A numerical method is proposed to simulate the propagation of transient poroelastic waves across 2D heterogeneous media, in the low frequency range. A velocity-stress formulation of Biot’s equations is followed, leading to a first-order system of partial differential equations. This system is splitted in two parts: a propagative one discretized by a fourth-order ADER scheme, and a diffusive one...

A RECENT seismic refraction profile1 in 2,800 fm. (5.1 km.) at latitude 34° 00' N, longitude 66° 30' W, in the Atlantic Ocean proved that basement rocks having a velocity of 7.58 km/sec. for compressional waves were covered by 1.37 km. of sediment. We tentatively identified this velocity with either the P n velocities used in earthquake seismology for the ultra basic layer immediately beneath t...

Otoacoustic emissions, sounds generated by the inner ear, are widely used for diagnosing hearing disorders and studying cochlear mechanics. However, it remains unclear how emissions travel from their generation sites to the cochlear base. The prevailing view is that emissions reach the cochlear base via a backward-traveling wave, a slow-propagating transverse wave, along the cochlear partition....

In this study, eighteen compressional P-wave seismic refraction profiles survey was conducted on the western side of Gulf Suez, Egypt, to map bedrock topography, which is vital information in foundation pole placement and design for large factory construction. The configuration consists 10 metres geophone intervals (12 24 channels) with a total length 3150 length. wave velocity distribution rev...

optimization of reservoir parameters is an important issue in petroleum exploration and production. the ant colony optimization(aco) is a recent approach to solve discrete and continuous optimization problems. in this paper, the ant colony optimization is usedas an intelligent tool to estimate reservoir rock properties. the methodology is illustrated by using a case study on shear wave velocity...

The statistical correlation between the locations of hot spots at the surface of Earth and the distribution of ultra-low-velocity zones at the base of the mantle has about a 1 percent chance of arising randomly. This correlation is more significant than that between hot spots and negative velocity anomalies in tomographic models of deep mantle compressional and shear velocity. This correlation ...

Two-dimensional solutions of compressional Alfven eigenmodes (CAE) are studied in the cold plasma approximation. For finite inverse aspect ratio tokamak plasmas the two-dimensional eigenmode envelope is localized at the low magnetic field side with the radial and poloidal localization on the order of u / f i and u/*, respectively, where rn is the dominant poloidal mode number. Charged fusion pr...

it is well established that the seismic ground response of surface topographies may differ from those of free field motion during earthquakes. complex nature of seismic wave scattering by topographical structures can only be solved accurately and economically using advanced numerical methods under realistic conditions. among the numerical methods, the boundary element is a powerful numerical te...

Ab initio finite temperature molecular dynamics simulations have been used to calculate the elasticity of hcp-Fe, bcc-Fe, FeS and FeSi at core conditions. The calculated compressional wave velocities are in excellent agreement with the most recent experimental data. However, the calculated shear wave velocities of all phases studied are significantly higher than those inferred from seismology. ...