Similar to horizontal earthquake motions, vertical motions are amplified depedent on the local site conditions which can be critical for safety of certain structures. Production natural gas in Groningen, Netherlands, results reservoir compaction causing low magnitude, shallow earthquakes recorded with a borehole seismic network. These recordings form an excellent data set understand how unconso...

The absorption of compressional and shear waves in many viscoelastic solids has been experimentally shown to follow a frequency power law. It is now well established that this type of loss behavior can be modeled using fractional derivatives. However, previous fractional constitutive equations for viscoelastic media are based on temporal fractional derivatives. These operators are non-local in ...

Nonlinear mixing and harmonic generation of compressional waves were studied in a 2D Yukawa (screened Coulomb) triangular lattice. The lattice was a monolayer of highly charged polymer microspheres levitated in a plasma sheath. Two sinusoidal waves with different frequencies were excited in the lattice by pushing the particles with modulated Ar+ laser beams. Waves at the sum and difference freq...

Previous work from our laboratory showed that the widely reported decrease in phase velocity with frequency (negative dispersion) for ultrasonic waves propagating through trabecular bone can arise from the interference of two compressional waves, each of which exhibits a positive dispersion. Previous simulations suggest that Bayesian probability theory can be employed to recover the material pr...

formulation is given in terms of the coupling of the fluctuating axial fields (Ẽz ,B̃z) and incorporates shear and compressional Alfvén waves, drift waves, and ion acoustic waves. The kinetic response of the electrons includes pitch-angle scattering ~Lorentz model! and the ions are treated as a magnetized, cold fluid. Detailed quantitative comparisons of the theoretical predictions are made with...

We present a novel nonlinear mechanism for exciting a gravitational radiation pulse (or a gravitational wave) by dust magnetohydrodynamic (DMHD) waves in dusty astrophysical plasmas. We derive the relevant equations governing the dynamics of nonlinearly coupled DMHD waves and a gravitational wave (GW). The system of equations is used to investigate the generation of a GW by compressional Alfvén...

SUMMARY The geophysical detection of magma bodies and the estimation dimensions, physical properties volume fraction each phase composing is required to improve forecasting volcanic hazards understand transcrustal magmatism. We develop an analytical model calculate P waves velocity in a three-phase consisting crystals gas bubbles suspended viscous melt. apply our speed sound as function tempera...