ISSN:
1420-9136
Source:
Springer Online Journal Archives 1860-2000
Topics:
Geosciences
,
Physics
Description / Table of Contents:
Resumen Utilizando todos los promedios anuales deF registrados por cada uno de los observatorios geomagnéticos instalados en el globo, se analizan, con el mayor detalle posible, las características presentadas, durante el periodo 1885–1951, por la evolución de la intensidad de la fuerza geomagnética. Teniendo en cuenta los errores que podría introducir la heterogeneidad que caracteriza e la distribución geográfica de los observatorios, se divide la superficie terrestre en ocho sectores idénticos. Para cada época han sido calculados los promedios de los gradientes anuales de la variación registrados en la totalidad de los observatorios instalados en cada sector y, promediando los valores obtenidos para los cuatro sectores correpondientes, se calculan las series de gradientes atribuibles a uno y otro hemisferios. Los promedios de los valores correspondientes a los dos hemisferios son considerados como representativos de la evolución atribuible al fenómeno en el conjunto del globo. Este método de análisis conduce a la conclusión de que nuestro planeta estuvo sometido a un proceso de reimanación en las épocas precedentes a 1895 y que, en esta época, se estableció un proceso de desimanación que fué neutralizado en 1915, permitiendo el establecimiento de un nuevo proceso de reimanación que ha persistido hasta la época 1941, desde la qual viene sometido nuestro planeta a otro proceso de desimanación. De estas oscilaciones se dedce la existencia de un periodo medio de 50 años para los ultimos ciclos de reimanación-desimanación. Utilizando las referencias obtenidas por los diversos investigadores que han aplicado el análisis armónico al estudio de la distribución general de la inanación terrestre, se establecen los gradientes de la variación experimentada por el valor medio del momento geomágnético entre las épocas 1885, 1922 y 1945, que son comparados con los revelados, para los mismos periodos, por las variaciones experimentadas por los promedios generales deF calculados en este trabajo. Finalmente se establecen los coeficientes representativos de la intensidad media anual de los procesos de reimanación y desimanación puestos de relieve en esta investigación.
Notes:
Summary Against what has been so far unanimously believed, our former investigations have proved that the neutralization of the process of dismagnetization which our planet has been going through had been fulfilled and that this process has been replaced by a process of re-magnetization; we could deduce also that the inversion of the sign in the medium gradients of the variation must have taken place in an epoch near 1930. But, both on account of the improper material used in that investigation and of the kind of analytic manipulations to which it was submitted it was impossible to achieve a detailed study of the characteristics that can be attributed to the evolution experienced by the intensity of the earth's magnetization. In this research we used all the yearly averages of the whole geomagnetic forceF, recorded by all the geomagnetic observatories that exist in the world; these figures have made it possible to establish the corresponding yearly gradients of the variation referring to the 1st January every year. In order to eliminate as far as possible the errors due to the lack of homogeneity in the geographic distribution of the observatories throughout the earth, we have divided its surface into eight equal sectors; by working out the average of all the gradients recorded in each epoch by all the observatories established in each sector we have obtained the medium gradients which we consider representatives of the evolution experienced byF in its corresponding sector. Working out the average of the gradients corresponding to each of the four sectors in which each hemisphere had been divided, we established the series of gradients of each hemisphere; finally, the averages of the latter can be considered as representative of the evolution experienced by the geomagnetic intensity during the period 1885.0-1950.0. Besides having made it possible for us to establish numerous considerations on the individual characteristics displayed by the secular variation in the eight sectors and in each hemisphere, this analytical method has enabled us to reveal that magnetic intensity of our planet has gone through the following variations: 1) Process of re-magnetization during the period 1885–1895. 2) Process of dismagnetization during the period 1895–1915. 3) Process of re-magnetization during the period 1915–1941. 4) Process of dismagnetization during the period 1941–1950. From these oscillations we infer an average period of 50 years for the last cycles of the remagnetization-dismagnetization wich makes it advisable to change the denomination (quite improper from now on) of secular variation given to this phenomenon when on account of lacking the necessary observations, essential to know its real duration it was that it lasted a long time.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01988603
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