Prolonged post-seismic deformation of the 1960 great Chile earthquake and implications for mantle rheology
Contemporary crustal deformation of the southern Andean margin shows an interesting feature: While nearly all coastal GPS sites move landward, consistent with interseismic deformation near a locked subduction fault, sites 300-400 km landward of the rupture region of the M-w 9.5 1960 Chile earthquake...
| Authors: | , , , , |
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| Format: | article |
| Status: | Published version |
| Publication Date: | 2002 |
| Country: | España |
| Institution: | Universidad de Barcelona |
| Repository: | Dipòsit Digital de la UB |
| OAI Identifier: | oai:diposit.ub.edu:2445/163191 |
| Online Access: | https://hdl.handle.net/2445/163191 |
| Access Level: | Open access |
| Keyword: | Subducció Terratrèmols Xile Subduction Earthquakes Chile |
| Summary: | Contemporary crustal deformation of the southern Andean margin shows an interesting feature: While nearly all coastal GPS sites move landward, consistent with interseismic deformation near a locked subduction fault, sites 300-400 km landward of the rupture region of the M-w 9.5 1960 Chile earthquake are moving in the opposite direction. We attribute the seaward motion of these inland sites to a prolonged crustal deformation due to mantle stress relaxation following the 1960 great earthquake. In order to reproduce the observed seaward motion using a three-dimensional finite element model we need to incorporate a mantle viscosity of about 3 x 10(19) Pa s. The possibility that the seaward motion is caused by a silent slip event on the plate interface at large depths cannot be completely excluded, and our analysis provides a working model for future field tests. |
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