Deep Earth Seismic Structure and Earthquake Source Processes from Long Period Waveform Modelling by Mark Paul Panning Doctor of Philosophy in Geophysics University of California at Berkeley Professor Barbara Romanowicz, Chair We model long-period seismic waveforms to investigate both the deep Earth velocity structure as well as earthquake source parameters. We utilize a normal modebased perturb...

Estimating an accurate velocity model is crucial for seismic imaging to obtain a good understanding of the subsurface structure. The objective of this thesis is to investigate methods of velocity analysis by optimizing seismic images. A conventional seismic image is obtained by zero-lag crosscorrelation of wavefields extrapolated from a source wavelet and recorded data on the surface using a ve...

Seismic reflection and refraction images illuminate the San Andreas Fault to a depth of 1 kilometer. The prestack depth-migrated reflection image contains near-vertical reflections aligned with the active fault trace. The fault is vertical in the upper 0.5 kilometer, then dips about 70 degrees to the southwest to at least 1 kilometer subsurface. This dip reconciles the difference between the co...

Seismic refraction profiles recorded layer. Crustal subsidence and periodic basaltic along the eastern Snake River Plain (ESRP) in southeastern Idaho during the 1978 YellowstoneSnake River Plain cooperative seismic profiling experiment are interpreted to infer the crustal velocity and attenuation (Q-i) structure of the ESRP. Travel-time and synthetic seismogram modeling of a 250 km reversed ref...

I present a frequency-independent 3D seismic attenuation model (indicated by Q−1 P ) for the crust of the Salton trough and the adjacent regions in southeastern southern California. The simul2000 tomographic algorithm was used to invert the frequency-independent attenuation operator t values measured from amplitude spectra of 23,378 P-wave arrivals of 1203 events through a recently developed 3D...

We address the problem of estimating seismic velocities inside the Earth which is necessary for obtaining seismic images in regular Cartesian coordinates. The main goals are to develop algorithms to convert time-migration velocities to true seismic velocities, and to convert time-migrated images to depth images in regular Cartesian coordinates. Our main results are three-fold. First, we establi...

Deciphering the origin of seismic velocity heterogeneities in the mantle is crucial to understanding internal structures and processes at work in the Earth. The spin crossover in iron in ferropericlase (Fp), the second most abundant phase in the lower mantle, introduces unfamiliar effects on seismic velocities. First-principles calculations indicate that anticorrelation between shear velocity (...

Wave-equation, finite-frequency imaging and inversion still face many challenges in addressing the inversion of highly complex velocity models as well as in dealing with nonlinear imaging e.g., migration of multiples, amplitude-preserving migration . Extended images EIs are particularly important for designing image-domain objective functions aimed at addressing standing issues in seismic imagi...

Nonlinear reverse-time migration is a modified reverse-time migration that accounts for the nonlinear relation between seismic data and model in order to image multiply scattered waves including multiples. The illumination of multiply scattered waves yields a representation of the Earth’s subsurface that is more sensitive to model parameters, which allows for advanced seismic interpretation. Th...

Vve examine seismic waves scattered from anisotropic heterogeneity with laboratory data and numerical modeling in order to develop modeling techniques for the characterization of fracture p'roperties in tight gas sands from surface seismic reflection data. Laboratory models representing features of a fractured reservoir were constructed using Phenolite (the "reservoir") embedded in a Lucite bac...