共查询到20条相似文献，搜索用时 62 毫秒
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1975年2月4日在中国辽宁省南部发生的海城7.3级地震,是该区有史以来最大的地震。这次地震作了较成功的预报,并采取了某些预防措施,使地震灾害大大减轻,人员伤亡大大减少。本文在“地震区域背景、地震参数及灾害情况”一节中指出了地震所处的活动构造背景、地震情况、震区的社会经济状况、人口密度以及灾害损失。在“震前对策”一节中说明,确定地震危险区后,如何组织监测、预报系统,怎样发布预报和采取防震措施。在“震时应急对策”一节中阐明,如何对待这种突然事件的发生,争取时间自救、互救,减少人员伤亡。最后三节概述了震后早期、震后晚期的抗震救灾对策,以及海城地震预报、预防所取得的社会经济效益。 相似文献
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正雅安地震发生后,"松而未滑、摇而未掉"的山体极易引发泥石流、滑坡等次生地质灾害,如果得不到及时的预警预报,同样会造成严重的人员伤亡及财产损失。汛期将至,雅安地质灾害预警预报工作怎样进行?雅安地质灾害监测预警示范区近几年获得了怎样的发展?针对这些问题,本刊记者采访了中国地质环境监测院副总工程师周平根。《地球》:据悉,自地震发生后, 相似文献
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2006年12月26日20时26分和20时34分,台湾屏东县相继发生两次芮氏规模7.0地震①.地震发生后,屏东县立即成立了"12.26震灾"灾害应变中心,积极开展灾害防救工作.通过此次地震的抢救过程,检讨分析应变中心应变机制之优缺点,希望今后能为相关单位进行莺大灾害抢救时提供参考,并得到更准确、适用、有效的抢救作业程序. 相似文献
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印度洋地震和海啸灾害引发的若干思考 总被引：6，自引：1，他引：5
本文通过对印度洋地震和海啸灾害的反思,认真思考了灾害防御中的若干重要问题,包括尽快建构国际社会统一灾害防御体系;应当高度重视非工程措施在灾害防御中的作用以及对政府灾害管理职责的重新审视等。 相似文献
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《国际地震动态》2021,(8)
针对2008年汶川M_S8.0地震、2013年雅安芦山M_S7.0地震和2017年九寨沟M_S7.0地震前后出现的热红外现象,对MODIS卫星1 km高分辨率亮度温度的原始数据进行均线差值振幅波动水平分析发现:(1)这3次地震前在震中附近区域均出现显著的差值振幅变化异常,先为低值异常,低至历史平均水平的50%以下,后又演变为高值异常,高值异常峰值均大于历史平均水平3倍以上;(2)汶川地震、雅安芦山地震、九寨沟地震分别在高值异常峰值的55天、35天、22天后发生;(3)异常优势分布区域并不在震中区域:汶川地震震前异常区主要位于震中西北区域的柴达木块体,雅安芦山地震、九寨沟地震震前异常区域位于震中西部的巴颜喀拉块体,其中,汶川地震震前异常区域面积远远大于后者。 相似文献
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太原市重型机器厂座落在太原古城汾河之畔.该厂是1950年新中国成立后自行设计建造的第一座重型机器厂,是我国的重点骨干企业之一.1.注重社会效益 提高防灾意识一个企业,不仅要抓好生产,为国创汇增值,同时也需防止灾害减值,提高抗御各种灾害的能力.1976年7月28日唐山7.8级地震,一霎间夺去了24万人的生命,整个城市毁于一旦,1975年2月4日海城7.3级地震,做出了预报,虽然遭到了严重破坏,但人员伤亡大大减少.次生灾害减轻.无数事实证明,建筑物抗震性能如何?群众掌握地震知识的多少,地震有无预报是至关重要的.随着社会的进步,经济的发展,地震所造成的灾害将越来越大,特别是城市.目前地震工程的崛起和地震对策的问世都力图取得最佳的社会效益.笔者认为,领导重视是关键.2.搞好防震抗震工作 开展地震科普宣传近年来,重机厂对防火、防汛工作颇为重视, 相似文献
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D. M. Pechersky A. A. Lyubushin Z. V. Sharonova 《Izvestiya Physics of the Solid Earth》2010,46(7):613-623
The data on geomagnetic reversals are compared with the changes in the organic world and with the lower-mantle plumes. The
times of the formation of plumes and the times of their appearance on the Earth’s surface relate to the intervals characterized
by the different frequencies of geomagnetic reversals, i.e., there is no interrelation between the formation of plumes and
the frequency of the changes in the geomagnetic field polarity. At the same time, a certain synchronism is observed between
the frequency of the geomagnetic reversals and the boundaries of the biostratigraphic ages, i.e., the changes in the organic
world in the long-period range. A hypothesis is proposed, which explains the change in the sign of the geomagnetic field by
the combined effect of the irregular rotation of the internal core relative to the mantle and the changes in the slope angle
of the axis of the Earth’s rotation, which, in turn, results in synchronous events on the Earth’s surface: the rates of changes
in the organic world. 相似文献
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The nutations of the planets Mars andEarth are investigated and compared. Alarge number of interior structureparameters are involved in the nutationcomputations. The comparison between the observations and the computationsprovides several constraints on these parmeters andtherefore allows a better understanding of the physics of the interior of theplanet. For the Earth, the high precision of the observations of the nutationshas led to a very good determination of interior properties of the planet. ForMars, observations of nutations are not yet available, and we review how theamplitude of the Martian nutations depends on the hypotheses consideredfor its interior. Although Mars is very similar to the Earth, its interior is not well known;for example, we don't knowif its core is liquid or solid. Only if the core is liquid,the Free Core Nutation (FCN) normal mode exists and can alter the nutationswhich are close to the resonance. From the observed geoids, it is known thatboth planets are not in hydrostatic equilibrium. The departure is larger forMars than for the Earth, and consequently, the implication of considering a convective mantle instead of a mantle in hydrostatic equilibrium described byClairaut's equation for the initial equilibrium state of the planet is largeron the Martian nutations than on the Earth nutations. The consequences of theuncertainty in the core dimensions are also examined and shown to be of a veryhigh influence for Mars if the core is liquid, due to the potential changes inthe FCN resonance. The influence of the presence of an inner core, which isknown to exist for the Earth, could be more important for Mars than for theEarth if the inner core is large. Due to the presence of Tharsis on Mars, thetriaxiality of this planet has, additionally, larger effects than on Earth. 相似文献
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综合APIA、HONOLULU、PAMATAI 3个地磁台三分量的11年周期变化的形态后,可定性地提出该变化源于内场。如内源为核幔边界的电涡流,则其中心点应位于3台之间。 相似文献
