Tectonics and Aftershocks of the Mw=8.8 2010 Chile earthquake rupture area from Oceanbottom Seismometer data

• Applicant: Professor Dr. Ingo Grevemeyer
• Subject Area: Geophysics
• Term: from 2011 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 196980164

The overarching aims of the group proposal have been described in the summary document. Destructive subduction zone earthquakes, like the Mw=8.8 27. February 2010 Chile earthquake, are caused by sudden slippage of the subduction megathrust fault. Once nucleation occurs locally, rupture can propagate and expand in an earthquake. However, rupture generally stops several tens of kilometers landward of the trench axis below the marine fore-arc at the so called updip limit of coseismic rupture. The location of the seaward updip limit is critical for defining the size of a tsunami generated by the earthquake. Aftershocks can be used defining the location of the updip limit. However, events reported in global catalogues have generally large uncertainties in the order of several tens of kilometres. Here, we will use data from a dense network of ocean bottom seismometers data that recorded for three month the aftershock sequence of the Great Mw=8.8 Chile earthquake of February 2010. Data will be used to define the geographical location and nature of the processes controlling the updip limit. Further, we will study stress changes and stress transfer between the subduction thrust and the subducting plate both updip and down-dip of the co-seismic rupture zone.

• DFG Programme: Research Grants
• Participating Persons: Professor Dr. Ernst R. Flüh; Professor Dr. Frederik Tilmann