Seismic cycle stress change in western Taiwan over the last 270 years

M. Mouyen (1) , Rodolphe Cattin (2) , Frédéric Masson (1, 2)

1 IPGS - Institut de physique du globe de Strasbourg
2 Géosciences Montpellier

The island of Taiwan is affected by intense seismic activity, which includes large events as the disastrous 1999 Chi-Chi earthquake. To improve seismic hazard assessment in this area, we estimate the effect of both interseismic loading and major events since 1736 on the state of stress of major active faults. We focus our approach on western Taiwan, which is the most densely populated part of Taiwan. We pay a specific attention to faults geometry and to both interseismic and coseismic slip distributions. Our results suggest that both earthquakes and interseismic loading before 1999 increase the Coulomb stress in the north-western part of the Chelungpu fault, a region which experienced the highest coseismic slip during the Chi-Chi earthquake. More importantly our results reveal a Coulomb stress increase in the southern part of the Changhua thrust fault, below a densely populated area.

Mots clés: Coloumb-stress; Taiwan; Chi-Chi earthquake

Domaines: Géophysique [physics.geo-ph]; Géophysique [physics.geo-ph]; Milieux et Changements globaux

M. Mouyen, Rodolphe Cattin, Frédéric Masson. Seismic cycle stress change in western Taiwan over the last 270 years. Geophysical Research Letters, 2010, 37, pp.L03306. ⟨10.1029/2009GL042292⟩. ⟨hal-00475590⟩