Velocity model estimation from seismic data using prestack depth migration is an un-derdetermined problem: there are many subtly diierent models which are not kinematically equivalent. As these models can give rise to dramatically diierent interpretations and decisions there is a clear need for a selection criterion in order to choose the "best" (i.e. geologically most plausible) one. Interpret...

Accurate earthquake source parameters such as fault mechanism, depth, and moment magnitude are not only important in seismic-hazard assessment, but also are crucial to studies of earthquake rupture processes and seismotectonics. Although large earthquakes (Mw 7+) may cause substantial damage, they occur less frequently. In contrast, moderate earthquakes (Mw 5.0–6.5) occur with much higher frequ...

Full waveform inversion of a p ? marine data set from the Gulf of Mexico provides estimates of the long-wavelength P-wave background velocity, anisotropic seismic source, and three high-frequency elastic parameter reeectivities which explain 70% of the total seismic data and 90% of the data in an interval around the gas sand target. The forward simulator is based on a plane-wave viscoelastic mo...

Gas-hydrates are crystalline form of water and methane that form at high pressure and low temperature. They have attracted the global attention due to their wide-spread occurrences in the permafrost and outer continental margins; potential as major energy resources; role in climate change etc. It is estimated that the carbon in gas-hydrates is two times the carbon content in fossil fuel reserve...

Full waveform inversion of a p-r marine data set from the Gulf of Mexico provides estimates of the longwavelength P-wave background velocity, anisotropic seismic source, and three high-frequency elastic parameter refiectivities that explain 70% of the total seismic data and 90% of the data in an interval around the gas sand target. The forward simulator is based on a planewave viscoelastic mode...

impedance (AI) and a parameter related to shear-wave velocity from seismic data, our ability to discriminate between different lithologies and fluid phases will increase. Prestack inversion on individual CDP gathers and inverting directly for VP, VS, and density have been tested in several ways, but the estimated parameters are often poorly determined. A more robust approach is to apply poststa...

Kirchhoff inversion theory tells us that reflection data provides information about the Fourier transform of the reflectivity function at each point in the illuminated subsurface. Thus, inversion formulas expressed as integrals in image point coordinates that closely characterize that Fourier domain are attractive for their relative simplicity. On the other hand, integrals over source/receiver ...

As oil and gas exploration moves into deeper offshore areas, Shallow Water Flow (SWF) from overpressured, unconsolidated/uncemented sands becomes a high profile drilling hazard. Laboratory measurements show that SWF sands have high seismic compressional to shear velocity (Vp/Vs) ratios. Thus, elastic seismic inversion for Vp/Vs provides a quantitative identification of SWF sands, and predrill p...

We present statistical and interval techniques for evaluating the uncertainties associated with geophysical tomographic inversion problems, including estimation of data errors, model errors, and total solution uncertainties. These techniques are applied to the inversion of traveltime data collected in a cross well seismic experiment. The inversion method uses the conjugate gradient technique, i...