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3-D Geophysical Imaging and Tectonic Modelling of Active Tectonics of the Upper Rhine Grabe Region

出版	2003
URL	http://books.google.com.hk/books?id=0mNYPgAACAAJ&hl=&source=gbs_api

註釋The Upper Rhine Graben is considered to be a classical example of a continental rift. The graben is associated with an increased seismicity in the seismically rather quiet foreland of the Alpine chain.The earthquakes result from activation of the faults in the graben under the compression caused by the on-going collision of the African and European continental plates. This thesis presents a study into the faults that are responsible for the earthquakes, and larger scale tectonics that cause the activity of these faults. On a crustal scale, the tectonics of the Upper Rhine Graben are dominated by faults that were already existing before the opening of the graben. The exact position, orientation, and depth extent of some of these active faults were previously unknown. In this study, they are derived from a crustal seismic velocity model, obtained from a local earthquake tomography. Integration of various geophysical and geological data for the region allowed precise interpretation of the crustal seismic velocity structure. Numerical modelling of the kinematics of the active system outlines the possible seismic hazard that is associated with the present-day configuration of faults under the current stress field.On a whole lithosphere scale, the tectonics are proven to be also influenced by pre-existing structures. A teleseismic travel time tomography yielded images of the seismic velocity structure of the entire lithosphere. The observed structures are not parallel to the graben axis and prove that the graben has not formed following the classical ideas about continental rifting. A new model for the formation, and present-day state of the graben in the foreland of the Alps is proposed in this thesis.