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Earthquake Early Warning Guideline Compliance

Earthquake Early Warning
Guideline Compliance

In order for users of receiving terminals to use Earthquake Early Warnings properly (according to their purpose of use), the Japan Meteorological Agency (JMA) has compiled the "Guidelines for Functions and Distribution Capability of Receiving Terminal Necessary for Appropriate Use of Earthquake Early Warning". (For details of these guidelines, please refer to the JMA website). (Japanese only)

The following is the compliance status of the Earthquake Early Warning Guidelines for the NERV Disaster Prevention App.

Choice of Device and Delivery

Time required from when the JMA announces an Earthquake Early Warning (Forecast) to the time the terminal starts reporting
Our system is designed and implemented in such a way that our system finishes the calculation process within a second after the Japan Meteorological Agency announces an Earthquake Early Warning (Forecast). However, in the case of a forecast, the system will only start distributing it after it has become highly accurate, so it is not necessarily distributed from the very first report. On the other hand, Earthquake Early Warning (Warning) is delivered immediately. It may take more than 1 second to actually deliver Earthquake Early Warning (Forecast/Warning) to the device due to the nature and conditions of the push notification server and the communication environment of the device as the device is a smartphone. Notifications may be delayed or may not be received due to communication conditions.
Adequate measures are in place to ensure uninterrupted delivery from the JMA to the terminal
A redundant, dedicated line is used from JMA to our distribution server. The communication from the delivery server to the device is via the Internet, and therefore may be interrupted depending on the communication environment (3G, LTE, Wi-Fi, etc.) and the operating conditions of the smartphone. In addition, we cannot control the delivery of notifications to smartphones as push notification servers are involved. Communication may be interrupted due to communication conditions with the notification server. Notifications may be delayed or not received due to communication conditions.
The time is always set to within ±1 second
The distribution server is time synchronised by NTP. The terminal depends on the user's time settings. (Normally the terminals are also synchronised automatically)
One that is well supported by delivery and licensing companies
As recommended in the guidelines.

Measures to be taken on terminals and lines

Recommendations for seismic bracing and other measures to protect against earthquake shaking
As recommended in the guidelines.
Uninterrupted power supply recommendation
As recommended in the guidelines.
The connection from the server to the terminal must be an always-on connection
The connection from the server to the device is usually an always-on connection such as in the case of 3G, LTE or Wi-Fi, but there may be delays or no notifications due to communication conditions.

Notification by expected grace period

Recommendation that the system should be alerted even if there is no grace period
You will be notified regardless of the grace period.
Recommendation that the safety alert continues for a grace period plus 10 seconds
In case of Earthquake Early Warning, it will sound for approximately 5 seconds. In the case of Earthquake Early Warning (Forecast), it may not sound depending on the volume of your device and the status of Silent/Do Not Disturb modes. As the grace period is not currently used, the alert will not continue.

Notifications according to expected seismic intensity

Recommendation that the terminal user is alerted when the required set seismic intensity is exceeded
At present, it is not possible for the terminal user to manually set the seismic intensity to be alerted. If the user is in an area with an expected seismic intensity of 1 or 2, the alert will be displayed on the screen and will not sound. If the seismic intensity is 3 or higher, the device will notify the user by sound or vibration in addition to the display, but it may not sound depending on the device settings such as silent mode or if vibration is disabled.

Notification by accurate information etc.

Recommendation to use Earthquake Early Warning based on data from multiple stations
This value is stricter than the recommended guideline value. Notifications are sent out only after the forecast accuracy has increased, so that notifications may not arrive in time for major movements. The emphasis is on not sending out notifications with large errors or incorrect values.

Notification of deep-onset earthquakes by the Earthquake Early Warning system

If the method of seismic intensity prediction is based on the conventional method, it is recommended not to report the seismic intensity because it is difficult to predict the seismic intensity accurately for deep-onset earthquakes
As recommended in the guidelines.

Content of the report

Recommendation that the first alarm be given by the NHK chime.
Recommendation that the expected seismic intensity and grace time should not be reported in detail.
However, if the terminal user understands the error and technical limitations of Earthquake Early Warning system, they may choose to be informed of the specific seismic intensity and grace time. Therefore, it is recommended to use expressions such as "arriving soon". If the location and magnitude of the seismic source are "hypothetical source elements", the forecasted seismic intensity should not be reported, except when the forecast is based on the PLUM method.
We don't use the NHK chime sound, as many users feel scared by it. The Earthquake Early Warning (Forecast) uses an arpeggio sequence as the notification sound, and the Earthquake Early Warning (Alert) uses this arpeggio notification sound combined with a voice alert ("Earthquake, Earthquake, Prepare for strong shaking"). The expected seismic intensity is aggregated and displayed in units of "area names used in Earthquake Early Warning and Seismic Intensity Information". The location and magnitude of the epicenter are as indicated in the guidelines for estimated epicenter information.

Earthquake Early Warning provided for the same earthquake or for another earthquake after an EEW has been provided

If the expected intensity or grace time is being reported, it is recommended that the content of the report be changed if the expected intensity increases or the grace time decreases
In all other cases, it is recommended that the content of the report is not changed.
For Earthquake Early Warning (Forecast), as a rule, there is only one notification sent to your device, but if you tap the notification and start the application, the latest forecast including the subsequent reports will be displayed. In case of Earthquake Early Warning (Alert), all subsequent reports will also be notified.

Handling of cancellation reports

Recommendation to report the cancellation of the Earthquake Early Warning when it is provided. The cancellation alarm for the Earthquake Early Warning that was not reported should not be reported.
As recommended in the guidelines.

Testing (Test Report)

Recommendation to carry out tests on the terminal that are carried out after receiving a test report. It is recommended that the terminal is normally set up so that it does not operate when it receives a test report.
There is no testing of the terminal performed after receiving the test report. Even if the distribution server receives the test report, it will not deliver it to the terminal.

Testing (Drill Report)

Recommendation to carry out drills by observing the alarm by the drill function of the terminal or by receiving a drill report. Normally, it is recommended to set the terminal so that it does not operate when it receives a drill report.
We do not test the terminal after receiving the drill report. Even if the distribution server receives the drill report, it will not deliver it to the terminal.

Contacting Distribution and Licensing Authorities

We recommend that you contact the distribution and licensing company for information on how to use the system
You can contact us via the Menu tab in the app and via the Contact Form on the website.

Use of the name "Earthquake Early Warning" in the application

In this application, we use the name of Earthquake Early Warning (Forecast) and Earthquake Early Warning (Alert) to inform you of an Earthquake Early Warning. In the Earthquake Early Warning (Forecast) and Earthquake Early Warning (Alert) screens displayed in the application, the seismic intensity estimation map is based on Gehirn Inc.'s own estimates of the seismic intensity for areas not announced by the JMA, combined with the information announced by the JMA. The warning area highlighted in red on the map are based on the information released by the JMA. Other information such as the name of the epicenter, the depth of the epicenter, the magnitude, expected maximum seismic intensity, and in the case of warnings, the areas subject to warnings, are shown as published by the JMA.


Accuracy of forecasting seismic intensity of deep-onset earthquakes

For deep-earthquakes, we do not provide notification and display of Earthquake Early Warning when the depth of epicenter is 150km or more, because the accuracy of seismic intensity estimations cannot be ensured technically. Even if the depth is less than 150km, the accuracy of seismic intensity estimation may not be sufficient.