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The depth to the top of magnetic dykes can be estimated from total field aeromagnetic data using the relation between the depth to magnetic sources and the autocorrelation function of magnetic data. By using synthetic anomalies we show that in the ideal case, depth can be determined to an accuracy of 10% or better, when the anomaly sources are two-dimensional dykes. However, the estimated depths depend on the width of the dykes. The estimated depth is about 0.6 times the actual depth to the top of thin dykes, and around the true depth for thick dykes having width-to-depth ratio around 3. The depth is considerably overestimated for very thick dykes (e.g., contacts, which is a special case of the thick dyke). Thus, the autocorrelation method requires that the width-to-depth ratio of the dyke is estimated independently to correctly estimate the depths. Alternatively, it must be assumed that the width-to-depth ratio for the two-dimensional source body is between 1.5 and 4. 相似文献
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As is known, the secular deceleration of the Earth's diurnal rotation is explained mainly by the tidal friction in the ocean. Below we consider this mechanism in some detail, taking into account also elastic deformations of the mantle under the action of ocean loading and the interaction between the tide-generating body, ocean tidal wave, liquid outer core, and solid inner core. It is shown that elastic displacements of the core-mantle boundary under the action of ocean loading are of about the same amplitude and phase as the elastic loading displacements of the Earth's outer surface. As a result, side by side with the mechanism of secular deceleration of diurnal rotation of the mantle, there are also (1) the opposite mechanism of secular acceleration of diurnal rotation of the outer liquid core and of the solid inner core and (2) the mechanism of excitation of differential rotation in the liquid core. Taking these effects into account, we compare theoretical and modern observed data on the eastward drift of the solid inner core. It is shown that the best agreement may be obtained if the turbulent viscosity of the liquid core is about 2 × 10
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Poise 相似文献
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On data of bottom sampling, carried out by means of grab, trawl and underwater photography in August–September of 1993 in the area of the Pechora Sea, quantitative regularities of macrobenthos distribution are described for the ecological monitoring purposes. Maps of -biodiversity and biomass indices, bottom communities and trophic zones, singled out by dominant method, are presented. Assessment of structure changes of the investigated area bottom communities during the last 60–70 years is fulfilled. It is shown that the described communities on the whole are of natural undisturbed character and that the revealed changes are within the natural fluctuations in the abundance of benthic populations or may be interpreted in terms of methodical differences in the data analysis and generalization by different authors. 相似文献
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地震激励下处于深水中的桥墩和周围水体的相互作用将对桥梁结构的动力响应产生较大影响。首先对地震作用下水-桥墩的相互作用理论做了概括,给出了动水压力对桥墩的作用效应及各自的适用范围;对主要的三种考虑流固耦合效应的分析方法做了对比,探讨了地震作用下影响水-结构相互作用的主要因素,并对今后的研究提出了建议。 相似文献
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Prof. Dr. W. A. Heiskanen 《Pure and Applied Geophysics》1958,41(1):1-18
Summary The author mentions the aims of the World-wide gravity project he established in the Ohio State University in Columbus, in 1950. He outlines the practical procedure of the gravimetric computations of the undulationsN and the vertical deflection components and and emphasizes that only by the global international cooperation and additional gravity observations at sea carried out during the last decade it has been possible to gather to Columbus the needed gravity material. Since there exist still large gravimetrically unsurveyed areas it is of vital significance to study what gravity anomalies are best to be used for these regions. The given figures concerning the accuracy of theN, and , estimated theoretically and obtained in practice, indicate that in the gravimetrically well surveyed parts of the world like in Europe and the United States we can get gravimetrically on basis of existing gravity material theN-values with accuracy of about 5–10 meters, and and with the accuracy of about 1. The geoid undulationsN are already computed in Columbus for more than 6000 points of the northern hemisphere. The sample maps show the interesting geoid of Europe and vicinity between the latitudes 60° and 30° and longitude 5° W and 30° E, drafted on basis of more than 1000N-values computed at the corners of 1°×1° squares. It is interesting to realize that the geoid undulations in all this area are positive, the extreme values being between 40 and 50 meters. The geophysical significance of the geoid maps of this kind is pointed out. 相似文献