How to set earthquake warning for Apple mobile phone?

The method of setting earthquake warning for Apple mobile phone is as follows:

Operating environment: apple 13Pro max, IOS 15.6. 1, ink weather version 9.0608.04.

1. Open the ink weather my page and click the settings icon in the upper right corner.

2. Find the earthquake warning option, and then click Enter.

3. Finally, after the earthquake warning is enabled, click the switch button and click Agree to open it.

The limitations of earthquake early warning are as follows:

There is an early warning blind spot. After the earthquake, it takes at least 3 to 5 seconds to process the information recorded by the nearest seismic station, and then an early warning message is issued, which makes it impossible to give an early warning within 20 to 30 kilometers of the epicenter. It is precisely this area where the ground movement is the strongest, so earthquake early warning is basically ineffective for the most severely damaged polar earthquake areas.

The warning results may be biased. The core principle of earthquake early warning is to estimate earthquake parameters by using a small number of signals recorded by a few seismic stations near the epicenter. Because of the incomplete signals used, it has a great influence on the determination of earthquake magnitude, especially the larger the magnitude, the smaller the initial warning result. In addition, when aftershocks occur intensively after the earthquake, signal superposition is likely to lead to a large early warning result.