Traces of Seismic Activity in Architectural Monuments in Derbent,Dagestan     

Korzhenkov  A. M.  Gadzhiev  M. S.  Ovsyuchenko  A. N.  Lar’kov  A. S.  Rogozhin  E. A. 《Izvestiya Atmospheric and Oceanic Physics》2020,56(7):633-656

Izvestiya, Atmospheric and Oceanic Physics - As a result of studies conducted in the city of Derbent, it is established that its monumental fortification structures erected at the end of the 560s...  相似文献   

Features of Winter Thunderstorms in Kamchatka     

Smirnov  S. E.  Mikhailov  Yu. M.  Mikhailova  G. A.  Kapustina  O. V. 《Geomagnetism and Aeronomy》2019,59(6):696-703

Geomagnetism and Aeronomy - Winter thunderstorms in Kamchatka are a rare meteorological phenomenon. Temporal variations of the quasi-static electric field and meteorological values at the Paratunka...  相似文献   

Earth’s Climate Does Not Depend on Variations in Cosmic Rays and Cloud Coverage     

Abdussamatov  H. I. 《Geomagnetism and Aeronomy》2019,59(7):935-941

Geomagnetism and Aeronomy - The hypothesis put forward by Svensmark and Friis-Christensen (1997), Svensmark (2007), Svensmark et al. (2017), and Stozhkov et al. (2017) assumes while completely...  相似文献   

Cycles on the Solar-type Stars and Cooler Dwarfs     

Bondar’  N. I.  Katsova  M. M.  Livshits  M. A. 《Geomagnetism and Aeronomy》2019,59(7):832-837

Geomagnetism and Aeronomy - Features of the development of activity cycles in the solar-type stars and fast-rotating cool dwarfs have been considered for 65 stars observed in some decades. Cycles...  相似文献   

Tsunami risk assessment: economic,environmental and social dimensions     

Yavuz  Cuneyt  Kentel  Elcin  Aral  Mustafa M. 《Natural Hazards》2020,104(2):1413-1442

Natural Hazards - In this study, we present a novel methodology that may be used to analyze tsunami risk along coastal regions. The application of the proposed methodology is demonstrated for the...  相似文献   

Tectonic and Geodynamic Settings of Formation of the Mesozoic Cumulative Dunite–Wehrlite–Olivine Clinopyroxenite—Gabbro Massif in Eastern Chukotka     

Ledneva  G. V.  Bazylev  B. A.  Layer  P.  Kuzmin  D. V.  Kononkova  N. N. 《Geotectonics》2020,54(4):455-476

Geotectonics - The dunite–wehrlite–clinopyroxenite–gabbro massif in Eastern Chukotka, a key object for geodynamic reconstructions of the Vel’may terrane, which represents...  相似文献   

Redshift Measurements for Galaxies in Clusters by Multislit Spectroscopy at the 1.5-m Telescope RTT150     

Khamitov  I. M.  Bikmaev  I. F.  Burenin  R. A.  Glushkov  M. V.  Melnikov  S. S.  Lyapin  A. R. 《Astronomy Letters》2020,46(1):1-11

Astronomy Letters - An example of simultaneous spectroscopic redshift measurements for a large number of galaxies in a cluster by multiobject spectroscopy with the medium- and low-resolution TFOSC...  相似文献   

