Modelos globales del campo magnético terrestre para los últimos 3000 añosdiscrepancias según las bases de datos usadas

Laburpena

Global modelling of the geomagnetic field is essential not only to understand how this field works and how it varies but also to constrain geodynamo models and cosmogenic nuclides production rates. Obtaining reliable models relies mainly on used databases. Archaeomagnetic and volcanic data provide a record of magnetic field practically instantaneous, which is due to the acquisition process of the remanence (thermoremanent magnetization). For the last 3000 years the spatial and temporal distribution of the available data, as well as the quality of some of the records, is very heterogeneous. This produces some inconsistences in the models, and particularly for the intensity results. In this work we present four global models for the last 3000 years generated using different databases: 1) archaeomagnetic data (SHA3k.a), 2) archaeomagnetic data selected following quality criteria (SHAQ3k.a), 3) archaeomagnetic and volcanic data (SHA3k.av) and 4) archaeomagnetic and volcanic data selected following quality criteria (SHAQ3k.av). We present here the differences between them and compare to already published global geomagnetic models (SHA.DIF.14k, ARCH3k.1, CALS3k.4b, pfm9k.1a).