Problems of Engineering Seismology: article

Аnnotation: The seismic coda waves attenuation characteristic in Ferghana basin were studied in this paper. The short-period coda waves of local earthquakes recorded by the CHISS in 1960-1984 and digital seismogram data of 100 earthquakes that occurred in Ferghana basin during 2005 to 2021 and recorded at stations of the KNET network have been analyzed. A detailed analysis of variations of the attenuation field within the Fergana Basin showed that it has a mosaic structure that changes with depth. It is consistent with the structure of the velocity field obtained by the seismotomography method, as well as with the conclusions drawn from the analysis of the density model. The features of the seismicity distribution relative to the position of blocks and weakened zones at different depths are considered. The correlation of contrasting objects of the attenuation field in the Fergana basin with objects contrasting in petrophysical characteristics in the pre-Mesozoic strata has been revealed. Oil and gas fields of the Fergana Basin are associated with zones of strong attenuation, which, probably, can be fluid migration channels, including hydrocarbons. Possible reasons for the increased sensitivity of the atmospheric baric field in the Namangan HMS region to the processes associated with the preparation and implementation of significant seismic events are also considered.