Dynamics of Global Climatic Changes and Possibility of Their Prediction Using Chemical Data from Greenland Ice     

Sergey R. Kotov 《Mathematical Geology》2003,35(4):477-491

Records from the Greenland Ice Sheet Project Two ice core are considered in terms of dynamical systems theory and nonlinear prediction. Dynamical systems theory allows us to reconstruct some properties of a phenomenon based only on past behavior without any mechanistic assumptions or deterministic models. A near-term prediction of temperature, including a mean estimate and confidence interval, is made for 800 years into the future. The prediction suggests that the present short-time global warming trend will continue for at least 200 years and be followed by a reverse in the temperature trend.  相似文献   

Chlorine-36 and C chronology support a limited last glacial maximum across central chukotka, northeastern Siberia, and no Beringian ice sheet     

Julie Brigham-Grette  Lyn M. Gualtieri  Olga Yu. Glushkova  Thomas D. Hamilton  David Mostoller  Anatoly Kotov 《Quaternary Research》2003,59(3):386-398

The Pekulney Mountains and adjacent Tanyurer River valley are key regions for examining the nature of glaciation across much of northeast Russia. Twelve new cosmogenic isotope ages and 14 new radiocarbon ages in concert with morphometric analyses and terrace stratigraphy constrain the timing of glaciation in this region of central Chukotka. The Sartan Glaciation (Last Glacial Maximum) was limited in extent in the Pekulney Mountains and dates to 20,000 yr ago. Cosmogenic isotope ages > 30,000 yr as well as non-finite radiocarbon ages imply an estimated age no younger than the Zyryan Glaciation (early Wisconsinan) for large sets of moraines found in the central Tanyurer Valley. Slope angles on these loess-mantled ridges are less than a few degrees and crest widths are an order of magnitude greater than those found on the younger Sartan moraines. The most extensive moraines in the lower Tanyurer Valley are most subdued implying an even older, probable middle Pleistocene age. This research provides direct field evidence against Grosswald’s Beringian ice-sheet hypothesis.  相似文献   

Mid–Cretaceous Episodic Magmatism and Tin Mineralization in Khingan-Okhotsk Volcano–Plutonic Belt, Far East Russia     

Kohei SATO  Anatoly A. VRUBLEVSKY  Sergei M. RODIONOV  Nikolai P. ROMANOVSKY  Munetomo NEDACHI 《Resource Geology》2002,52(1):1-14

Abstract: Age of magmatism and tin mineralization in the Khingan‐Okhotsk volcano–plutonic belt, including the Khingan, Badzhal and Komsomolsk tin fields, were reviewed in terms of tectonic history of the continental margin of East Asia. This belt consists mainly of felsic volcanic rocks and granitoids of the reduced type, being free of remarkable geomagnetic anomaly, in contrast with the northern Sikhote‐Alin volcano–plutonic belt dominated by oxidized‐type rocks and gold mineralization. The northern end of the Khingan‐Okhotsk belt near the Sea of Okhotsk, accompanied by positive geomagnetic anomalies, may have been overprinted by magmatism of the Sikhote‐Alin belt. Tin–associated magmatism in the Khingan‐Okhotsk belt extending over 400 km occurred episodically in a short period (9510 Ma) in the middle Cretaceous time, which is coeval with the accretion of the Kiselevka‐Manoma complex, the youngest accretionary wedge in the eastern margin of the Khingan‐Okhotsk accretionary terranes. The episodic magmatism is in contrast with the Cretaceous‐Paleogene long–lasted magmatism in Sikhote–Alin, indicating the two belts are essentially different arcs, rather than juxtaposed arcs derived from a single arc. The tin‐associated magmatism may have been caused by the subduction of a young and hot back‐arc basin, which is inferred from oceanic plate stratigraphy of the coeval accre‐tionary complex and its heavy mineral assemblage of immature volcanic arc provenance. The subduction of the young basin may have resulted in dominance of the reduced‐type felsic magmas due to incorporation of carbonaceous sediments within the accretionary complex near the trench. Subsequently, the back‐arc basin may have been closed by the oblique collision of the accretionary terranes in Sikhote–Alin, which was subjected to the Late Cretaceous to Paleogene magmatism related to another younger subduction system. These processes could have proceeded under transpressional tectonic regime due to oblique subduction of the paleo‐Pacific plates under Eurasian continent.  相似文献   

