Spectral Analysis of Profile Topographic Data Using Modified F-Approximations     

Stepanova  I. E.  Kerimov  I. A.  Spesivtsev  A. A.  Timofeeva  V. A.  Mikhailov  P. S. 《Izvestiya Physics of the Solid Earth》2021,57(4):573-581

Izvestiya, Physics of the Solid Earth - Abstract—Analytical approximations are constructed and spectral analysis carried out for the profile data on terrain elevations obtained from global...  相似文献   

Asymptotic estimates of the mean probability of radiative transfer through an exponentially correlated stochastic medium     

G. A. Mikhailov 《Izvestiya Atmospheric and Oceanic Physics》2012,48(6):618-624

Various models of exponentially correlated random fields associated with Poisson point ensembles, as well as algorithms for simulating radiative transfer in stochastic media of that type, are considered. Asymptotic estimates for the mean probability of particle (quantum of radiation) passage, assuming that the flow of trajectory intersections with domains of constant random density is Poissonian and using the central limit theorem for the corresponding optical length, are made.  相似文献   

Large-scale aseismic creep in the areas of the strong earthquakes revealed from the GRACE data on the time variations of the Earth’s gravity field     

V. O. Mikhailov  M. Diament  A. A. Lyubushin  E. P. Timoshkina  S. A. Khairetdinov 《Izvestiya Physics of the Solid Earth》2016,52(5):692-703

The refinement of the accuracy and resolution of the monthly global gravity field models from the GRACE satellite mission, together with the accumulation of more than a decade-long series of these models, enabled us to reveal the processes that occur in the regions of large (M_w≥8) earthquakes that have not been studied previously. The previous research into the time variations of the gravity field in the regions of the giant earthquakes, such as the seismic catastrophes in Sumatra (2004) and Chile (2010), and the Tohoku mega earthquake in Japan (2011), covered the coseismic gravity jump followed by the long postseismic changes reaching almost the same amplitude. The coseismic gravity jumps resulting from the lower-magnitude events are almost unnoticeable. However, we have established a long steady growth of gravity anomalies after a number of such earthquakes. For instance, in the regions of the subduction earthquakes, the growth of the positive gravity anomaly above the oceanic trench was revealed after two events with magnitudes M_w=8.5 in the Sumatra region (the Nias earthquake of March 2005 and the Bengkulu event of September 2007 near the southern termination of Sumatra Island), after the earthquake with M_w=8.5 on Hokkaido in September 2007, a doublet Simushir earthquake with the magnitudes M_w = 8.3 and 8.1 in the Kuriles in November 2006 and January 2007, and after the earthquake off the Samoa Island in September 2009 (M_w=8.1). The steady changes in the gravity field have also been recorded after the earthquake in the Sichuan region (May 2008, M_w = 8.0) and after the doublet event with magnitudes 8.6 and 8.2, which occurred in the Wharton Basin of the Indian Ocean on April 11, 2012. The detailed analysis of the growth of the positive anomaly in gravity after the Simushir earthquake of November 2006 is presented. The growth started a few months after the event synchronously with the seismic activation on the downdip extension of the coseismically ruptured fault plane zone. The data demonstrating the increasing depth of the aftershocks since March 2007 and the approximately simultaneous change in the direction and average velocity of the horizontal surface displacements at the sites of the regional GPS network indicate that this earthquake induced postseismic displacements in a huge area extending to depths below 100 km. The total displacement since the beginning of the growth of the gravity anomaly up to July 2012 is estimated at 3.0 m in the upper part of the plate’s contact and 1.5 m in the lower part up to a depth of 100 km. With allowance for the size of the region captured by the deformations, the released total energy is equivalent to the earthquake with the magnitude M_w = 8.5. In our opinion, the growth of the gravity anomaly in these regions indicates a large-scale aseismic creep over the areas much more extensive than the source zone of the earthquake. These processes have not been previously revealed by the ground-based techniques. Hence, the time series of the GRACE gravity models are an important source of the new data about the locations and evolution of the locked segments of the subduction zones and their seismic potential.  相似文献   

Marine gravity measurements without referencing to the coastal base stations     

L. K. Zheleznyak  P. S. Mikhailov  V. N. Soloviev 《Izvestiya Physics of the Solid Earth》2014,50(2):212-214

The experience of areal gravity surveying in the open ocean with the correction of measurements by the EGM2008 gravity field model is described. It is concluded that correction of the gravimeter measurements by the model data is admissible and reasonable.  相似文献   

Some problems of landslide monitoring using satellite radar imagery with different wavelengths: Case study of two landslides in the region of Greater Sochi     

V. O. Mikhailov  E. A. Kiseleva  E. I. Smol’yaninova  P. N. Dmitriev  V. I. Golubev  Yu. S. Isaev  K. A. Dorokhin  E. P. Timoshkina  S. A. Khairetdinov 《Izvestiya Physics of the Solid Earth》2014,50(4):576-587

The problems of processing and interpreting the data provided by radar satellite interferometry for the conditions of landslides covered by vegetation are analyzed in two case studies of landslides in the Northern Caucasus in the region of Kepsha and Mamaika villages in the vicinity of the railway tunnels. The estimates of the displacement fields are obtained by the method of persistent scatterers using the StaMPS program package. The five-year experience of landslide monitoring shows that in the unfavorable conditions of satellite radar interferometry, proper selection of the strategy of satellite image processing is vital. In the present paper, we discuss, in particular, the crop selection, the selection of the master image, reference area, and digital elevation model. For the landslide located in the sparsely populated region near Kepsha village, we used the data from the ascending and descending tracks of the long-wavelength ALOS and shorter-wavelength ENVISAT satellites. For the landslide in the region of Mamaika village with a large number of different buildings serving as good scatterers for radar signals, we used the images from the ENVISAT and from TerraSAR satellite, which transmits even shorter waves. The average line-of-sight (LOS) displacement velocities V _LOS for the landslide near Kepsha village measure at most 10 mm per annum, which means that this landslide has remained stable at least since 2004. The landslide in Mamaika village is significantly more active. The average LOS displacement velocities in the active part of this landslide attain 60 mm per annum. The artificial corner reflector installed on the segment of the landslide where natural scatterers of radar signal are absent made it possible to estimate the LOS displacement velocity on this segment of the slope at 49 mm per annum.  相似文献   

