In the Chile-Project, we use seismological data to investigate the subduction process and related phenomena. The Atacama Desert serves us as a natural laboratory that yields exellent conditions for such studies. The results we obtain are not only valid for this regions, but can to some extend be transfered to subduction zones around the world.
The Chile project is currently committed to the investigation of subduction-related seismicity. The seismic gap of the northern Chilean subduction zone experienced it's last activation in the 1877 M=8.5 Iquique earthquake. Since then the subducting Nazca Plate and the overriding South American Plate have been mutually locked. The central part of the segment ruptured in the recent 2014 M=8.1 Pisagua earthquake. Prior to that, during the late inter-seismic phase of the earthquake cycle, we operated two dense temporary seismometer-networks in this tectonic key region. The networks recorded waveforms of over 7,000 weak seismic events. These micro-earthquakes witness a variety of seismogenic processes such as metamorphic mineral reactions, fluid migration or deformation due to tectonic stress.
The localizations of the seismic events alone deliver a clear image of the earth's interior in this region: large continental fault zones and a triple seismic zone within the subducting slab can be clearly identified. The deeper analysis of the data set promises to reveal previously unrecognized details of the subduction process and its related phenomenons.
Seismic activity in the subducting slab and the overriding plate of the Northern Chilean subduction zone.
Quelle: Wasja Bloch
Earlier activities of our group in the investigation of the northern Chilean subduction zone include the acquisition of continental-scale wide-angle seismic profiles, commitment in the DFG-SFB "Deformation Processes in the Andes" and participation in the ANCORP reflection seismic experiment.