The separation of the geomagnetic field originated in the core, in the asthenosphere, and in the crust
| Autor: | X. Q. Gao, F. T. Gizzi, W. J. Dong, G. P. Gregori |
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| Jazyk: | angličtina |
| Rok vydání: | 1999 |
| Předmět: | |
| Zdroj: | Annals of Geophysics, Vol 42, Iss 2 (1999) |
| Druh dokumentu: | article |
| ISSN: | 1593-5213 2037-416X |
| DOI: | 10.4401/ag-3713 |
| Popis: | The separation of the field produced by different internal sources can be accomplished by means of the so-called spatial spectrum of the geomagnetic field of internal origin. It is shown how such a rationale, when suitably interpreted, allows to recognize the field that is originated by electric currents that flow either on the Inner-Core Boundary (ICB), or on the Core-Mantle Boundary (CMB), or on the Asthenosphere-Lithosphere Boundary (ALB). It appears crucial, however, to rely on satellite measurements alone, because ground-based and ship- and air-borne records are severely perturbed by the crustal field. Therefore, it is shown, on the basis of a critical reconsideration of a few key-papers in the literature, that the best approach is to avoid mixing together all kinds of measurements. Satellite data are best suited for recognizing the dynamo field, while ground-based, ship- and air-borne records, which are measured much closer to crustal sources, are best suited, after subtraction of the satellite-derived dynamo field, for inferring the geomagnetic anomalies that are to be associated with crustal sources alone. |
| Databáze: | Directory of Open Access Journals |
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