Scheduled Cruises in 2001

Summary of a recent cruise on margins research (D.011)

Location :   Southern Chile

Research ship and cruise identifier: SPOC (onshore)

Started :   9 October 2001

Ended :   6 December 2001

Principal Scientist/Investigator :   C. Krawczyk, O. Oncken, P. Wigger, K. Bataille

Laboratory :   GFZ Potsdam, Germany; Free University Berlin, Germany; Concepcion, Chile

Other investigators:J. Mechie, M. Araneda, C. Reichert

E-mail contact for further information :   lotte@gfz-potsdam.de

Scientific objectives:   Between 36° and 39° S, a combined onshore-offshore, active-passive seismic experiment was carried out in 2001 linking marine profiles (see cruise SO-161) to the subduction features observed onshore. SPOC (Subducion Processes Off Chile) comprised: (1) a pilot near-vertical incidence reflection (NVR) seismic experiment covering the coastal onshore-offshore transition at an W-E line to test the structural and reflectivity potential of tracing the seismogenic plate interface, (2) a 3D-wide angle reflection/refraction component simultaneously recording the airgun pulses from RV SONNE with 32 3-component stations deployed in an array and 50 stations along 3 W-E profiles; and (3) recording of explosive shots fired at the ends of the three profiles to compare different segments of the margin. The vision of our integrated study is a quantitative understanding of megathrust earthquake seismicity in subduction zones including processes operating at the seimogenic plate interface and their effect for surface deformation in the area of the 1960 Southern Chile earthquake.