Seismic coherence in the presence of signal time-delay fluctuations
Journal Title: Геофизический журнал - Year 2018, Vol 40, Issue 2
Abstract
One of the main seismic attributes widely used to identify and study lateral changes in the geological environment, such as pinch-outs, faults, fractured zones, and buried paleochannels, is the coherence of seismic images. In the article, a new method for calculation of this popular seismic attribute is proposed. It is based on a generalized mathematical model of the seismic image. The model allows for arbitrary variations of not only signal amplitudes and noise variances, but also residual signal time delays within a space-time window that slides along the image and wherein the coherence calculation is performed. The residual time delays are fluctuations in the arrival times of the signal after subtracting the trend approximated by first- or second-order polynomials. An iterative algorithm for an optimized estimation of the parameters of the generalized mathematical model of the seismic image, which are necessary for the new method of calculating coherence, is described. The algorithm uses deterministic regularization. The proposed method is tested and compared with one of the traditional analogs on synthetic data. Moreover, the new coherence measure has been successfully used in the study of fractured zones in coal-bearing strata of the Donetsk basin and in the study of a gas field in the Dnieper-Donets depression.
Authors and Affiliations
Yu. K. Tyapkin, I. V. Mendrii, O. Yu. Shchegolikhin, O. M. Tiapkina
To the problem of the origin of the Bug series rocks
The age of the Bug series rocks is an object for discussion. Isotopic methods do not give a distinct answer, because in the same outcrop, the same sample and even in the same crystal of zircon several dates of formation...
Peculiarities of the geomagnetic field secular variations at the 20th solar activity cycle
The decrease of solar and; correspondingly; geomagnetic activities at the 20th cycle has reflected on the secular variations of the geomagnetic field. On the continental magnetic observatories of the Earth north hemisphe...
Earth’s crust of large deposits of non-ferrous metals in Bulgaria
The proposed publication explores the main results of the study of the Earth’s crust in the largest ore regions in Bulgaria - Panagyurishte and Central Rhodopes. The concept of its continental type has been confirmed, an...
Secular variations of the geomagnetic field on litosphere plates of the Earth
The dependence of the value and sign of the geomagnetic secular variations (SV) refined of 3- and 11-year components on the position of observatories at different tectonic plates is investigated. The observatories of the...
Velocity divisibility of the mantle beneath the Ukrainian Shield
Within the limits of three-dimensional Tailor approximation P-velocity model of the mantle under the Ukrainian shield it has been shown that the mantle under it, according to its velocity characteristics, can be subdivid...