A Real-time Earthquake Magnitude Estimation Method for Earthquake Early Warning System

Abstract

The invention discloses a real-time earthquake magnitude estimation method used in an earthquake early warning system. The moment magnitude obtained by using the seismic moment, that is, the corresponding moment magnitude is estimated every 1 second after the signal is detected, and increases to 20s with time. Left and right yield an estimated magnitude that is very close to the actual magnitude. The invention uses the seismic moment to obtain the moment magnitude, which can effectively overcome the magnitude saturation problem in medium and large earthquakes (M>6), and the seismic moment has a clear relationship with the amplitude Ω0 at zero frequency in the earthquake, and has a clear physical significance. The method of the present invention is real-time, and the corresponding moment magnitude can be estimated every 1 second after the signal is detected, and the estimated magnitude very close to the actual magnitude can be obtained as the time increases to about 20 seconds, which can be effectively applied to earthquake early warning system.

Description

technical field [0001] The invention relates to a novel earthquake magnitude estimation method used in an earthquake early warning system, in particular to a spectrum inversion method for overcoming the magnitude saturation problem of medium and large earthquakes and estimating real-time magnitude. Background technique [0002] In recent years, large [0003] Earthquakes are becoming more and more frequent, and may even cause secondary disasters such as tsunamis, landslides, collapses, and ground fissures. In our country, there have been many destructive earthquakes in history, especially the Sichuan earthquake in 2008. It can be seen that earthquake disasters have caused a great threat to people's life and property safety. [0004] The earthquake early warning system refers to the use of the characteristics that the propagation speed of seismic waves is lower than that of radio waves after an earthquake, and early warning of places where seismic waves have not yet arrived....

AI Technical Summary

Problems solved by technology

Therefore, it is determined that the seismometers corresponding to the above magnitudes can only reflect earthquakes within a certain frequency range, and outside this range, due to the limitation of instrument performance, it is impossible to measure seismic waves with a period greater than 20s radiated when an earthquake occurs (especially for large magnitude 7.0 After the surface wave magnitude), the determined magnitude cannot reflect the actual magnitude of the earthquake, that is, the phenomenon of "magnitude saturation" appears

[0007] (2) The physical meaning is not clear

The current magnitude estimation method is only determined by the amplitude of the instrument's pointer swing, which has no clear physical meaning and cannot profoundly reveal the relationship between earthquake magnitude and frequency

[0008] (3) Not real-time

The currently used magnitude estimation method takes a long time. It usually takes 1-3 minutes to get the magnitude accurately for an earthquake analysis, which cannot be practically applied to the earthquake early warning system.

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