[1] We present first-principles results for elastic moduli (bulk, K, and shear, G) and acoustic velocities (compressional, VP, shear, VS, and bulk VΦ) of olivine (a) and wadsleyite (b) (Fex,Mg1 x)2SiO4, at high pressure (P) and temperature (T) with varying iron content (0≤ x≤ 0.125). Pressure and temperature derivatives of these properties are analyzed. We show that adding 12.5% of Fe in forste...

S U M M A R Y Seismic tomography has been one of the primary tools to image the interior of the earth and other elastic structures. To date the inversions of compressional (P) and shear (S) wave speeds have been carried out separately under the assumption that P traveltimes are affected only by the P wave speed of the elastic media and S traveltimes by the S wave speed. Using numerical and anal...

The propagation of surface waves in a fluid- saturated porous isotropic layer over a semi-infinite homogeneous elastic medium with an irregularity for free and rigid interfaces have been studied. The rectangular irregularity has been taken in the half-space. The dispersion equation for Love waves is derived by simple mathematical techniques followed by Fourier transformations.  It can be seen t...

it is very important to study and simulate s-wave structure for near surface (alluvium parts, in particular) owing to its direct relationship to urban facilities in geotechnical and earthquake engineering studies. so, in seismic microzonation, the first step is to study and identify s-wave pattern in alluvium in order to categorize different parts of cites according to s-wave velocity. current ...

A one dimensional, computational model for the propagation of ultra low frequency (ULF; 1–100 mHz) wave fields from the Earth’s magnetosphere through the ionosphere, atmosphere and into the ground is presented. The model is formulated to include solutions for high latitudes where the Earth’s magnetic field, (B0), is near vertical and for oblique magnetic fields applicable at lower latitudes. Th...

Qualitative and quantitative analysis of seismic waveforms sensitive to the core–mantle boundary (CMB) region reveal presence ultralow-velocity zones (ULVZs) that have a strong decrease in compressional (P) shear (S) wave velocity, an increase density within thin structures. However, understanding their physical origin relation other large-scale structures lowermost mantle are limited due incom...

We derive a generalized equation that governs the spreading of liquid films under high-frequency (MHz-order) substrate vibration in the form of propagating surface waves and show that this single relationship is universally sufficient to collectively describe the rich and diverse dynamic phenomena recently observed for the transport of oil films under such substrate excitation, in particular, R...

We study compressional pulsations in Pc5 frequency range observed in the dawn-side at distances of about 10 RE , close to the magnetic equator. We use data obtained during two events of conjunctions between Equator-S and Geotail: 1000–1700 UT on 9 March 1998, and 0200–0600 UT on 25 April 1998. In both events, pulsations are observed after substorm activity. The pulsations are antisymmetric with...

In shear wave far detection logging, dipole-source radiation is the main factor influencing amplitude of reflected waves. this paper, a method derived with far-field asymptotic solution to calculate waves in fluid-filled borehole. Then simulated under both low and high frequencies. addition, influences formation elastic parameters on are analyzed variations characteristics source frequency bore...