b-Values Observations in Taiwan: A Review

Abstract

High seismicity with spatial heterogeneity in Taiwan makes this region one of the best natural laboratories for seismological researches. Numerous seismicity studies, including the b-value, have been performed for more than one century. One of the possible ways to mitigate seismic risk is predicting an impending earthquake through various kinds of seismic precursors observations. The first seismic precursors project in Taiwan started in 1978. The temporal variation in b-value prior to a forthcoming earthquake has been considered a significant seismic precursor for earthquake prediction. In this review study, we focus on the studies of b-values of earthquakes in Taiwan, including the spatial distribution of b-values, temporal variation in b-values, correlation between the b-value and fractal dimension, and correlation between the band p-value of Omori law for aftershocks. Also included is the relation between the spatial distribution of b-values and regional geotectonics. The properties and controlling factors of b-value and earthquake monitoring in Taiwan will also be briefly described.

Systematic correlations of the earthquake frequency‐magnitude distribution with the deformation and mechanical regimes in the Taiwan orogen

“…The investigations of regional seismicity characteristics, including the variations of b value with time and space, have been conducted extensively for decades (see review of Wang et al . []). More recent relevant studies have been addressed more on the issues of seismic mitigation and probabilistic forecast by examining either the spatiotemporal change of the b values before large events such as the 1999 M w 7.6 Chi‐Chi earthquake [ Chan and Wu , ] or the break of the G‐R scaling for the events of magnitude greater than 7 in Taiwan [ Wu et al, ].…”

“…The very rapid rate of crustal deformation on the order of several microstrain per year [Chang et al, 2003] and frequent recurrence of earthquakes (on average about 3 times annually for M > 6) with a diversity of faulting styles make the island one of the most seismically hazardous regions in the world and the best natural laboratories for earthquake studies as well. The investigations of regional seismicity characteristics, including the variations of b value with time and space, have been conducted extensively for decades (see review of Wang et al [2015]). More recent relevant studies have been addressed more on the issues of seismic mitigation and probabilistic forecast by examining either the spatiotemporal change of the b values before large events such as the 1999 M w 7.6 Chi-Chi earthquake [Chan and Wu, 2013] or the break of the G-R scaling for the events of magnitude greater than 7 in Taiwan .…”

Real-time probabilistic seismic hazard assessment based on seismicity anomaly

“…In the traditional PSHA framework (Cornell, 1968;Wang et al, 2016), the probability of an earthquake occurrence follows the Poisson process and the average recurrence interval for an annual frequency of exceedance can be expressed as…”

“…The forecasting probability of the PI method presents a distribution of cumulative forecasting probability for M L ≥ 5.0. We referred to the average character of the Gutenberg-Richter law in Taiwan (Gutenberg and Richter, 1944;Wang et al, 2015) to convert it into the probability density function (PDF). It can correspond to the specific magnitude conditions for P (Z > z | m, loc).…”

“…PSHA determines the probability of exceeding the ground motion level over a specified time period based on the occurrence rate of earthquakes and ground motion prediction equations (GMPEs). The occurrence rate of earthquakes is generally described by the truncated exponential model (Cosentino et al, 1977) and the characteristic earthquake model (Schwartz and Coppersmith, 1984;Wang et al, 2016). The earthquake occurrence rate computed from these models will not change with time regardless of whether the data being used are from long-term observations or paleoseismic studies.…”