Some aspects of interpretation of tensor gradiometry data     

V. O. Mikhailov  M. Diament 《Izvestiya Physics of the Solid Earth》2006,42(12):971-978

Aspects of the interpretation of measured data on the gravity gradient tensor (GGT) are examined. The problem is posed in relation to the great progress achieved in recent years in the development of instrumentation and the method of GGT measurements on mobile carriers. In our opinion, the new methods of measurement and the new data obtained with their help require the development of new methods of interpretation of potential fields. The paper addresses two methods taking advantage of simultaneous measurements of all components of the GGT and anomalies of the gravitaty field V _z. It is shown that the joint analysis of all GGT components can provide independent constraints on the noise level in various components. The method of tensor deconvolution proposed in the paper is a tensor analogue of the Euler method. The method is based on the calculation of invariants and is, therefore, stable with respect to the orientation uncertainties of the measuring system. The method provides means for estimating the structural index and, therefore, is particularly effective in the treatment of fields that contain isometric and/or elongated anomalies. The calculation of invariants and the tensor ratio can also be used for the development of procedures enabling automatic estimation of the axis strike azimuths of elongated anomaly-forming bodies.  相似文献   

Electric and electromagnetic processes in the near-Earth atmosphere before earthquakes on Kamchatka     

Yu. M. Mikhailov  G. A. Mikhailova  O. V. Kapustina  G. I. Druzhin  S. E. Smirnov 《Geomagnetism and Aeronomy》2006,46(6):796-808

Simultaneous records of the diurnal variations in the quasistatic electric field in the near-Earth atmosphere, fluxes of discrete electromagnetic pulses in the VLF band, source azimuths, narrowband filter output emission intensity at frequencies of 4.65 and 5.3 kHz, and time forms and spectra of VLF pulses have been analyzed. The anomalous behavior of these parameters in October 2002 and August 2004 with different time delay was accompanied by earthquakes near the southeastern coast of Kamchatka at distances of 250–400 km from the registration points. Based on the results of a fine frequency-time analysis of the broadband records of VLF signals, it has been indicated for the first time that discrete electromagnetic pulses observed in anomalous fluxes before earthquakes were signals of local thunderstorm processes.  相似文献   

Long-Term Water Level Variations in the Kiliya Branch of the Danube Delta     

Mikhailov  V. N.  Povalishnikova  E. S.  Morozov  V. N. 《Water Resources》2001,28(2):167-173

Water level variations in the Kiliya Branch of the Danube Delta over the period of 40 years (1958–1997) were analyzed. These level variations were subdivided into three components related to long-term variations of the share of the branch runoff and its redistribution within a year resulting from the Danube flow regulation; subsidence of deltaic deposits; and backup caused by the rising Black Sea level. It was revealed that, during the low-flow period, this backup had propagated to the river mouth at a distance of 160 km.  相似文献   

The effect of the pore space microstructure on hydrophobization of oil and gas reservoirs     

N. N. Mikhailov  V. A. Kuz’min  K. A. Motorova  L. S. Sechina 《Moscow University Geology Bulletin》2016,71(6):436-444

The results of theoretical and experimental studies of the effect of the microstructure of the pore space on the hydrophobization of oil and gas reservoirs are presented. A possible mechanism of formation of the microstructured wettability is described, which demonstrates that hydrophobization of the inner pore space in mixed wettability can be associated either with large or small pore sizes. It was proven experimentally that the process of hydrocarbon adsorption depended on the shape, size, and distribution of pores, the mineralogical composition (particle composition and size, presence of clay), as well as on the time of contact of hydrocarbons with the inner pore surface. The concept of the hydrophilic nature of rock prior to the migration of oil into it can be considered as accurate. However, as was shown in the experiments, oil could be present in the small pores (up to 10 μm), which was especially significant for the carbonate reservoirs.  相似文献   

