HR: 11:35h
AN: T42A-06    [Abstracts]
TI: Imaging the Chilean Subduction Zone at 38° S Using Prestack Kirchhoff Depth Migration Within Project TIPTEQ
AU: * Gross, K
EM: kolja@geophysik.fu-berlin.de
AF: Freie Universität Berlin, Fachrichtung Geophysik, Malteserstr. 74-100, Berlin, 12249 Germany
AU: Buske, S
T42A-06 AF: Freie Universität Berlin, Fachrichtung Geophysik, Malteserstr. 74-100, Berlin, 12249 Germany
AU: Wigger, P
T42A-06 AF: Freie Universität Berlin, Fachrichtung Geophysik, Malteserstr. 74-100, Berlin, 12249 Germany
AU: Micksch, U
T42A-06 AF: GeoForschungsZentrum Potsdam, Telegrafenberg, Potsdam, 14473 Germany
AU: Krawczyk, C M
T42A-06 AF: GeoForschungsZentrum Potsdam, Telegrafenberg, Potsdam, 14473 Germany
AU: Stiller, M
T42A-06 AF: GeoForschungsZentrum Potsdam, Telegrafenberg, Potsdam, 14473 Germany
AU: Araneda, M
T42A-06 AF: SEGMI, San Sebastian 2750, Of. 704, Las Condes, Santiago, 6760197 Chile
AU: Bataille, K
T42A-06 AF: Universidad de Concepción, Dep. Ciencias de la Tierra, Concepción, 160-C Chile
AU: Bribach, J
T42A-06 AF: GeoForschungsZentrum Potsdam, Telegrafenberg, Potsdam, 14473 Germany
AU: Lüth, S
T42A-06 AF: Freie Universität Berlin, Fachrichtung Geophysik, Malteserstr. 74-100, Berlin, 12249 Germany
AU: Lüth, S
T42A-06 AF: GeoForschungsZentrum Potsdam, Telegrafenberg, Potsdam, 14473 Germany
AU: Mechie, J
T42A-06 AF: GeoForschungsZentrum Potsdam, Telegrafenberg, Potsdam, 14473 Germany
AU: Schulze, A
T42A-06 AF: GeoForschungsZentrum Potsdam, Telegrafenberg, Potsdam, 14473 Germany
AU: Shapiro, S A
T42A-06 AF: Freie Universität Berlin, Fachrichtung Geophysik, Malteserstr. 74-100, Berlin, 12249 Germany
AU: Ziegenhagen, T
T42A-06 AF: GeoForschungsZentrum Potsdam, Telegrafenberg, Potsdam, 14473 Germany
AB: The Chilean continental margin is one of the most seismically active subduction systems and serves as a natural laboratory to study mega-thrust earthquakes. Investigations with respect to the structural and petrophysical properties of the corresponding seismogenic coupling zone are the key to understand the triggering mechanisms and processes that generate those mega-thrust earthquakes. This is one of the main aims of the interdisciplinary project TIPTEQ (from The Incoming Plate to mega-Thrust EarthQuake processes). As part of this project an approximately 95 km long 3C near-vertical reflection seismic profile was shot in southern Central Chile at about 38° S in January 2005. The profile runs from the Pacific Ocean to the Central Valley along a west-east trending line crossing the relocated hypocentre of the historic 1960 Valdivia earthquake (Mw=9.5). An additional expanding spread (ESP) experiment focuses on the down-dip limit (30-50 km depth) of the seismogenic coupling zone. Furthermore, three-hole (Camouflet) shooting configurations were carried out as a pilot study to test SH-wave generation in a crustal regime. This paper focuses on the structural imaging results using prestack Kirchhoff depth migration. Close to the coast the oceanic crust is clearly visible and can be traced below a strongly heterogeneous accreted overburden further inland down to depths of about 50 km. At the eastern end of the seismic section, a strong reflector appears at about 60 km depth, which runs perpendicular to the extrapolated plate interface. Taking into account results from previous experiments and other components of project TIPTEQ, we will present an interpretation of the subduction zone image with special emphasis on its structural features.
DE: 1242 Seismic cycle related deformations (6924, 7209, 7223, 7230)
DE: 3060 Subduction zone processes (1031, 3613, 8170, 8413)
DE: 7209 Earthquake dynamics (1242)
DE: 8123 Dynamics: seismotectonics
SC: Tectonophysics [T]
MN: Fall Meeting 2005