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 2297
Velocity structure in Naeen Region, Central Iran
Dr. Zohrehsadat Riazirad
Geophysics Azad University Science & Research branch M.Y.R.C IASPEI
In this study, seismic velocity of crust has been derived for Naeen region in south central of Iran. The
velocities of layers were obtained from the time-distance curves by a least squares method. The
average velocities for the events in a distance range 250-800 km provided the upper mantle velocity.
Similarly, the mean value of seismic velocities for the distance range 110-150 km gave crustal velocity.
Using data from International Institute of Earthquake Engineering and Seismology (IIEES) from
recorded local earthquakes creates an opportunity to image crust and upper mantle in the region. At
first step we obtained a 1-D velocity model by analysis of the travel-time curves for nearly 875 P and S
wave arrival times from 647 local earthquakes. Recorded earthquakes were classified along the four
separate profiles, and corresponding travel-time curves were analyzed. Seismic wave velocity of the
crust is Vpg=6.40.01 (km/s) and Vsg=3.50.2 (km/s). Wave velocity of the Moho is Vpn=8.050.02
(km/s) and Vsn=3.70.2 (km/s).Depth for Moho discontinuities were obtained 391 km. This result is well
correlates with the results of the previous gravimetric crustal studies.
Keywords: velocity, crust, iran