I present a frequency-independent three-dimensional (3-D) compressional wave attenuation model (indicated by quality factor Qp) for the crust and uppermost mantle of Northern and central California. The tomographic inversion used t∗ values measured from amplitude spectra of 80,988 P wave arrivals of 3247 events recorded by 463 network stations through a 3-D seismic velocity model. The model has...

Two marine walkaway VSP lines are recorded by three-component receivers positioned in a dolomite layer. The layer has a high seismic velocity relative to the surrounding rocks and may be fractured. The recorded wavefield is analysed to determine whether this acquisition is suitable to image details of the internal structure of the layer. The principal arrivals in the wavefield are a dominant ho...

We present a frequency-independent three-dimensional (3-D) compressional wave attenuation model (indicated by the reciprocal of quality factor Qp) for Kı̄lauea Volcano in Hawai‘i. We apply the simul2000 tomographic algorithm to the attenuation operator t∗ values for the inversion of Qp perturbations through a recent 3-D seismic velocity model and earthquake location catalog. The t∗ values are me...

The petrophysical analysis of the early Eocene Sui Main Limestone (SML) has been conducted in Kharnhak-1 well for the prospect of the hydrocarbon exploration of the Khairpur-Jacobabad High, Middle Indus Basin, Pakistan. The petrophysical analysis of SML is carried out on the basis of well logs including gamma ray, spontaneous potential, resistivity, neutron, and density logs. These analyses lea...

S U M M A R Y Previous 2-D modelling of seismic waveforms and traveltimes has revealed a large-scale ridge-like velocity anomaly beneath Africa, which is usually referred to as the African superplume. The structure starts from the southern Indian Ocean and extends northwestwards into the Atlantic Ocean, with its base on the core–mantle boundary. The structure has relatively sharp lateral bounda...

The evolution and viscous damping of cosmic magnetic fields in the early universe, is analysed. Using the fact that the fluid, electromagnetic, and shear viscous energy-momentum tensors are all conformally invariant, the evolution is transformed from the expanding universe setting into that in flat spacetime. Particular attention is paid to the evolution of nonlinear Alfvén modes. For a small e...

2014 A mechanism for the launching of acoustic bulk waves in narrow beams into a solid is discussed. The excitation is at the free surface or on the interface of a layered half-space for which the material of the layer has higher characteristic velocities than those of the substrate material. For a range of layer thickness greater than that corresponding to the cut-off value for the Rayleigh-li...

A theory of porous media with voids filled by two immiscible fluids should comply with Laplace’s law of capillary pressure at the pore level. For the convenience of practical use, it ideally should also involve only the generic elastic coefficients of the mineral grains and pore-filling fluids and avoid the use of “bulk” coefficients of the dry solid frame, whose measurement involves idealized ...