High frequency (8-15 KHz) seismic waves that travel between two boreholes are used to probe the detailed structure of rock in the Los Alamos Scientific Labora:ory Fenton Hill geothermal energy reservoir. Because of the unique ability to control fluid pressure in the reservoir, we can make in situ seismic measurements at different fluid pressures and apply the results of pertinent laboratory mea...

Reverse-time migration is a two-way time-domain finite-frequency technique that accurately handles the propagation of complex scattered waves and produces a band-limited representation of the subsurface structure that is conventionally assumed to be linear in the model parameters. Because of this underlying linear single-scattering assumption, most implementations of this method do not satisfy ...

Landslides triggered by strong earthquakes often caused most of the global damage and most of all casualties related to the events, such as shown by the M = 7.7 Peru earthquake in 1970, by the M = 7.6 El Salvador earthquake in 2001 or by the M = 7.4 Khait (Tajikistan) earthquake in 1949. The obvious impact of a landslide on the population is directly related to its movement. Yet, prediction of ...

In this paper, we describe a commercial vision system for the digitisation and extraction of horizons drawn with coloured pencils on seismic sections. The system combines image processing and statistical pattern recognition techniques together with a graphical user interface to provide a solution that is more accurate, faster and involves less user interaction than the manual method.

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post failure analysis of massive structure infers that soil-structure interaction (ssi) is a crucial phenomena influencing seismic response of massive structures. cable-stayed bridge’s popularity and numbers are increasing now-a-days because of economical longer span & aesthetic good look. the current paper examines the effect of depth of foundation on seismic response of cable-stayed bridg...

Performance based seismic design (PBSD) is a cogent design approach that allows engineers to design structures with a predictable seismic performance for a specified level of hazard. In contrast to the conventional limit state or strength and serviceability based design in which a structure is designed to withstand severe load combinations and be functional under normal load conditions, PBSD go...

Seismic anisotropy is an efficient way to investigate the deformation field within the upper mantle. In the framework of rigid tectonic plates, we make use of recent tomographic models of azimuthal anisotropy for deriving the best rotation pole of the Pacific plate in the uppermost 200km of the mantle. It is found to be in good agreement with current plate motion (NUVEL1, HS3 and NNR). However,...

This paper reports on the damage of Wushi bridge in a recent Taiwan 921 earthquake. Damage to Wushi bridge appeared in the superstructure, the substructure and the approaches. Typical types of damage are discussed and illustrated in this paper. A review of the bridge design specifications in Taiwan is also presented to give the background on the seismic design of Taiwan highway bridges.

Pletser et al. performed a seismic-refraction survey on Devon Island with the goal of assessing the feasibility of astronauts carrying out such operations on Mars to detect subsurface water. We demonstrate that the seismic analysis is fundamentally flawed. The survey performed in this test will likely bear little resemblance to future crewed geophysical surface operations, and better methods ex...