Structure and petrophysical properties of the Southern Chile subduction zone along 38.25°S from seismic data Active and passive source data from two seismic experiments within the interdisciplinary project TIPTEQ (from The Incoming Plate to mega Thrust EarthQuake processes) were used to image and identify the structural and petrophysical properties (such as P and S velocities Poissons ratios pore pressure density and amount of fluids) within the Chilean seismogenic coupling zone at 38.25°S where in 1960 the largest earthquake ever recorded (Mw 9.5) occurred. Two S wave velocity models calculated using traveltime and noise tomography techniques were merged with an existing velocity model to obtain a 2D S wave velocity model which gathered the advantages of each individual model. In a following step P and S reflectivity images of the subduction zone were obtained using different pre stack and post stack depth migration techniques. Among them the recent prestack line drawing depth migration scheme yielded revealing results. Next synthetic seismograms modelled using the reflectivity method allowed through their input 1D synthetic P and S velocities to infer the composition and rocks within the subduction zone. Finally an image of the subduction zone is given jointly interpreting the results from this work with results from other studies. The Chilean seismogenic coupling zone at 38.25°S shows a continental crust with highly reflective horizontal as well as (steep) dipping events. Among them the Lanalhue Fault Zone (LFZ) which is interpreted to be east dipping is imaged to very shallow depths. ...