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1.
Propagation of electromagnetic (EM) waves from an earthquake focus in the conductive Earth has been investigated using 1/1,000,000 scaling models taking earth-ionosphere and ocean-Moho plane parallel-plate waveguides into account. Microwaves at a frequency, ωm, a million times higher than that of seismic EM signal (SEMS), ω, were generated at the model focus. They are propagated in a salt solution modeling the earth's crust and reflected by ocean, fault planes, ionosphere and Moho plane all made by aluminum. Distribution of EM power was mapped by scanning a detector antenna over the model Earth's surface. The skin depth, δ, calculated by the exact skin depth equation, 1/δ=ω(μ/2)1/2 [(1+(1/ωρ)2)1/2 −1]1/2 where dielectric constant, and permeability, μ are the same but resistivity, ρ, 10−6 times smaller than that of Earth, gave 10−6 times small skin depth validating the model scaling index. Images for evanescent and wave-ripple standing waves disturbed by normal, strike-slip and dip-slip conductive fault planes have been obtained using an aluminum plate. The co-circular contour map above the epicenter due to evanescence was pushed to the north east direction from the epicenter by the presence of ocean for the Loma Prieta earthquake, while to north direction for the Kobe earthquake. The intensity of EM ULF emissions for the Loma Prieta earthquake is discussed quantitatively. 相似文献
2.
Huang Qinghua Ikeya Motoji and Huang PeihuaDepartment of Earth Space Sciences Graduate School of Science Osaka University Osaka Japan Department of Earth Space Sciences University of Science Technology of China Hefei China 《中国地震研究》1997,(1)
Electric field effect on animals has been studied to investigate its relation with seismic anomalous animal behaviors(SAABs)in China.Freshwater eel,crucian carp,catfish,and soft-shelled turtle responded to the threshold electric field of 1-10 V/m,while duck,goose,cat,sheep,pig,dog,and chicken all responded to the ground electric field of about tens of V/m,depending on the species as well as on individuals.Most of the behaviors caused by electric field were similar to those reported as SAABs such as alignment,sudden movement,panic,and convulsion.The intensity of electric field due to a major earthquake would have been over these threshold values.Numerical estimation based on an electromagnetic model of a fault has been made to induce SAABs as electric shocks to pulsed electric fields in electro-physiology.The seismic electric signals(SES)intensity might be estimated from the observation of SAABs. 相似文献
3.
Age estimates of NaCl and NaHCO3 in the sediments at Searles Lake, California have been obtained using electron spin resonance (ESR). ESR signals are identified as H+Ca2+---CO33− or H+---CO2− electron type and hole CO3− type centres, stabilized by impurities in NaHCO3 and in NaCl. The total dose of natural radiation (TD) and the tentative ESR ages were determined using these signals based on U, Th and K analyses assuming uranium series disequilibrium for a simple infinite medium. Although ESR ages are concordant with the stratigraphy, radiation assessment considering the loss and incorporation of radioactive elements must be made to get reliable absolute ages. 相似文献
4.
Ikeya Motoji 《中国地震研究》1998,(3)
We present an electromagnetic model of a fault using the piezoelectric effect and the elastic dislocation theory to investigate theoretically the spatial distribution of the stress-induced charges associated with faulting. The relevant seismic electric field associated with these induced charges can be estimated quantitatively. Therefore, this simple model would provide a solid framework for additional theoretical developments on the explanations of the anomalous seismoelectric signals. The spatial distribution of the stress-induced charges around a vertical rectangular fault showed complicated characteristics. The estimation of the electric field associated with the stress-induced charges during the 1995 Kobe earthquake was consistent with the previous investigation from some reported anomalous seismic phenomena. 相似文献
5.
据有关报导,１９９５年神户地震前家用电器出现了奇怪的异常现象。我们在实验室中利用范德格拉夫静电发电机用磨擦生电的方法,证实了这些收音机和电视的噪音以及频道混乱现象的存在。 相似文献
6.
