Processed seismic data for seismic line 11 across the Santorini-Amorgos Tectonic Zone from Poseidon cruise POS338 (2006)

In this active-source experiment at the Santorini-Amorgos Tectonic Zone, multi-channel seismic reflection data was collected during Poseidon cruise POS338 in 2006 (chief scientist Prof. Dr. Christian Hübscher, University of Hamburg). The airgun seismic source was a single G.I. gun that was used in true G.I. mode (Injector volume: 45 cubic inches; Generator volume: 105 cubic inches) producing a signal of 100 Hz main frequency. The seismic data was recorded with a 24-channel streamer of 600 m length (25 m channel spacing), and stored in SEG-Y format. The processed data files presented here are for seismic line 11 which is discussed in the Preine et al. (2020) paper. These SEG-Y data files allow the reconstruction of each step described in that paper. A short description of each file is included on the data download page and in the accompanying File Description document. Preine et al. (2020) use the faint diffracted wavefield contained in the data to calculate a depth-velocity model for depth migration. Their method works by first modelling the reflected wavefield and then subtracting it from the input-data in the zero-offset domain. The resulting Diffraction-Only section is used to (i) focus the diffractions and derive so-called diffraction-images and to (ii) calculate wavefront attributes and to perform wavefront tomography in order to arrive at a depth-velocity model. This model is manually refined in order to arrive at focused diffractions and is then used for FD depth migration. Seismic line 11 was oriented in a NW-SE direction. The line lies to the northeast of Santorini island and crosses the Santorini-Anafi basin as well as the Amorgos basin. The line is part of a wide collection of reflection seismic profiles acquired during this Poseidon cruise. This seismic survey was funded by the German Research Foundation (Deutsche Forschungsgesellschaft, DFG) with the aim to image the Santorini-Amorgos Tectonic Zone which is well known for its catastrophic volcanic eruptions, earthquakes, and tsunamis.