How fast are alerts?
Jolt's server checks published JMA information about once a minute and sends a notification when a report matches your settings. Jolt is not an Earthquake Early Warning service. Delivery can be delayed by JMA publication and network conditions.
What is Shindo?
Shindo is the intensity scale used in Japan. It measures how strongly the ground shakes at a place, separate from magnitude. You can set the minimum Shindo that triggers an alert.
Where does the data come from?
Earthquake and tsunami information comes from the Japan Meteorological Agency. Evacuation sites come from the Geospatial Information Authority.
Do I need to set my location?
Precise location is processed on your device to sort earthquakes and evacuation sites by distance. For regional alerts, only your selected prefecture code is sent to the alert service. Precise latitude and longitude are not sent.
Which languages are supported?
The interface and key safety guidance support 50 languages. Switch anytime from the top bar, independent of your system language. Remote alert text is currently available in English and Japanese.