HR: 1340h
AN: S13D-1100    [Abstracts]
TI: Seismic Tomography of the Mygdonia Basin (Northern Greece) Using Earthquakes Located With a Double-Difference Algorithm
AU: * Galanis, O C
EM: ogalanis@lemnos.geo.auth.gr
AF: Geophysical Laboratory, Department of Geology, Aristotle University of Thessaloniki, PO Box 352-1, Thessaloniki, 54006 Greece
AU: Papazachos, C B
EM: costas@lemnos.geo.auth.gr
AF: Geophysical Laboratory, Department of Geology, Aristotle University of Thessaloniki, PO Box 352-1, Thessaloniki, 54006 Greece
AU: Scordilis, E M
EM: manolis@lemnos.geo.auth.gr
AF: Geophysical Laboratory, Department of Geology, Aristotle University of Thessaloniki, PO Box 352-1, Thessaloniki, 54006 Greece
AU: Hatzidimitriou, P M
EM: takis@lemnos.geo.auth.gr
AF: Geophysical Laboratory, Department of Geology, Aristotle University of Thessaloniki, PO Box 352-1, Thessaloniki, 54006 Greece
AB: The structure of the area of the Mygdonia Basin has been extensively studied during the last decade and its seismic potential is sufficient to produce an adequate set of seismic phase data. This makes the broader Mygdonia Basin area an appropriate "test-site" for developing and testing new techniques regarding regional-local scale seismic tomography. In the present work, the P- and S-wave velocity structure of the broader area of the Mygdonia Basin is studied by the inversion of traveltimes of earthquakes. The main objective is to produce a more detailed velocity model of the structure of the area, using a technique based on double differences. The quality of the results of seismic tomography depends, among other factors, on the errors in the locations of the earthquakes used. To reduce these errors, the double difference earthquake location algorithm can be used to relocate the earthquakes before introducing them in travel-time tomography. Using a local-scale 1-D and preliminary 3-D seismic wave velocity model of the area, we have implemented a 3-D ray tracing routine, which was incorporated in the original double-difference algorithm. To further improve the quality of the results, we have merged all available arrival time data from permanent and temporary networks, regional or local. These data were used in both earthquake location and tomography inversion. The applicability of the method is demonstrated through synthetic tests and an improvement of the obtained velocity images is clearly identified by both synthetic and real data.
DE: 8180 Tomography
DE: 9335 Europe
DE: 7220 Oceanic crust
DE: 7260 Theory and modeling
DE: 7205 Continental crust (1242)
SC: Seismology [S]
MN: 2004 AGU Fall Meeting