Seismic waves are non-stationary due to its propagation through the earth. Time-frequency transforms are suitable tools for analyzing non-stationary seismic signals. Spectral decomposition can reveal the non-stationary characteristics which cannot be easily observed in the time or frequency representation alone. Various types of spectral decomposition methods have been introduced by some resear...

Seismic denoising is a key step in seismic signal processing for enhancing the resolution of the seismic signal. In this paper, a seismic denoising method is introduced by using variational mode decomposition (VMD) combined with wavelet transform. VMD is used to decompose the seismic data into a series of intrisic mode functions (IMFs) from low frequency to high frequency. Since the noise is al...

An application of Bayes theorem to seismic signal ltering is implemented. A best basis strategy is derived as an hypothesis test with maximum entropy priors. Cost functionals are derived. In this approach the best basis is determined as the basis least likely to t the prior noise model. Sub-band varianace estimates contain all of the information regarding the background noise. A Bayes estimator...

Earthen dams and levees are prone to progressive failure through internal erosion of their structure. Internal erosion is often invisible to current methods of inspection until it manifests itself at the exterior surface. This study focuses on the novel use of passive seismic interferometry to monitor temporal changes in earthen embankments caused by internal erosion. This technique uses the am...

SUMMARY Temporal variations in the elastic behavior of the Earth's crust can be monitored through the analysis of the Earth's seismic response and its evolution with time. This kind of analysis is particularly interesting when combined with the reconstruction of seismic Green's functions from the cross-correlation of ambient seismic noise, which circumvents the limitations imposed by a dependen...

In seismic data processing, random noise seriously affects the seismic data quality and subsequently the interpretation. This study aims to increase the signal-tonoise ratio by suppressing random noise and improve the accuracy of seismic data interpretation without losing useful information. Hence, we propose a structureoriented polynomial fitting filter. At the core of structure-oriented filte...

Coda-wave interferometry is a technique to detect small seismic velocity changes using phase changes in similar waveforms from repeating natural or artificial sources. Seismic interferometry is another technique for detecting seismic velocity changes from cross-correlation functions of ambient seismic noise. We simultaneously use these two techniques to clarify seismic velocity changes at Sakur...

An analysis of a passh'e seismic method for subsur­face imaging is presenled. in which ambienl seismic noise is em­ployed as the source of iIIu,;"ination of undergro~nd scal~erers.The imaging algorithm can ,"corporate new data mto the '!'lagein a recursive fashion, which causes image background nOise todiminish over time. Under the assumption of spatially-incoherentambie...

There are two main approaches for pore pressure estimation: geological using basin modeling and geophysical using seismic velocity. In this paper, seismic velocity was used for pore pressure estimation. The impact of the input data quality in terms of signal-to-noise ratio (SNR) and frequency bandwidth on the accuracy of seismic velocity analysis and, ultimately, the reliability of pore pressur...