Earthquake Early Warning, country by country

What EEW actually is

Earthquake Early Warning systems do not predict earthquakes. They detect the leading P-wave from a seismic event, compute the expected magnitude and location, and push an alert before the slower but more destructive S-wave and surface waves arrive. The warning window depends on how far you are from the epicentre: zero seconds if you are at the epicentre, 30 seconds or more if you are hundreds of kilometres away.

The honest framing for travellers: EEW gives you between 5 and 30 seconds in most useful cases. That is enough to drop, cover, and hold on; enough to get out from under heavy shelving; enough to pull a car to the side of the road; not enough to evacuate a building or run anywhere. The action is the same as for an unwarned earthquake (Drop-Cover-Hold-On per the earthquake survival guide), executed faster.

The relevant question for travellers is which countries have operational EEW that will reach your phone, and what the alert sounds like so you recognise it. That varies by country.

Japan (JMA)

The world’s most-developed civilian EEW system, operational since 2007. JMA detects, computes, and pushes alerts via cell broadcast to every phone in the predicted shaking zone within 3 to 8 seconds of P-wave detection. The alert sound is a distinctive descending two-tone chime followed by the spoken warning “緊急地震速報” (kinkyū jishin sokuhō, “Emergency Earthquake Alert”) and the predicted intensity (shindo level). TV channels interrupt programming with the same alert; trains stop automatically on receiving the signal.

Practical: install the JMA-affiliated “Yurekuru Call” or “NHK World Disaster Information” app on arrival in Japan, or just rely on the default phone-system cell broadcast which works without any app. Tested monthly. The 2011 Tōhoku event gave Tokyo about 80 seconds of warning (one of the best documented near-source-far-warning cases).

Mexico (SASMEX)

SASMEX is the world’s longest-running operational EEW system, started after the 1985 Mexico City disaster and formalised in 1991. The system covers Mexico City and several other major cities, with the alert broadcast through a dedicated radio system, public sirens across the city, and the SkyAlert app. The alert is a distinctive series of beeps followed by a spoken “Alerta Sísmica” announcement.

Practical: Mexico City residents recognise the alert instantly. Visitors should download the SkyAlert app on arrival, and any seismic event triggers public siren-and-radio broadcasts that are unmistakable. The 19 September 2017 Puebla earthquake gave central Mexico City about 15 seconds of warning, enough for many people to reach doorways or street.

United States (ShakeAlert)

ShakeAlert covers California, Oregon, and Washington (the US West Coast in operational deployment since 2018, public alerts since 2019 in California). The system is run by USGS in partnership with state agencies. Alerts go to phones via three main channels:

• Wireless Emergency Alerts (WEA): the standard cell-broadcast channel that delivers AMBER alerts and weather warnings. ShakeAlert uses WEA for M5.0+ events. Alert is the standard WEA tone (loud staccato beeping).
• MyShake app (Berkeley/USGS): delivers more sensitive alerts (M4.5+) with seconds more notice.
• Android Earthquake Alerts System: enabled by default on Android phones, uses accelerometer crowd-sourced detection plus ShakeAlert data.

The alert sounds like the WEA tone for most users; the MyShake app has its own distinct alarm. Most coastal-California residents have experienced the alert at least once since 2019. Practical: keep Android Earthquake Alerts enabled (default on Android), or install MyShake if on iPhone.

New Zealand (Long-or-Strong)

New Zealand operates a different paradigm: there is no full-coverage automated EEW system. Instead, GeoNet (the national seismic network) teaches the Long-or-Strong rule as official guidance. The rule:

Long: earthquake shaking that lasts a minute or more.

Strong: earthquake shaking strong enough that it’s hard to stand up.

If either applies and you are at the coast: get gone.

This is functionally a natural-warning protocol substituted for instrumental EEW. After the 2016 Kaikōura earthquake the rule was extensively publicised; it’s now taught in schools and posted at coastal community centres. The GeoNet app delivers post-event information and tsunami warnings but not pre-arrival EEW.

Taiwan (CWA)

Taiwan’s Central Weather Administration runs an operational EEW system that delivers alerts via cell broadcast to all phones on the island. The 1999 Chi-Chi earthquake (M7.7, ~2,400 dead) was the impetus; the system has been operational and refined since the early 2000s. The April 2024 Hualien earthquake (M7.4) showed the system working at scale; Taipei got around 10 seconds of warning.

South Korea (KMA)

KMA operates EEW since 2015 (after the 2011 Tōhoku exposed South Korean preparedness gaps). Alerts go to all phones via cell broadcast. Less seismically active than Japan or Taiwan but the 2017 Pohang earthquake (M5.4) and 2024 Buan earthquake (M4.8) both triggered the public alert.

Europe (Italy, Türkiye, Romania, Iceland)

• Italy (INGV): an operational EEW system covers central and southern Italy. The 2016 Amatrice and 2016 Norcia earthquakes prompted faster public-alert integration. Cell broadcast deployment expanded after the 2023 Türkiye earthquake.
• Türkiye (AFAD / Kandilli): Türkiye has invested heavily in seismic monitoring after the 1999 İzmit and 2023 Kahramanmaraş earthquakes; EEW deployment is partial as of 2026 with continued expansion.
• Romania (REWS): Bucharest is exposed to intermediate-depth Vrancea earthquakes; the REWS system (Romania Earthquake Warning System) is operational with cell-broadcast for the capital region.
• Iceland (IMO): limited EEW research-stage deployment focused on volcanic-area seismic events; visitors should rely on the broader IMO volcano alert system.
• Greece, Portugal: monitoring networks exist; public-alert EEW deployment is partial.

Global fallback options

For travellers visiting countries without operational EEW, two crowd-sourced systems work in most places:

• Android Earthquake Alerts System: enabled by default on Android phones globally. Uses the phone’s own accelerometer (and the swarm of other Android phones nearby) to detect P-waves and broadcast alerts via Google Play Services. Coverage is functional in most regions.
• MyShake (Berkeley/USGS): works globally; same physics. Available on iOS and Android.
• SkyAlert: Mexico-based but operates in several Latin American countries.

These crowd-sourced systems are less reliable than government-grade networks but cover much of the planet where no national system exists.

What to do when the alert fires

The alert will be one of: a distinctive country-specific sound, a WEA-style staccato siren, or a MyShake-app alarm. Recognise it on day 1 of any trip to an earthquake-prone country (test sounds are usually available on the system’s official site).

The response window depends on distance from the epicentre. The action is the same regardless:

• Drop, Cover, Hold On immediately. Do not look around. Do not check the news. Drop.
• If you are in a car: pull over, away from overpasses, power lines, or large buildings. Stay in the car.
• If you are outdoors: move away from buildings, walls, power lines. Crouch.
• If you are in bed: stay there, pull pillow over head if heavy objects on shelves above could fall.
• If you are near the coast and the shaking is long or strong: after shaking stops, move inland and uphill immediately (per the tsunami evacuation guide).
• After shaking stops: follow the aftershock guide for re-entry decisions.

One more time

EEW gives you 5 to 30 seconds in most cases. The action is the same as without EEW (Drop-Cover-Hold-On); the system just runs it faster. Country-by-country coverage varies; Japan, Mexico, the US West Coast, Taiwan, and South Korea have mature operational systems delivering to phones via cell broadcast. Crowd-sourced fallback (Android Earthquake Alerts, MyShake) covers much of the rest. Recognise the alert sound on day 1; respond automatically when it fires. The Field Manual’s earthquake survival guide covers the Drop-Cover-Hold-On rule and its variants.