FESIBILITIES OF PASSIVE SEISMIC EXPLORATION METHODS IN STUDYING THE GEOLOGICAL STRUCTURE OF THE ARCTIC REGIONS OF WESTERN SIBERIA (YAMAL PENINSULA)
A.A. Dobrynina1,2, A.V. Sankov1, I.V. Buddo1, I.A. Shelokhov1, V.A. Sankov1
1Institute of the Earth’s crust Siberian Branch of the Russian academy of science,Irkutsk, Russia
2N.L.Dobretsov geological institute Siberian Branch of the Russian academy of science,Ulan-Ude, Russia
Keywords: Arctic, passive seismic, ambient noise, upper part of the section, pingo, hard to recover reserves.
Abstract
The paper provides a brief overview of methods based on the analysis of natural ambient noises of the Earth (passive seismic exploration methods): methods of spatial autocorrelation, seismic interferometry and spectral ratios of seismic noise components, as well as their application to studying the structure and properties of the upper part of the section in Arctic conditions. The analysis and interpretation of the upper part of the section through pingos in the Arctic zone were carried out using passive seismic methods (spectral component ratios). The resulting two-dimensional sections reflect the horizontal layered structure of the upper part of medium – four main layers are clearly visible on the profiles which may be interpreted as the upper sedimentary layer, the basement layer, and two intermediate layers that differ in velocity characteristics. The section is disturbed by vertical and inclined heterogeneities that extend from faults in the basement to the surface and are characterized by high anisotropy of properties and reduced rigidity. The spatial correlation of the identified subvertical heterogeneities with the position of pingos on the surface suggests that these areas represent weakened zones, possibly fault zones or conductive channels. Based on the results of the review of scientific publications, a conclusion was made about the reliability of the results obtained by passive seismic methods, which is confirmed by other independent geophysical research methods. Passive seismic methods demonstrate high efficiency when working in hard-to-reach areas, such as the Arctic zone, since they do not require long-term installation of an observation network, and when using spectral ratio methods, they do not require a large number of seismic stations. They are especially useful when studying hard to extract resources characterized by a complex structure of the upper part of the section (the first meters), since they allow for the rapid study of the upper part of the section for depths from the first meters to tens of kilometers during reconnaissance work without significant financial and labor costs. From an environmental point of view, passive seismic methods are the most gentle, as they are non-invasive and non-destructive.
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