TY - JOUR
T1 - Focal mechanisms and seismotectonic stress in North Central Taiwan in relation with the Chi-Chi earthquake
AU - Mozziconacci, Laetitia
AU - Angelier, Jacques
AU - Delouis, Bertrand
AU - Rau, Ruey Juin
AU - Béthoux, Nicole
AU - Huang, Bor Shouh
N1 - Funding Information:
The senior author benefited of grant support from MRT-IUF. This work is part of the France–Taiwan cooperation in Earth Sciences supported by the French CNRS, the National Science Council of Taiwan and the IFT (Taipei) and BRT (Paris). This work was also made possible because of the existence of data provided by BATS and CWB networks, which is acknowledged with thanks. We are also grateful to the anonymous reviewers for their very useful comments.
PY - 2009/3/10
Y1 - 2009/3/10
N2 - The aftershock sequence of the 1999 Chi-Chi earthquake (Mw = 7.6) provided a large number of focal mechanisms recorded with BATS Centroïde Moment Tensors (CMT) which allowed us to perform reliable stress tensor inversions in North Central Taiwan. These inversions were done for three time-periods corresponding to the post-seismic phase of the 1999 Chi-Chi earthquake (Mw 7.6). In the last period the 2003 Chengkung earthquake (Mw = 6.5) occurred on the vicinity of our study area and its influence is also examined. For comparison between seismotectonic regimes of the pre- and post- Chi-Chi periods, we also carried out stress inversion using published focal mech of the pre Chi-Chi period. For each period, we delineated seismogenic domains with relatively homogeneous stress regimes in agreement with the local structures. The boundaries of these domains vary during the whole post Chi-Chi period as seismic activity decays. A 25° clockwise rotation of the main compressive stress σ1 is observed between the pre and the post Chi-Chi periods in the domain located near the northern termination of the Chi-Chi rupture. A stress perturbation related to the Chengkung earthquake could be detected in the eastern part of the Central Range. We present an interpretation of the determined stress regimes in terms of changes in mechanical behaviour of the Sanyi-Puli transfer zone.
AB - The aftershock sequence of the 1999 Chi-Chi earthquake (Mw = 7.6) provided a large number of focal mechanisms recorded with BATS Centroïde Moment Tensors (CMT) which allowed us to perform reliable stress tensor inversions in North Central Taiwan. These inversions were done for three time-periods corresponding to the post-seismic phase of the 1999 Chi-Chi earthquake (Mw 7.6). In the last period the 2003 Chengkung earthquake (Mw = 6.5) occurred on the vicinity of our study area and its influence is also examined. For comparison between seismotectonic regimes of the pre- and post- Chi-Chi periods, we also carried out stress inversion using published focal mech of the pre Chi-Chi period. For each period, we delineated seismogenic domains with relatively homogeneous stress regimes in agreement with the local structures. The boundaries of these domains vary during the whole post Chi-Chi period as seismic activity decays. A 25° clockwise rotation of the main compressive stress σ1 is observed between the pre and the post Chi-Chi periods in the domain located near the northern termination of the Chi-Chi rupture. A stress perturbation related to the Chengkung earthquake could be detected in the eastern part of the Central Range. We present an interpretation of the determined stress regimes in terms of changes in mechanical behaviour of the Sanyi-Puli transfer zone.
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U2 - 10.1016/j.tecto.2007.11.003
DO - 10.1016/j.tecto.2007.11.003
M3 - Article
AN - SCOPUS:60949086285
VL - 466
SP - 409
EP - 426
JO - Tectonophysics
JF - Tectonophysics
SN - 0040-1951
IS - 3-4
ER -