共查询到20条相似文献，搜索用时 78 毫秒
1.
广东省强震观测的现状与展望 总被引：1，自引：0，他引：1
介绍了国内外以及广东省强震观测的历史现状，以大量的事实、数据说明广东省强震观测工作过去的辉煌和目前的落后状况，提出了我省今后开展强震工作的设想，特别指出要改变以前强震仪除被动等待强地震外就无所作为的情况，扩展用途，增加显示度，为用户着想。 相似文献
2.
3.
简要回顾了我国水工结构强震观测的历史，介绍了水工结构强震观测的现状、特点和监测技术，以及大坝地震安全报警和强震观测记录的应用，对今后水工结构强震观测工作提出了若干建议。 相似文献
4.
介绍了在美国加州地区开展的两个强震观测计划,即美国国家强震观测计划和加州强震观测计划的一些情况,重点提供了结构响应观测台阵方面的信息;给出了上述两个计划的网址;简要归纳了利用这两个计划的强震数据所开展的一些结构研究工作. 相似文献
5.
强烈地震动的计测称之为强震观测。强震观测不仅记录大地震的走时过程，而且还测到具有广义强震观测的强地震动的最大值和计测烈度。强震观测在经历阪神大震灾后10年期间有了很大的变化，取得引人注目的进展和成果。 相似文献
6.
强震观测的发展趋势和任务 总被引：25，自引：1，他引：25
本文介绍了近几年来世界各国强震观测的发展趋势，对我国强震观测工作的现状和存在的一些主要问题作了简要的评述，并在此基础上讨论了发展我国强震观测工作的方向和任务。 相似文献
7.
《日本地震学会新闻通讯》 《国际地震动态》2002,(9):20-23
前言 (强震观测事业的历史 )1 955年 1月 3 1日 ,科学技术厅资源调查委员会向内阁总理大臣提交“关于强震测定计划的建议”,并以此为契机开始了强震观测。为了使建议从组织上得到落实 ,1 956年 1 2月在东京大学地震研究所设置了强震测定委员会。1 958年 1 1月 ,资源调查委员会又向科学厅长官提出了促进观测计划实施的请求。1 964年 1 1月 1 7日 ,日本学术会议向内阁总理大臣提交的“加强抗震工程研究的报告”中提出 :希望增设强震计并充分利用所获取的记录资料。 1 965年在东京大学地震研究所设置了强震观测中心 ,经费由国家财政拨款。 1 96… 相似文献
8.
9.
江苏地区强震观测30年 总被引：1，自引：0，他引：1
从1972年原国家地震局南京地震大队与原国家地震局工程力学研究所合作筹建长江大桥强震观测台网起至今，江苏省的强震观测已经走过了30年的路程。30年中，江苏强震台网在1974年溧阳地震，1983年荷泽地震和1990年常熟地震中获得的有科学价值的地震记录，为大型桥梁空间动力性质的分析提供了实证资料，也为中国东部深井地震性质等重要科学问题的研究提供了实证资料，江苏省地震局的科技人员还进行了大量与强震观测相关的科研工作，至今，在江苏省及邻近地区已形成了固定观测与流动观测相结合的强震观测台网，本文简要的回顾了江苏强震观测30年历程，并展望了未来发展的前景。 相似文献
10.
介绍了一种专门使用数字信号处理器(DSP)和可编程逻辑器件(CPLD)来实现数字强震仪的低功耗设计,给出了系统的结构框图,并且就数字强震仪在硬件设计和软件实现的节能技术进行了描述。该强震仪完全能够满足自由场的强震观测和建筑物的结构观测。 相似文献
11.
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
12.
