A monopole or a dipole source in a fluid borehole generates acoustic waves, part of which propagate along the borehole and the other part enter the formation propagating as Por S-waves. The refracted waves propagating along the borehole wall are used to determine Pand S-wave velocities. However, a significant fraction of the seismic energy radiates into the formation. In this laboratory study, ...

The time-arrival location of seismic P-wave is an important problem in the seismic research field. The modulus maxima of wavelet transform is a useful method for picking up the singularities of function. For applying the modulus maxima method to investigate the arrival time, it is necessary to eliminate the influence of random factors. Based on standard deviation, we present a method to reduce ...

The practical limits on resolution of images from seismic or radar (electromagnetic) data depend on the spectrum of the source pulse, the incompleteness of the recording geometry, and the fidelity with which one can model the reference medium. These factors together prevent one from recovering a point image from data produced by a point diffractor in a given body. A simple imaging formula quant...

Long earthquake sequences are generated using the 2D physically based lattice solid numerical model in a system representing an evolving fracture zone of the Earth's crust subjected to shear. Cycles of seismic activity are observed in which the rate of seismic energy release of simulated earthquakes accelerates in the lead-up to the largest events. During a cycle, the cumulative number of event...

Introduction: Several experiments performed by the astronauts on the Moon (e.g., the Apollo Lunar Surface Experiments Package, ASLEP), and proposed experiments as ground-prep for the return of humans to the Moon (RPLP-2/LPRP-2) involve the use of seismic (acoustic) energy for exploration. These seismic signals can be used for a wide array of purposes, from imaging the Lunar interior to detectin...

Energy calculations are generally made through an empirical application of the famihar Gutenberg-Richter energy-magnitude relationships. The precise physical significance of these relationships is somewhat uncertain. We make use here of the recent improvements in knowledge about the earthquake source to place energy measurements on a sounder physical basis. For a rumple trapezoidal far-field di...

[1] We relate seismologically observable parameters such as radiated energy, seismic moment, rupture area, and rupture speed to the dynamics of faulting. To achieve this objective, we computed the radiated energy for 23 subduction zone earthquakes recorded between 1992 and 2001; most of these earthquakes have a magnitude Mw > 7.5, but we also included some smaller (Mw 6.7) well-studied subducti...

A careful analysis of low-frequency seismic events on Soufrièere Hills volcano, Montserrat, points to a source mechanism that is non-destructive, repetitive, and has a stationary source location. By combining these seismological clues with new field evidence and numerical magma flow modelling, we propose a seismic trigger model which is based on brittle failure of magma in the glass transition....

This paper proposes a method for the prediction of pore size values in hydrocarbon reservoirs using 3D seismic data. To this end, an actual carbonate oil field in the south-western part ofIranwas selected. Taking real geological conditions into account, different models of reservoir were constructed for a range of viable pore size values.  Seismic surveying was performed next on these models. F...

in this paper the traditional covering plaster of masonry buildings is supplied with polypropylene and steel fiber to enhance their seismic behavior. the plaster mix proportion is determined by some initial mortar tests. also, one story, single span masonry building specimen plastered with different mortars is tested on a shaking table 8 times under a seismic input and the performance of the sp...