Mantle plumes are hypothetical hot, narrow mantle upwellings that are often invoked to explain hotspot volcanism with unusual geophysical and geochemical characteristics. The mantle plume is a well-established geological structure in computer modeling and laboratory experiments but an undisputed seismic detection of one has yet to be made. Vertically continuous low shear velocity anomalies in t...

We have developed seismic velocity models for the heated rock surrounding a tunnel in Yucca Mountain tuff and compared the results with field data obtained at the Yucca Mountain drift scale test DST facility from 1998 to 2002. During that time, the tunnel was heated to replicate the effects of long-term storage of decaying nuclear waste and to study the effects of extreme temperatures on the su...

Seismic analysis of data from the Blake Outer Ridge indicates the presence of hydratebearing sediments overlaying gas-saturated sediments in this region. In an attempt to determine possible lateral and vertical variations of the hydrate and gas sediments, I performed a 2-D velocity analysis along two approximately perpendicular seismic lines. Subsequent determination of the seafloor and BSR ref...

Seismic velocity changes and nonvolcanic tremor activity in the Parkfield area in California reveal that large earthquakes induce long-term perturbations of crustal properties in the San Andreas fault zone. The 2003 San Simeon and 2004 Parkfield earthquakes both reduced seismic velocities that were measured from correlations of the ambient seismic noise and induced an increased nonvolcanic trem...

The instrumental seismic intensity of Japan Meteorological Agency (JMA) uses three types of filters which consist of high-cut, low-cut and period functions. An extended function of the low-cut filter is used to evaluate the effect of long-period range on seismic intensity in the paper. An asymptotic filter processing of acceleration in the extended function is proposed to express seismic intens...

The high water storage capacity of minerals in Earth's mantle transition zone (410- to 660-kilometer depth) implies the possibility of a deep H2O reservoir, which could cause dehydration melting of vertically flowing mantle. We examined the effects of downwelling from the transition zone into the lower mantle with high-pressure laboratory experiments, numerical modeling, and seismic P-to-S conv...

Under operator, matrix and inverse theory, seismic-wave imaging can be considered a unified process—mapping from data space to model space. The main topics in seismic-wave imaging include (1) seismic-data interpolation, regularization and redatuming, which mainly decrease the imaging noise; (2) seismic-wave illumination analysis, which predicts whether a target reflector can be imaged and evalu...

At an EOR field in South Oman an extensive synthetic modeling study was done in order understand steam flow behaviour within the reservoir. To understand the permeability distribution within the steam flooded zone, a simulated “Close-the-Loop” workflow was executed based on scenario modeling that relates changes in acoustic properties (velocity and density) with those in reservoir properties su...

We used continuous recordings in Sichuan, China to track the temporal change in elastic properties of the medium, namely the seismic speed, at a regional scale in a 2 year period which includes the great Wenchuan Mw 7.9 earthquake. The data are recorded by a temporary network of 156 broad-band seismographs, in a 200km × 200km region that covers the southern 2/3 of the fault system activated dur...

1 T a b l e o f C o n t e n t s Abstract i i Acknowledgments viii Problem and Thesis Objective I Review of Previous Work 2 Multi-Criteria Optimal Design 2 Reliability-Based Design Earthquake Identification 6 A Time Variant Approach to Performance-Based Engineering 9 Seismic Performance Evaluation For Steel Moment Frames 10 Optimal Probabilistic Seismic Demand Models For Typical Highway Overpass...