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| Titel |
High-Resolution Seismicity Image of the Shallow Part of the Subduction Zone Beneath Mejillones in Northern Chile |
| VerfasserIn |
Jörn Kummerow, Wasja Bloch, Pablo Salazar, Peter Wigger, Günter Asch, Serge A. Shapiro |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250109705
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| Publikation (Nr.) |
 EGU/EGU2015-9641.pdf |
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| Zusammenfassung |
| We analyze slab-related seismicity which has been recorded by a recently (June
2013) installed local seismic monitoring system on the Mejillones peninsula in the
forearc region of Northern Chile. The monitoring system consists of 20 seismic
stations and is complemented by components of the permanent IPOC (Integrated
Plate Boundary Obervatory Chile) seismic network, providing a singular on-shore
possibility to study in detail the relatively shallow seismicity of the subducting Nazca
slab.
To date, about thousand local seismic events have been identified. Precise earthquake
relocation involving a local 2.5D velocity model and improved arrival time picks from an
iterative cross-correlation based technique allows to trace sharply the slab interface between
25km and 40km depth. Furthermore, we observe distinct and continuous seismic activity on
a near-vertical structure which transects the subducting oceanic crust from 40km to
50km depth. Location, orientation and size of this plane correspond to the rupture
fault of the MW6.8 Michilla intraslab earthquake which occurred weeks after the
MW7.7 Tocopilla earthquake of November 2007. We discuss here particularly the
results from cluster analysis and the spatio-temporal signatures of the recorded
seismicity. |
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