Frequency characteristics of coda and determination of medium parameters in Lingwu region, China |
| |
| Authors: | Mingzhi Yang |
| |
| Institution: | (1) Seismological Bureau of Ningxia Hui Autonomous Region, 750001 Yinchuan, China |
| |
| Abstract: | In this paper, considering the influences of source spectrum, the scattering property of medium and instrument response on
the dominant frequency of coda, a method of using the coda of local earthquake to determine the correlation length of medium
andQ-value is given. We find the following formula as: {fx719-1} wheret* =t/Q, f is the dominant frequency of coda,u
1 andu
2 are the parameters depend on the correlation length and the corner frequency of the source spectrum respectively,I(f) is a function of instrument response. If the source parameter is given, we can obtain the correlation length andQ-value by means of the inversion of observed curves off-t of coda. We processed the data of coda wave of more than 40 earthquakes from 1982 to 1989 in Lingwu region, China, determined
the correlation length andQ-value, and preliminarily studied the temporal change of correlation length before and after moderately strong earthquakes.
The result suggests that there are indications that the correlation length of medium decreases before the moderate earthquake.
The Chinese version of this paper appeared in the Chinese edition ofActa Seismologica Sinica,14, 62–70, 1992. |
| |
| Keywords: | Lingwu region coda correlation length temporal change |
| 本文献已被 SpringerLink 等数据库收录！ |
|