An analysis is presented of data on chlorophyll a concentrations of the total and the netplankton (>10 μm), determined either in April to June or in August to September from
48°N to 15°S along 175°E in the Pacific Ocean during 6 years by the NOPACCS (Northwest Pacific Carbon Cycle Study). Particular
attention was given to the variability of absolute concentrations of the netplankton chlorophyll a and their percentage shares of the total chlorophyll a concentration. Below 0.2 μg l−1 of surface total chlorophyll a, the netplankton chlorophyll a showed low percentage shares (such as 12.7% on average) with a large variation, but above 0.2 μg l−1 it was 35.9% on average with less variation, showing an accelerated increase at high total chlorophyll a concentrations. High netplankton chlorophyll a concentrations in surface waters were observed at high latitudes, in waters having high chlorophyll a concentrations at sub-surface depth, and in equatorial upwelling. The percentage shares of netplankton in the total chlorophyll
a in the euphotic zone were 8.5% and 25.9% above and below 0.2 μg l−1, respectively, although the data points scattered over a wide range (from 7.2% to 53.8%) depending on differences in water
masses, depths and seasons. High chlorophyll a concentrations and high percentage shares of netplankton corresponded to high ambient nitrate plus nitrite concentrations.
Integrated netplankton chlorophyll a concentrations in the euphotic zone varied from 0.7 to 19.5 mg m−2 in waters below 0.2 μg l−1 of surface total chlorophyll a, and from 2.0 to 29.5 mg m−2 above 0.2 μg l−1, and the percentage shares of netplankton for the former were 7.4% on average and 23.7% for the latter.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
7.
Condensed aromatic rings are important skeletal components with regard to the recalcitrant nature of humic acids (HAs) in the environment. However, they have not been extensively studied. The relative content and composition (size distribution) of condensed aromatic rings in HAs were obtained from various soils subjected to transmission electron microscopy (TEM) and X-ray diffraction (XRD) profile analysis. In the XRD profiles of all the HAs, the 11 band that was derived from the carbon layer planes was clearly observed. Analysis of the 11 band indicated that the size of the carbon layer planes in HAs ranged from 0.48-1.68 nm, corresponding to 4- to 37-ring condensed aromatic structures. The contents of the total and larger carbon layer planes were larger in HAs with darker color and larger aromatic carbon content. At the same time, the carbon layer planes in HAs were smaller than those in a carbon black reference (from 0.24 to >3.66 nm). In the TEM analysis, fringes observed in HAs were less distinct and less ordered than those in carbon black, which was in agreement with the XRD result. 相似文献
8.
Abstract Electron spin resonance (ESR) analyses of quartz grains in fault gouge were performed for a core sample taken from the Nojima Fault that moved during the 1995 Kobe earthquake (Hyogo-ken Nanbu earthquake). Distribution of radiation-induced defects in the gouge at a depth of 389.4 m was measured by extracting quartz grains from seven discrete positions within 30 mm of the fault plane on the granite side. The decrease in E'1 and Al centers was observed within 2 mm of the fault plane, suggesting partial annealing due to faulting. Partial annealing even at that depth suggested that conventional ESR dating, which is based on the hypothesis of complete annealing during faulting, was not applicable. Theoretical calculations of the temperature rise and of the thermal annealing of defects have been made by assuming a simple annealing model of heat generation on the fault plane. Thermal energy was calculated to have been approximately 8 MJ/m2 to explain the profile of the heat-affected region. Thermal energy was much larger than the one estimated from hydrothermal solution, and corresponded to the frictional heat calculated for a normal stress of 20 MPa, a displacement of 2 m, and a frictional coefficient of 0.2. 相似文献
9.
Photosynthetic pigment system of picophytoplankton of cyanophytes was examined with five strains isolated from the Kuroshio
water at the depth of 70 m. Examination was made for the absorption spectra of intact cells of each strain. Analysis of pigment
composition was also made withSynechococcus NIBB 1059 and 1071, which were isolated from surface waters of the Gulf Stream and Kuroshio area, respectively. Results indicated
that (1) all strains contain phycoerythrin with a very high concentration, and (2) the phycoerythrin in these strains contains
two chromophores, phycoerythrobilin and phycourobilin, and (3) a large abundance of phycoerythrin and phycourobilin in the
phycoerythrin enablesSynechococcus picophytoplankton to absorb effectively the light in the blue-green region at the subsurface depth. These characteristics
suggest that cyanophytes in the subsurface water can collectt the blue-green light and perform actively photosynthesis even
at the bottom of euphotic layer. 相似文献
10.
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