A number of tools and advancements have been developed over the course of the last decade for public use in regional seismic disaster planning. This paper addresses some of the considerations and approaches that influence state-of-theart regional seismic loss assessments and risk management, with particular emphasis on approaches applied to areas having potentially high consequence but low prob...

This paper describes new procedures for processing data acquired with 4C seismic sensors distributed as horizontal arrays on the seafloor and seismic sources positioned either at the sea surface or on the seafloor. Two types of images can be produced from 4C seismic data: a P-P image and a P-SV (converted-shear) image. For P-P imaging, the large elevation difference between deep-water seafloor ...

[1] Seismic studies of the deep mantle suffer from the fact that the probing seismic waves must traverse the highly heterogeneous and poorly resolved shallow structure. One potential way forward is to develop highresolution models of the crust and upper mantle using other information. Here we describe the construction of a geodynamic a priori model of some aspects of upper mantle seismic veloci...

We investigate a pseudo-seismic approach based on the so-called inverse Q-transform as an alternative way of processing transient electromagnetic (TEM) data. This technique transforms the diffusive TEM response into that of propagating waves obeying the standard wave-equation. These transformed data can be input into standard seismic migration schemes with the potential of giving higher resolut...

High-precision modeling of seismic-wave propagation in heterogeneous media is very important to seismological investigation. However, such modeling is one of the difficult problems in the seismological research fields. For developingmethods of seismic inversion and high-resolution seismic-wave imaging, the modeling problem must be solved as perfectly as possible. Moreover, for long-term computa...

Seismic images and the geologic information they provide contribute significantly to our understanding of the earth’s subsurface. In this thesis, I focus on methods relevant for constructing and interpreting seismic images, including methods for velocity estimation, seismic imaging, and interpretation, which together address key aspects of reflection seismic data processing. Specifically, I pro...

High-resolution seismic reflection techniques successfully imaged structural features associated with a sinkhole that formed catastrophically as a result of dissolution of the Permian-age Hutchinson Salt in central Kansas. Symmetric steep sided chimney structure formed instantaneously, which over time has continued to gradually enlarge and elongate to the east, forming an open bowl. Orthogonal ...

S U M M A R Y The resolution of the 3-D density structure in the Earth’s deep interior has long eluded geoscientists. High-quality data from digital seismic instruments emplaced this decade have renewed interest in the measurement of low-frequency Earth normal modes with the goal of extracting heterogeneous density structure. Here we perform a series of synthetic experiments aimed at investigat...

elastic energy of seismic wave is lost through propagation into the earth. various factors affect seismic energy. some of them are frequency independent and recovered in processing steps. but other factors such as intrinsic absorption of medium are frequency dependent and cannot be recovered by processing methods. lost energy caused by these factors is called attenuation. there are various meth...

Data coverage, expressed as path density of Rayleigh wave group velocities, is shown in Figure 1. Coverage is best at intermediate periods, and reduces particularly at very long periods. It is also considerably lower for Love waves than for Rayleigh waves, especially at periods above about 100 sec. Resolution estimates are shown in Figure 2. Average resolution across the Paci c is about 600 km ...