IASPEI - Picture Gallery

IUGG XXIV General Assembly July 2-13, 2007 Perugia, Italy
(S) - IASPEI - International Association of Seismology and Physics of the Earth's
Interior
JSS014 Poster presentation 2299
Seismic traveltaime curves of the local earthquake in East- SouthEast of
Iran
Dr. Zohrehsadat Riazirad
Geophysics Azad University Science & Research branch M.Y.R.C IASPEI
Seismic travel time for simultaneous determination of velocity and interface structure is presented that
is applicable to any type of body wave seismic data. This study is velocity and depth of the crust in E-SE
of Iran using local earthquakes. Wealth of data from recorded local earthquakes creates an opportunity
to image crust and upper mantle in the region. These earthquakes on January 2005 to January 2006
were recorded in the BNDS, KRBR, NASN and ZHSE stations (IIEES) that ML≥3 were used to calculate
the velocity of body wave and the thickness of the crust in these regions. The velocities of layers were
obtained from the travel time curves by a least squares method. The apparent velocities for each event
were obtained in a least squares manner. At first step we obtained a 1-D velocity model by analysis of
the travel-time curves for nearly 20000 P, S wave arrival times from 647 local earthquakes. According to
this study the velocity of crust is Vpg= 6.30.01 (km/s), Vsg=3.50.2 (km/s) and suggested a 493 (km)
crustal thickness. In additional velocity of upper mantel is Vpn= 8.000.02 (km/s) in Kerman region. The
velocity of crust is Vpg= 6.20.1 (km/s), Vsg=3.550.05 (km/s) and suggested a 445 (km) crustal
thickness. In additional velocity of upper mantel is Vpn= 8.050.05 (km/s) in Bandar-e abbas region. The
velocity of crust is Vsg=3.50.2 (km/s). In additional velocity of upper mantel is Vpn= 8.000.2 (km/s) in
Zahedan region. This well correlates with the results of the previous gravimetric crustal studies.
Keywords: earthquake, travel time