It is essential to use statistical models and theoretical analysis of the data for preparing comprehensive geological and seismic hazard mapping. A cellular automaton consists of an array of cells, each one of which has a finite number of possible states, together with a rule for updating all cells simultaneously based only on the states of neighboring cells. In the present paper, Ising cellula...

Seismic evaluations of many existing deck-truss bridges have revealed the vulnerability of their substructure and members of their superstructure. An innovative retrofit strategy developed by the authors includes replacement of the existing non-ductile end and lower-end bracing with ductile panels by incorporating energy dissipating devices to act as fuses, which can yield and dissipate energy ...

The solar seismic waves excited by solar flares (" sunquakes ") are observed as circular expanding waves on the Sun's surface. The first sunquake was observed for a flare of July 9, 1996, from the Solar and Heliospheric Observatory (SOHO) space mission. However, when the new solar cycle started in 1997, the observations of solar flares from SOHO did not show the seismic waves, similar to the 19...

Oilfield Review Summer 2010: 22, no. 2. Copyright © 2010 Schlumberger. For help in preparation of this article, thanks to Abdulmohsin Al-Dulaijan, South Rub Al-Khali Co. Ltd, South Rub Al-Khali, Saudi Arabia; Jarrah Al-Genai, Kuwait Oil Company, Kuwait City, Kuwait; Danny Burns, Beach Petroleum, Adelaide, South Australia, Australia; Daniele Colombo, Saudi Aramco, Dhahran, Saudi Arabia; Dennis C...

Analysis of the refracted arrivals on a seismic reflection profile recorded along the wall of a tunnel at an iron mine near Thabazimbi, South Africa, shows variations in P-wave velocity in dolomite away from the de-stressed zone that vary between 4.4 and 7.2 kmrs, though values greater than 5.8 kmrs predominate along most of the profile. The seismic velocities at the tunnel wall, however, vary ...

The ability to produce from low permeability, tight gas reservoirs is directly tied to the ability to repetitively perform successful hydraulic fracturing in a series of closely spaced wells. The key question is whether the induced fractures remain open and permeable, which is in part a function of the stress field and the emplacement of proppant. We study the ability to detect and characterize...

Shake table testing of a 1/5 scale model of a slender bridge steel truss pier that uses a controlled rocking approach as a means of seismic protection was conducted. The controlled rocking approach allows the pier to uplift from its base while passive energy dissipation devices steel yielding devices or fluid viscous dampers are implemented across the uplifting location to control the response....

We have carried out numerical simulations of seismic ground motion radiating from a mega-earthquake whose rupture process is governed by a multi-scale heterogeneous distribution of fracture energy. The observed complexity of the Mw 9.

Plans call for five T-phase stations to be installed as part of hydroacoustic segment of the International Monitoring System (IMS), for use in detecting nuclear explosions in the oceans. The ability to detect T-phase signals at the seismic T-phase stations relies on an understanding of the transition from ocean-borne acoustic energy to seismic energy. Observations of the seismic T-phase indicat...