[1] We measure direction and amplitude of ocean-generated continuous seismic noise in the western United States. Slowness direction of the noise is determined using array beamforming, and particle motion direction from individual three-component stations. We find two surprising results. First, the noise is highly monodirectional at all sites, regardless of coastal distance. A single narrow gene...

We introduce a novel finite-difference (FD) approach for seismic wave extrapolation in time. We derive the coefficients of the finite-difference operator from a lowrank approximation of the space-wavenumber, wave-propagator matrix. Applying the technique of lowrank finite-differences, we also improve the finite difference scheme of the two-way Fourier finite differences (FFD). We call the new o...

We introduce a novel technique for seismic wave extrapolation in time. The technique involves cascading a Fourier Transform operator and a finite difference operator to form a chain operator: Fourier Finite Differences (FFD). We derive the FFD operator from a pseudo-analytical solution of the acoustic wave equation. 2-D synthetic examples demonstrate that the FFD operator can have high accuracy...

Defining the oceanic lithosphere as a thermal boundary layer allows to explain, to first order, age-dependent bathymetry and isotropic wave speeds. In contrast, SS precursors and receiver functions suggest a subhorizontal interface within this layer, on top of a radially anisotropic zone. Comparing a suite of geodynamic scenarios against surface wave dispersion data and seismic discontinuities,...

[1] Recent studies attribute land double-frequency (DF) microseism observations to deep water generation. Here we show that near-coastal generation is generally the dominant source region. This determination is based on observations at land and ocean seismic stations, buoys, gravity-wave hindcasts, and on beamforming results from continental seismic arrays. Interactions between opposing ocean w...

We use multi-channel analysis of surface waves (MASW) on seismic data in an attempt to test data acquisition parameters and compare those results to reaffirm existing general theoretical recommendations and rules of thumb. Of particular interest were optimum seismic receiver spread size, minimum and maximum receiver offsets and dominant geophone frequency for best-case fundamentalmode dispersio...

Elastic anisotropy is present where the speed of a seismic wave depends on its direction. In Earth's mantle, elastic anisotropy is induced by minerals that are preferentially oriented in a directional flow or deformation. Earthquakes generate two seismic wave types: compressional (P) and shear (S) waves, whose coupling in anisotropic rocks leads to scattering, birefringence, and waves with hybr...

In general, Green’s functions obtained with seismic interferometry are only estimates of the true Green’s function, introducing uncertainties to the information recovered from them. However, there are still many cases in which the sourcereceiver geometries are suitable for seismic interferometry, usually allowing the recovery of kinematic information. Here we show how to use the singular value ...

The conversion between seismic and electromagnetic energies was discovered in a fluidfilled porous formation. When seismic waves propagate through a fluid-saturated porous formation, relative motion between the pore fluid and the solid matrix is generated and cation motion in the fluid is formed. The streaming electric current induces electromagnetic waves in the formation. There is an opposite...