The recent structure of Mahe Island (the Seychelles archipelago)     

L. V. Panina  V. A. Zaitsev 《Moscow University Geology Bulletin》2016,71(2):131-136

Complex studies were carried out, including structural and geomorphological analyses of space images and statistical processing of their deciphering results, which revealed the blocky pattern of the recent dislocations of Mahe Island, thus defining their relationships with a jointing pattern in granite outcrops. The results were compared with the geological data and instrumental observations of modern movements.  相似文献   

The role of spatial heterogeneity of the environment in soil fauna recovery after fires     

K. B. Gongalsky  A. S. Zaitsev 《Doklady Earth Sciences》2016,471(2):1265-1268

Forest fires are almost always heterogeneous, leaving less-disturbed sites that are potentially suitable as habitats for soil-dwelling creatures. The recovery of large soil animal communities after fires is therefore dependent on the spatial structure of the burned habitats. The role of locally less disturbed sites in the survival of soil macrofauna communities along with traditionally considered immigration from the surrounding undisturbed habitats is shown by the example of burnt areas located in three geographically distant regions of European Russia. Such unburned soil cover sites (perfugia) occupy 5–10% of the total burned habitats. Initially, perfugia are characterized by much higher (200–300% of the average across a burned area) diversity and abundance of soil fauna. A geostatistical method made it possible to estimate the perfugia size for soil macrofauna at 3–8 m.  相似文献   

Strong Tidal Mixing and Ventilation of Cold Intermediate Water at Kashevarov Bank, Sea of Okhotsk   总被引：1，自引：0，他引：1  

Konstantin A. Rogachev  Eddy C. Carmack  Alexandr S. Salomatin 《Journal of Oceanography》2000,56(4):439-447

Tidal mixing at the Kashevarov Bank, Sea of Okhotsk, has been investigated using observations of bottom pressure and currents. The tides are dominated by the diurnal constituents. The water motion over the Bank is predominantly controlled by strong diurnal tidal currents, which bring cold water on the bank from its source, a cold intermediate layer. The temperature fluctuations are about 1.2°C at the southern edge of the bank. The maximum observed velocity is about 164 cm/s at the top of the bank. A superposition of the original diurnal constituents K₁ and O₁ reveals a strong fortnightly (M_f) variability of the current speed. Tidal-induced mixing is responsible for ventilation of the cold intermediate layer of the Sea of Okhotsk. Strong tidal mixing creates a well-defined tidally mixed front around the bank. This front acts like a barrier separating well-mixed water on the bank from stratified water on its flanks. There is a residual current of the order of 10 cm/s.  相似文献   

Influence of the Solar Activity Cycle on the Gasdynamic Structureof the Heliospheric Interface     

Nikolai Zaitsev 《Astrophysics and Space Science》2000,274(1-2):149-156

The effects of the 11 year solar activity cycle on the heliospheric plasma interface in the presence of neutral H-atoms have been investigated. Our calculations show that nonstationary processes of such kind lead to1) a decrease of the mean interstellar plasma density in the interface;2) a sequence of shocks and rarefaction waves moving from the heliopause (HP)to the bow shock (BS); 3) an expansion of the region between the BS and HP;4) the TS excursion along the upwind direction is within 30%of the mean solar distance. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Undamped Oscillations of Electric Current in Coronal Magnetic Loops and in Magnetic Loop Arcades     

Zaitsev  V. V. 《Geomagnetism and Aeronomy》2018,58(7):871-876

Geomagnetism and Aeronomy - The possibility of the existence of undamped oscillations of the electric current in coronal magnetic loops and loop arcades due to the presence of a photospheric...  相似文献   

Evolution of Electric Current and Resistance in the Flare Loop in the Course of Loop Shrinkage     

Zaitsev  V. V.  Stepanov  A. V. 《Geomagnetism and Aeronomy》2020,60(7):915-920

Geomagnetism and Aeronomy - Analysis of the phenomenon of the shrinkage of a coronal magnetic loop during the impulsive phase of a flare makes it possible to determine both the evolution of...  相似文献   