Pyroclastic surges and flows from the 8–10 May 1997 explosive eruption of Bezymianny volcano, Kamchatka, Russia   总被引：2，自引：0，他引：2  

Alexander Belousov  Barry Voight  Marina Belousova  Anatoly Petukhin 《Bulletin of Volcanology》2002,64(7):455-471

The 8-10 May 1997 eruption of Bezymianny volcano began with extrusion of a crystallized plug from the vent in the upper part of the dome. Progressive gravitational collapses of the plug caused decompression of highly crystalline magma in the upper conduit, leading at 13:12 local time on 9 May to a powerful, vertical Vulcanian explosion. The dense pyroclastic mixture collapsed in boil-over style to generate a pyroclastic surge which was focused toward the southeast by the steep-walled, 1956 horseshoe-shaped crater. This surge, with a temperature <200 °C, covered an elliptical area >30 km² with deposits as much as 30 cm thick and extending 7 km from the vent. The surge deposits comprised massive to vaguely laminated, gravelly sand (Md -1.2 to 3.7J sorting 1.2 to 3J) of poorly vesiculated andesite (mean density 1.82 g cm^-3; vesicularity 30 vol%; SiO₂ content ~58.0 wt%). The deposits, with a volume of 5-15᎒⁶ m³, became finer grained and better sorted with distance; the maximal diameter of juvenile clasts decreased from 46 to 4 cm. The transport and deposition of the surge over a snowy landscape generated extensive lahars which traveled >30 km. Immediately following the surge, semi-vesiculated block-and-ash flows were emplaced as far as 4.7 km from the vent. Over time the juvenile lava in clasts of these flows became progressively less crystallized, apparently more silicic (59.0 to 59.9 wt% SiO₂) and more vesiculated (density 1.64 to 1.12 g cm^-3; vesicularity 37 to 57 vol%). At this stage the eruption showed transitional behavior, with mass divided between collapsing fountain and buoyant column. The youngest pumice-and-ash flows were accompanied by a sustained sub-Plinian eruption column ~14 km high, from which platy fallout clasts were deposited (~59.7% SiO₂; density 1.09 g cm^-3; vesicularity 58 vol%). The explosive activity lasted about 37 min and produced a total of ~0.026 km³ dense rock equivalent of magma, with an average discharge of ~1.2᎒⁴ m³ s^-1. A lava flow ~200 m long terminated the eruption. The evolutionary succession of different eruptive styles during the explosive eruption was caused by vertical gradients in crystallization and volatile content of the conduit magma, which produced significant changes in the properties of the erupting mixture.  相似文献   

Features of the long-term transformation of the Krasnodar reservoir,near the mouth of the Kuban River,Russia     

POGORELOV Anatoly  LAGUTA Andrey  KISELEV Evgeny  LIPILIN Dmitry 《地理学报(英文版)》2021,31(12):1895-1904

The article considers the long-term(1941–2018) transformation of the Krasnodar valley reservoir, the largest in the North Caucasus. The main functions of the Krasnodar reservoir are irrigation of rice systems and flood protection of land in the Krasnodar reservoir region and the Republic of Adygea. According to topographic maps, Landsat satellite images(1974–2018) and field observations(2016–2018), four stages of transformation of the floodplain reservoir are identified. The selected stages are characterized by both natural causes(the transformation of the filling deltas into the extended deltas, etc.) and man-made causes(runoff diversions in the delta areas, etc.). The key factor of transformation is the formation of deltas of rivers flowing into the reservoir. Each of the selected stages, against the background of a gradual reduction in the area and volume of the reservoir, is characterized by the peculiarities of the formation of river deltas with the formation of genetically homogeneous sections of delta regions. During the period of operation of the reservoir, the delta of the main Kuban River moved up to 32.4 km and took away an area of 35.4 km~2 of the reservoir. During the formation of the deltas of the Kuban and Belaya rivers, a bridge was formed on the Krasnodar reservoir. The evolution of the delta regions led to the division of the reservoir into two autonomous reservoirs. The total area of the delta regions was 85.9 km~2 by 2018, i.e., 21% of the initial area of the reservoir. The transformation of the Krasnodar reservoir leads to a decrease in its regulated volume and gradual degradation.  相似文献   

