TRANSALP seismic diffraction imaging

Abstract of the accompanying scientific journal publication:Seismic diffraction imaging (SDI) along the north-south oriented TRANSALP seismic line across the Eastern Alps (Munich, Germany to Venice, Italy) reveals hitherto unresolved seismic stratigraphy in the German Molasse Basin as well as details of fault and fracture networks along the front of the Alpine orogenic wedge. In contrast to conventional approaches, SDI de-rives its theoretical foundation from the field of optics and utilizes the diffracted seismic wave-field. This wavefield is orders of magnitude weaker than seismic reflections, but provides supe-rior illumination of the traversed medium. Contrary to the common notion that diffraction im-aging is only feasible for modern, more regular acquisition geometries such as in marine seis-mics, our results show that it can also be applied successfully to less favorable datasets as measured under Alpine conditions along TRANSALP. SDI therefore overcomes limitations of controlled source and passive seismic measurements (heterogeneous distribution of sources and receivers, comparably low lateral resolution) along the TRANSALP line. South of the Molasse Basin, diffractivity allows us to better distinguish the S-dipping foliation and bounding thrusts of the folded Subalpine Molasse, the Helvetic and Penninic Nappes and the Northern Calcere-ous Alps.Datasets provided: TRANSALP_cmpstack.sgy Common-midpoint (CMP) stack of the TRANSALP seismic line (SEG-Y format) TRANSALP_diffraction_image.sgy Difraction image derived from the TRANSALP CMP stack (SEG-Y format)