scholarly journals Accumulative landforms in valleys with gas-hydrothermal manifestations of the Kuril-Kamchatka region

2021 ◽  
Vol 946 (1) ◽  
pp. 012028
Author(s):  
E V Lebedeva ◽  
R V Zharkov

Abstract Within the watercourse valleys of geothermal zones, where manifestations of gas-hydrothermal activity are noted, the processes of relief formation are accompanied by chemical and thermal effects. Thermal waters contribute to the formation of specific accumulative landforms both directly in the channel and in the bottom and on the sides of river valleys. Similar phenomena have been studied in river valleys draining the slopes of the Mendeleev volcano (Kunashir Island), Baransky volcano (Iturup Island), Mutnovsky volcano and Uzon-Geyzernaya caldera (Kamchatka). The typification of accumulative relief forms is carried out, the influence of gas-hydrothermal manifestations on fluvial and slope processes is determined.

2016 ◽  
pp. 46-66
Author(s):  
Тю Фю Dulepova

The aeolian processes play an important role in the relief formation under the semiarid conditions of the intermountain basins of Southern Siberia. Ancient sand landforms occur in different regions of Siberia — the Ob, Chuya, Аley, Yenisei, Аngara, Selenga, Chikoy, Khilok and Chara river valleys and Lake Baikal coasts. The sandy coasts of Lake Baikal are of great interest in terms of floristic diversity determined by a high degree of endemism. Despite centuries of study of the lake basin, sand vegetation is poorly described in the literature. This study presents an analysis of 184 relevés of psammophytic vegetation from the Republic of Buryatia (Severobaikalsky, Barguzinsky, Pribaikalsky districts) and Irkutsk region (Olkhon Island) obtained in 2009–2014.


1973 ◽  
Vol 15 (1) ◽  
pp. 89-97 ◽  
Author(s):  
V.A. Volchenkova ◽  
A. V. Zotov ◽  
L.V. Klochkov ◽  
V.A. Frank-Kamenetskiy

2021 ◽  
pp. 1-17
Author(s):  
Christopher M. Schiller ◽  
Cathy Whitlock ◽  
Sabrina R. Brown

Abstract Changes in climate and fire regime have long been recognized as drivers of the postglacial vegetation history of Yellowstone National Park, but the effects of locally dramatic hydrothermal activity are poorly known. Multi-proxy records from Goose Lake have been used to describe the history of Lower Geyser Basin where modern hydrothermal activity is widespread. From 10,300 cal yr BP to 3800 cal yr BP, thermal waters discharged into the lake, as evidenced by the deposition of arsenic-rich sediment, fluorite mud, and relatively high δ13Csediment values. Partially thermal conditions affected the limnobiotic composition, but prevailing climate, fire regime, and rhyolitic substrate maintained Pinus contorta forest in the basin, as found throughout the region. At 3800 cal yr BP, thermal water discharge into Goose Lake ceased, as evidenced by a shift in sediment geochemistry and limnobiota. Pollen and charcoal data indicate concurrent grassland development with limited fuel biomass and less fire activity, despite late Holocene climate conditions that were conducive to expanded forest cover. The shift in hydrothermal activity at Goose Lake and establishment of the treeless geyser basin may have been the result of a tectonic event or change in hydroclimate. This record illustrates the complex interactions of geology and climate that govern the development of an active hydrothermal geo-ecosystem.


Author(s):  
SERGEI ALEKSEEV ◽  
LIUDMILA ALEKSEEVA ◽  
ALEKSEI ORGILIANOV

The object of this research is the groundwaters and surface waters of the Sentsa River Basin. The area of explorations is situated in the Eastern Sayan hydrogeological folded region. Cold and thermal waters occur in the PR and PZ metamorphic and igneous rock. These waters are discharged through the spring series in the river valleys laid along fault zones. The main type of fieldwork was hydrogeological sampling. The analysis of the macrocomponent composition of waters was conducted in the «Geodynamics and Geochronology Center» (Institute of the Earth’s Crust SB RAS, Irkutsk), the trace element composition was determined by ICP MS on an Element-2, Finnigan MAT (Germany) at the Vinogradov Institute of Geochemistry SB RAS (Irkutsk). The scientific novelty consists in the fact that this article provides not only the characteristics of chemical composition of cold and thermal waters, but also the primary data on the distribution of microelements in the ground and surface waters of the Sentsa River Basin. Groundwater (thermal and cold) are revealed to have a bicarbonate Ca-Na composition, withal river and lake waters are generally bicarbonate Ca. Thermal waters (in the Khoyto-Gol River Basin) are largely enriched in Li, Be, B, Si, Mn, Ge, As, Br, Rb, Sr, Cs, Ba, W and depleted in Al, P, Cu, Zn, Ag relative to surface and rainwater. The REE distribution profile in groundwater and surface waters have peculiarities that are characterized by a positive europium anomaly and the prevalence of light REE over heavy ones.


2015 ◽  
Vol 03 (05) ◽  
pp. 1-5 ◽  
Author(s):  
I. V. Bragin ◽  
G. A. Chelnokov ◽  
R. V. Zharkov ◽  
O. V. Chudaev ◽  
N. A. Kharitonova
Keyword(s):  

Author(s):  
K.C. Newton

Thermal effects in lens regulator systems have become a major problem with the extension of electron microscope resolution capabilities below 5 Angstrom units. Larger columns with immersion lenses and increased accelerating potentials have made solutions more difficult by increasing the power being handled. Environmental control, component choice, and wiring design provide answers, however. Figure 1 indicates with broken lines where thermal problems develop in regulator systemsExtensive environmental control is required in the sampling and reference networks. In each case, stability better than I ppm/min. is required. Components with thermal coefficients satisfactory for these applications without environmental control are either not available or priced prohibitively.


Author(s):  
A. G. Jackson ◽  
M. Rowe

Diffraction intensities from intermetallic compounds are, in the kinematic approximation, proportional to the scattering amplitude from the element doing the scattering. More detailed calculations have shown that site symmetry and occupation by various atom species also affects the intensity in a diffracted beam. [1] Hence, by measuring the intensities of beams, or their ratios, the occupancy can be estimated. Measurement of the intensity values also allows structure calculations to be made to determine the spatial distribution of the potentials doing the scattering. Thermal effects are also present as a background contribution. Inelastic effects such as loss or absorption/excitation complicate the intensity behavior, and dynamical theory is required to estimate the intensity value.The dynamic range of currents in diffracted beams can be 104or 105:1. Hence, detection of such information requires a means for collecting the intensity over a signal-to-noise range beyond that obtainable with a single film plate, which has a S/N of about 103:1. Although such a collection system is not available currently, a simple system consisting of instrumentation on an existing STEM can be used as a proof of concept which has a S/N of about 255:1, limited by the 8 bit pixel attributes used in the electronics. Use of 24 bit pixel attributes would easily allowthe desired noise range to be attained in the processing instrumentation. The S/N of the scintillator used by the photoelectron sensor is about 106 to 1, well beyond the S/N goal. The trade-off that must be made is the time for acquiring the signal, since the pattern can be obtained in seconds using film plates, compared to 10 to 20 minutes for a pattern to be acquired using the digital scan. Parallel acquisition would, of course, speed up this process immensely.


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