Continuous monitoring of in situ reservoir responses to stress transients provides insights into the evolution of geothermal reservoirs. By exploiting the stress dependence of seismic velocity changes, we investigate the temporal evolution of the reservoir stress state of the Salton Sea geothermal field (SSGF), California. We find that the SSGF experienced a number of sudden velocity reductions...

Repeated seismic surveys of the Landers, California, fault zone that ruptured in the magnitude (M) 7.5 earthquake of 1992 reveal an increase in seismic velocity with time. P, S, and fault zone trapped waves were excited by near-surface explosions in two locations in 1994 and 1996, and were recorded on two linear, three-component seismic arrays deployed across the Johnson Valley fault trace. The...

In general, Green’s functions obtained with seismic interferometry are only estimates of the true Green’s function, introducing uncertainties to the information recovered from them. However, there are still many cases in which the sourcereceiver geometries are suitable for seismic interferometry, usually allowing the recovery of kinematic information. Here we show how to use the singular value ...

Seismic tomography traditionally inverts for velocity field on a regularly spaced and fixed-in-space model grid. Such an approach is not able to adequately describe pinchouts or wedge-shaped velocities as commonly seen at basin boundaries, faulted rock beds, and back-arc mantle wedges. A regularly spaced model grid also requires the use of a large number of model variables. This paper shows a d...

3D seismic data acquisition brought a sea change in subsurface imaging. The bridge between geology and seismic is P/S wave velocity of different subsurfaces/lithology. The technique has acquired prime importance due to its inherent strength of determining seismic velocity/amplitudes of the different medium. Lithological variations estimations is possible due to proper Vp/Vs ratio or either velo...

I develop a unified approach for approximating phase and group velocities of qP seismic waves in a transversally isotropic medium with the vertical axis of symmetry (VTI). While the exact phase velocity expressions involve four independent parameters to characterize the elastic medium, the proposed approximate expressions use only three parameters. This makes them more convenient for use in sur...

Attenuation and velocity dispersion are strongly dependent on pore fluids, particularly partial gas saturation, and thus could become valuable direct hydrocarbon indicators. Unfortunately, application of these properties is not frequent due to incomplete understanding of the phenomena and lack of appropriate tools to extract the information. Laboratory measurements at frequencies and amplitudes...

We address the problem of estimating seismic velocities inside the earth which is necessary for obtaining seismic images in regular Cartesian coordinates. We derive a relation between the true seismic velocities and the routinely obtained so called ”time migration velocities”, which are some kind of mean velocities. We formulate an inverse problem and show that it is ill-posed. We suggest three...

Earth is inhomogeneous, which means its elastic characteristics change with depth. The seismic method employs the propagation of waves throughout the earth to locate different structures and stratigraphy. Understanding the wave propagation is an important matter in exploration seismology; therefore modeling of seismic wave is an important tool. To validate the interpreted earth model out of the...

[1] Like most other major continental rifts, the Baikal rift zone (BRZ) in Siberia is presumably underlain by a hot and partially molten mantle, which has a reduced seismic velocity relative to surrounding areas. Recent seismic tomography studies, however, gave conflicting results about the depth extent and even the existence of the low-velocity anomaly beneath the BRZ, suggesting that addition...