Geophysical and Geodetic Search for Transients in the Northern Chile Coupling Zone

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The tectonic situation in northern Chile with the eminent danger of catastrophic earthquakes and the outline of the entire Bündelantrag have been described in the covering paragraph (see Appendix). Our subproject TP1 covers both the search and analysis of slow slip, expressed through slow earthquakes and non-volcanic tremors (NVT) and the analysis of fast slip during earthquakes, as well as the possible interconnection of the two phenomena. With respect to the latter, we want to analyze both distribution and evolution of the general seismicity and the rupture processes of large earthquakes with a focus on the recent Tocopilla event (14th November 2007, magnitude 7.8) at the southern edge of the seismic gap using our own local data. The GFZ and IPG (Paris) are operating since several years a common permanent geophysical Plate Boundary Observatory (PBO) in the Iquique seismic gap in northern Chile with about 15 stations (operating and under construction) which are continuously recording broadband seismic data, strong motion, and GPS and MT data. Several stations have already real time data transmission to Potsdam. Additional temporary off shore experiments (TP2, H. Kopp and TP6, J. Behrmann, proposed within this Bündelantrag) will collect seismic and tilt data at the shallow part of the coupling zone at the ocean bottom. The work proposed here is the beginning of a long-term scientific analysis of the PBO data and near realtime monitoring of general seismicity, slow earthquakes, and tectonic tremors. Similar observations are at present conducted at several plate boundaries in the world (Cascadia, California, Mexico, Japan) with very promising success. Since the Andean subduction belongs to the most vigorous ones, we expect also good results.