits, and particularly "the determination of par ...

, which is currently not capable of producing decisive event warnings.

Time lag and wave projection

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 progresses away from the

hypocentre A hypocenter or hypocentre (), also called ground zero or surface zero, is the point on the Earth's surface directly below a nuclear explosion, meteor air burst, or other mid-air explosion. In seismology, the hypocenter of an earthquake is its p ...

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 Pressure (symbol: ''p'' or ''P'') is the force applied perpendicular to the surface of an object per unit area over which that force is distributed. Gauge pressure (also spelled ''gage'' pressure)The preferred spelling varies by country and eve ...

and shear waves, with the pressure wave travelling faster than the shear wave. The pressure waves are always smaller in amplitude than the damaging shear waves that are the most destructive to structures, particularly buildings that have a resonant period similar to those of the radiated waves. 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 A model is an informative representation of an object, person, or system. The term originally denoted the plans of a building in late 16th-century English, and derived via French and Italian ultimately from Latin , . Models can be divided in ...

of the region that determines appropriate responses to specific events.

Transit safety

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 (BART) is a rapid transit system serving the San Francisco Bay Area in California. BART serves List of Bay Area Rapid Transit stations, 50 stations along six routes and of track, including eBART, a spur line running t ...

(Bay Area Rapid Transit) and LA Metro. The appropriate response is dependent on the warning time, the local right-of-way conditions, and the current speed of the train. Warning time Nepal Earthquake

Deployment

As of 2025,

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...

South Korea South Korea, officially the Republic of Korea (ROK), is a country in East Asia. It constitutes the southern half of the Korea, Korean Peninsula and borders North Korea along the Korean Demilitarized Zone, with the Yellow Sea to the west and t ...

Israel Israel, officially the State of Israel, is a country in West Asia. It Borders of Israel, shares borders with Lebanon to the north, Syria to the north-east, Jordan to the east, Egypt to the south-west, and the Mediterranean Sea to the west. Isr ...

and

Transnistria Transnistria, officially known as the Pridnestrovian Moldavian Republic and locally as Pridnestrovie, is a Landlocked country, landlocked Transnistria conflict#International recognition of Transnistria, breakaway state internationally recogn ...

have comprehensive, nationwide earthquake early warning systems that notify people in the affected areas via

Cell Broadcast Cell Broadcast (CB) is a method of simultaneously sending Short Message Service, short messages to multiple mobile telephone users in a defined area. It is defined by the ETSI's GSM committee and 3GPP and is part of the 2G, 3G, 4G and 5G standa ...

(CB), TV alerts, radio announcements or via civil defence sirens. Countries such as

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

, the

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

, and

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

have regional earthquake warning systems which notify people using the same technologies mentioned above. In particular, the Mexican Seismic Alert System, which covers areas of central and southern Mexico, including

Mexico City Mexico City is the capital city, capital and List of cities in Mexico, largest city of Mexico, as well as the List of North American cities by population, most populous city in North America. It is one of the most important cultural and finan ...

and

Oaxaca Oaxaca, officially the Free and Sovereign State of Oaxaca, is one of the 32 states that compose the political divisions of Mexico, Federative Entities of the Mexico, United Mexican States. It is divided into municipalities of Oaxaca, 570 munici ...

, uses civil defence sirens, while ShakeAlert, which covers

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

, and

Washington Washington most commonly refers to: * George Washington (1732–1799), the first president of the United States * Washington (state), a state in the Pacific Northwest of the United States * Washington, D.C., the capital of the United States ** A ...

in the United States and

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

in Canada, uses

Wireless Emergency Alerts Wireless Emergency Alerts (WEA), formerly known as the Commercial Mobile Alert System (CMAS) and, prior to that, as the Personal Localized Alerting Network (PLAN), is an alerting network in the United States designed to disseminate emergency a ...

(WEA). Countries such as

Guatemala Guatemala, officially the Republic of Guatemala, is a country in Central America. It is bordered to the north and west by Mexico, to the northeast by Belize, to the east by Honduras, and to the southeast by El Salvador. It is hydrologically b ...

El Salvador El Salvador, officially the Republic of El Salvador, is a country in Central America. It is bordered on the northeast by Honduras, on the northwest by Guatemala, and on the south by the Pacific Ocean. El Salvador's capital and largest city is S ...

