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Seismicity and geometry of the south Chilean subduction zone (41.5°S–43.5°S): Implications for controlling parameters
Author(s) -
Lange D.,
Rietbrock A.,
Haberland C.,
Bataille K.,
Dahm T.,
Tilmann F.,
Flüh E. R.
Publication year - 2007
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2006gl029190
Subject(s) - subduction , geology , forearc , induced seismicity , seismology , fault (geology) , seismic zone , plate tectonics , tectonics
In 2005 an amphibious seismic network was deployed on the Chilean forearc between 41.75°S and 43.25°S. 364 local events were observed in a 11‐month period. A subset of the P and S arrival times were inverted for hypocentral coordinates, 1‐D velocity structure and station delays. Main seismic activity occurred predominantly in a belt parallel to the coast of Chiloé Island in a depth range of 12–30 km presumably related to the plate interface. The 30° inclination of the shallow part of the Wadati‐Benioff zone is similar to observations further north indicating that oceanic plate age is not controlling the subduction angle of the shallower part for the Chilean subduction zone. The down‐dip termination of abundant intermediate depth seismicity at approximately 70 km depth seems to be related to the young age (and high temperature) of the oceanic plate. Crustal seismicity is associated with the Liquiñe‐Ofqui fault zone and active volcanoes.