S U M M A R Y We demonstrate that the distribution of seismic noise sources affects the accuracy of Green’s function estimates and therefore isotropic and anisotropic tomographic inversions for both velocity and attenuation. We compare three methods for estimating seismic noise source distributions and quantify the potential error in phase velocity, azimuthal anisotropy and attenuation estimate...

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...

Geophysical imaging provides a unique perspective on metasomatism, because it allows the present day fluid distribution in the Earth’s crust and upper mantle to be mapped. This is in contrast to geological studies that investigate midcrustal rocks have been exhumed and fluids associated with metasomatism are absent. The primary geophysical methods that can be used are (a) electromagnetic method...

In the February 1991 issue of GEOPHYSICS, Anton Ziolkowski gives a scathing criticism of statistical wavelet estimation methods. Among other points, Ziolkowski questions the validity of the randomness assumption. This assumption allows statistical methods to estimate the seismic source wavelet autocorrelation from the seismic trace autocorrelation. In this study, we examine this traditional ass...

We introduce an open-source MATLAB software package, named Crazyseismic, for passive seismic data preprocessing. Built-in core functions such as seismic phase travel-time calculation and multichannel cross correlation significantly improve the efficiency of data processing. Compared with conventional command-line-style toolboxes, all functions in Crazyseismic are embedded in one single graphic ...

Recently, co-seismic seismic source characterization based on GPS measurements has been completed in near- and far-field with remarkable results. However, the accuracy of the ground displacement measurement inferred from GPS phase residuals is still depending of the distribution of satellites in the sky. We test here a method, based on the double difference (DD) computations of Line of Sight (L...

Seismic interferometry processing is applied to an active seismic survey collected on ocean bottom seismometers (OBS) deployed at 900-m water depth over a carbonate/ hydrates mound in the Gulf of Mexico. Common midpoint processing and stacking of the extracted Green’s function gives the subsurface PP reflectivity, with a horizontal resolution of half the receiver spacing. The obtained seismic s...

More robust seismic interpretation canbe donewhen an interpretation project uses both compressional (P) and shear (S)data rather thanusingonlyoneseismicmode,whether thatmodebeaPmodeoranSmode.Unfortunately, this fundamental interpretation principle is frustrated by the cost and difficulty of deploying S-wave sources and by the limited availability of direct-S sources. We introduce a new seismic ...

We have developed an inversion formulation for velocity and attenuation structure using seismic attributes, including envelope amplitude, instantaneous frequency and arrival times of selected seismic phases. We refer to this approach as AFT inversion for amplitude, (instantaneous) frequency and time. Complex trace analysis is used to extract the different seismic attributes. The instantaneous f...

Iran is located in a seismically active region and exposed to seismic activity from many seismic sources and active faults. Probabilistic seismic hazard assessment is the basis for many pre and postearthquake risk management issues. Definition and parameterization of active faults and seismic sources are among the most important aspect for reliable PSHA studies. In this paper an effort in desig...