Localized fault slip to the trench in the 2010 Maule, ChileMw= 8.8 earthquake from joint inversion of high-rate GPS, teleseismic body waves, InSAR, campaign GPS, and tsunami observations
| Autor: | Juan Carlos Báez Soto, Chao An, Christophe Vigny, Thorne Lay, X. Tong, Luis Rivera, Han Yue |
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| Rok vydání: | 2014 |
| Předmět: |
geography
geography.geographical_feature_category Hypocenter Slip (materials science) Fault (geology) Geodesy Plate tectonics Geophysics Space and Planetary Science Geochemistry and Petrology Trench Interferometric synthetic aperture radar Earth and Planetary Sciences (miscellaneous) 14. Life underwater Episodic tremor and slip Geology Aftershock Seismology |
| Zdroj: | Journal of Geophysical Research: Solid Earth. 119:7786-7804 |
| ISSN: | 2169-9313 |
| DOI: | 10.1002/2014jb011340 |
| Popis: | The 27 February 2010, Mw 8.8 Maule earthquake ruptured ~500 km along the plate boundary offshore central Chile between 34°S and 38.5°S. Establishing whether coseismic fault offset extended to the trench is important for interpreting both shallow frictional behavior and potential for tsunami earthquakes in the region. Joint inversion of high-rate GPS, teleseismic body waves, interferometric synthetic aperture radar (InSAR), campaign GPS, and tsunami observations yields a kinematic rupture model with improved resolution of slip near the trench. Bilateral rupture expansion is resolved in our model with relatively uniform slip of 5–10 m downdip beneath the coast and two near-trench high-slip patches with >12 m displacements. The peak slip is ~17 m at a depth of ~15 km on the central megathrust, located ~200 km north from the hypocenter and overlapping the rupture zone of the 1928 M ~8 event. The updip slip is ~16 m near the trench. Another shallow near-trench patch is located ~150 km southwest of the hypocenter, with a peak slip of 12 m. Checkerboard resolution tests demonstrate that correctly modeled tsunami data are critical to resolution of slip near the trench, with other data sets allowing, but not requiring slip far offshore. Large interplate aftershocks have a complementary distribution to the coseismic slip pattern, filling in gaps or outlining edges of large-slip zones. Two clusters of normal faulting events locate seaward along the plate motion direction from the localized regions of large near-trench slip, suggesting that proximity of slip to the trench enhanced extensional faulting in the underthrusting plate. |
| Databáze: | OpenAIRE |
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