HR: 1340h
AN: S13B-1051    [Abstracts]
TI: A Shear Wave Velocity Structure in the Eastern Mediterranean From Surface Wave Dispersion
AU: * Di Luccio, F
EM: diluccio@ingv.it
AF: Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, Rome, 00143 Italy
AU: Pino, A N
EM: pino@ingv.it
AF: Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, Rome, 00143 Italy
AB: Regional moderate earthquakes are analyzed to obtain a shear wave velocity model in the complex tectonic setting of the Eastern Mediterranean. The analysis of surface waves from broadband waveforms is based upon the fitting of the fundamental mode of Love and Rayleigh waves. Since the surface waves from different periods travel at different velocities, hence their displacements vary with depth and their analysis can give a constrain to the earth structure. Besides, analyzing dispersive signals is faster than modeling the whole waveforms, which requires the computation of the Green's functions. The behaviour of the computed group velocities as a function of period gives information on the crustal (short periods) and upper mantle structure (long periods). The study area was divided into separate regions, each characterized by specific paths, both pure and mixed. For each source to receiver path the group velocities are obtained using a Multiple Filter Analysis code (see Herrmann and Ammon, 2002), where the Rayleigh and Love waves are selected from the vertical and tangential displacement, respectively. Although the group velocities are quite low in the study area in the 10-100s period range, important differences are observed even in adjacent regions, at longer as well as shorter periods.
DE: 7220 Oceanic crust
DE: 7255 Surface waves and free oscillations
DE: 7205 Continental crust (1242)
DE: 7218 Lithosphere and upper mantle
SC: Seismology [S]
MN: 2004 AGU Fall Meeting