Hydrological and morphological processes at river mouths of the Caspian Sea Region as possible analogs of expected changes of mouths of other rivers in Russia and the world     

V. N. Mikhailov  M. V. Mikhailova  M. V. Isupova 《Water Resources》2014,41(5):489-504

Present changes in the regime and structure of mouths of rivers, which empty into the Caspian Sea, are discussed. The similarities and differences of these processes at the mouths of different rivers of the Caspian Region were revealed. Assessment was made of the impact of changes in river water runoff and sediment load and in the Caspian Sea level as well as the nearshore zone relief and local hydraulic engineering activities on the processes under study. Anomalous features of the processes occurring at the mouths of the Volga and Terek rivers were revealed and explained. Hydrological and morphological processes typical of the present mouths of the rivers of Ural, Sulak, and Kura were revealed; these processes could be accepted as universal and possible analogs in assessing the expected changes at the mouths of other rivers in Russia and the world in the XXI century.  相似文献   

Sequence of Early Precambrian metamorphic events in the southern Prince Charles Mts., Eastern Antarctica     

V. S. Semenov  E. N. Kamenev  V. M. Mikhailov  I. A. Kamenev  S. V. Semenov 《Geology of Ore Deposits》2009,51(8):723-740

The results of geological study of the mountain framework of the southern part of the Lambert Glacier, Mawson Escarpment, Eastern Antarctica, are discussed. The studied territory is of key importance for understanding the regional geological history. The Ruker and the Lambert rock complexes have been distinguished at the Mawson Escarpment. The former is subdivided into the Mawson and Menzies groups. The polymetamorphic rocks of the Mawson Group comprise granite gneiss, orthopyroxene gneiss, and crystalline schists dated at >3000 Ma combined with tectonic wedges and blocks of the variegated sequence with ultramafic (komatiitic) rocks. The find of those rocks allows us to suggest that an ancient granite-greenstone domain existed in the territory of the Prince Charles Mts.; this domain is retained only as tectonic wedges amongst granite gneisses of the Mawson and Menzies groups composed of polymetamorphic terrigenous rocks with basic sills. The following sequence of metamorphic mineral assemblages in the Menzies Group has been established: (1) And-Crd ± St, (2) Ky-St-Grt-Bt-Ms, (3) Sil-Grt-Crd. The andalusite-type metamorphism of rocks pertaining to the Menzies Group probably has the same age as greenschist metamorphism of rocks belonging to the Collaboration Group (2917 ± 82–2878 ± 65 Ma at Mt. Ruker). The formation of kyanite-staurolite mineral assemblage (mounts Stinear, Maguire, Rymill; South Mawson Escarpment) might be related to a metamorphic event dated at 2400–2350 Ma. The formation of sillimanite-garnet and sillimanite-cordierite assemblages with staurolite relics correlates in time with emplacement of the MacColly granite 600–500 Ma ago. Polymetamorphic rocks of the Lambert Complex are migmatites and gneisses, often with orthopyroxene relics. Blocks of ultramafic rocks are localized amongst granite gneisses. The superimposed metamorphism of amphibolite and granulite facies took place 1800 Ma ago. The model Nd age of ultramafic rocks (2500 Ma) is treated as the time of emplacement of magma into the rocks of the Lambert Complex. Isotopic and geochemical evidence for Early Paleozoic granulite-facies metamorphism is known.  相似文献   

The uranium content in Dictyonema shale of the Kaibolovo–Gostilitsy Area in the Baltic basin (Leningrad Region)     

V.?I.?VyalovEmail author  A.?Kh.?Bogomolov  V.?A.?Mikhailov  E.?V.?Semenov 《Moscow University Geology Bulletin》2017,72(5):326-331

This paper reports the data on the uranium content in Dictyonema shale and phosphate rock in the Kaibolovo–Gostilitsy Area of the Baltic Basin (Leningrad Region). Specific features of the uranium ore in the studied area and stratigraphic rock sequence of the Early Ordovician Pakerort horizon are considered. A high uranium concentration in the Dictyonema shale layer has been determined, the correlation of uranium with other elements was defined, probable conditions of uranium ore genesis are described, and predicted uranium resources within the studied area are estimated.  相似文献   

Effect of Asphaltenes on Wettability of Gas and Oil Saturated Reservoir Rocks     

Mikhailov  N. N.  Ermilov  O. M.  Sechina  L. S. 《Doklady Earth Sciences》2019,486(1):465-467

Doklady Earth Sciences - The wettability by asphaltenes of siliciclastic and carbonate drill–cores from oil and gas condensate fields extracted with n-hexane and chloroform was studied. The...  相似文献   

Relationship Between the Spins and Masses of Supermassive Black Holes in Distant Active Galactic Nuclei with z > 4     

Mikhailov  A. G.  Piotrovich  M. Yu.  Buliga  S. D.  Natsvlishvili  T. M.  Gnedin  Yu. N. 《Astronomy Reports》2019,63(6):433-444

Astronomy Reports - Hybrid models for the generation of relativistic jets are used to place constraints on the spins of supermassive black holes (SMBHs) in active galactic nuclei at redshifts z...  相似文献