On the possibility of an intra-Earth source of Sq-variations of the Earth's magnetic field

Author(s):  
Beibit Zhumabayev ◽  
Ivan Vassilyev

<p>Analysis of the direction of motion of the vector of Sq-variations of the Earth's magnetic field, depending on the time of day and season of the year, shows that the observed Sq-variation is similar to the magnetic field created by a negatively charged spherical body moving in space. Transformations of the Sq-variation vector from the local coordinate system of the magnetic observatory to the ecliptic coordinate system are performed. A possible connection between the origin of the Sq-variation and the electric dipole moment of quartz molecules oriented towards the center of the Earth during the crystallization of the mineral and causing the electric and dipole magnetic fields of the Earth is considered. A scheme for conducting an experiment that allows us to separate the effects of extraterrestrial and extraterrestrial sources of Sq-variations is proposed.</p>

The westward drift of the non-dipole part of the earth’s magnetic field and of its secular variation is investigated for the period 1907-45 and the uncertainty of the results discussed. It is found that a real drift exists having an angular velocity which is independent of latitude. For the non-dipole field the rate of drift is 0.18 ± 0-015°/year, that for the secular variation is 0.32 ±0-067°/year. The results are confirmed by a study of harmonic analyses made between 1829 and 1945. The drift is explained as a consequence of the dynamo theory of the origin of the earth’s field. This theory required the outer part of the core to rotate less rapidly than the inner part. As a result of electromagnetic forces the solid mantle of the earth is coupled to the core as a whole, and the outer part of the core therefore travels westward relative to the mantle, carrying the minor features of the field with it.


2021 ◽  
Author(s):  
Lemgharbi Abdenaceur ◽  
Hamoudi Mohamed ◽  
Abtout Abdeslam ◽  
Abdelhamid Bendekken ◽  
Ener Aganou ◽  
...  

<p>In order to understand the spatial and temporal behavior of the Earth's magnetic field, scientists, following C.F. Gauss initiative in 1838 have established observatories around the world. More than 200 observatories aiming to continuously record, the time variations of the magnetic field vector and to maintain the best standard of the accuracy and resolution of the measurements.</p><p>This study focused on the acquisition and analysis of the magnetic data provided by the Algerian magnetic observatory of Tamanrasset (labelled TAM by the International Association of Geomagnetism and Aeronomy). This observatory is located in southern Algeria at 5.53°E longitude, 22.79°N Latitude. Its altitude is 1373 meters above msl. TAM is continuously running since 1932, using old brand variometers, like Mascart and La Cour with photographic recording at the very beginning. Nowadays modern electronic equipment are used in the framework of INTERMAGNET project. Very large geomagnetic database collected over a century is available. We will describe the history and the various improvement of the methods and instrumentation.</p><p>Preliminary analysis of time series of the observatory data allowed to distinguish two kinds of data: the first type, with low resolution, collected between 1932 and 1992. This data set comes from the annual, monthly, daily and hourly means. The second one with high resolution is represented by minutes and seconds sampling rate since 1993 when TAM was integrated to the world observatory network, INTERMAGNET. Part of the second dataset contains many gaps. We try to fill these gaps thanks to mathematical methods. Absolute measurements and repeat station data allow better accuracy in the secular variations and an improved regional model.</p><p>Keywords: TAM observatory, temporal variation, terrestrial magnetic field, secular variations, INTERMAGNET.</p>


1984 ◽  
Vol 1 ◽  
pp. 50-65
Author(s):  
William J. Frazier

“Scientific creationists” have created their own version of geology in order to defend their axiomatic insistance on a young Earth. To “prove” the Earth's youth, they cite (among other things) measured decay-rates of Earth's magnetic field and concentrations of elements in seawater. They also state that all plutons are quick frozen, that plutonic igneous rocks bear no relation to modern volcanism, and that all sedimentary rocks must be interpreted in terms of a “global hydrologic singularity,” i.e. Noah's Flood.Having explicitly denied uniformitarianism and embraced catastrophism, “Creationists” renege by using uniformitarian reasoning over and again. They practice “pick & choose” empiricism by citing only those data which seem to support their case. “Creationists” even choose when and if to apply scientific principles, e.g. their use of thermodynamics to “disprove” organic evolution while ignoring thermodynamics' implications for magma cooling and metamorphism.The methods of “Creationism” are clearly intended not to increase knowledge of the Earth but to delude the scientifically unsophisticated. Thus, “Creationism” can hardly be considered a science. Further, its repeated use of fallacious thinking brands “Creationism” as hopelessly illogical and its disingenuous statements and tactics disqualify it from even the ranks of nonempirical epistemological systems.


2003 ◽  
Vol 3 (3/4) ◽  
pp. 171-177 ◽  
Author(s):  
G. Duma ◽  
Y. Ruzhin

Abstract. Statistic analyses demonstrate that the probability of earthquake occurrence in many earthquake regions strongly depends on the time of day, that is on Local Time (e.g. Conrad, 1909, 1932; Shimshoni, 1971; Duma, 1997; Duma and Vilardo, 1998). This also applies to strong earthquake activity. Moreover, recent observations reveal an involvement of the regular diurnal variations of the Earth’s magnetic field, commonly known as Sq-variations, in this geodynamic process of changing earthquake activity with the time of day (Duma, 1996, 1999). In the article it is attempted to quantify the forces which result from the interaction between the induced Sq-variation currents in the Earth’s lithosphere and the regional Earth’s magnetic field, in order to assess the influence on the tectonic stress field and on seismic activity. A reliable model is obtained, which indicates a high energy involved in this process. The effect of Sq-induction is compared with the results of the large scale electromagnetic experiment "Khibiny" (Velikhov, 1989), where a giant artificial current loop was activated in the Barents Sea.


