How to set the pre-earthquake?

Mobile phone earthquake warning function, open the settings, open the tutorial

1. First open the phone settings.

2. Find "Security" in the phone settings, and then click.

3. Click "SOS Emergency Contact" in the security interface.

4. Click "Natural Disaster Warning" on the SOS emergency contact interface.

5. Click the button to the right of "Earthquake Warning".

6. After the prompt pops up, click "Agree" to open the earthquake early warning function (this function requires permission to use location information, use camera, make phone calls, access network, etc.).

How long can earthquake warning be advanced?

An earthquake: it takes 15 seconds for longitudinal waves to reach the epicenter, and 32 seconds for shear waves to reach the epicenter. Earthquake warning can only be issued 17 seconds in advance. Secondary earthquake: it takes 72 seconds for longitudinal waves to reach the epicenter ground, and it takes 157 seconds for shear waves to reach the epicenter ground, so earthquake warning can be issued 85 seconds in advance.

Earthquake early warning means that before the earthquake comes, the Seismological Bureau will issue an early warning in advance and let residents see it at the first time through mobile phones, televisions and other communication methods to reduce casualties and losses.

2021September 16, many people received it for the first time on their mobile phones. Some people received a 49-second countdown warning, some people received 3 1 second, and some people received 6 seconds.

What is the principle of earthquake early warning?

After the earthquake, the weak P-wave travels fast and can reach the ground first, and the early warning system will be notified. Seismic wave is a kind of mechanical wave, which has a certain propagation speed. When an earthquake happens, we must wait for the corresponding seismic waves to spread to people's places. This time difference leaves room for earthquake warning. When the earthquake occurs, the first P wave vibrates up and down, and the vibration amplitude is small, which takes about 10 seconds to 1 minute.