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141.
Based on the data of differential satellite interferometry, the field of displacements of the Earth’s surface in the line-of-sight direction is determined for the region of the Altai Earthquake that struck on September 27, 2003. The displacements are estimated for unforested areas of Chuia and the Kurai depressions, and for a part of their mountainous surroundings. In that part of the region where unwrapping of the data was possible, the amplitude of displacements amounts up to 150 cm for Chuia and 100 cm for the Kurai depressions. In order to locate the surface of the seismic rupture and to find the field of displacements on this surface, the method for the combined inversion of the displacements data, provided by satellite interferometry (the present work) and geodesy [Gol’din et al., 2005], is suggested and applied. The admissible range of the parameters of the rupture was specified from the seismology and seismotectonics data. The combined use of geodetic and satellite interferometry data makes the solution of the inverse problem more stable and yields a seismic momentum estimate, which is consistent with the seismological determinations. We discuss the possible contributions of various postseismic processes; in particular, based on analyzing the energy of the aftershocks, we assess the contribution of the postseismic creep to the displacements, determined from the interferometry and geodesy data, for different coseismic and postseismic time intervals.  相似文献   
142.
The preliminary results of observations of VLF electromagnetic signals (atmospherics) in the mountains of North Vietnam (Dien Bien Phu, 21°23′50″ N, 103°0′28″ E) are presented. Primarily, signals of typical atmospherics with a maximum in the frequency range of 4–9 kHz were observed; sometimes they were accompanied by so-called “tails” at frequencies less than 1 kHz, and also tweeks of usually short duration (about 10 ms) were observed. Several parameters of the ionosphere, as well as the distance to sources of atmospherics (in accordance to the data of the World Wide Lightning Location Network (TOGA)), were estimated by spectral-temporal characteristics of tweeks.  相似文献   
143.
We consider data obtained when the parameters of the ionospheric Es and F2 layers and the vertical gradient of the electric potential in the surface atmosphere were simultaneously measured during the preparatory period of crustal earthquakes with M = 5.0–6.2 in the Kamchatka region. The appearance of anomalously high Es, accompanied by an increase in frequency parameters of the sporadic layer and the regular F2 layer, was detected on days when possible earthquake precursors, as determined earlier, occurred in atmospheric electric fields. The presumed earthquake precursors in the ionosphere are divided into two groups with different earthquake lead times ranging from several hours to two weeks. Empirical dependences are presented that connect the lead time of an earthquake (from the moment of the appropriate anomaly’s occurrence in the ionosphere or in the atmospheric electric field to the moment of the shock) and the epicentral distance to the observation point with the earthquake magnitude. These dependences are different for the two groups of presumed earthquake precursors, but they are close inside each group of possible precursors selected on the basis of quasistatic electric field measurements and revealed in ionospheric parameter variations.  相似文献   
144.
We have performed a spectral analysis of variations in the E z component of a quasistatic electric field in the atmospheric surface layer in a wide band of internal gravity waves (from 5 min to 3 h) for quiet and seismically active conditions as well as high thunderstorm activity. Observational data of the field for September, 1999 and August–September, 2002, were used. It has been shown that, if there are no thunderstorms or earthquakes, the background spectrum includes oscillations with maxima at periods of T ∼ 1.8 and 1 h, 40, 30, 15, and 10–13 min. Their intensity in the range of periods of 0.5–3.0 h is two or more orders of magnitude higher than the intensity of maxima in the range of 5–30 min. Before earthquakes, with anomalies in diurnal variations of field intensity, there is a tendency of increased background spectrum at maxima noted there. In both ranges of oscillation periods, the spectral intensity increases by one to one and a half orders of magnitude. Under high thunderstorm activity, the variability is higher as compared to the spectra of earthquake precursors by both locations of maxima and their intensity. The intensity of maxima exceeds the maxima on the eve of earthquakes one to one and a half orders of magnitude in the range of periods 0.5–3.0 h and two and more orders of magnitude in the range of periods 5–30 min.  相似文献   
145.
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   
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148.
Izvestiya, Physics of the Solid Earth - Abstract—The empirical results on estimating the resolution and high-frequency noise in the Earth’s gravity models are presented. The Schmidt...  相似文献   
149.
The diurnal variations in electrical (quasistatic electric field and electrical conductivity) and meteorological (temperature, pressure, relative humidity of the atmosphere, and wind speed) parameters, measured simultaneously before strong earthquakes in Kamchatka region (November 15, 2006, М = 8.3; January 13, 2007, М = 8.1; January 30, 2016, М = 7.2), are studied for the first time in detail. It is found that a successively anomalous increase in temperature, despite the negative regular trend in these winter months, was observed in the period of six–seven days before the occurrences of earthquakes. An anomalous temperature increase led to the formation of “winter thunderstorm” conditions in the near-surface atmosphere of Kamchatka region, which was manifested in the appearance of an anomalous, type 2 electrical signal, the amplification of and intensive variations in electrical conductivity, heavy precipitation (snow showers), high relative humidity of air, storm winds, and pressure changes. With the weak flow of natural heat radiation in this season, the observed dynamics of electric and meteorological processes can likely be explained by the appearance of an additional heat source of seismic nature.  相似文献   
150.
Astronomy Letters - The Spectrum–Röntgen–Gamma (SRG) space observatory was launched from Baikonur on July 13, 2019, and is currently on a flight trajectory in the vicinity of the...  相似文献   
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