Nicaragua Nicaragua, officially the Republic of Nicaragua, is the geographically largest Sovereign state, country in Central America, comprising . With a population of 7,142,529 as of 2024, it is the third-most populous country in Central America aft ...

Costa Rica Costa Rica, officially the Republic of Costa Rica, is a country in Central America. It borders Nicaragua to the north, the Caribbean Sea to the northeast, Panama to the southeast, and the Pacific Ocean to the southwest, as well as Maritime bo ...

, and

Romania Romania is a country located at the crossroads of Central Europe, Central, Eastern Europe, Eastern and Southeast Europe. It borders Ukraine to the north and east, Hungary to the west, Serbia to the southwest, Bulgaria to the south, Moldova to ...

have deployed systems that alert only specific users through applications that have to be installed individually on their smart devices, while systems are being developed and tested in

Italy Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

Turkey Turkey, officially the Republic of Türkiye, is a country mainly located in Anatolia in West Asia, with a relatively small part called East Thrace in Southeast Europe. It borders the Black Sea to the north; Georgia (country), Georgia, Armen ...

Switzerland Switzerland, officially the Swiss Confederation, is a landlocked country located in west-central Europe. It is bordered by Italy to the south, France to the west, Germany to the north, and Austria and Liechtenstein to the east. Switzerland ...

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...

, and

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania, between the Indian Ocean, Indian and Pacific Ocean, Pacific oceans. Comprising over List of islands of Indonesia, 17,000 islands, including Sumatra, ...

. The earliest automated earthquake pre-detection systems were installed in the 1990s; for instance, in

, the Calistoga fire station's system which automatically triggers a citywide siren to alert the entire area's residents of an earthquake. 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.

Canada

In 2009, an early warning system called ShakeAlarm was installed and commissioned in

Vancouver Vancouver is a major city in Western Canada, located in the Lower Mainland region of British Columbia. As the List of cities in British Columbia, most populous city in the province, the 2021 Canadian census recorded 662,248 people in the cit ...

. 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 The Fraser River () is the longest river within British Columbia, Canada, rising at Fraser Pass near Blackrock Mountain (Canada), Blackrock Mountain in the Rocky Mountains and flowing for , into the Strait of Georgia just south of the City of V ...

. In this application, the system automatically closes the gates at the tunnel entrances if there is a dangerous seismic event inbound. 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 more are being planned. On 29 August 2024, the Canadian Earthquake Early Warning system was launched in

Natural Resources Canada Natural Resources Canada (NRCan; ; )Natural Resources Canada is the applied title under the Federal Identity Program; the legal title is Department of Natural Resources (). is the department of the Government of Canada responsible for natural r ...

(NRCan), and is expected to be expanded to southern

Quebec Quebec is Canada's List of Canadian provinces and territories by area, largest province by area. Located in Central Canada, the province shares borders with the provinces of Ontario to the west, Newfoundland and Labrador to the northeast, ...

and eastern

Ontario Ontario is the southernmost Provinces and territories of Canada, province of Canada. Located in Central Canada, Ontario is the Population of Canada by province and territory, country's most populous province. As of the 2021 Canadian census, it ...

later in 2024. Alerts generated by this system are delivered to the public via the country's

National Public Alerting System The National Public Alerting System (NPAS; ), branded as Alert Ready (), is the emergency population warning, national warning system in Canada, broadcast to Canadian television, radio, and wireless devices. The system consists of infrastructure ...

(Alert Ready). The early warning system was developed in cooperation with the

United States Geological Survey The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on Mar ...

(USGS) and is based upon USGS's ShakeAlert system. While the two systems are distinct, USGS and NRCan share processing software, algorithms, and real-time data.

China

The earliest earthquake warning system in China was built in the 1990s. The devastation of the

2008 Sichuan earthquake An earthquake occurred in the province of Sichuan, China at 14:28:01 China Standard Time on May 12, 2008. Measuring at 8.0 (7.9–8.3 ), the earthquake's epicenter was located boxing the compass, west-northwest of Chengdu, the provincial ...

stimulated China's investment in nationwide earthquake early warning systems. Large amounts of monitoring stations, sensors, and analytic systems were installed to improve the accuracy, responsiveness, and comprehensiveness of the earthquake data. In June 2019, the (ICL; , ), part of the national earthquake early warning system, successfully warned various townships of a M6.0 earthquake 10–27 seconds before the shockwave arrived. In 2023, the China Earthquake Administration announced that the national earthquake early warning system has been completed, with 150,000 monitoring stations, managed by 3 national centres, 31 provincial centres, and 173 prefectural and municipal centres. It is the largest seismic network of its kind in the world.