River and sea water interaction and delta formation in tidal mouth area of the Fraser River (Canada)     

V. N. Mikhailov  M. V. Mikhailova  E. P. Rets 《Water Resources》2007,34(5):571-586

The history of studies and development of water resources of the Fraser River (Canada) and its mouth area is presented. The history of the Fraser River delta development and the hydrologomorphological processes that occur at this delta are discussed. Close attention is given to the analysis of processes of dynamic interaction and mixing of river and sea water under the joint impact of river flow and tidal fluctuations.  相似文献   

The Impact of Deltas on the Mean Long-Term Water River Runoff     

Mikhailov  V. N. 《Water Resources》2004,31(4):351-356

Specific features of the water balance of river deltas located in different geographic zones are discussed. Variations in the mean long-term water runoff in river deltas are estimated. As revealed, the river water runoff increases in the deltas located in subarctic, subequatorial, and equatorial regions, where precipitation exceeds evaporation, while the river water runoff decreases in deltas located in the temperate zone, subtropics, and tropics, where evaporation exceeds precipitation. It is noted that increase in water runoff is typical of the river deltas of the world as a whole.  相似文献   

Neutral gas composition changes and E×B vertical plasma drift contribution to the daytime equatorial F2-region storm effects     

A. V. Mikhailov  M. Förster  M. G. Skoblin 《Annales Geophysicae》1994,12(2-3):226-231

Theoretical model calculations along with ground-based observations from Huancayo ionosonde station and ESRO-4 gas analyzer data, were used to estimate the contribution of neutral gas composition changes and E×B vertical plasma drift to the observed F2-layer storm effects at the geomagnetic equator. Atomic oxygen concentration increase may give the main contribution to the positive NmF2 effect when drift velocity changes are small, but negative storm effects, on the other hand, are related mostly to vertical drift variations.  相似文献   

Influence of the Component Composition of Adsorbed Oil on the Microstructural Wettability of Hydrocarbon Reservoirs     

Mikhailov  N. N.  Ermilov  O. M.  Sechina  L. S. 《Doklady Earth Sciences》2021,496(2):107-111

Doklady Earth Sciences - The physicochemical mechanism of the development of microstructural wettability in oil and gas reservoirs is experimentally justified. It is shown that this mechanism is...  相似文献   

Initial Galactic Magnetic Fields and the Biermann Battery Mechanism     

Mikhailov  E. A.  Andreasyan  R. R. 《Astronomy Reports》2021,65(9):715-722

Astronomy Reports - There are regular magnetic fields with inductions of several microgauss observed in numerous galaxies. The generation of these fields is explained by the dynamo associated with...  相似文献   

Lineament fabric from airborne LiDAR and its influence on triggered earthquakes in the Koyna-Warna region,western India     

Kusumita Arora  R. K. Chadha  Y. Srinu  Adrien Selles  Srinagesh Davuluri  Vladimir Smirnov  Alexander Ponomarev  V. O. Mikhailov 《Journal of the Geological Society of India》2017,90(6):670-677

We present the results of the first airborne LiDAR survey flown in the Koyna-Warna region and examine the relationship between the lineament fabric and the ongoing seismicity in the region. Our studies reveal that earthquakes of M≥4.0 for the period 1968 to 2016 are strongly correlated with a 10 km wide N-S fracture zone, which not only represents the surface expression of seismically active basement faults, but also act as conduits for water percolation between the Koyna and Warna reservoirs. A decreasing trend in the annual distribution of earthquakes was observed from 1985. A new burst of seismic activity in 1993 followed the impoudment of the Warna reservoir. We report a change in annual seismicity pattern, where seismicity peaks during September and December in the pre-Warna period, with a new peak emerging during March-April subsequent to the impoundment of Warna reservoir. A model is proposed to explain the seismicity along dominant N-S lineaments and the impact of Warna reservoir impounding which altered the hydrogeologic regime in the region.  相似文献