HR: 0830h
AN: S51D-0079    [PDF]
TI: Active Crustal Structures in the Southern Rhine Graben: From Local Earthquake Tomography and Reflection Seismics to Numerical Modelling.
AU: * Lopes Cardozo, G
EM: lopes.cardozo@eost.u-strasbg.fr
AF: Institut de Physique du Globe de Strasbourg, 5 Rue Ren‚ Descartes, Strasbourg, 67084 France
AU: Cornu, T
EM: tristan.cornu@falw.vu.nl
AF: Faculty of Earth and Life Sciences, Vrije Universiteit., De Boelelaan 1085, Amsterdam, 1081HV Netherlands
AU: Granet, M
EM: michel.granet@eost.u-strasbg.fr
AF: Institut de Physique du Globe de Strasbourg, 5 Rue Ren‚ Descartes, Strasbourg, 67084 France
AB: A better understanding of the seismogenic structures in the southernmost Rhine Graben is needed for future seismic hazard assessment studies. It has been proven difficult to link seismic activity to known geological structures in this region. The seismogenic part of the crust of the southern Rhine Graben is investigated with the use of a detailed Local Earthquake Tomography (LET). This tomography is combined with seismic profiles to come to a 3D image of the structures in the crust. The calculated velocity model can be compared with the results from $P_n$ anisotropy calculations, gravimetry, deep reflection seismic profiles, and industry seismic sections to retrieve the exact location of the faults. Interpretation of the crustal velocity structure of the Rhine Graben shows a dominance of inherited Variscan structures, some of which were not recognised as seismically active until today. The velocity model and the interpretation of seismic sections show that the tectonics of the northeastern extend of the Jura Mountains are influenced by the presence of a Permo-Carboniferous trough system that is activated today. The involvement of the pre-Triassic basement contradicts the pure thin-skin development of the mountain belt. The faults that are derived from the geophysical imaging serve as input for a numerical modelling experiment. Aim of this experiment is to obtain insight in the kinematics of the various faults, and the associated stress and strain localisation inside the crustal model.
DE: 7230 Seismicity and seismotectonics
DE: 8107 Continental neotectonics
DE: 8123 Dynamics, seismotectonics
DE: 8164 Stresses--crust and lithosphere
DE: 8180 Tomography
SC: Seismology [S]
MN: 2003 Fall Meeting