investigation of velocity structure based on seismic wave propagation have been performed in recent years in different parts of iran that results obtained is effective in the analysis of seismic zones and locate earthquakes with reasonable accuracy. on a broad scale, the seismotectonics of southern iran are controlled by active convergence between the arabian and eurasian tectonic plates that a...

Information about reservoir properties usually comes from two sources: seismic data and well logs. The former provide an indirect, low resolution image of rock velocity and density. The latter provide direct, high resolution (but laterally sparse) sampling of these and other rock parameters. An important problem in reservoir characterization is how best to combine these data sets, allowing the ...

geological conditions of tabriz, a growing city in nw-iran, are strongly influenced by north tabriz fault (ntf). north tabriz fault is a major seismogenic fault in nw-iran. so, for a correct seismic microzonation, shear wave velocity (vs) structure in different part of city should be determined. but urban conditions, such as ambient noise due to cultural activity, restrict the general applicati...

The disadvantages of conventional seismic tomographic ray tracing and inversion by calculus-based techniques include the assumption of a single ray path for each source– receiver pair, the non-inclusion of head waves, long computation times, and the difficulty in finding ray paths in a complicated velocity distribution. A ray-tracing algorithm is therefore developed using the reciprocity princi...

We have developed seismic velocity models for the heated rock surrounding a tunnel in Yucca Mountain tuff and compared the results with field data obtained at the Yucca Mountain drift scale test DST facility from 1998 to 2002. During that time, the tunnel was heated to replicate the effects of long-term storage of decaying nuclear waste and to study the effects of extreme temperatures on the su...

geophysical techniques remain the only ways to remotely and non-destructively sense the earth’s near subsurface and as such have the most promising prospect for rapid and accurate detection of underground tunnels. today, electrical resistivity and seismic refraction geophysical methods have been greatly developed to identify structures and underground cavities. in this study, the ability of the...

S U M M A R Y We investigate the seismic velocity contrast across the San Andreas fault (SAF) in the Parkfield area using fault zone head waves (FZHW) that propagate along the bimaterial fault interface and direct P waves. We systematically analyse large data sets of near-fault waveforms recorded by several seismic networks over the period 1984–2005. Clear FZHW are observed at many stations on ...

The current emphasis in seismic stratigraphy has This process of wavelet extraction, followed by the focussed on velocity inversion and the generation of derivation of the reflectivity sequence, allows the the pseudo-acoustic log from the seismic trace. ideal pre-conditioning for seismic velocity inverThere are several published methods on wavelet sion. extraction which invariably make assumpti...

Substantial progress has occurred during the past 15 years in development of shallow CDP seismic-reflection techniques, but there are occasional interpretation problems with the resulting data. We discuss examples of the pitfalls of the method, along with some procedures to help avoid them. Problems that often occur include spatial aliasing of ground roll, interpreting processed ground-coupled ...