Waveform inversion is a velocity-model-building technique based on full waveforms as the input and seismic wavefields as the information carrier. Conventional waveform inversion is implemented in the data domain. However, similar techniques referred to as image-domain wavefield tomography can be formulated in the image domain and use a seismic image as the input and seismic wavefields as the in...

S U M M A R Y One way of developing a wave-equation approach to seismic imaging is based on the concept of downward continuation of observed surface reflection data. Seismic imaging is typically based on the single scattering approximation, and assumes the knowledge of a smooth background model in which the mentioned downward continuation is carried out using the double-squareroot (DSR) equatio...

[1] We present a high resolution 3 dimensional (3D) P wave velocity model for Tenerife Island, Canaries, covering the top of Teide volcano (3,718 m a.s.l.) down to around 8 km below sea level (b.s.l). The tomographic inversion is based on a large data set of travel times obtained from a 3D active seismic experiment using offshore shots (air guns) recorded at more than 100 onshore seismic statio...

iran is located between two lithospheric plates (euroasia, arabian) and these two plates converge toward each other with a velocity of 25 mm/yr rate. shortening that produced from this convergence with makran subductin shows faulting and folding in zagros orogenic belt, alborz and kopedagh in north and sliding in sum strike slip faults with north-south trend in central iran. the nw-se trending ...

Seismic tomography revealed a low seismic velocity (-5%) and high Poisson's ratio (+6%) anomaly covering about 300 square kilometers at the hypocenter of the 17 January 1995, magnitude 7.2, Kobe earthquake in Japan. This anomaly may be due to an overpressurized, fluid-filled, fractured rock matrix that contributed to the initiation of the Kobe earthquake.

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...

Velocity models used for wavefield-based seismic imaging represent approximations of the velocity characterizing the area under investigation. The real subsurface velocity can at best be approximated by the combination of a known background velocity and unknown multi-scale heterogeneities. Here, we model the multi-scale heterogeneity assuming a fractal behavior and compare this type of heteroge...

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...