Behrmann, Jan Hinrich

Krawczyk, C. M.

Kukowski, Nina

Rietbrook, A.

Schilling, F.

TIPTEQ Research Group

English

OceanRep

Geophysical Research Abstracts, Vol. 9, 09295, 2007SRef-ID: 1607-7962/gra/EGU2007-A-09295© European Geosciences Union 2007Changing material properties across the south centralChile forearc and impact on seismogenic zonebehaviourJ.H. Behrmann (1), N. Kukowski (2), C.M. Krawczyk (2), A. Rietbrock (3), F.Schilling (4) and the TIPTEQ Research Group(1) Marine Geodynamics, IFM-GEOMAR, Kiel, Germany (Fax: +49-431-6002922 /jbehrmann@ifm-geomar.de), (2) GFZ Potsdam, Telegrafenberg, 14473 Potsdam, Germany(Fax: +49-331-288-1370 / nina@gfz-potsdam.de, (3) University of Liverpool, 4 BrownlowStreet, Liverpool L69 3GP, UKThe position of the seismogenic zone and the processes within and around it are de-termined by the material within the subduction channel. Material properties are in-fluenced by changing temperature and pressures, and by the composition. The jointTIPTEQ-projects, which focus on petrophysics and process simulation of the SouthernChile subduction zone, enable to investigate the material properties and their changesfrom the sedimentary material potentially entering the subduction channel down tothe downdip end of the seismogenic zone, and through high temperature high pressurelaboratory experiments even deeper. Information on material properties is reflected inthermal and mechanical numerical model simulations, which then are validated withthe help of geophysical data acquired by the other TIPTEQ projects. Here we presenta summary of material properties relevant for the seismogenic processes and how theychange during subduction material transport. There is evidence, for example, that rockfrictional properties of sedimentary material that is fed into the subduction zone variesis space, along with mineral composition. For time-dependent changes, our numeri-cal simulations suggest that the drop of friction along the plate interface has a majorimpact on the mechanical behaviour of the forearc. High temperature, high pressurelaboratory experiments underline the importance of water in influencing key physicalproperties. Seismic events detected in dehydration experiments emphasize the capac-ity of such metamorphic reactions as earthquake generators. The joint interpretationbased on geophysical data, laboratory experiments and numerical simulation is thebase for a better understanding of seismogenesis at the Southern Chile convergentplate margin.

Changing material properties across the South Central Chile forearc and impact on seismogenic zone behaviour

Abstract

Similar works

Full text

Available Versions

OceanRep