Despite the close links between the fields of time-reversed acoustics, seismic interferometry and Marchenko imaging, a number of subtle differences exist. This paper reviews the various focusing conditions of these methods, the causality/acausality aspects of the corresponding focusing wavefields, and the requirements with respect to omnidirectional/singlesided acquisition. INTRODUCTION It has ...

flow unit characterization plays an important role in heterogeneity analysis and reservoir simulation studies. usually, a correct description of the lateral variations of reservoir is associated with uncertainties. from this point of view, the well data alone does not cover reservoir properties. because of large well distances, it is difficult to build the model of a heterogenic reservoir, but ...

Fragility curves represent the probabilities that structural damages, under various levels of seismic excitation, will exceed the specified damage states by means of earthquake intensity damage relations. Conceptual aspects related to seismic vulnerability, damage and risk evaluation are discussed first, together with a short review of the most widely used possibilities for the seismic evaluati...

Plane-wave destruction filters originate from a local plane-wave model for characterizing seismic data. These filters can be thought of as a time–distance (T -X) analog of frequency-distance (F-X) prediction-error filters and as an alternative to T -X prediction-error filters. The filters are constructed with the help of an implicit finitedifference scheme for the local plane-wave equation. Sev...

Plane-wave destruction filters originate from a local plane-wave model for characterizing seismic data. These filters can be thought of as a T -X analog of F -X prediction-error filters and as an alternative to T -X prediction-error filters. The filters are constructed with the help of an implicit finite-difference scheme for the local plane-wave equation. On several synthetic and real-data exa...

The California Integrated Seismic Network uses a large array of expensive seismometers that measure ground motion. However, the network is unable to provide reliable real-time source estimation due to the sparseness of the sensors. The Community Seismic Network project at Caltech plans to create a dense seismic network by leveraging small, inexpensive accelerometers attached to personal compute...

most geologic changes have a seismic response but sometimes this is expressed only in certain spectral ranges hidden within the broadband data. spectral decomposition is one of the methods which can be utilized to help interpreting such cases. there are several time-frequency methods including: short-time fourier transform (stft), continuous wavelet transform (cwt), wigner-ville distribution (w...

Seismic tomography is a technique for illuminating the physical dynamics of the Earth by seismic waves generated by earthquakes or explosions. In both industry and academia, the seismic exploration does not yet have the capability of imaging seismic tomography in real-time and with high resolution. There are two reasons. First, at present raw seismic data are typically recorded on sensor nodes ...

limited seismic data quality and complex tectonics make for less than ideal interpretation conditions. however, modern geometric attributes including coherency has shown to be effective in showing the lateral extents of subtle and small-scale geologic features not usually visible in conventional seismic sections. this geometric attributes are better suited than some older generation seismic att...

is a collection of routines to draw surfaces, contours and so on. In this work we are presenting a version, that functions over work stations with the operative system UNIX, that count with the graphic ambiance X-WINDOW with the tools XLIB and OSF/MOTIF. This implant was realized for the work stations DEC 5000-200, DEC IPX, and DEC ALFA of the CINVESTAV (Center of Investigation and Adva...