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Izvestiya, Physics of the Solid Earth - Abstract—Variations in the vertical electric field and atmospheric current in the near-surface atmosphere, accompanying strong earthquakes, are... 相似文献
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The ultrabasic–basic magmatic evolution of the lower mantle material includes important physicochemical phenomena, such as the stishovite paradox and the genesis of superdeep diamonds. Stishovite SiO2 and periclase–wüstite solid solutions, (MgO · FeO)ss, associate paradoxically in primary inclusions of superdeep lower mantle diamonds. Under the conditions of the Earth’s crust and upper mantle, such oxide assemblages are chemically impossible (forbidden), because the oxides MgO and FeO and SiO2 react to produce intermediate silicate compounds, enstatite and ferrosilite. Experimental and physicochemical investigations of melting phase relations in the MgO–FeO–SiO2–CaSiO3 system at 24 GPa revealed a peritectic mechanism of the stishovite paradox, (Mg, Fe)SiO3 (bridgmanite) + L = SiO2 + (Mg, Fe)O during the ultrabasic–basic magmatic evolution of the primitive oxide–silicate lower mantle material. Experiments at 26 GPa with oxide–silicate–carbonate–carbon melts, parental for diamonds and primary inclusions in them, demonstrated the equilibrium formation of superdeep diamonds in association with ultrabasic, (Mg, Fe)SiO3 (bridgmanite) + (MgO · FeO)ss (ferropericlase), and basic minerals, (FeO · MgO)ss (magnesiowüstite) + SiO2 (stishovite). This leads to the conclusion that a peritectic mechanism, similar to that responsible for the stishovite paradox in the pristine lower mantle material, operates also in the parental media of superdeep diamonds. Thus, this mechanism promotes both the ultrabasic–basic evolution of primitive oxide–silicate magmas in the lower mantle and oxide–silicate–carbonate melts parental for superdeep diamonds and their paradoxical primary inclusions. 相似文献
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Spivak A. A. Rybnov Yu. S. Riabova S. A. Kharlamov V. A. 《Doklady Earth Sciences》2021,498(2):487-490
Doklady Earth Sciences - The results of data analysis of instrumental observations of microbaric variations in the atmospheric pressure carried out at the Mikhnevo Geophysical Observatory and at... 相似文献
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V. V. Adushkin A. A. Spivak V. A. Kharlamov 《Izvestiya Physics of the Solid Earth》2012,48(2):104-116
Extraterrestrial forcing of natural environmental processes by gravitational interaction between the Sun, the Moon, and the
Earth is considered. Based on the instrumental data, the main periodical components and cycles are identified in the time
variations of some geophysical fields at the boundary between the Earth’s crust and the atmosphere. Correlation analysis shows
that the lunar-solar tides are the key factor responsible for diurnal and quasi-biweekly variations in the ground electric
field, radon emanation, water level in wells, and microseismic vibrations. The tidal influence on the various-scale movements
of the blocks of the Earth’s crust is analyzed. In the context of the vertical, lateral, and rotational motion of crustal
blocks, which is very important for the platforms, a new, precession-like type of displacements is revealed. These movements
develop as a result of the nonsynchronous tidal responses of the block and the adjacent interblock gaps or tectonic structures
whose strength and strain properties are different in different directions. 相似文献
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The gravitational interaction in the Earth–Moon–Sun system is considered from the standpoint of influencing the formation of time variations in the geophysical fields and some natural processes. The analysis of the results of instrumental observations revealed the main periodicities and cycles in the time variations of subsoil radon volumetric activity with the same periods as the vertical component of the variations of the tidal force. The amplitude modulation of seismic noise by the lunar-solar tide is demonstrated. It is shown that the intensity of relaxation processes in the Earth’s crust has a near-diurnal periodicity, whereas the spectrum of groundwater level fluctuations includes clearly expressed tidal waves. Based on the data on the tilts of the Earth’s surface, the role of tidal deformation in the formation of the block motions in the Earth’s crust is analyzed. A new approach is suggested for identifying tidal waves in the atmosphere by analyzing micropulsations of the atmospheric pressure with the use of adaptive rejection filters. 相似文献
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Mariano J. Albano Carlos Rumbold Ignacio L. Chiesa Guadalupe Vazquez Eduardo D. Spivak Sandra M. Obenat 《新西兰海洋与淡水研究杂志》2019,53(1):15-32
We report the occurrence of the invasive amphipod Monocorophium acherusicum in Mar del Plata port, Argentina, using morphological and molecular analysis and estimated mean abundance to detect monthly variations of this population. We compared M. acherusicum morphology with that of M. insidiosum and Crassicorophium bonelli, the two most similar locally occurring species, to establish the diagnostic characteristics for the correct identification of them; moreover, we provide some taxonomic notes about others corophiids regionally distributed. M. acherusicum were collected in a subtidal biofouling community and its mean abundance was maximum in summer. In the molecular analysis, the maximum-likelihood tree showed that specimens from Mar del Plata were clustered with M. acherusicum specimens from GenBank and Boldsystems. We support and confirm the species identity in Mar del Plata port using DNA barcoding and with taxonomic methods. 相似文献
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Claudia Bas Toms Luppi Eduardo Spivak Laura Schejter 《Estuarine, Coastal and Shelf Science》2009,83(4):569-576
The estuarine brachyuran crab Neohelice granulata export their larvae from the parental intertidal population of the Mar Chiquita coastal lagoon, and probably other populations, to marine waters. The degree of larval dispersion or self-recruitment of populations is unknown. We evaluated the presence of all larval stages of N. granulata in coastal waters of Argentina between 37.9° and 35.8° S, at two different spatial scales: a broad scale of tens to hundreds of kilometers from the Río de la Plata estuary in the north, to Mar Chiquita lagoon in the south, and a small scale of hundreds of meters to some kilometers around the mouth of Mar Chiquita, during spring and summer. Additionally, we registered the larval composition and density at San Clemente creek population, in Samborombon Bay (Río de la Plata estuary), every 3 h along a 30-hour period. Evidence indicates that larval release of N. granulata is temporally synchronized with nocturnal ebb tides and all development from Zoea I to Zoea IV occur in areas close to the parental population, even with very different oceanographic characteristics. A possible mechanism based on salinity selection and wind-driven transport is proposed for such behavior, and some considerations related to the connectivity of present populations are made. 相似文献