Seismic inversion of soil damping and stiffness using multichannel analysis of surface wave measurements in the marine environment

Determination of soil material damping is known to be difficult and uncertain, especially in the offshore environment. Using an advanced inversion methodology based on multichannel spectral analysis, Scholte and Love wave measurements are used to characterize subsea soil from a North Sea site. After normalization, a determinant-based objective...

Application of seismic interferometry by multidimensional deconvolution to ambient seismic noise recorded in Malargüe, Argentina

Obtaining new seismic responses from existing recordings is generally referred to as seismic interferometry (SI). Conventionally, the SI responses are retrieved by simple crosscorrelation of recordings made by separate receivers: one of the receivers acts as a ‘virtual source’ whose response is retrieved at the other receivers.When SI is applied...

Seismic attenuation analyses of fracturing in reservoir rocks

In this study seismic wave velocity and seismic wave attenuation in dry Bentheimer sandstone, Indiana limestone, and Whitby shale are studied while continuously deforming and therefore increasingly fracturing the rock samples up until macroscopic failure. A pulse transmission technique at a central frequency of 1 MHz is used in combination with...

Models for seismic wave propagation in periodically layered porous media

Several models are discussed for seismic wave propagation in periodically layered poroelastic media where layers represent mesoscopic-scale heterogeneities that are larger than the pore and grain sizes but smaller than the wavelength. The layers behave according to Biot’s theory. Wave propagation normal to the layering is considered and the...

Upscaling in porous media: Consequences of reducing the phase on the dynamic behavior of a homogenized medium

Effective-medium approaches are widely used to model initially heterogeneous systems: it saves computational time. In poroelasticity (two-phase media), it is advantageous to use one-phase effective medium if possible: it simplifies computations even more. In this paper we discuss situations where phase reduction introduces significant inaccuracy...

On estimating attenuation from the amplitude of the spectrally whitened ambient seismic field

Measuring attenuation on the basis of interferometric, receiver-receiver surface waves is a non-trivial task: the amplitude, more than the phase, of ensemble-averaged cross-correlations is strongly affected by non-uniformities in the ambient wavefield. In addition, ambient noise data are typically pre-processed in ways that affect the amplitude...

Generalized minimum-phase relations for memory functions associated with wave phenomena

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...

Monitoring changes in velocity and Q using non-physical arrivals in seismic interferometry

Application of seismic interferometry to records from receivers at the Earth’s surface from sources in wells retrieves the reflection response measured at the receivers as if from virtual sources located also at the surface. When the wavefields experience intrinsic losses during propagation, non-physical arrivals (ghosts) would appear in the...

True-Amplitude Seismic Imaging Beneath Gas Clouds

A gas cloud is a region of gas accumulation in the subsurface, which can severely deteriorate the seismic data quality from deeper reflectors. Due to complex wave propagation through the anomaly and the resulting transmission imprint on the reflections from below this area, the image below the gas cloud is usually not properly recovered. The...

An ambiguity in attenuation scattering imaging