Existence of gas-hydrates in the marine sediments elevates the velocity of seismic waves, whereas even a small amount of underlying free-gas decreases the seismic velocity considerably. These changes in velocities can be used for the assessment of gas-hydrates. The traveltime inversion is an effective method to derive a 2-D velocity structure from the seismic data. We have applied the method to...

An ever present goal of seismic processing and inversion is to extract meaningful geology information from seismic data. The simplest possibility is to invert for seismic impedances, or, considering density constant, invert for velocities. Here I use a micro genetic algorithm program to achieve this goal. I use a real sonic log to compute a synthetic seismic trace and then use that trace as inp...

Analysis of the refracted arrivals on a seismic reflection profile recorded along the wall of a tunnel at an iron mine near Thabazimbi, South Africa, shows variations in P-wave velocity in dolomite away from the de-stressed zone that vary between 4.4 and 7.2 kmrs, though values greater than 5.8 kmrs predominate along most of the profile. The seismic velocities at the tunnel wall, however, vary ...

the goal of this laboratory study is to investigate the effect of pore shapes on seismic wave velocities in carbonate rocks under reservoir conditions. in this research, 41 core plugs of carbonate rocks from oil fields of the southwest of iran were prepared. the compressional and shear wave velocities were measured in both dry and brine saturated samples under several pressures especially reser...

Sonobuoys provide an alternative to using long streamers while conducting multi-channel seismic (MCS) studies, in order to provide deeper velocity control. We present analysis and modeling techniques for interpreting the sonobuoy data and illustrate the method with ten overlapping sonobuoys collected in the Ross Sea, offshore from Antarctica. We demonstrate the importance of using the MCS data ...

For three years we have used synthetic and field data to investigate the effectiveness of commercial refraction tomography codes on both simple and complex subsurface velocity structures, with the ultimate goal of determining the suitability of the method for karst problems. The results of these studies indicate that refraction tomography is able to resolve karst features under some conditions....

north-east khorasan is one of the most active regions in the world because of is setting on the alpine-himalayan belt. historical and geological backgrounds suggest that this region has experienced many destructive earthquakes throughout history. compared with the historical background, the seismicity of the region, in the present century, is better known both from the macroseismic and instrume...

velocity analysis is one of the most important step in seismic data processing. it affects not only many processing steps directly and indirectly, but also is known as a primary interpretation of the data. however, it can also be assumed as one of the most time consuming processing step. the conventional velocity analysis method measures the energy amplitude along hyperbolic trajectories within...

Detailed seismic modeling and imaging of Earth’s deep interior is providing key information about lower-mantle structures and processes, including heat flow across the core-mantle boundary, the configuration of mantle upwellings and downwellings, phase equilibria and transport properties of deep mantle materials, and mechanisms of core-mantle coupling. Multichannel seismicwave analysismethods t...