Vol 23, No 2 (2023)

Quantitative assessment of the territory continentality is an urgent task, because in the conditions of climate change, the index of continentality can be taken into account when developing geographical forecasts of landscape development. The purpose of this study is to assess the change in the index of continentality of Western Siberia in the conditions of the current trend in climate development. The statistical series of observations on seven meteorological stations in Western Siberia served as the information base of the study. The long-term changes in the average January and average July temperatures, as well as the amount of precipitation for the cold (October-March) and warm (April-September) periods of the year were analyzed. Calculations for the time intervals of 1961–1990 and 1991–2015 allowed us to conclude that the climate continentality of Western Siberia is weakening under the conditions of regional climate development.

The analysis of changes in the near-surface air temperature of the Northern Hemisphere is given. To identify years in which there was a violation of the series homogeneity, the stepwise trend method was applied using Kolmogorov statistics. It is shown that the identified homogeneous climatic intervals basically correspond to the natural climatic periods of the state of the Earth’s climate system. The assessment of the significance of temperature changes in homogeneous climatic areas was carried out by the method of confidence intervals using Student’s t-test. Based on the confirmed statistical significance, the conclusion is made about the climatic significance of changes in the surface air temperature of the Northern Hemisphere.

Based on the review of the published data, the article analyzes the study of the problem of oil pollution migration in the upper part of the geological environment in the conditions of the Far North, where the movement of oil pollution occurs mainly in the layer of seasonal freezing and thawing of the cryolithozone. The factors influencing the spreadability and transport of oil, including the focus on the processes of formation of possible migration routes into frozen rocks are considered. It was concluded that the processes of thawing and freezing of the active layer due to the displacement of oil from the freezing zone into the thawing zone have the biggest impact on the nature and distribution of oil pollution. The conclusion is made about the possibility of penetration of oil pollution from the contaminated active layer into the underlying permafrost.

Our own research data as well as numerous publications of recent years on modern problems of oil potential in the West Siberian oil and gas province were used in this study. Based on the Palyanovskaya, Talinskaya and adjacent areas of the Krasnoleninsky arch, the issues of deposits structure and confinement to certain regional levels of the section, the problems of unconventional reservoirs formation in the zones of tectonic deformations and hydrothermal-metasomatic changes in pre-Jurassic basement rocks (Paleozoic granites), as well as problems of highly permeable “supercollector” (the lower horizons of the Jurassic complex – Sherkalinskaya formation) and an almost impermeable reservoir with difficult to recover huge hydrocarbon reserves (its upper horizons – Bazhenov formation) are discussed. The oil deposits distribution in the Jurassic part of the section was shown to comply with the fluid migration model with the participation of deep hydrocarbon fluid. New types of unconventional reservoirs have been identified in the basement granites and in the unloading zones in the Jurassic deposits of the sedimentary cover.