On the absolute geomagnetic intensity fluctuations in Mexico over the last three millennia

Abstract

Earth Magnetic Field is characterized by continuous variations in terms of direction and intensity. These fluctuations occur with periodicities of the order of years to tens of thousands of years and constitute the principal characteristic of the geomagnetic field. Revealing such variations at a regional scale has a significant impact in geophysics, but also in archaeology and thus represents a clear example of interdisciplinary research. Due to the importance of non-dipole field components in the secular variation, reference curves can only be constructed for limited areas, commonly within less than 1200 km radius. Three recently reported paleosecular variation curves for most Mesoamerica show contradictory trends, probably due to inappropriate selection of data and the criteria applied to individual intensity determinations. The use of unpublished data, essentially reported in thesis, may lead the discrepancy over the reported curves. Here, we report a critical revaluation of existing published and unpublished data with particular emphasis on the sample-radiometric age relationship for the last 3600 years.