TY - JOUR

T1 - Maximum magnitudes in aftershock sequences in Taiwan

AU - Chan, Chung Han

AU - Wu, Yih Min

N1 - Funding Information:
Our work was supported by the Central Weather Bureau and the National Science Council, Taiwan.

PY - 2013/9/5

Y1 - 2013/9/5

N2 - In this work, Båth's Law, the b-value in Gutenberg-Richter Law (G-R Law) in the form of the 1/. β relationship, and both the a- and b-values in the G-R Law were introduced in order to estimate maximum aftershock magnitudes of earthquake sequences in the Taiwan region. The averaged difference of magnitude between the mainshock and the maximum aftershock is 1.20, and is consistent with Båth's Law, however, with a large uncertainty. The large uncertainty implies that the difference may result from a variable controlled by other factors, such as the aftershocks number of an earthquake sequence and magnitude threshold for mainshock. With 1/. β, since 86% of the earthquake sequences with a M≥. 6.0 mainshock follow this relationship, the upper bound of the maximum magnitude can be estimated for an earthquake sequence with a large mainshock. The a- and b-values in the G-R Law was also considered by evaluating maximum aftershock magnitudes. As there are low residuals between the model and the observations, the results suggest that the G-R Law is a good index for maximum aftershock magnitude determinations. In order to evaluate the temporal decays of maximum aftershock magnitudes, modified Omori's Law was introduced. Using the approaches mentioned above, the maximum magnitudes and the temporal evolution of an earthquake sequence could be modeled. Among them, the model of the G-R Law has the best fit with observations for most of earthquake sequences. It shows its feasibility. The results of this work may benefit seismic hazards mitigation in the form of rapid re-evaluations for short-term seismic hazards immediately following devastating earthquakes.

AB - In this work, Båth's Law, the b-value in Gutenberg-Richter Law (G-R Law) in the form of the 1/. β relationship, and both the a- and b-values in the G-R Law were introduced in order to estimate maximum aftershock magnitudes of earthquake sequences in the Taiwan region. The averaged difference of magnitude between the mainshock and the maximum aftershock is 1.20, and is consistent with Båth's Law, however, with a large uncertainty. The large uncertainty implies that the difference may result from a variable controlled by other factors, such as the aftershocks number of an earthquake sequence and magnitude threshold for mainshock. With 1/. β, since 86% of the earthquake sequences with a M≥. 6.0 mainshock follow this relationship, the upper bound of the maximum magnitude can be estimated for an earthquake sequence with a large mainshock. The a- and b-values in the G-R Law was also considered by evaluating maximum aftershock magnitudes. As there are low residuals between the model and the observations, the results suggest that the G-R Law is a good index for maximum aftershock magnitude determinations. In order to evaluate the temporal decays of maximum aftershock magnitudes, modified Omori's Law was introduced. Using the approaches mentioned above, the maximum magnitudes and the temporal evolution of an earthquake sequence could be modeled. Among them, the model of the G-R Law has the best fit with observations for most of earthquake sequences. It shows its feasibility. The results of this work may benefit seismic hazards mitigation in the form of rapid re-evaluations for short-term seismic hazards immediately following devastating earthquakes.

KW - Båth's Law

KW - Earthquake sequence

KW - Gutenberg-Richter Law

KW - Modified Omori's Law

KW - Taiwan

UR - http://www.scopus.com/inward/record.url?scp=84879314759&partnerID=8YFLogxK

U2 - 10.1016/j.jseaes.2013.05.006

DO - 10.1016/j.jseaes.2013.05.006

M3 - 期刊論文

AN - SCOPUS:84879314759

SN - 1367-9120

VL - 73

SP - 409

EP - 418

JO - Journal of Asian Earth Sciences

JF - Journal of Asian Earth Sciences

ER -