We extract downward-propagating Pand S-waves from industrial noise generated by human and/or machine activity at the surface propagating down a borehole at Cold Lake, Alberta, Canada, and measure shear-wave splitting from these data. The continuous seismic data are recorded at eight sensors along a downhole well during steam injection into a 420–470-m-deep oil reservoir. We crosscorrelate the w...

AlfvŽn waves are ubiquitous in space plasmas and are the means by which information about changing currents and magnetic fields are communicated. Shear AlfvŽn waves radiated from sources with cross field scale size on the order of the electron inertial length, δ = c/ωpe, have properties which differ considerably from planar Magneto-hydrodynamic waves. Currents of cross field size , δ, are commo...

Away from surface and bottom boundary layers turbulent mixing is primarily driven by breaking internal waves. While internal wave energy is generated mostly in the form of large-scale waves (typically internal tides), it is the smallest-scale internal waves that break through shear or convective instabilities to produce turbulence. When waves are reasonably linear (as opposed to, for example, s...

Simplified asymptotic equations describing the resonant nonlinear interaction of equatorial Rossby waves with barotropic Rossby waves with significant midlatitude projection in the presence of arbitrary vertically and meridionally sheared zonal mean winds are developed. The three mode equations presented here are an extension of the two mode equations derived by Majda and Biello [1] and arise i...

The behavior of elastic waves in a three-dimensional isotropic incompressible material is studied. Unlike compressible elastodynamics, where there are nonlinear interactions of shear and pressure waves, with incompressible elastodynamics the only waves present are shear waves. In an isotropic system, shear waves are linearly degenerate, and therefore global solutions to the perturbative incompr...

A new conceptual non-thermal anti-icing system for helicopter rotor blades is introduced. Theoretical calculations predict that certain ultrasonic modes generated by horizontal shear waves produce sufficient interface stresses between a host structure and ice to remove the accreted ice layer. Experimentally obtained ultrasonic shear dispersion curves are compared to theoretical predictions for ...

It is demonstrated that an AT-cut quartz crystal driven in the thickness-shear-wave mode and typically used as a sensor to monitor the viscoelastic shear-wave properties of a fluid also produce longitudinal pressure waves. Unlike the shear wave, these waves are capable of long-range propagation through the fluid and of reflection at its boundaries, notably at an outer fluid–air interface. They ...

Surface waves, named here as Dyakonov–Tamm waves, can exist at the planar interface of an isotropic dielectric material and a chiral sculptured thin film (STF). Due to the periodic nonhomogeneity of a chiral STF, the range of the refractive index of the isotropic material is smaller but the range of the propagation direction in the interface plane is much larger, in comparison to those for the ...

Waves associated to large scale oceanic motions are gravity waves (Poincaré waves which disperse fast) and quasigeostrophic waves (Rossby waves). In this Note, we show by semiclassical arguments, that Rossby waves can be trapped and we characterize the corresponding initial conditions.