We address the problem of time to depth conversion of time migrated seismic images and show that the Dix velocities estimated from time migration velocities are the true seismic velocities divided by the geometrical spreading of image rays. We pose an inverse problem: to find seismic velocities from Dix velocities and suggest two algorithms for solving this problem. One algorithm is based on th...

Continental intraplate seismicity seems often episodic, clustered, and migrating. The observed seismicity shows both spatial clustering in seismic zones and scattering across large plate interiors, temporal clustering followed by long periods of quiescence, and migration of seismicity from one seismic zone to another. Here, we explore the complex spatiotemporal patterns of intraplate seismicity...

Seismic imaging produces images of contrasts in physical parameters in the subsurface, e.g., velocity or impedance. To build such images, a background model describing the wave kinematics in the earth is necessary. In practice, the structural image and background velocity model are unknown and have to be estimated from the acquired data. Migration velocity analysis deals with estimation of the ...

Many processes in seismic data analysis and seismic imaging can be identified with solution operators of evolution equations. These include data downward continuation and velocity continuation. We have addressed the question of whether isochrons defined by imaging operators can be identified with wavefronts of solutions to an evolution equation. Rays associated with this equation then would pro...

With the development of computational power, there has been an increased focus on data-fitting related seismic inversion techniques for high fidelity seismic velocity model and image, such as full-waveform inversion and least square migration. However, though more advanced than conventional methods, these data fitting methods can be very expensive in terms of computational cost. Recently, vario...

Seismic imaging based on single-scattering approximation is based on analysis of the match between the source and receiver wavefields at every image location. Wavefields at depth are functions of space and time and are reconstructed from surface data either by integral methods (Kirchhoff migration) or by differential methods (reverse-time or wavefield extrapolation migration). Different methods...

One of the risks of large-scale geologic carbon sequestration is the potential migration of fluids out of the storage formations. Accurate and fast detection of this fluids migration is not only important but also challenging, due to the large subsurface uncertainty and complex governing physics. Traditional leakage detection and monitoring techniques rely on geophysical observations including ...

In this letter, the solutions to three seismic processing problems are presented that exploit the multiscale and multi-angular properties of the curvelet transform. Data regularization, multiple removal, and restoration of migration amplitudes are all formulated in terms of a sparsity promoting program that employs the high degree of sparsity attained by curvelets on seismic data and images. Fo...