The Upper Bajocian-Lower Bathonian boundary section in the outskirts of Saratov: Molluscan characteristics and biostratigraphy

The analysis of all available data on the structure of the Bajocian-Bathonian boundary section in the outskirts of Saratov (Sokur quarry) and the taxonomic composition of its ammonites, belemnites, and bivalves revealed a continuous succession of the Pseudocosmoceras michalskii (Upper Bajocian), Oraniceras besnosovi, and Arcticoceras ishmae (Lower Bathonian) zones. In connection with the critique by Meledina et al. (2009), correlation of Bajocian and Bathonian boundary strata of the Central Russia and Northern Siberia is discussed. The inconsistency of Siberian bivalve and belemnite assemblages with Central Russian ammonite zones is explained by heterochronous invasions of different molluscan groups.     

Spatial and temporal variability and monitoring of hydrophysical fields of the Black Sea

As part of the Russian-Ukrainian program “The Black Sea as a Simulation Model of the Ocean,” the monitoring of the marine environment is considered using modern measuring systems. On the basis of historical and contemporary observation data, we estimate the spatial and temporal scales of dominant processes in the Black Sea. We describe the main measuring systems used to monitor the structure and variability of the hydrophysical fields. Examples characterizing the specific features of the Black Sea processes are presented.     

Automated construction of the boundaries of basin geosystems for the Volga Federal District

Using the Volga (Privolzhskii) Federal District as an example, we offer the solution of such a currently central scientific and methodological problem as automated identification of the boundaries of basin geosystems under different landscape and geomorphological conditions in terms of multiresolution digital elevation models. The main stages of work are described, namely the development of the digital elevation model, its hydrological adjustment, identification of the boundaries of basin geosystems, and validity assessment of results obtained. The technique has been developed for constructing a hydrologically valid digital elevation model with the purpose of identifying the boundaries of basin geosystems.     

Comparison of ground-based and satellite measurements of total ozone

Presented are the results of studies dealing with the analysis of discrepancies in the data on total ozone measurements carried out using different instruments. The results of measurements with ground-based spectral (UV and visible) and filter instruments and spaceborne nadir scanning instruments are used as initial data. As a result of the analysis of relative systematic and random discrepancies, it is concluded that the data of filter instruments are of insufficient accuracy for diagnosing total ozone values. The analysis of linear trends revealed the presence of considerable differences in the data series obtained by spectral instruments. It is concluded that there is every reason to hope for obtaining the most homogeneous measurement data in Russia using the instruments operating in the Chappuis band.     

Hydrochemical and atmochemical mercury dispersion zones over hydrothermal vents of the submarine Piip Volcano in the Bering Sea

Signs of mercury input and dispersion in the water mass and the atmosphere over the submarine Piip Volcano have been revealed. The mercury from hydrothermal vents has been found to release mostly as a component of hydrothermal-gas bubbles rising through the water mass to the sea’s surface. The mercury’s dispersion and the seawater’s enrichment with it is a consequence of the partial dissolution of the gas bubbles. The atmochemical dispersion zone is represented by an area of higher mercury concentration with two maximums shifted in the direction of the wind (northeastward) from the northern and southern peak of the volcano.     

Gaseous admixtures in the atmosphere over Moscow during the 2010 summer

In the summer of 2010, the Moscow megacity during two months was within the zone of action of a blocking anticyclone. The accumulation of pollutants in a closed air mass sharply changed the surface air quality. At the end of July-the first half of August, the extreme situation became even more complicated, because the air from regions of turf and grass fires came into Moscow. According to measurement data of the Moscow IAP RAS station, the maximal hourly mean concentrations of chemically active gases NO, NO₂, CO, O₃, and SO₂ were 175.9, 217.4, 15.8, 134.2, and 15.2 ppb, respectively. For NO₂ and CO, these values are largest over the entire decadal period of observations at the station and many times exceed the MPC level (see table). The concentrations of greenhouse gases CO₂, CH₄, and nonmethane hydrocarbons also sharply increased. Analysis of the variability of gas contents in the surface air and in the atmospheric boundary layer showed a close relation between extreme changes in the atmospheric composition and its vertical stratification.     

Active mud volcanism in the West Alboran Basin: Geochemical evidence of hydrocarbon seepage

The West Alboran Basin was previously classified as a mud volcanic province consisting of two mud volcano (MV) fields that are inactive at the present day: the Northern (Spanish) and the Southern (Moroccan) fields. The discovery of the first active mud volcano (Carmen; cruise TTR-17) in 2008, along with several pockmarks at the central part of the basin, motivates more careful geological and geochemical analysis of previous data and comparison to new observations.Gas bubbling from the crater of Carmen MV was observed and recorded using an underwater TV-system and a large TV-grab sample. The gas mainly consisted of methane with less than 1% wetness. However, all sets of homologues up to pentane were detected in the mud breccia of Carmen MV. Both molecular and stable carbon isotopic compositions, and their distribution along the core length, suggest a deep thermogenic source of hydrocarbons (HCs). Composition of the pore water from Carmen MV also points to a deep source of mud volcanic water. The isotopic results indicate that the source of mud volcanic water is the dehydration of clay minerals in the thermal zone of the smectite-to-illite transformation. Our observations allow us to infer the presence of structure II gas hydrates in mud breccia on the top of Carmen MV.High HC gas saturation in sediments in some pockmarks accompanied with live chemosynthetic fauna directly indicates the strong seepage activity of these structures. For the first time, authigenic carbonate crusts and chimneys with associated living chemosynthetic bivalves and tubeworms were sampled from a seep site in the West Alboran Sea. Authigenic carbonates consist of aragonite and calcite, and are characterized by a light carbon isotopic signature, up to −37.2‰ PDB, which points to their methane-derived origin.     

Nature of the diffusion, generation, and drift of the geomagnetic dipole from 1900 to 2010

It will be shown below that the main axial dipole component suffers magnetic diffusion only, so it tends to be diminished by a factor of e per 2110 years. This time interval allows us to specify the value of the core’s conductivity and estimate roughly the configuration for the current source of the axial dipole in the core and the minimal time before the upcoming inversion (excursion). The dipole component perpendicular to the axis of revolution is less than the main axial component by an order of magnitude, and has generating, drift, and diffusion components as well. This generating component is characterized by two intervals of growth by a factor of e, 98, and 540 years, which allow us to estimate the a-effect. The drifting component consists of differently directed waves enveloping the globe for 46 000 years, which leads to estimation of the w-effect. The nature of inversion dynamics is also estimated.