河北省地区地磁场的变化特征

利用河北省各地磁台站1986～2005年的地磁观测资料,对该地区地磁场长期变、短周期变化及与太阳黑子的活动特征进行了总结分析.这对进一步认识河北地区地磁场变化规律及其特征,为地震预报提供有实用价值的第一手资料都是十分有意义的.     

北京地磁场变化特征分析

根据北京国家地球观象台北京地震台1987—2013年地磁观测资料,分析该台地磁场长期变化和短期变化,认为北京地磁场长期变化具有缓慢上升、缓慢下降和逐渐恢复上升的形态,短期变化受太阳黑子活动强度影响,对了解北京地区地磁场变化特征具有一定意义。     

北京磁测预报地震效能分析

北京磁测预报地震是以压磁理论与感应磁效应为物理基础的,应用差值比较、图象演变、快谱幅比、统计参量等方法,分析地磁资料,研究震磁前兆信息,开展地震监测预报工作。以１９９２￣１９９７年期间书面的预报意见为依据,分析了地震预报效能,结果表明,北京磁测的地震监测预报有一定的实际效果与积极作用,今后应当加强震磁前兆的观测研究。     

Google Earth在流动地磁选点的应用

野外流动地磁测量是地震监测预报的重要手段之一,在参加流动地磁监测工作中,经过探索与实践,通过利用Google Earth应用于野外流动地磁选点工作中,形成了一套包括室内展图、收集有关测区范围内地质构造、地形地貌以及交通、生活等基础资料,结合GPS手持机导航,初步圈划测区测点的布设的工作流程。     

The deviation of the total geomagnetic field direction from the dipole field direction as a manifestation of the non-dipole field

Summary The angle between the total geomagnetic field direction and the axial dipole field direction was computed for the whole of the Earth's surface for the epoch 1945. It was supposed that the dipole field exerts a latitude-dependent influence on the surface manifestation of the non-dipole field. A modifying function of latitude was estimated to eliminate this influence. The isolines of the resulting quantity were plotted.     

Solution of the magnetic survey problem by integrating components of the geomagnetic field gradient

Coherent solution of the problem of magnetic survey, based on integrating the geomagnetic field gradient, is theoretically justified. The sources and the ways of minimization of the method methodical errors have been determined. The theory of magnetic measurements on the run is developed, and the prerequisites for increasing magnetic survey accuracy are created.     

小煤窑采空区的地面磁场观测结果及其初步推断

在神朔铁道神木至大柳塔段,为了了解地下煤窑空洞与隧道情况,布设了６条测线,共计３８８个测点,进行了地磁总强度观测工作。根据观测数据,分析了测区的磁场分布特征。由此初步推断,测区东南部的Ｅ区负异常是由地下矿道引起的;测区中部的Ｄ区负异常也是有地下矿道的部分贡献,测区其他部分,由于存在地下浅层铁磁性物质与铁轨的严重影响,地下矿道的位置与走向需要进一步讨论。     

Computation and analysis of the geomagnetic field model in China and its adjacent area for 2003

Based on the geomagnetic data at 135 stations and 35 observatories in China in 2003, the Taylor polynomial model and the spherical cap harmonic model in China and its adjacent area for 2003 were established. In the model calculation, the truncation order of the model and the influences of the boundary restriction on the model calculation were carefully analyzed. The results show that the geomagnetic data used are precise and reliable, and the selection of the truncation order is reasonable. The Taylor polynomial model and the spherical cap harmonic model in China and its adjacent area established in this paper are consistent very well.     

Spectrum of the geomagnetic field in central Europe

mam na n uu nmaaum n a mumuu ¶rt; n. ammu ama 27-¶rt;a auau uuauuu n amuaa 7 ¶rt;nu amu nu¶rt; 1960–68 . ¶rt;a m ¶rt; mum nma maa m nmaum n nu a amumu.     