Summary The maintenance of the axisymmetric component of the flow in the atmosphere is investigated by means of a steady-state, quasi-geostrophic formulation of the meteorological equations. It is shown that the meridional variations in the time-averaged axisymmetric variables can be expressed as the sum of three contributions, one being due to the eddy heat transport, another to the eddy momentum transport, and a third to the convective-radiative equilibrium temperature which enters the problem through the specification of a Newtonian form of diabatic heating. The contributions by the large scale eddies are evaluated through the use of observed values for the eddy heat and momentum transports.The contributions from each of the three forcing mechanisms to the temperature and zonal wind fields are invstigated individually and found to be of about equal importance. The sum of the three contributions are also presented for the temperature, the zonal wind, the stream function associated with the mean meridional circulation and the corresponding vertical motion. Although the results fail to reproduce the main observed features of the lower stratosphere, they are found to be in good agreement with observations in the middle latitude troposphere. At any pressure level, for example, the computed mean zonal wind has a jet-like profile and the axis of the jet is found to slope to the south with height, as observed in the atmosphere.Based in part on a thesis submitted by the first author as partial fulfillment of the requirements for the Ph.D. degree at the University of Michigan. — Publication No. 194 from the Department of Meteorology and Oceanography, The University of Michigan. 相似文献
13.
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
14.
15.
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
16.
V. E. Pavlov T. Yu. Tolmacheva R. V. Veselovskiy A. V. Latyshev A. M. Fetisova I. V. Bigun 《Izvestiya Physics of the Solid Earth》2017,53(5):702-713
Until recently, the existing data prevented the geophysicists from accurately dating the Bysy-Yuryakh stratum, which outcrops in the middle reach of the Kotuy River, constraining the time of its formation to a wide interval from the end of the Late Cambrian to the beginning of the Silurian. The obtained paleomagnetic data unambiguously correlate the Bysy-Yuryakh stratum to the Nyaian regional stage and constrain its formation, at least a considerable part of it, by the Tremadocian. This result perfectly agrees with the data on the Bysy-Yuryakh conodonts studied in this work and yields a spectacular example of the successful application of paleomagnetic studies in solving important tasks of stratigraphy and, correspondingly, petroleum geology. Within the Bysy-Yuryakh stratum, we revealed a large normal-polarity interval corresponding to the long (>1 Ma) period when the geomagnetic reversals were absent. This result, in combination with the data for the Tremadocian and Middle–Upper Cambrian sequences of the other regions, indicates that (1) the rate of occurrence of the geomagnetic reversals on the eve of the Ordovician Moyero superchron of reversed polarity was at most one reversal per Ma; (2) the superchron does not switch on instantaneously but is preceded by a certain gradual change in the operation conditions of the dynamo mechanism which, inter alia, manifests itself by the reduction of the frequency of geomagnetic reversals with the approach of the superchron. This finding supports the views according to which a process preparing the establishment of the superchrons takes place at the core–mantle boundary. 相似文献
17.
18.
The global database on the paleointensity, containing determinations of the virtual dipole moment (VDM) for a stable (normal) regime of the geomagnetic field in a time interval of up to 3.5 Ga, is supplemented by new VDM determinations and analyzed. The field generation process started no later than 3–3.5 Ga (earlier data are absent) at the stage of the Earth’s core formation. Since that time, the dipole value has differed from its present value by no more than an order of magnitude, and the deviations that have already been detected tend toward smaller values. The distribution of VDM values in the time interval 0–400 Ma is bimodal, which apparently reflects the presence of two different generation levels of the geomagnetic field distinguished by a relatively large value (close to the present field value) and a relatively small value (approximately half as large as the present value). The total duration of decreased VDM values appreciably exceeds that of increased VDM values (179.1 and 28.6 Myr, respectively). On the whole, data on the paleointensity do not contradict the hypothesis about the dipole nature of the field over the last 400 Myr; however, the number of determinations at high paleolatitudes is too small to draw decisive conclusions on the validity (or invalidity) of the dipole field approximation based solely on paleointensity data. 相似文献
19.
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
20.
Geomagnetism and Aeronomy - The evolution of the magnetic configuration in the solar corona is studied. The curvature of the K-corona helmets obtained from an analytical approximation of the... 相似文献