Earthquake warning

Earthquake disaster warning app - let the warning inform you in time!
[Technical principle]
The earthquake early warning system utilizes the difference in the propagation speed of seismic longitudinal waves (P waves) and shear waves (S waves). P-waves have a fast propagation speed but a small destructive force, while S-waves have a slow propagation speed but a large destructive force.
The system captures P-waves through monitoring instruments, quickly estimates seismic parameters, and issues early warnings before the arrival of S-waves.
[System Composition]
A dense network of seismic observation stations is used to capture seismic wave signals.
The intelligent processing system can quickly analyze seismic parameters and issue early warnings.
[Warning Release]
Early warning information is released through electronic communication systems, such as radio, television, the Internet, and mobile phones.
Although the warning time is short, it can effectively reduce casualties and economic losses.
[Significance of early warning]
When the warning time is 3 seconds, it can reduce 14% of casualties; When the warning time is 10 seconds, it can reduce 39% of casualties.
The earthquake early warning system can also be used for emergency response in major projects such as high-speed railways and nuclear power plants to prevent the occurrence of secondary disasters.
[Subscription Service]
Subscription service: Provide continuous weekly, monthly, quarterly, and annual subscription services;
2. Subscription price: 18 yuan/week for continuous weekly package, 38 yuan/month for continuous monthly package, 88 yuan/month for continuous quarterly package, and 1988 yuan/year for continuous annual package;
3. Payment: After the user confirms the purchase and makes the payment, it will be credited to the iTunes account. Apple iTunes account will be charged 24 hours before expiration, and the subscription period will be extended by one subscription period after successful deduction;
4. Cancel subscription: To cancel the subscription, open the iPhone "Settings" -> enter "iTunes Store and App Store" -> click "Apple ID" -> select "View Apple ID" -> enter the "Account Settings" page -> click "Subscription" -> select "Earthquake Disaster Warning" to cancel the subscription. If the subscription is not closed at least 24 hours before the end of the subscription period, the subscription will be automatically renewed;
User agreement: https://docs.qq.com/doc/DRmNvbVFaZm9LVG9t
Privacy agreement: https://docs.qq.com/doc/DRmNUSHBNQ291blRQ
Subscription agreement: https://docs.qq.com/doc/DRmx1SmpBb1BHbFZp