Magnetic torque acting on the mantle in a non-stationary geomagnetic field

Zusammenfassung Das Gesetz der Erhaltung von Drehimpuls eines aus Stoff und elektromagnetischem Feld zusammengesetzten materiellen Systems wird auf die unter den Bedingungen der Dynamik gegenseitiger Bewegungen des Kernes und Mantels gültige Form überführt. Es wird gezeigt, dass die Zeit?nderung des aus mechanischer und elektromagnetischer Komponente bestehenden Gesamtdrehimpulses des Mantels nur von der Feldgr?sse an der Grenze Kern—Mantel abh?ngt. Für das station?re geomagnetische Feld ist aus dem Drehimpulserhaltungsgesetz die Komponente des Drehmoments magnetischen Ursprungs abgeleitet, die in der Drehachse der Erde liegt. Aus der Ausdrückung für die in der Drehachse der Erde liegende Komponente des Drehmoments ergibt sich, dass dieselbe nur vom Felde an der Grenze Kern—Mantel abh?ngt. Wenn die Voraussetzung erfüllt ist, dass der Kern und der unterste leitf?hige Teil des Mantels vom Gesichtspunkt der Dynamik gegenseitiger Bewegungen des Kernes und Mantels ein in bezug auf die ?usseren periodischen elektromagnetischen und mechanischen Einflüsse geschlossenes System bildet, dann erfolgt aus dem Drehimpulserhaltungsgesetz in nichtstation?rem Felde, dass die Zeit?nderung des mechanischen Drehimpulses des Mantels durch die ?nderung des Drehimpulses des elektromagnetischen Feldes im Mantel in entgegengesetztem Sinn des Vorzeichens ausgeglichen werden muss.

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Address: Šafárikovo nám. 12, Bratislava.     

Types of variations in the geomagnetic field spectrum

The purpose of archaeomagnetic research is to investigate the structure of the geomagnetic field and its evolution. This paper is a study of this type. In our preceding studies, we divided the geomagnetic field into dipole and nondipole components. It was then shown that the dipole component consists of the predominant 1200-yr variation and the remainder δ. The δ variation is the subject of this paper. Detailed study and comparison of the characteristic features of two 1200-yr variations (the dipole and δ variations) in both the declination and inclination indicates that, according to most of their features, they can be assigned to different types of waves, namely, traveling waves (the dipole variation) and standing waves (the δ variation). Successive averaging in time and space yielded averaged data on δI and δD not only for various parts of the world (Europe, Asia, and America) but also for the western and eastern hemispheres.     

Long-term variations in geomagnetic and solar activities and secular variations of the geomagnetic field components

Summary After the removal of the eleven-year periodicity, long-term patterns of the aa indices of geomagnetic activity and of Wolf's sunspot numbers are defined. The positions of maxima and minima exhibit the same regularities as the secular variations of the geomagnetic filed components. This result is associated with the motion of the Sun round the barycentre of the solar system.Presented at symposium Planet 88, Tihany, September 1988.     

Periodicity in the changes of the direction of the geomagnetic field

a au ¶rt;a a¶rt;u naam, m m uu anau n m aum u m u. aam u¶rt;a nuuu u u au am nmu m au. ¶rt;m nu¶rt;umu, m m m a mu u. n¶rt;mauau auumu aama u¶rt;a u um ¶rt; um aamu.     

On the intensity of the geomagnetic field in the geological past

A detailed analysis of the data on the intensity of the geomagnetic dipole and frequency of its reversals presented in the world’s paleointensity databases provided the arguments in favor of the hypothesis of the negative correlation between the average virtual dipole moment (VDM) and the frequency of the reversals on the interval from 5 Ma to 100 Ma ago. However, the statistical confidence level of this hypothesis is only 60–70%, which is far below 95%, the standard required confidence level of a hypothesis to be considered statistically reliable. At a high level of confidence (above 99%), the presence of a positive correlation between the mean value and variance of VDM for a number of intervals of stable polarity in the Cenozoic and Mesozoic is confirmed. This finding means that the distribution of VDM on these time intervals is certainly non-Gaussian and is rather described by the gamma- or lognormal law. At the same time, in contrast to the earlier intervals, the histogram of VDM for the Brunhes epoch is closer to the normal distribution. Compared our conclusions with the published results on the numerical modeling of the geodynamo, we found that they are consistent in terms of a probable negative correlation between the average VDM and reversal frequency, as well as the lack of correlation between the average VDM and the length of the interval of stable polarity.