HR: 0800h
AN: S31A-0284    [Abstracts]
TI: Surface Wave Tomography of the Central Alps: Merging Traditional Source and Non-traditional Noise Dispersion Measurements
AU: * Fry, B
EM: bill.fry@erdw.ethz.ch
AF: Institute for Geophysics ETH-Zurich, ETH-Hoenggerberg HPP (P6.2), Zurich, 8093 Switzerland
AU: Stehly, L
EM: Laurent.Stehly@ujf-grenoble.fr
AF: Laboratoire de Geophysique Interne et Tectonophysique Universite Joseph Fourier de Grenoble, B.P. 53, cedex 9, Grenoble, 38041 France
AU: Campillo, M
EM: Michel.Campillo@ujf-grenoble.fr
AF: Laboratoire de Geophysique Interne et Tectonophysique Universite Joseph Fourier de Grenoble, B.P. 53, cedex 9, Grenoble, 38041 France
AU: Boschi, L
EM: boschi@tomo.ig.erdw.ethz.ch
AF: Institute for Geophysics ETH-Zurich, ETH-Hoenggerberg HPP (P6.2), Zurich, 8093 Switzerland
AU: Giardini, D
EM: giardini@seismo.ifg.ethz.ch
AF: Institute for Geophysics ETH-Zurich, ETH-Hoenggerberg HPP (P6.2), Zurich, 8093 Switzerland
AB: The lithospheric structure of the central Alps is complex. Modeling the shear wave velocity structure of this region is hindered by the complexity. Furthermore, traditional passive source tomography is complicated by non-uniform distribution of regional earthquake sources; there is a paucity of regional waves arriving from the north. Recently developed methods of measuring surface wave dispersion from the cross correlation of ambient seismic noise from station couples provide more uniform path coverage. By combining new noise-based dispersion observations with our existing traditional source-station-station (SSS) database, we expect to achieve a dramatic improvement in resolution within the region of interest. We have applied cross correlation and dispersion measurement techniques to month-long continuous data recorded in and proximal to the central Alps (including the TomoCH and SDSNet arrays). Resultant dispersion curves extracted from the ambient seismic noise have been merged with dispersion curves measured with traditional SSS methods to create a broad band dispersion database. We are currently inverting noise and composite SSS-noise data to generate 1D Vs profiles and 2D group velocity maps, testing both linear and non-linear algorithms. Independent control on the resulting models is provided by Vp and moho models based on active and passive source body wave tomography.
DE: 7205 Continental crust (1219)
DE: 7218 Lithosphere (1236)
DE: 7255 Surface waves and free oscillations
DE: 7270 Tomography (6982, 8180)
SC: Seismology [S]
MN: Fall Meeting 2005