Relating Seismic Subduction Images in Southern Peru to Mineralogy

Abstract:

We use data from the recent PeruSE seismic experiment in southern Peru to compare the variation in properties between the normal-dip portion of the subduction interface and the flat slab-mantle interface. The analysis includes migration of the receiver functions to determine the variations in shear and compressional velocities, and the detail measurements of along amplitudes of the receiver-function images. Converted amplitudes at the top and bottom of the Nazca oceanic crust are used to constrain shear wave velocity and density of the subducted crust, and these values are compared to those determined from the experimental mineral physics. We also separately examine the stations closest to the coast to explore how structural variations near the plate interface can be linked to along-strike change in frictional behavior in the seismogenic zone. The results will be compared to the flat subduction zones in Mexico and central Chile.