AIM To explore the relationship of liver and spleen shear wave velocity in patients with liver cirrhosis combined with portal hypertension, and assess the value of liver and spleen shear wave velocity in predicting the prognosis of patients with portal hypertension. METHODS All 67 patients with liver cirrhosis diagnosed as portal hypertension by hepatic venous pressure gradient in our hospita...

We present high-resolution compressional wave to shear wave velocity ratios (Vp∕Vs) beneath Kı̄lauea’s summit caldera by applying an in situ estimation method using waveform cross-correlation data for three similar earthquake clusters. We observe high Vp∕Vs ratios (1.832 and 1.852) for two event clusters surrounded by the low background Vp∕Vs value of 1.412 at ∼2.1 km depth below the surface. Th...

The observed shear-wave velocity VS in Earth's core is much lower than expected from mineralogical models derived from both calculations and experiments. A number of explanations have been proposed, but none sufficiently explain the seismological observations. Using ab initio molecular dynamics simulations, we obtained the elastic properties of hexagonal close-packed iron (hcp-Fe) at 360 gigapa...

Abstract This paper considers the uncertainty in shear wave velocity (Vs) of soil and rock profiles for use earthquake site response calculations. is an important contributor to response, which turn ground motions seismic hazard. The begins with a discussion different types how they are characterized probabilistic hazard analysis, this differentiation particularly ambiguous case properties. fol...

Multicomponent seismic images are composed of different combinations of downgoing and upgoing wavefields. Each wave mode has different propagation velocity and polarization direction and thus carries unique, direction-dependent information about the subsurface. Differences in propagation velocity cause events in convertedor shear-wave images to appear at later times than the compressional-wave ...

Dispersion of Love waves is studied in a self-reinforced layer lying over an elastic non-homogeneous half space. The wave velocity equation is found to be in perfect agreement with the corresponding classical result when the anisotropic elastic parameters tend to zero. Dispersion curves for the shear wave velocity ratio and the effect of anisotropy and heterogeneity have been shown graphically....

Five parameters are needed to describe VTI anisotropy in 2-D elastic media. With conventional streamer data, an optimal parameterization for full-waveform inversion (FWI) consists in using the horizontal velocity vh, the anellipicity parameter η, and the parameter that relates the horizontal-to-vertical velocity, ε. This parameterization, derived with a pseudo-acoustic formulation of the wave e...

Shear wave velocities from full waveform acoustic logs were determined at DSDP Site 613 using the spectral ratio inversion method. Discrete shear wave velocities for a 350 meter interval at 0.5-2 meter depth increments were calculated. Shear wave velocities were not evaluated for the upper 130m of the log because of data recording problems. The sediments of Site 613 represent a progression from...

Ab initio molecular dynamics simulations were performed to investigate the elasticity of cubic CaSiO3 perovskite at high pressure and temperature. All three independent elastic constants for cubic CaSiO3 perovskite, C11, C12, and C44, were calculated from the computation of stress generated by small strains. The elastic constants were used to estimate the moduli and seismic wave velocities at t...