Caracterización de las variaciones rápidas de la intensidad arqueomagnética en el Mediterráneo durante los últimos 4000 años

Abstract

One of the main challenges in Earth Sciences is to understand the origin and behaviour of the Earth’s magnetic field (or geomagnetic field) which presents wide variations in both time and space. Direct geomagnetic measurements indicate that the geomagnetic dipolar moment has slightly decayed by about 3.2% per century since 1600 CE. During the last 80 years this rate of change has accelerated up to values of 5.8% per century. Due to this rapid decrease, the present value of the geomagnetic dipole moment is the lowest observed through the last three millennia. On the other hand, the geomagnetic field acts as a protective shield against high-energy solar particles, and thus the decreasing of the field translates into the higher entry of these particles into the atmosphere, which can lead to less protection against extreme Space Weather events, such as solar storms. These events reveal the importance of investigating the range of variation of the geomagnetic field on relatively short time scales, from decades to centuries. In this context, to better understand the present and future variations of the Earth’s magnetic field, it is essential to know how the geomagnetic field has changed in the past time. In addition, this also provides crucial information to understand the evolution of the Earth’s interior and, specifically, about the dynamics of its outer core, where this important phenomenon has its main origin.