Temporal Variation of b Value with Statistical Test in Wenchuan Area, China Prior to the 2008 Wenchuan Earthquake

Entropy

Haixia Shi¹  Peng Han²  Weiyun Xie³  Katsumi Hattori⁴ 

[1]China Earthquake Networks Center, Beijing 100045, China

[2]Department of Earth and Space Sciences, Southern University of Science and Technology, Shenzhen 518055, China

[3]Graduate School of Science and Engineering, Chiba University, Chiba 263-8522, Japan

[4]Graduate School of Science, Chiba University, Chiba 263-8522, Japan

关键词: b value;    Mc;    AIC;    bootstrap;    Gutenberg–Richter;   

DOI  :  10.3390/e24040494

来源: DOAJ

【 摘 要 】

The Gutenberg–Richter b value describes the ratio between large and small events. A number of studies have suggested that the b value decreases before large earthquakes. In this study, we investigate the temporal variation of the b value of an area along the main rupture zone of the 2008 Wenchuan earthquake (M8.0) prior to the great event. Before estimating b values, we tested the earthquake catalog to make sure that we use the reliable frequency–magnitude distribution by the calculation of MC (completeness of magnitude). We define parameter P (ΔAIC ≧ 2) values to examine the significance level of b-value changes in the temporal variation by combining a boostrap method with Akaike’s Information Criterion (AIC). The b value in the main rupture zone shows a long-term decrease trend. We then focus on a smaller area where the initial rupture starts. The results show that b values significantly changed about 3 months before the 2008 Wenchuan earthquake in the initial rupture area, indicating that the b value has a potential capability to monitor and detect precursory phenomena of great earthquakes.

【 授权许可】

Unknown