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Andriy Gnyp 《Acta Geophysica》2010,58(4):587-603
Three groups of recurrent events have been identified within the 2005–2006 Mukacheve series of about forty M
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0.3–1.8 near-surface earthquakes. After a cross-correlation analysis of their waveforms and subsequent relocation with application
of the adjusted arrivals and station terms it turned out that they most likely belong to at least two distinct crustal layers
separated by an interface at about 4 km; the seismic activation started deeper and progressed upwards. As concerns polarities
of first arrivals, the same source mechanism was inferred within individual groups, indicating a normal faulting along the
Az ≈ 120° with a slight component of right lateral slip; this finding is consistent with data available on some other local
sources, as well as with an ambient field of extensional stresses in the local crust and a significant horizontal gradient
of vertical movements across the epicenter area of the Mukacheve series. 相似文献
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V. P. Isupov A. G. Vladimirov N. Z. Lyakhov S. L. Shvartsev S. Ariunbileg M. N. Kolpakova S. S. Shatskaya L. E. Chupakhina L. V. Kuibida E. N. Moroz 《Doklady Earth Sciences》2011,437(1):352-356
Analysis of major- and trace-element compositions of water in hypersaline soda closed basin lakes of Northwestern Mongolia
and Chuya basin (Gorny Altai) shows high enrichment in 238U (up to 1 mg/l). Proceeding from new data, uranium accumulation in water has been attributed to (i) location of the lakes
and their watersheds in potential provinces of U-bearing rocks and (ii) uranium complexing with carbonate in presence of carbonate
(bicarbonate) anions. Among the explored hypersaline soda lakes of the area, the greatest uranium resources are stored in
Lake Hyargas Nuur (about 6000 ton). 相似文献
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Shigeaki Ono Artem R. Oganov John P. Brodholt Lidunka Vo
adlo Ian G. Wood Andriy Lyakhov Colin W. Glass Alexander S. Ct G. David Price 《Earth and Planetary Science Letters》2008,272(1-2):481-487
Iron sulfide (FeS) was investigated using first-principles calculations up to a pressure of 400 GPa. A number of new phase transitions were found. An antiferromagnetic MnP-type structure, FeS II, was confirmed to be stable at low pressures, whereas at high pressures (40–135 GPa) we find a new stable phase, with a non-magnetic MnP-type structure, FeS VI. The observed first-order change in the cell shape between the two phases can be explained by the difference in magnetic configurations. The calculated cell parameters, atomic coordinates, and bulk modulus of non-magnetic MnP-type phase are consistent with those determined from experiment. The upper pressure limit of the stability of the non-magnetic MnP-type phase was calculated to be 135 GPa. A hitherto unsuspected phase transition from the non-magnetic MnP-type to a phase with Pmmn symmetry, FeS VII, was identified using the evolutionary crystal structure prediction (USPEX) method. The structure of the Pmmn phase has no known analogues, but can be described as a distortion of the NaCl-type structure. The Pmmn phase with the distorted NaCl-type structure is stable from 135 GPa at least up to 400 GPa. According to previous experiments and the present study, the transition sequence of FeS at low temperatures is as follows: troilite ➔ antiferromagnetic MnP-type phase ➔ monoclinic phase ➔ non-magnetic MnP-type phase ➔ Pmmn phase. The calculated volume reduction from the monoclinic to the non-magnetic MnP-type phase is 1.0% at 40 GPa, which is in good agreement with experimental observations. The calculated volume reduction from the non-magnetic MnP-type to the Pmmn phase is 3.7% at 135 GPa. 相似文献
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Gavrilov B. G. Ermak V. M. Lyakhov A. N. Poklad Yu. V. Rybakov V. A. Ryakhovsky I. A. 《Geomagnetism and Aeronomy》2020,60(6):747-753
Geomagnetism and Aeronomy - The paper presents the results of the reconstruction of the effective height h' and the slope of the profile β of the electron concentration in the D layer of... 相似文献
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Andriy Gnyp 《Acta Geophysica》2014,62(6):1246-1261
Relative locations of recurrent earthquakes can be recovered from values of cross-correlation coefficients between their waveforms at a single station, provided that an idea of Menke (1999) that the values depend inversely exponentially from separation between the sources is true. An algorithm developed in Gnyp (2013) based on this idea was applied here for recovering relative locations of the two groups of the 2005–2006 recurrent earthquakes in Mukacheve, Ukraine, from the sets of cross-correlation coefficients between their records at the four local network stations to find out whether the locations were in principle reproducible independently at each of the stations, at epicentral distances from about 6 to 64 km. The resulting sets of locations occurred in good agreement with each other, which may be considered as an experimental evidence for validity of the Menke’s dependence over the corresponding range of distances. The reproducibility of relative locations has been analyzed in terms of existence and uniqueness of the inverse problem’s solution, and in connection with data completeness and the influence of noise on it. 相似文献
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Andriy Gnyp 《Acta Geophysica》2013,61(5):1074-1087
An algorithm was designed for inverting the set of cross-correlation coefficients between the records of recurrent earthquakes by a single station for their relative locations based on an assumption of Menke (1999) that the cross-correlation is only a function of separation between the sources and decays exponentially with it. Tested on synthetic data sets, the algorithm easily recovered the true relative locations, the initial ones seeded randomly. Inversion of the cross-correlation coefficients between the records of the two groups of the Mukacheve 2005–2006 recurrent earthquakes by the station Mukacheve steadily produced an almost flat shape of hypocenter cloud for each of the groups, final relative locations of hypocenters being almost the same for different initial seedlings. The combined set of cross-correlation coefficients for both groups was also inverted, and the shape of the combined hypocenter cloud was almost flat again. These results compare well with ones obtained earlier (Gnyp 2010) by relocating the Mukacheve earthquakes with the use of differential arrivals and source specific station terms. 相似文献