Vol 55, No 11 (2019)

Temporal variations of the black carbon (BC) concentration and air temperature measured in the surface atmosphere at the Tiksi Hydrometeorological Observatory (Yakutia) in May–September 2012–2018 have been analyzed. The average daily air temperature in July and August during the longest (1–2 days) episodes of abnormally high BC concentrations (greater than 1000 ng/m³) in comparison with the days outside these episodes can increase by 10–11°C (at an average temperature of around 9°C for these two months). However, the presence of one or two synchronous episodes of abnormally high values of both parameters within a month increases the average monthly air temperature by only 0.4–0.7°C (within the standard deviation of interannual variations) and can hardly lead to significant climatic effects for the region of observations.

An elevation of the ozone level in surface air due to climate change and increasing atmospheric pollution can lead to an increase in the morbidity and mortality of a population. The correlation between anomalously high surface concentrations of ozone in Moscow and morbidity and mortality in various age groups of the population in summer 2010 has been studied. The correlation of moderate ozone concentrations with the frequency of cardiovascular disease and mortality in a nonindustrialized area in the south of Kirov oblast is presented for comparison. The connection between high surface concentrations of ozone in Moscow and pneumonia incidence rate in various age groups is demonstrated. A statistically reliable correlation is observed in the groups of men and women of 31–60 years of age and older, but not in the respective groups of 15- to 30-year-olds. The population’s overall mortality and mortality in the group of people older than 70 also shows a significant correlation with surface ozone concentrations, with elderly people being the most vulnerable. The frequency of ambulance calls related to cardiovascular disease increased significantly in the south of Kirov oblast (a nonindustrialized area) when the average daily maximal allowed ozone concentration (MAC_ad) was exceeded for several days in a row and the SOMO35 integral parameter of ozone dose was 678 µg/m³ day. Neither anomalously high air temperatures at low ozone concentrations nor the smoke from forest fires caused an increase in the number of ambulance calls. This study has demonstrated that the Russian MAC_ad standard for ozone, 30 µg/m³, is justified.

The effect of temporal shifts in diurnal geomagnetic variation with 6- and 12-h intervals relative to the day–night cycle on the activity of digestive glycosidases (maltase and amylolytic activity) and their sensitivity to the in vitro influence of heavy metal ions (Cu²⁺, Zn²⁺, Pb²⁺, Cd²⁺) at a concentration of 25 mg/L has been studied in roach Rutilus rutilus (L.) underyearlings. Amylolytic activity (the total activity of starch-hydrolyzing enzymes: α-amylase, glucoamylase, and maltase) is determined by the modified Nelson method, maltase activity by the glucoseoxidase method with a Fotoglukoza clinical biochemistry kit. It is found that exposing embryos to both 6- and 12-h shifts in diurnal geomagnetic variation reduces the activity of maltase and its sensitivity to the effect of zinc and cadmium ions. Amylolytic activity increases only in roach underyearlings exposed to a 6-h shift in diurnal geomagnetic variation as embryos. The sensitivity of starch-hydrolyzing enzymes to the influence of copper (6- and 12-h shifts) and cadmium (12-h shift) increases. The decrease in the enzyme activity and its increased sensitivity to the inhibitory effect of heavy metals may reduce the efficiency of carbohydrate hydrolysis in roach underyearlings. The increase in the amylolytic activity can be considered as adaptation of the digestive system of the fish to a 6-h shift in diurnal geomagnetic variation relative to the day–night cycle during embryogenesis.

The study results of the temporal and spatial variability of geomagnetic and telluric fields driven by anomalous space weather are presented for the central and eastern parts of the Fennoscandian shield. Data from the Scandinavian network of geomagnetic observations IMAGE are analyzed together with the measurements of the geomagnetically induced currents (GIC) in nearby electric power lines of Karelia and the Kola Peninsula, as well as synthesized telluric fields. To synthesize telluric fields from the observed geomagnetic variations, we use magnetotelluric impedance estimates obtained during the BEAR electromagnetic sounding experiment in Fennoscandia. A comparison of the spectral composition of geomagnetic, telluric, and GIC variations in various sites and for various space weather events has shown that time derivative of the geomagnetic field (dB/dt), which is commonly used as a measure of GIC disturbances, does not fully control the latter. The analyzed telluric fields and observed GICs demonstrate a significant dependence on the induction response of the electrically conducting Earth interiors, the character of which varies greatly in different geological domains of the Fennoscandian shield. The regional spatial variations in the telluric field and GICs caused by the geoelectric structure heterogeneity are superimposed on the regular decreasing trend in their amplitudes with increasing distance from auroral latitudes. Based on magnetotelluric sounding data, estimates of the extreme values of telluric fields during geomagnetic storms and substorms are obtained for different sites, which is the key information for predicting GICs in regional power lines.