Gyrosynchrotron Model of Microwave Sources Associated with the Magnetic Field Neutral Line     

Zaitsev  V. V. 《Geomagnetism and Aeronomy》2019,59(7):898-903

Geomagnetism and Aeronomy - The main properties of microwave radiation sources over the magnetic field neutral line, which follow from the assumption of a gyrosynchrotron mechanism of radio...  相似文献   

Kimberlites of the Manchary pipe: a new kimberlite field in Central Yakutia     

A.P. Smelov  A.P. Andreev  Z.A. Altukhova  S.A. Babushkina  K.A. Bekrenev  A.I. Zaitsev  E.D. Izbekov  O.V. Koroleva  V.M. Mishnin  A.V. Okrugin  O.B. Oleinikov  A.A. Surnin 《Russian Geology and Geophysics》2010,51(1):121-126

This paper reports new petrographic and mineralogical data on the Manchary kimberlite pipe, which was discovered south of Yakutsk (Central Yakutia) in 2007–2008, 100 km. The pipe breaks through the Upper Cambrian carbonate deposits and is overlain by Jurassic terrigenous rock masses about 100 m thick. It is composed of greenish-gray kimberlite breccia with a serpentine-micaceous cement of massive structure. The porphyry texture of kimberlite is due to the presence of olivine, phlogopite, and picroilmenite phenocrysts. The SiO₂ and Al₂O₃ contents of the groundmass are indicative of typical noncontaminated kimberlites. The groundmass has a significant content of ore minerals: Fe- and Cr-spinels, perovskite, magnetite, and, less commonly, magnesian Cr-magnetite. Pyropes occur in kimberlites as sharp-edged fragments and show uneven distribution. Chemically, they belong to lherzolite, wehrlite, or nondiamondiferous dunite–harzburgite parageneses. Garnets corresponding to lherzolites of anomalous composition make up 8%; this is close to the garnet content of Middle Paleozoic kimberlites from the Yakutian kimberlite province. The pyropes from the new pipe are compositionally similar to those from diamond-poor Middle Paleozoic kimberlites in the north of the Yakutian diamondiferous province. Chemically, pyropes from the Manchary pipe and those from the modern alluvium of the Kengkeme and Chakyya Rivers differ substantially. Consequently, the rocks of the pipe could not be a source of pyropes for this alluvium. They probably occured from other sources. This fact along with numerous “pipelike” geophysical anomalies, suggest the existence of a new kimberlite field in Central Yakutia.  相似文献   

The tsunami on Sakhalin on August 2, 2007: Mareograph evidence and numerical simulation     

A. I. Zaitsev  D. P. Kovalev  A. A. Kurkin  B. V. Levin  E. N. Pelinovskii  A. G. Chernov  A. Yalciner 《Russian Journal of Pacific Geology》2009,3(5):437-442

Instrumental data on the tsunami registration on Sakhalin and Hokkaido islands are presented. The numerical simulation of the tsunami propagation in the Tatar Strait was performed. The results of the calculations are in satisfactory agreement with the observed data.  相似文献   

Community Structure in the Amber Forest: Study of the Arthropod Syninclusia in the Rovno Amber(Late Eocene of Ukraine)   总被引：1，自引：1，他引：0  

Evgeny E.?PERKOVSKY  Alexandr P.?RASNITSYN  Аnatoly P. VLASKIN  Sergej P.?RASNITSYN 《《地质学报》英文版》2010,84(4):954-958

<正>Arthropodan syninclusions in the Late Eocene Rovno amber were examined using x~2 to reveal correlation of the component groups(some taxa of Diptera,ants,aphids,and mites) supposedly indicative of the biocoenotic relationships in the ancient amber forest.Three tightly correlated groups were identified,representing a putative aerial plankton guild(Chironomidae+Ceratopogonidae) and two tree-trunk guilds,one of which (Dolichopodidae+Germaraphis) is possibly connected to more open or/and more hygrophilous habitats than the other(Sciara zone Diptera +"Acarus"rhombeus).The ants were not linked with any of the above components.  相似文献