The composition of volatile components in olivines from Yakutian kimberlites of various ages: Evidence from gas chromatography–mass spectrometry

The composition of volatiles from fluid and melt inclusions in olivine phenocrysts from Yakutian kimberlite pipes of various ages (Olivinovaya, Malokuonapskaya, and Udachnaya-East) were studied for the first time by gas chromatography–mass spectrometry. It was shown that hydrocarbons and their derivatives, as well as nitrogen-, halogen-, and sulfur-bearing compounds, played a significant role in the mineral formation. The proportion of hydrocarbons and their derivatives in the composition of mantle fluids could reach 99%, including up to 4.9% of chlorineand fluorine-bearing compounds.     

Paradoxes of the comparative analysis of ground-based and satellite geodetic measurements in recent geodynamics

The comparative analysis of the Earth’s surface deformations measured by ground-based and satellite geodetic methods on the regional and zonal measurement scales is carried out. The displacement velocities and strain rates are compared in the active regions such as Turkmenian–Iranian zone of interaction of the Arabian and Eurasian lithospheric plates and the Kamchatka segment of the subduction of the Pacific Plate beneath the Okotsk Plate. The comparison yields a paradoxical result. With the qualitatively identical kinematics of the motion, the quantitative characteristics of the displacement velocities and rates of strain revealed by the observations using the global navigational satellite system (GNSS) are by 1–2 orders of magnitude higher than those estimated by the more accurate methods of ground-based geodesy. For resolving the revealed paradoxes, it is required to set up special studies on the joint analysis of ground-based and satellite geodetic data from the combined observation sites.     

Relation between deformation and seismicity in the active fault zone of Kamchatka, Russia

In the regional geodetic network of the Russian Far East, an active fault zone of the Kamchatka peninsula has been selected in order to study the relation between seismic activity and deformation. This paper provides the first results of a detailed and high-precision 3-km long levelling profile, along which geodetic data have been collected weekly for almost three years. The data processing and analytical methods that were originally used have been elaborated for this particular type of very small local network. In the active fault zone, two distinct ways of releasing accumulated potential energy, i.e. seismicity and 'fault superintensive movements', have been registered. The inverse correlation that is discovered between deformation rate and seismic activity could be useful in earthquake forecasts.     

Induced Deformations of Fault Zones

Izvestiya, Physics of the Solid Earth - Empirical data obtained by studying the Earth’s surface deformations in the fault zones induced by exogenous, endogenous, and manmade processes are...     

New approaches to laser desorption/ionization of chemical compounds for geochemical studies

Two new versions of surface-assisted laser desorption/ionization method are considered. One version is based on a combination of this method with thermal desorption sample injection and may be applied for determination of chemical compounds that are transformed into a gas phase without decomposition by heating. Another version is based on laser-induced electron-transfer desorption/ionization and could be used for determination of compounds with low proton affinity. The possibilities of the new approaches are illustrated by the example of determination of aminoacids, medical compounds, chlorophyll, as well as gold in sulfide ores.     

Paleoenvironmental proxy records from Lake Hovsgol, Mongolia, and a synthesis of Holocene climate change in the Lake Baikal watershed

Here we discuss paleoenvironmental evolution in the Baikal region during the Holocene using new records of aquatic (diatom) and terrestrial vegetation changes from Hovsgol, Mongolia's largest and deepest lake. We reconcile previous contradictory Baikal timescales by constraining reservoir corrections of AMS dates on bulk sedimentary organic carbon. Synthesis of the Holocene records in the Baikal watershed reveals a northward progression in landscape/vegetation changes and an anti-phase behavior of diatom and biogenic silica proxies in neighboring rift lakes. In Lake Baikal, these proxies appear to be responsive to annual temperature increases after 6 ka, whereas in Lake Hovsgol they respond to higher precipitation/runoff from 11 to 7 ka. Unlike around Lake Baikal, warmer summers between 6 and 3.5 ka resulted in the decline, not expansion, of forest vegetation around Lake Hovsgol, apparently as a result of higher soil temperatures and lower moisture availability. The regional climatic proxy data are consistent with a series of 500-yr time slice Holocene GCM simulations for continental Eurasia. Our results allow reevaluation of the concepts of ‘the Holocene optimum’ and a ‘maximum of the Asian summer monsoon’, as applied to paleoclimate records from continental Asia.     

The Cyclic-Wave Character of the Distribution of Chemical Elements in the Water of the Source of the Angara River (Runoff of Lake Baikal)

Doklady Earth Sciences - The cyclic-wave character of the change in the chemical composition of the source of the Angara River, i.e., the runoff of Lake Baikal, indicating the presence of the...     

Post-processing and forecasts updating in automated systems of flash flood forecasting

This paper completes the series of three articles devoted to automated forecasting of flash floods [3, 5] and describes an effective approach of forecast updating through post-processing operations, which can be useful only in conjunction with such fast and efficient real-time re-calibration algorithms as SLS-based methods are. In particular, a proposed methodology is aimed to reduce negative consequences of scarce or low-quality data that can corrupt optimized parameters and, therefore, lower forecasting efficiency. A new modification of SLS-based optimization that supposes simultaneous re-calibration of the model and correction of the model input by generating of ensemble noises (SLS-E) is presented.     

Dependence of sand soil compressibility on soil physical properties

A relationship between soil physical properties and its compressibility has been analyzed.The formulae to determine soil density and porosity have been substantiated in compression tests.The regularity of changes in compressibility of thawed sand soils with various degrees of water content has been experimentally identified.     

Giant pulses from the millisecond pulsar PSR B1937+214

We have detected giant pulses from the millisecond pulsar PSR B1937+214 at the lowest frequency of 112 MHz. The observed flux density at the pulse peak is ～40 000 Jy, which exceeds the average level by a factor of 600. Pulses of such intensity occur about once per 300 000 periods. The brightness temperature of the observed giant pulses is T _B≈10³⁵ K. We estimated the pulse broadening by interstellar scattering to be τ_sc=3–10 ms. Based on this estimate and on published high-frequency measurements of this parameter, we determined the frequency dependence of the pulse broadening by scattering: τ_sc(f)=25 × (f/100)^?4.0±02.