HR: 0800h
AN: S51A-0984    [Abstracts]
TI: Variation of fundamental mode Rayleigh wave group velocity dispersion in Iran and the surrounding region
AU: * Rham, D
EM: dr291@cam.ac.uk
AF: Bullard Laboratories, Dept. of Earth Sciences, University of Cambridge, Madingley Rise, Madingley Road, Cambridge, CB3 0EZ United Kingdom
AU: Priestley, K
EM: keith@esc.cam.ac.uk
AF: Bullard Laboratories, Dept. of Earth Sciences, University of Cambridge, Madingley Rise, Madingley Road, Cambridge, CB3 0EZ United Kingdom
AU: Tatar, M
EM: mtatar@iiees.ac.ir
AF: International Institute of Earthquake Engineering and Seismology, No. 26, Arghavan St., Dibaji shomali Ave., Farmanieh, Tehran, 19395/3913 Iran (Islamic Republic of)
AU: Paul, A
EM: Anne.Paul@obs.ujf-grenoble.fr
AF: Laboratoire de Geophysique Interne et Tectonophysique, Geosciences-UJF, 1381 rue de la Piscine, Grenoble, 38041 France
AU: Hatzfeld, D
EM: denis.hatzfeld@ujf-grenoble.fr
AF: Laboratoire de Geophysique Interne et Tectonophysique, Geosciences-UJF, 1381 rue de la Piscine, Grenoble, 38041 France
AU: Radjaee, A
EM: aradjaee@dena.iiees.ac.ir
AF: International Institute of Earthquake Engineering and Seismology, No. 26, Arghavan St., Dibaji shomali Ave., Farmanieh, Tehran, 19395/3913 Iran (Islamic Republic of)
AU: Nowrouzi, G
EM: gnowrouzi@dena.iiees.ac.ir
AF: International Institute of Earthquake Engineering and Seismology, No. 26, Arghavan St., Dibaji shomali Ave., Farmanieh, Tehran, 19395/3913 Iran (Islamic Republic of)
AU: Kaviani, A
EM: ayoubkaviani@yahoo.com
AF: International Institute of Earthquake Engineering and Seismology, No. 26, Arghavan St., Dibaji shomali Ave., Farmanieh, Tehran, 19395/3913 Iran (Islamic Republic of)
AU: Tiberi, C
EM: christel.tiberi@lgs.jussieu.fr
AF: Laboratoire de Tectonique,Universite Pierre et Marie Curie-Paris, 4 place jussieu, Paris, 75252 France
AB: We present group velocity dispersion results from a study of regional fundamental mode Rayleigh waves propagating across Iran and the surrounding region. Data for these measurements come from field deployments within Iran by the University of Cambridge (UK) and the Universite Joseph-Fourier (FRA) in conjunction with International Institute of Earthquake Engineering and Seismology (Iran), within Oman by the Universite Pierre et Marie Curie-Paris (FRA), in addition to data from IRIS and Geofone. 1D path-averaged dispersion measurements have been made for ~800 source-receiver paths using multiple filter analysis. We combine these observations in a tomographic inversion to produce group velocity images between 15 and 60~s period. Because of the dense path coverage, these images have substantially higher lateral resolution for this region than is currently available from global and regional group velocity studies. We observe variations in short-period group velocity which is consistent with the surface geology. Low group velocity (2.45-2.55~km/s) at short periods (15-20~s) is observed beneath the south Caspian Basin, northern Iran, the Persian Gulf, the Zagros, the Makran, northern Afghanistan and southern Pakistan. Somewhat higher group velocity (2.60-2.70~km/s) at these periods occurs in central Iran. At intermediate periods (30-40~s) group velocities over most of the region are low (2.90-3.10~km/s) compared to Arabia. At longer periods (50-60~s) group velocities remain low (3.35-3.45~km/s) over most of Iran but there is a suggestion of higher group velocities beneath the northern and central Zagros.
DE: 7205 Continental crust (1219)
DE: 7208 Mantle (1212, 1213, 8124)
DE: 7218 Lithosphere (1236)
DE: 7255 Surface waves and free oscillations
DE: 7270 Tomography (6982, 8180)
SC: Seismology [S]
MN: Fall Meeting 2005