国家地震局代表团赴美访问概况

经国务院批准,应美国科学基金会和美国地质调查局的邀请,由国家地震局方樟顺局长为团长的代表团一行5人于1990年5月26日—6月10日赴美国进行了正式访问和学术考察。代表团此次赴美的主要任务是在双方正式同意将中美地震科技合作协议继续延长第三个五年的基础上,与美国对口部门就中美地震科技合作议定书进行工作会晤,并访问考察美方的有关学术机构、大学和地震预报实验场。双方代表工作会晤于1990年6月1日在美国地质调查局总部举行。参加会晤的美方人员有美国地质调查局局长佩克博士(副部级)、     

中国地震代表团赴苏联访问和考察

应苏联科学院的邀请,国家地震局组成了以局长方樟顺为团长的5人代表团,于1989年10月23日至11月2日赴苏联进行了访问和考察。此行的主要目的是相互交流地震监测预报及减轻地震灾害工作的情况和科研成果,增进了解,并初步商讨两国在地震科技方面的合作事项。代表团先后访问、考察了苏联科学院及其所属的大地物理研究所、乌兹别克加盟共和国科学院及其所属的地震研究所和抗震研究所、塔吉克加盟共和国科学院及其所属的地震与抗震建筑研究所以及有关研究单位的地震台站和     

中国地震局水库地震代表团访问比利时和意大利

由中国地震局副局长刘玉辰率领的水库地震代表团一行 5人于 2 0 0 0年 9月 1 4～ 2 9日访问了比利时和意大利。这次出访的目的是推进中比地震科技合作 ,建立中意政府间的地震科技合作并签署合作框架协议 ,了解和借鉴意大利在水库地震研究和监测方面的主要成果、先进技术和经验。代表团重点访问了比利时皇家天文台、意大利地震调查所、意大利的里雅斯特大学 ,顺访了 Abdus Salam国际理论物理中心。1　访比利时皇家天文台皇家天文台负责比利时的地震监测工作 ,与中国地震局有着多年良好的合作关系。PaulPaquet台长向代表团介绍了皇家天文台…     

中国地震代表团赴希腊访问考察

根据中希两国科技合作协定,以国家地震局局长方樟顺为团长的中国国家地震局地震代表团于1992年5月19—28日赴希腊进行了短期访问。本文根据访问中了解到的情况,较详细地介绍了希腊的地震灾害情况、主要地震研究单位及其科研工作、地震工作的管理与协调体系,以及 VAN 法地震电信号预报系统。     

中国地震代表团赴俄罗斯联邦访问

应俄罗斯科学院的邀请,以中国国家地震局局长方樟顺为首的中国国家地震局地震代表团于1992年5月29日至6月8日访问了俄罗斯联邦。此次出访的主要任务是与俄罗斯科学院进行地震科学技术合作会谈,并签定中国国家地震局和俄罗斯科学院地震科学技术合作议定书。代表团在俄罗斯逗留期间访问了科学院大地物理研究所,参观了该所奥布宁斯克中央地     

新疆维吾尔自治区地震科技代表团抵乌兹别克和土库曼两加盟共和国访问

1991年5月3日至17日,以新疆维吾尔自治区地震局副局长李大贵同志为团长的中华人民共和国新疆维吾尔自治区地震科技代表团一行6人应邀分别访问了苏联乌兹别克加盟共和国科学院地震研究所和土库曼加盟共和国科学院地震研究所,受到了两地震研究所的热烈欢迎。 新疆与苏联中亚地区的地震科技合作开始于1989年。此次新疆地震科技代表团访问乌兹别克和土库曼两加盟共和国地震研究部门,进一步扩展了中苏地区间的地震科技合作,加深了双方之间的了解和友谊。新疆与苏联中亚地区具有相似的地质构造特征和地震活动特征。双方都具有长期地震研究的历史和经验,同时又具有各自的优势。加强和不断发展这一交流与合作将会大大提高两地区地震研究水平和地震预报水平。     

中国地震考察组赴智利和南极考察

根据中国和智利两国科学技术混合委员会双边科技合作交流协定中有关地震科技合作交流的项目,由国家地震局安启元局长和研究员张国民、副研究员徐祥文组成中国地震考察组于1987年12月1日至12月10日在智利作了为期10天的地震考察、友好访问和科技交流。之后考察组还访问了中国南极基地。     

中朝地震科学研讨会在北京举行

根据1989年3月中朝两国地震局共同签署的“中朝地震科技交流与合作计划书”,应国家地震局邀请,以朝鲜地震局副局长金成男同志为团长的朝鲜地震代表团一行6人于7月3—13日访问了我国,参加了中朝首次举办的地震科学研讨会,并考察了地震遗迹。7月4日上午,中朝地震科学研讨会在地质所正式开幕。以国家地震局副局长高文学为团长、震害防御司副司长李裕彻等10人组成的中国地震代表团和以朝鲜地震局副局长金成男为团     

中国地震专家代表团访问澳大利亚

为开展中国和澳大利亚两国间的地震科技合作,应澳大利亚基础工业和能源部的邀请,以国家地震局副局长周锐为团长的中国地震专家代表团一行6人,于1989年4月29日至5月7日对澳大利亚进行了短期的访问。澳大利亚基础工业和能源部所属的矿产资源局及澳大利亚地震中心接待了代表团。5月1日,代表团访问了矿产资源局,并同罗兰特局长进行了会晤。矿产资源局地球物理部主任迪那姆博士介绍了该局的组织机构、澳大利亚的地震活动性及地震研究工作状况。澳大利亚地震中心主任米尔赫特博士介绍了澳大利亚开展地震核查研究工作的情况。中国地震专家代表团团长周锐向澳方科学家介绍了国家地震局的组织机构、职能和地震科研情况,     

中日韩“历史地震与地震危险性评价国际研讨会”简介

2003年11月10—14日,以中国地震局地球物理研究所研究员时振梁为团长,李裕澈、吴戈、金学申、曹学锋为团员的“历史地震与地震危险性评价国际研讨会代表团”赴韩国济州岛参加了由韩国气象厅气象研究所主持召开的第三次中日韩三国历     

On the synchronism in the events within the core and on the surface of the earth: the changes in the organic world and in the polarity of the geomagnetic field in the phanerozoic

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.     

On the maintenance of the axisymmetric part of the flow in the atmosphere

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.     

On the gravimetric undulations of the geoid and the deflections of the vertical

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.     

太平洋中部地磁台11年周期变化的研究

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。     

On the variation in the geomagnetic dipole over the geological history of the Earth

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.     

Magnetic stratigraphy of the Ordovician in the lower reach of the Kotuy River: the age of the Bysy-Yuryakh stratum and the rate of geomagnetic reversals on the eve of the superchron

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.     

Comparison Between the Nutations of the Planet Mars and the Nutations of the Earth

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.     

Evolutionary Changes in the Configuration of the Magnetic Field of the Solar Corona in the Epoch of the Minimum

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...