Geomagnetic Secular Variation in the Canary Islands: paleomagnetic data, models and application to paleomagnetic dating

Resumen

This work explores the reasonability of using the Geomagnetic Secular Variation to date recent lava flows in the Canary Islands, which could contribute to improve the knowledge about the recent volcanic evolution of the Canary Islands and the corresponding volcanic hazards. An evaluation of the secular variation in the Canary Islands during the last 400 years is performed with published paleomagnetic data from well known historical lava flows (Soler et al., 1984). A regional Paleosecular Variation Curve (PSVC) has been calculated using the Bayesian statistics and has been compared with global geomagnetic models constructed from historical and instrumental geomagnetic observations for the last four centuries (GUFM1 model, Jackson et al., 2000; IGRF-11, IAGA, 2009) and from archeomagnetic and paleomagnetic data for the last 3 ka (ARCH3K.1 model, Korte et al., 2009). The global ARCH3K.1 model and the regional European SCHA.DIF.3K model (Pavón-Carrasco et al., 2009) relocated to the Canary Islands have been used to obtain paleomagnetic ages for the historical lava flows, which have been compared with historical ages to estimate the error that could be expected to affect any paleomagnetic ages obtained by this procedure in older lava flows. A paleomagnetic dating of two older lava-flows (Lavas Negras del Teide, Tenerife; Montaña Quemada, La Palma) is proposed and compared with radiometric ages.