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991.
In Turkey, neotectonic activity originated from the collision of the Arabian and Anatolian land masses during the Middle Miocene. As a result of the collision, westward escape of the Anatolian block introduced E-W compression in Western Turkey which began to be relieved by N-S extension. The North Anatolian Fault (NAF) is the major active strike-slip fault that was formed under the neotectonic regime. The rates of the motion along this fault estimated by several authors are in the range of 0.4–2.9 cm/a according to kinematic data. In Turkey, the first studies of crustal movements by geodetic methods were started in the west section of the NAF in 1972. So far, individual activities and studies coordinated by multidisciplinary projects have been realized in this region. The results obtained from available geodetic data indicate the motion of the Anatolian block relative to Eurasia. 相似文献
992.
993.
The equations of motion applying to the wind field in a forest canopy are simplified to a balance between the shearing stress gradient and either the form-drag of the leaves in the upper dense canopy, or the overall horizontal pressure gradient in the more open space beneath. The equations imply that, in descending through the forest, the stress and wind vectors turn through an angle which depends on the forest characteristics and on the stability and the speed of the airflow above the forest. The turning is roughly confirmed by an overall average measured on a very flat site near Thetford, Norfolk, covered by an extensive uniform pine forest. 相似文献
994.
995.
R. Arjmandi Ph.D. M. Tavakol M.Sc M. Shayeghi PhD. 《International Journal of Environmental Science and Technology》2010,7(1):175-182
In most rice paddies in Mazandaran Province, diazinon is applied to control Chilo suppressalis. Due to the extensive application of insecticides in the rice paddies of the Caspian coasts of Iran, this investigation was carried out on the rice fields in order to obtain the necessary data and information on the concentration of insecticide residues. A total of 125 samples were taken from five areas of Amol township in 2007. Then, according to the analysis of variance procedures, the water samples were statistically analyzed after the spraying of diazinon. Results indicate that the insecticide was used frequently to control stem boring caterpillar of rice. The residuals of this toxic chemical were observed in the majority of stations from the day after the spraying until one to two months later. The greatest level of diazinon was observed in station 1 in amount of 1.14 ppm. This study revealed that the physical and chemical properties of the studied diazinon such as fumigation characteristic as well as the ecological conditions and soil type influence the reduction and eventual removal of the insecticides during the cultivation and harvest periods. 相似文献
996.
V. V. Egorova N. I. Volkova R. A. Shelepaev A. E. Izokh 《Mineralogy and Petrology》2006,88(3-4):419-441
Summary Ultramafic and mafic xenoliths in Ordovician Agardag alkaline basalt dikes from the Sangilen Plateau, southeastern Siberia,
provide samples from the upper mantle and crust beneath central Asia. Three major groups were distinguished among the xenoliths:
Group I xenoliths are spinel lherzolites, Group II xenoliths are spinel-garnet clinopyroxenites, and Group III comprises gabbroic
xenoliths with two subgroups: Group IIIa comprises garnet bearing gabbroids and Group IIIb is represented by garnet-free gabbroids.
The spinel lherzolite xenoliths represent the uppermost lithospheric mantle beneath the Sangilen Plateau and have geochemical
characteristics similar to those of primitive mantle. Spinel-garnet clinopyroxenite and gabbroic xenoliths are of igneous
origin and represent fragments of intrusive bodies crystallized at depths close to the mantle-crust boundary, as well as in
the lower and the upper crust. The gabbroic xenoliths are evidently the crystallization products of melts similar in major
and trace element composition to parental magma of the Bashkymugur gabbronorite-monzodiorite intrusion. Gabbroic xenoliths
from the Ordovician Agardag alkaline basalt dikes demonstrate the presence of intermediate magmatic chambers within the crust
beneath the Sangilen Plateau during the Early Palaeozoic. The relatively high equilibration temperatures of the mantle and
lower crust xenoliths in the Agardag alkaline basalt dikes are largely attributable to a plume occurring beneath the Sangilen
Plateau during the Ordovician. 相似文献
997.