Rapid variability of active galactic nuclei: The 160min periodicity in NGC 3516, NGC 4151 and Quasar 3C 273     

V. A. Kotov  V. I. Haneychuk  V. M. Lyuty 《Astronomische Nachrichten》1994,315(5):333-342

The analysis of all the available data between 1968 and 1991 on rapid variability of optical and X-ray luminosity of three AGNs, NGC 3516, NGC 4151 and 3C 273, shows the presence of small-amplitude (˜ 1 %) but statistically confident (≈︁ 5s̀) periodicity of 160.0105 (± 6) min. Within the error limits it coincides with the period P₀ = 160.0101 (± 1) min of global oscillations of the Sun. An independence of the observed period on AGN red shift z favours the hypothesis about a cosmological origin of the 160min oscillation.  相似文献   

The use of multi‐frequency acquisition to significantly improve the quality of fibre‐optic‐distributed vibration sensing          下载免费PDF全文

A.H. Hartog  L.B. Liokumovich  N.A. Ushakov  O.I. Kotov  T. Dean  T. Cuny  A. Constantinou  F.V. Englich 《Geophysical Prospecting》2018,66(Z1):192-202

Unlike conventional sensors that measure the passage of seismic waves at a single position, distributed vibration sensing systems, also known as distributed acoustic sensing systems, detect the passage of seismic waves by averaging a measurement of strain over a section of fibre‐optic cable. Distributed vibration sensing systems work by transmitting pulses of light down the fibre and measuring the phase of the Rayleigh backscatter. At random positions along the fibre, however, fading occurs; this is where the amplitude of the backscattered signal is very small due to cancellation of the scattered electric fields, resulting in anomalously noisy traces in a common source gather. This paper addresses the problem of fading in a particular form of distributed vibration sensors: a new optical arrangement of the instrumentation is described that allows the measurement to be carried out quasi‐simultaneously at multiple optical interrogation frequencies. The interrogation frequencies are chosen to be sufficiently different that their fading properties are distinct and the diversity thus obtained is used to aggregate the data obtained to substantially reduce the noise caused by fading. As well as reducing the effects of fading, the aggregation of the independent results can also help to reduce the overall noise of the measurement and improve the linearity of the distributed vibration sensing system.  相似文献   

Superfast Exoplanets and 9600 s     

Kotov  V. A. 《Earth, Moon, and Planets》2019,123(1-2):1-8

Earth, Moon, and Planets - Motion of a substantial part of the superfast exoplanets is found to be in the close resonance with the well-known “solar” timescale $$P_{0} \approx 0.11$$...  相似文献   

Fast Spinning of Planets     

V. A. Kotov 《Earth, Moon, and Planets》2018,122(1-2):43-52

Spin periods of Jupiter, Saturn, Uranus and Neptune are specified by the analysis of the resonant motion of large satellites: \(P = 0.445(2)\,\hbox {d}\), 0.448(1) d, 0.673(9) d and 0.561(7) d, respectively. They occur to be near-commensurate with \(P_0=9600.606(12)\,\hbox {s}\), the period of the “cosmic” oscillation, discovered first in the Sun, then in other variable objects of the Universe. The like analysis of spin rates of the total set of the largest and fastest rotators of the Solar system (with mean diameters \(\ge 500\,\hbox {km}\) and \(P < 2\,\hbox {d}\),—of planets, asteroids and satellites) resulted in the best commensurable, or “synchronizing”, timescale 9594(65) s, coinciding fairly well with \(P_0\) too (the probability that the two timescales could agree by chance, is less than \(10^{-5}\)). True origin of this odd common resonance of our planetary system is unknown.  相似文献   

The Age,Sources, and Tectonic Setting of Tin-Bearing Granites of the Yazovka Complex of the Baikal–Patom Fold-Thrust Belt     

Larin  A. M.  Kotov  A. B.  Salnikova  E. B.  Sklyarov  E. V.  Kovach  V. P.  Plotkina  Yu. V.  Anisimova  I. V.  Podolskaya  M. M. 《Doklady Earth Sciences》2020,490(2):55-59

Doklady Earth Sciences - Granite–porphyries of the Yazovka complex occur in the northern part of the Riphean Baikal–Patom fold-thrust belt within the Tonod Uplift of the Early...  相似文献