Japan

Japan’s Earthquake Early Warning system was put to practical use in 2006. The system that warns the general public was installed on 1 October 2007. Retrieved on 2008-06-29. It was modelled partly on the Urgent Earthquake Detection and Alarm System () of

Japan Railways The Japan Railways Group, commonly known as the or simply JR, is a network of railway companies in Japan formed after the division and privatization of the government-owned Japanese National Railways (JNR) on April 1, 1987. The group comprise ...

(JR), which was designed to enable the automatic braking of bullet trains. 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 The speed of light in vacuum, commonly denoted , is a universal physical constant exactly equal to ). It is exact because, by international agreement, a metre is defined as the length of the path travelled by light in vacuum during a time i ...

, much faster than seismic waves.

Mexico

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

with 12 sensors, the system now has 97 sensors and is designed to protect life and property in several central and southern Mexican states.

United States

The

(USGS) began research and development of an early warning system for the

West Coast of the United States The West Coast of the United States, also known as the Pacific Coast and the Western Seaboard, is the coastline along which the Western United States meets the North Pacific Ocean. The term typically refers to the Contiguous United States, contig ...

in August 2006, and the system became demonstrable in August 2009. Following various developmental phases, version 2.0 went live during the autumn of 2018, allowing the "sufficiently functional and tested" system to begin Phase 1 of alerting California,

and

. Even though ShakeAlert could alert the public beginning 28 September 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 application, released on 31 December 2018 (although it only alerted for shaking in the

Los Angeles Los Angeles, often referred to by its initials L.A., is the List of municipalities in California, most populous city in the U.S. state of California, and the commercial, Financial District, Los Angeles, financial, and Culture of Los Angeles, ...

area). On 17 October 2019, California Governor's Office of Emergency Services (Cal OES) announced a statewide rollout of the alert distribution system in California, using

mobile app A mobile application or app is a computer program or software application designed to run on a mobile device such as a smartphone, phone, tablet computer, tablet, or smartwatch, watch. Mobile applications often stand in contrast to desktop appli ...

s and the

(WEA) system. California refers to its system as the California Earthquake Early Warning System. A statewide alert distribution system was rolled out in Oregon on 11 March 2021 and in Washington on 4 May 2021, completing the alert system for the West Coast.

Global systems

Earthquake Network

In January 2013, Francesco Finazzi of the

University of Bergamo The University of Bergamo (; acronym: UniBG) is an Italian public university located in Bergamo, Italy. It was founded on 11 December 1968 and is organized in seven departments, three campuses and forty-one degree courses. History The University ...

started the Earthquake Network research project which aims to develop and maintain a

crowdsourced Crowdsourcing involves a large group of dispersed participants contributing or producing goods or services—including ideas, votes, micro-tasks, and finances—for payment or as volunteers. Contemporary crowdsourcing often involves digit ...

earthquake warning system based on smartphone networks. Smartphones are used to detect 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 epicentre 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 smartphones. The app requires the phone to receive the alerts.

MyShake

In February 2016, the

Berkeley Seismological Laboratory The Berkeley Seismological Laboratory (BSL) is a research lab at the Department of Geology at the University of California, Berkeley. It was created from the Berkeley Seismographic Stations, a site on the Berkeley campus where Worldwide Standard ...

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a Public university, public Land-grant university, land-grant research university in Berkeley, California, United States. Founded in 1868 and named after t ...

(UC Berkeley) released the MyShake mobile app. The app uses

s in phones that are stationary and connected to a power supply to record shaking and relay that information back to the laboratory. The system issues automated warnings of earthquakes of magnitude 4.5 or greater. UC Berkeley released a Japanese-language version of the app in May 2016. By December 2016, the app had captured nearly 400 earthquakes worldwide.