The thermal maturity of sedimentary basins as revealed by magnetic mineralogy     

Mansour M. Abdelmalak  Stéphane Polteau 《Basin Research》2020,32(6):1510-1531

The thermal evolution of sedimentary basins is usually constrained by maturity data, which is interpreted from Rock-Eval pyrolysis and vitrinite reflectance analytical results on field or boreholes samples. However, some thermal evolution models may be inaccurate due to the use of elevated maturities measured in samples collected within an undetected metamorphic contact aureole surrounding a magmatic intrusion. In this context, we investigate the maturity and magnetic mineralogy of 16 claystone samples from Disko-Svartenhuk Basin, part of the SE Baffin Bay volcanic margin. Samples were collected within thermal contact metamorphic aureoles near magma intrusions, as well as equivalent reference samples not affected by intrusions. Rock-Eval pyrolysis (T_max), and vitrinite reflectance (Ro) analysis were performed to assess the thermal maturity, which lies in the oil window when 435°C ≤ T_max ≤ 470°C and 0.6%–0.7% ≤ Ro ≤ 1.3%. In addition, we performed low- (<300K) and high-temperature (>300K) investigations of isothermal remanent magnetization to assess the magnetic mineralogy of the selected samples. The maturity results (0.37% ≤ Ro ≤ 2%, 22°C ≤ T_max ≤ 604°C) show a predominance of immature to early mature Type III organic matter, but do not reliably identify the contact aureole when compared to the reference samples. The magnetic assemblage of the immature samples consists of iron sulphide (greigite), goethite and oxidized or non-stoichiometric magnetite. The magnetic assemblage of the early mature to mature samples consists of stoichiometric magnetite and fine-grained pyrrhotite (<1 μm). These results document the disappearance of the iron sulphide (greigite) and increase in content of magnetite during normal burial. On the other hand, magnetite is interpreted to be the dominant magnetic mineral inside the contact aureole surrounding dyke/sill intrusions where palaeotemperatures indicate mature to over-mature state. Interestingly, the iron sulphide (greigite) is still detected in the contact aureole where palaeotemperatures exceeded 130°C. Therefore, the magnetic mineralogy is a sensitive method that can characterize normal burial history, as well as identify hidden metamorphic contact aureoles where the iron sulphide greigite is present at temperatures beyond its stability field.  相似文献   

Analysis of the Sky Scanning Efficiency in the Lyra-B Space Experiment     

S. V. Zhmailov  M. E. Prokhorov 《Astronomy Reports》2020,64(1):34-57

The Lyra-B space experiment (SE) is a high-precision multicolor multiple all-sky photometric survey of stars and star-like objects. The experiment will be conducted from the Russian segment of the International Space Station (ISS). For this purpose, a 0.5-m telescope will be installed onboard (or, more precisely, outboard) the ISS, which will observe stars in a scanning mode. The Lyra-B SE was included in the program of scientific experiments at the ISS fairly long ago. At the beginning of the SE design it was thought that the ISS would exist “eternally” and the time needed for the full-fledged implementation of the experiment would be allocated. Today, however, the situation has changed. In 2025 the ISS will possibly cease to exist either as the space station as a whole or in the form in which it exists now. Hence there arises the problem to perform the entire volume of observations in a maximally short time, i.e., to find an optimal sky scanning strategy that would ensure a maximum duration of observations. In addition, we consider two related questions: with what density will the observations be distributed over the sky and how many times will a point in the sky fallen within the field of view of the Lyra-B telescope be observed in successive orbital revolutions? This question is important for investigating variable stars, determining the orbits and axial rotation periods of asteroids, and ensuring a specified photometric accuracy over the entire sky.  相似文献   

Cyclical one-way continental rupture-drift in the Tethyan evolution: Subduction-driven plate tectonics     

Wan  Bo  Wu  Fuyuan  Chen  Ling  Zhao  Liang  Liang  Xiaofeng  Xiao  Wenjiao  Zhu  Rixiang 《中国科学:地球科学(英文版)》2019,62(12):2005-2016

Numerous continents have rifted and drifted away from Gondwana to repeatedly open ocean basins over the past-500 millionyears.These Gondwana-derived continents drifted towards and collided with components of the Eurasian continent to successively close the preexisting oceans between the two.Plate tectonics satisfactorily describes the continental drift from Gondwana to Eurasia but does not define the geodynamic mechanism of continuously rifting to collisions of continents in the Tethy an Realm.After reappraisal of geological records of the rift,collision and subduction initiation from the surface and various geophysical observations from depth,we propose that Eurasia-directed subducting oceanic slabs would have driven Tethyan system in the Phanerozoic.The Eurasia-directed subduction would have dragged the passive Gondwana margin to rift and drift northwards,giving birth to new oceans since the Paleozoic.The closure of preexisting oceans between the Gondwana-derived continents and Eurasia led to continental collisions,which would have induced the initiation of oceanic subduction in the Tethyan Realm.Multiple episodic switches between collision-subduction-rift repeatedly led to the separation of continental fragments from Gondwana and dragged them to drift towards Eurasia.The final disappearance of Neo-Tethy s would have induced collision of the Gondwana-derived continents with the Eurasian continent,giving rise to the Cenozoic Alpine-Zagros-Himalayan collisional system.Therefore,the Eurasia-directed oceanic subduction would have acted as a 'one-way train' that successively transferred the ruptured Gondwana continental fragments in the south,into the terminal in the north.In this regard,the engine of this "Tethyan one-way train" is the negative buoyancy of subducting oceanic slabs.  相似文献