Earthquake Early Warning and J-Alert: What the Alerts Mean
The first time your phone screams out a warning, it is easy to panic. Knowing what these alerts are â and what to do in the few seconds they give you â turns a frightening sound into a useful head start.
Japan has one of the most advanced warning systems in the world for earthquakes and other major emergencies. Two names you will hear are the Earthquake Early Warning and J-Alert. They are different tools, but both may reach you through the same loud alert on your phone. Here is what each one means and how to react.
What the Earthquake Early Warning is
The Earthquake Early Warning is a warning that strong shaking is on its way. When an earthquake begins, it sends out fast, weak waves first, followed by slower, stronger waves that do the real shaking. Sensors detect the first waves and issue a warning before the strong shaking arrives. That warning may give you anywhere from a few seconds to a little longer â sometimes only seconds â to protect yourself.
The loud alert sound
When a warning is issued for your area, phones in Japan make a distinctive, loud alarm and show a message on screen, even if the phone is on silent. It is intentionally hard to ignore. Hearing it for the first time is startling, but the sound itself is a good thing: it means the system is working and you have been given a warning.
What to do in those seconds
Do not waste the warning trying to figure out what is happening. Use it to protect your body immediately with the standard response, Drop, Cover, and Hold On:
- Drop to your hands and knees so the shaking cannot knock you over.
- Cover your head and neck, and get under a sturdy table if one is nearby.
- Hold On to that shelter until the shaking stops.
If you cannot get under something, move away from windows, tall furniture, and anything that could fall, and cover your head with your arms. Do not rush outside during the shaking, where falling objects are a common danger.
The warning is a prediction of shaking, not a guarantee. Sometimes the shaking is weaker than expected, and sometimes strong shaking arrives with almost no warning at all â especially if the earthquake is very close to you. Treat every alert seriously and react straight away.
What J-Alert is
J-Alert is Japan's national warning system for major emergencies. It is used by the government to send urgent information quickly to the public through channels such as mobile phones, local loudspeakers, and broadcasters. It can cover events beyond earthquakes, including tsunami and other serious national emergencies. When a J-Alert message appears, read it and follow the instructions it gives.
Make sure alerts are on
Phones bought in Japan usually receive these emergency alerts automatically. If you brought a phone from abroad, open your phone's settings and check that emergency and government (wireless emergency) alert notifications are turned on. It is worth confirming this today rather than discovering during a real event that your phone stayed silent.
Do not panic â practise instead
A warning only helps if your body already knows what to do. Talk through Drop, Cover, and Hold On with the people you live with, and physically practise it a few times so the reaction becomes automatic. Look around each room and notice where you would take cover. When the alert sounds for real, you will move first and think later â which is exactly what you want.
For the full picture of what to do before, during, and after a quake, see our earthquake guide. One of the most effective things you can do in advance is secure your furniture so it cannot fall on you during the shaking.
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Disclaimer
This article is general information, not official advice. During an emergency, follow the latest instructions from Japanese national and local authorities.