Android Earthquake Alerts System

On 11 August 2020,

Google Google LLC (, ) is an American multinational corporation and technology company focusing on online advertising, search engine technology, cloud computing, computer software, quantum computing, e-commerce, consumer electronics, and artificial ...

announced that its

Android operating system Android is an operating system based on a modified version of the Linux kernel and other open-source software, designed primarily for touchscreen-based mobile devices such as smartphones and tablets. Android has historically been developed by ...

would begin using accelerometers in devices to detect earthquakes (and send the data 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. Initially, the system only collected earthquake data and did not issue alerts (except for the West Coast of the United States, where it provided alerts issued by the USGS's ShakeAlert system and not from Google's own detection system). At this early stage, data collected by Android devices was only used to provide fast information on a nearby earthquake via

Google Search Google Search (also known simply as Google or Google.com) is a search engine operated by Google. It allows users to search for information on the World Wide Web, Web by entering keywords or phrases. Google Search uses algorithms to analyze an ...

, but it was always planned to issue alerts based on Google's detection capabilities in the future. On 28 April 2021, Google announced the rollout of the alert system to

Greece Greece, officially the Hellenic Republic, is a country in Southeast Europe. Located on the southern tip of the Balkan peninsula, it shares land borders with Albania to the northwest, North Macedonia and Bulgaria to the north, and Turkey to th ...

and

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

, the first countries to receive alerts based on Google's own detection capabilities. Google's alerts were extended to

, the

Philippines The Philippines, officially the Republic of the Philippines, is an Archipelagic state, archipelagic country in Southeast Asia. Located in the western Pacific Ocean, it consists of List of islands of the Philippines, 7,641 islands, with a tot ...

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a landlocked country primarily in Central Asia, with a European Kazakhstan, small portion in Eastern Europe. It borders Russia to the Kazakhstan–Russia border, north and west, China to th ...

Kyrgyzstan Kyrgyzstan, officially the Kyrgyz Republic, is a landlocked country in Central Asia lying in the Tian Shan and Pamir Mountains, Pamir mountain ranges. Bishkek is the Capital city, capital and List of cities in Kyrgyzstan, largest city. Kyrgyz ...

Tajikistan Tajikistan, officially the Republic of Tajikistan, is a landlocked country in Central Asia. Dushanbe is the capital city, capital and most populous city. Tajikistan borders Afghanistan to the Afghanistan–Tajikistan border, south, Uzbekistan to ...

Turkmenistan Turkmenistan is a landlocked country in Central Asia bordered by Kazakhstan to the northwest, Uzbekistan to the north, east and northeast, Afghanistan to the southeast, Iran to the south and southwest and the Caspian Sea to the west. Ash ...

, and

Uzbekistan , image_flag = Flag of Uzbekistan.svg , image_coat = Emblem of Uzbekistan.svg , symbol_type = Emblem of Uzbekistan, Emblem , national_anthem = "State Anthem of Uzbekistan, State Anthem of the Republ ...

in June 2021. In September 2024, Google announced their warnings would now cover the entire United States (including areas not monitored by USGS's ShakeAlert); at the time, the earthquake alerts could be delivered to 97 other countries.

OpenEEW

On 11 August 2020,

Linux Foundation The Linux Foundation (LF) is a non-profit organization established in 2000 to support Linux development and open-source software projects. Background The Linux Foundation started as Open Source Development Labs in 2000 to standardize and prom ...

IBM International Business Machines Corporation (using the trademark IBM), nicknamed Big Blue, is an American Multinational corporation, multinational technology company headquartered in Armonk, New York, and present in over 175 countries. It is ...

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. This project is supported by

USAID The United States Agency for International Development (USAID) is an agency of the United States government that has been responsible for administering civilian United States foreign aid, foreign aid and development assistance. Established in 19 ...

, the

Clinton Foundation The Clinton Foundation (founded in 2001 as the William J. Clinton Presidential Foundation, and renamed in 2013 as the Bill, Hillary & Chelsea Clinton Foundation) is a nonprofit organization under section 501(c)(3) of the U.S. tax code. It was e ...

, 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 GitHub () is a Proprietary software, proprietary developer platform that allows developers to create, store, manage, and share their code. It uses Git to provide distributed version control and GitHub itself provides access control, bug trackin ...

repositories.

References

External links

{{commons
Earthquake Early Warning
– California Institute of Technology
Bayesian Networks for Earthquake Magnitude Classification in a Early Warning SystemEarthquake Network
– The Earthquake Network project website
Earthquake Early Warning for Developing Countries
– Grillo website
An Open Source Earthquake Early Warning System
– OpenEEW website

– Android System *

Time lag and wave projection

Transit safety

Deployment

Canada

China

Japan

Mexico

United States

Global systems

Earthquake Network

MyShake

Android Earthquake Alerts System

OpenEEW

See also

References

External links