Ionosphere Disturbances Preceding Earthquakes according to the Data of Ground Based Station of the Vertical Ionospheric Sounding Wakkanai 总被引:1,自引:0,他引:1
S. A. Pulinets A. D. Legen’ka V. V. Hegai V. P. Kim L. P. Korsunova 《Geomagnetism and Aeronomy》2018,58(5):686-692
The paper analyzes the data of manual ionograms processing of hourly measurements of the critical frequency foF2 of the F2 ionospheric layer at the Wakkanai ionospheric vertical sounding station (Japan) in a geomagnetically quiet environment before a series of earthquakes with magnitude M > 6.0, for which the station entered the earthquake preparation zone, in order to detect possible Ionospheric Disturbances Preceding Earthquakes (IDPE), and to determine their quantitative characteristics. Detected IDPE, in the opinion of the authors, can be related to the processes of preparation of the corresponding earthquakes, i.e., to be Ionospheric Precursors of Earthquakes (IPE). 相似文献
998.
<Emphasis Type="Italic">M</Emphasis><Subscript>W</Subscript>9 Tohoku earthquake in 2011 in Japan: precursors uncovered by natural time analysis 下载免费PDF全文
Panayiotis A. Varotsos Nicholas V. Sarlis Efthimios S. Skordas Mary S. Lazaridou-Varotsos 《地震科学(英文版)》2017,30(4):183-191
This paper reviews the precursory phenomena of the 2011 M W9 Tohoku earthquake in Japan that emerge solely when we analyze the seismicity data in a new time domain termed natural time. If we do not consider this analysis, important precursory changes cannot be identified and hence are missed. Natural time analysis has the privilege that enables the introduction of an order parameter of seismicity. In this frame, we find that the fluctuations of this parameter exhibit an unprecedented characteristic change, i.e., an evident minimum, approximately two months before Tohoku earthquake, which strikingly is almost simultaneous with unique anomalous geomagnetic field variations recorded mainly on the z component. This is consistent with our finding that such a characteristic change in seismicity appears when a seismic electric signal (SES) activity of the VAN method (from the initials of Varotsos, Alexopoulos, Nomicos) initiates, and provides a direct confirmation of the physical interconnection between SES and seismicity. 相似文献
999.
B. A. Kagan A. A. Timofeev E. V. Sofina 《Izvestiya Atmospheric and Oceanic Physics》2010,46(5):652-662
The modeling results of surface and internal M2 tides for summer and winter periods in the Arctic Ocean (AO) are presented. We employed a modified version of the three-dimensional
finite-element hydrothermodynamic model QUODDY-4 differing from the original model by using a rotated (instead of spherical)
coordinate system and by considering the equilibrium-tide effects. It has been shown that the modeling results for the surface
tide differs little from the results obtained earlier by other authors. According to these results, the amplitudes of internal
tidal waves (ITWs) in the AO are significantly lower than in other oceans and the ITWs proper have the character of trapped
waves. Their source of generation is located at the continental slope northwest of the New Siberian Islands. Our results are
consistent with the fields of average (over a tidal cycle) and integral (by depth) densities of baroclinic tidal energy, the
maximum baroclinic tidal velocity, and the coefficient of diapycnic mixing. The local rate of baroclinic tidal energy dissipation
at the AO ridges increases as it approaches the bottom, as was observed on Mid-Atlantic and Hawaii ridges (but merely within
the bottom boundary layer) and is two to three orders of magnitude lower than in other oceans. The ITW degeneration scale
in the AO is several hundreds of kilometers in summer and winter, remaining within the range of its values between 100 and
1000 km in mid- and low-latitude oceans. In both seasons, the integral (over the AO area) rate of baroclinic tidal energy
dissipation is two orders of magnitude lower than the global estimate (2.5 × 1012 W). 相似文献
1000.
Deshcherevskii A. V. Modin I. N. Sidorin A. Ya. 《Izvestiya Atmospheric and Oceanic Physics》2018,54(10):1490-1511
Izvestiya, Atmospheric and Oceanic Physics - In geophysical studies, particularly when searching for precursors of earthquakes, there are problems of investigating the geoelectric structure of the... 相似文献