Multi-component acoustic characterization of porous media

The characterization of porous materials (e.g., sandstone) is very important for geotechnical and reservoir engineers. For this purpose, often use is made of acoustic waves that are sent through the medium. The desired material parameters can then be estimated from the measured signals. However, often only the velocity or the attenuation of the...

Source parameters and radiation efficiency for intermediate-depth earthquakes in Northeast Japan

We estimated source parameters of 216 intermediate-depth (65–150 km) earthquakes (Mw 4.0–7.0) in the Pacific slab beneath Japan along using Hi-net data. We made determinations of static stress drop, radiated energy and radiation efficiency, along with estimates of the whole path attenuation, to study the source scaling as a function of...

Global-scale seismic interferometry: Theory and numerical examples

Progress in the imaging of the mantle and core is partially limited by the sparse distribution of natural sources; the earthquake hypocenters are mainly along the active lithospheric plate boundaries. This problem can be approached with seismic interferometry. In recent years, there has been considerable progress in the development of seismic...

Seismic exploration?scale velocities and structure from ambient seismic noise (>1?Hz)

The successful surface waves retrieval in solid?Earth seismology using long?time correlations and subsequent tomographic images of the crust have sparked interest in extraction of subsurface information from noise in the exploration seismology. Subsurface information in exploration seismology is usually derived from body?wave reflections >?1?Hz,...

High-resolution lithospheric imaging with seismic interferometry

In recent years, there has been an increase in the deployment of relatively dense arrays of seismic stations. The availability of spatially densely sampled global and regional seismic data has stimulated the adoption of industry-style imaging algorithms applied to converted- and scattered-wave energy from distant earthquakes, leading to...

Effective poroelastic model for one-dimensional wave propagation

An effective poroelastic model is proposed that describes seismic attenuation and dispersion in periodically layeredmedia. In this model, the layers represent mesoscopic-scale heterogeneities (larger than the grain and pore sizes but smaller than the wavelength) that can occur both in fluid and solid properties. The proposed effectivemedium is...

Extraction of P-wave reflections from microseisms

The last few years there has been a growing number of body-wave observations in noise records. In 1973 Vinnik conjectured that P-waves would even be the dominant wavemode, at epicentral distances of about 40 degrees and onwards from an oceanic source. At arrays far from offshore storms, surface waves induced by nearby storms would not mask the...

Retrieval of Elastodynamic Reflections From Passive Double-Couple Recordings

Virtual Green's functions obtained by seismic interferometry (SI) can provide valuable reflectivity data that can complement tomographic inversion schemes. However, virtual reflections are affected by illumination irregularities that are typical of earthquake-induced wavefields recorded by the receiver array. As a consequence, irregular...