1982 ◽  
Vol 35 (2) ◽  
pp. 242-254 ◽  
Author(s):  
Carl Tyrén

The Earth's magnetic field has long provided us with a directional reference of almost worldwide usable coverage. This paper examines the use of the magnetic field for ground referenced motion and position measurementsWhere E is the vector representation of an electrical field, v vehicle velocity and B a magnetic field, the electromagnetic law of induction, E = v × B, indicates one possibility for measuring ground speed; the magnetic and electrical fields experienced by vehicle mounted sensors being used to solve the equation for v. This method however only gives the component of v perpendicular to the magnetic field. There are also certain difficulties associated with the measurement of B, which should be only the magnetic field of the Earth at the location of the vehicle, and E, which should be only the electrical field resulting from vehicle motion relative to the magnetic field of the Earth. The main problem appears to be the inseparability of motion dependent and non dependent electrical fields, a problem analogous to that of gravitation-acceleration inseparability for inertial navigation systems. The relative magnitudes of the vehicle-motiondependent E-field, of the order of 10−5 (volt/metre)/(metre/second), and the ever-present and very variable non-motion-dependent E-field between a highly conductive atmospheric layer at an altitude of about 50 km and the surface of the Earth, of some 102 volt/metre, are particularly unfavourable. Another potential basis for a ground-speed measurement system is the heterogeneous character of the intensity of the Earth's magnetic field.


GEODYNAMICS ◽  
2011 ◽  
Vol 2(11)2011 (2(11)) ◽  
pp. 284-286
Author(s):  
V. Semenov ◽  
◽  
J. Vozar ◽  
Yu. P. Sumaruk ◽  
B. Ladanivskyy ◽  
...  

It is known that magnetic poles of the Earth is accelerated and is now being ≈ 50 km/year (Olsen & Mandea, 2007) while the geomagnetic pole (the dipole part), which is computed (fictitious) value, has much less velocity. It is believed that the magnetospheric outer ring currents are held by the dipole part of the Earth’s magnetic field. The low frequency magnetic variations of that source allow determine the current position of the source axis and its corresponding pole which as shown experimentally precesses around the geomagnetic pole.


2021 ◽  
pp. 39-52
Author(s):  
A. N. Dmitriev ◽  
Yu. V. Pakharukov

A variant of the thermoelectric model of the Earth's dipole magnetic field is considered. It is based on geothermoelectric currents present in the planet's core. The currents cyclically change their direction, which leads over time either to warming on the Earth, if their movement is directed towards the Earth's crust, or to cooling, when moving towards the inner core. With each change in the direction of movement of the thermal currents, the poles of the Earth's magnetic field are inverted simultaneously. The inversion process is instantaneous (on the scale of planetary time) and is not the result of a gradual reversal on the 180° Earth's magnetic axis. At the moment of inversions of thermal currents in the core, the total geomagnetic field decreases to the level of 4.6∙10-6 T, which is constantly supported by thermal currents of semi-conducting rocks of the lower mantle. The considered version of the thermoelectric model of the Earth's magnetic field may be promising for studying the magnetic fields of planets in the Solar system.


Author(s):  
William Lowrie

The Earth is surrounded by a magnetic field, which originates inside its molten core, and which for centuries has helped travellers to navigate safely across uncharted regions. The magnetic field protects life on the Earth by acting as a shield against harmful radiation from space, especially from the Sun. ‘The Earth’s magnetic field’ explains that the magnetic field at the Earth’s surface is dominantly that of an inclined dipole. The Sun’s deforming effect on the magnetic field outside the Earth is described, as are the magnetic fields of other planets. The magnetism of rocks forms the basis of palaeomagnetism, which explains how plate tectonics displaced the continents and produced oceanic magnetic anomalies whenever the geomagnetic field reversed polarity.


2005 ◽  
Vol 23 (9) ◽  
pp. 3081-3088 ◽  
Author(s):  
S. J. Reay ◽  
W. Allen ◽  
O. Baillie ◽  
J. Bowe ◽  
E. Clarke ◽  
...  

Abstract. The oil industry uses geomagnetic field information to aid directional drilling operations when drilling for oil and gas offshore. These operations involve continuous monitoring of the azimuth and inclination of the well path to ensure the target is reached and, for safety reasons, to avoid collisions with existing wells. Although the most accurate method of achieving this is through a gyroscopic survey, this can be time consuming and expensive. An alternative method is a magnetic survey, where measurements while drilling (MWD) are made along the well by magnetometers housed in a tool within the drill string. These MWD magnetic surveys require estimates of the Earth's magnetic field at the drilling location to correct the downhole magnetometer readings. The most accurate corrections are obtained if all sources of the Earth's magnetic field are considered. Estimates of the main field generated in the core and the local crustal field can be obtained using mathematical models derived from suitable data sets. In order to quantify the external field, an analysis of UK observatory data from 1983 to 2004 has been carried out. By accounting for the external field, the directional error associated with estimated field values at a mid-latitude oil well (55° N) in the North Sea is shown to be reduced by the order of 20%. This improvement varies with latitude, local time, season and phase of the geomagnetic activity cycle. By accounting for all sources of the field, using a technique called Interpolation In-Field Referencing (IIFR), directional drillers have access to data from a "virtual" magnetic observatory at the drill site. This leads to an error reduction in positional accuracy that is close to matching that of the gyroscopic survey method and provides a valuable independent technique for quality control purposes.


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