The problem of the settlement of the territory of the Northern Caucasus in the Paleolithic and its dependence on volcanic activity factors, climate, and shift in ecological niches is very relevant in modern domestic and foreign studies. Previous research at Mezmaiskaya cave in the northwestern Caucasus revealed that volcanism significantly affected the Middle Paleolithic population of this region and the disappearance of the Neanderthal population. In 2016, the first stratified Middle Paleolithic site was discovered in the Elbrus region (Republic of Kabardino–Balkaria), on the northern slopes of the central Caucasus. This site was called Saradj-Chuko grotto. This region is fundamentally important for understanding the dynamics of the Northern Caucasus settlement in the Paleolithic because it is located at the crossroads between the northern and southern slopes. The only obsidian outcrop in the Northern Caucasus is located also here. Obsidian is a volcanic raw material that was highly valued by ancient people in that period and transported by Neanderthals hundreds of kilometers. We have investigated the chemical composition and morphology of minerals in 76 samples of the ZZ0 longitudinal section in Saradj-Chuko grotto. As a result, traces of volcanic activity were revealed in 2 (6A and 4) out of 11 layers. It has been found that volcanism in the Middle Paleolithic affected the settlement of the Elbrus region and most likely the entire northern slope of the central Caucasus. Specifically, layer 6A (where ash was found) overlaps layer 6B (the level of active habitation in the grotto). After the eruption recorded in layer 6A, the Neanderthals only occasionally visited the cave. Preliminary conclusions are made about a possible source of ash in these layers of Saradj-Chuko grotto. The materials were analyzed in a wide context of the currently known data on the presence of ashes in other sites of the Caucasus.

Earthquakes of magnitude M ≥ 6.5 have been unknown in Fennoscandia for almost 900 years of historical data, but a sharp outburst of postglacial seismic activity with earthquake magnitude up to M ≥ 8 revealed by paleoseismogeological studies occurred there in 11 000–9000 BP. This outburst sharply decreased in time to the relatively low modern seismic activity almost exponentially. Strong paleoearthquakes were not randomly distributed over the timeline, but formed a group, or a cluster, confined to the maximum phase of deglaciation. This indicates a sharp nonstationary mode of paleoseismicity. On this basis, a conclusion about the fundamental difference between the geodynamic regimes of paleo- and ordinary modern seismicity has been drawn. An analysis of the historical seismicity of Fennoscandia over the past ~900 years has shown that the magnitude of the strongest known earthquake, in contrast to paleoearthquakes, did not exceed 6.5. It is logical to assume that the occurrence of earthquakes of intensity 9–10 on the territory of Fennoscandia is very unlikely now or in the near future. Therefore, when assessing seismic hazard and the environs of critical engineering facilities, including nuclear power plants, it is hardly necessary to take into account paleoearthquakes. One exception may be assessing the seismic hazard for disposal sites of highly toxic and nuclear waste, the biological hazard period of which can reach 100 000 years or more, which is comparable with glaciation periods.

In this publication we consider how local seismicity in the Racha-Dzhava seismic zone of the Caucasus changed in time under the influence of large earthquakes that occurred in 1971–2011. In order to divide the whole studied period into time intervals within which the total energy released by local earthquakes was summed up, we use the averaged focal mechanisms (obtained from the first P-waves arrivals) of earthquakes presented in the Seismological Bulletins of the Caucasus. The averaged focal mechanisms were built according to the method of K. Aki, in the terms of which a set of weak local earthquakes with a close distribution of the first P-waves arrivals are considered one large earthquake. The change in averaged focal mechanisms with time is revealed; this is associated with a change in tectonic stresses within the Racha-Dzhava zone. We also compare the changes in directions of tectonic stresses and the influence of strong earthquakes. It is shown that one of the factors of an abrupt and short-term change in a stress state and in a local seismicity level is an impact of distant strong and catastrophic earthquakes. The results can be interesting for understanding some aspects of local seismic activity and the causes of changes in the stress field and the activity of seismic process in the Racha-Dzhava seismic zone.

The first data on the eastern part of Taman Bay are based on an ultra-high-resolution seismic survey. The seismoacoustic complexes of a profile are compared with Novochernomorsk and Karangat sediments to Lower Chauda sediments of the Quaternary age. The fold structure of Quaternary sediments of this area is confirmed. An analysis of the bedding of the newest marine sediments of the bottom and the submergence of the ancient city of Phanagoria in the beginning of the 1st century AD indicate the Late Holocene tectonic activity of the Taman Bay depression. Two profile areas exhibit signal coherence gaps interpreted as areas of gas accumulations. The gas emissions are probably morphologically related to a wing of the adjacent Akhtaniz Anticline and are interpreted as a result of clay diapirism of the Maikop Group.

This paper describes a new approach to orbital tuning for the adjustment of proxy-based paleoclimate chronologies; the approach involves the synchronization of reconstructed paleotemperatures with quasi-temperature series derived from data on changes in insolation at the top of the atmosphere. The time lag between insolation and induced temperature reaction is estimated using a physical model describing the relationship between changes in the ground surface heat flux and ground surface temperature. The resulting time-lag estimates are in good agreement with the results of empirical analysis of independent age markers.

The comprehensive analysis of geological, geophysical, and geochemical data makes it possible to obtain the most complete picture of the geological structure of the central part of the Ninety East Ridge (NER), the Osborn Plateau, and the adjacent part of the Central Basin. This region has been established to be a complex tectonic structure. In respect of the revealed structural features of the major near-NS faults of Indrani, Indira, and Lanka, they are not transform faults. Based on the generalization of all available data on the northern and southern parts of the NER, supplemented by the studies of the NER’s central part, it is found out that the NER was constructed on the continental crust of an ancient continent, likely Lemuria. According to a new formation model, the NER is a relict fragment of this continent, preserved in the form of a block or an escarp, as an extended horst structure. This paper involves the primary data obtained by different Russian scientific and production organizations in the course of expeditions in the Central Basin during the 1980–1990s, as well as other data, including those obtained from foreign sources.

A method for calculating of the Earth’s surface displacements due to atmospheric loading effect is presented. The load displacements are calculated by the expansion coefficients of the surface atmospheric pressure fields of the European ERA5 reanalysis project for the spherical functions, as well as the load Love numbers that we calculated earlier. The obtained time series of displacements along three axes (vertical, in the direction to the north and east) are compared with the works of other authors.