Coseismic versus interseismic ground deformations, fault rupture inversion and segmentation revealed by 2003 Mw 6.8 Chengkung earthquake in eastern Taiwan

• Published in: Geophysical research letters 2006-01, Vol.33 (2), p.n/a
• Main Authors: Wu, Y. M., Chen, Y. G., Shin, T. C., Kuochen, H., Hou, C. S., Hu, J. C., Chang, C. H., Wu, C. F., Teng, T. L.
• Format: Article
• Language: English
• Subjects: Earth sciences; Earth, ocean, space; Exact sciences and technology
• ISSN: 0094-8276; 1944-8007
• DOI: 10.1029/2005GL024711

The 2003 Chengkung earthquake (Mw 6.8) provided diagnostic evidence for a source model showing the deformation process of the seismogenic Chihshang fault in eastern Taiwan. The aftershocks show a fault‐bend at a depth of 18 km. Coseismic ground displacements recorded by strong‐motion records allow us to deduce instant rupturing of this event. Our resulting model shows a fault length of ∼33 km and dip‐slip dominant rupture on fault‐plane deeper than 18 km. Estimated coseismic displacements constrain two fault planes: one at 5–18 km depth dipping 60°E and 18–36 km depth dipping 45°E. The uppermost fault‐plane of the Chihshang Fault (0–5 km) did not break immediately after the main shock; however, it may have a major role in after‐slip and even interseismic ground deformation. The Taiyuan basin developed in the hanging wall is a geomorphic feature consistent with and adequately explained by coseismic ground displacements.