HR: 0800h
AN: GP41C-04 [Abstracts]
TI: Archeomagnetic Results From Spain
AU: * Chauvin, A
EM: Annick.Chauvin@univ-rennes1.fr
AF: Geosciences-Rennes UMR CNRS 6118, Universite de Rennes 1
Campus de Beaulieu Bat 15
CS 74205, Rennes, 35042cedex, France
AU: Gomez-Paccard, M
EM: miriamgomez@hotmail.fr
AF: Geosciences-Rennes UMR CNRS 6118, Universite de Rennes 1
Campus de Beaulieu Bat 15
CS 74205, Rennes, 35042cedex, France
AU: Lanos, P
EM: Philippe.Lanos@univ-rennes1.fr
AF: UMR CNRS IRAMAT 5060 et Geosciences-Rennes UMR CNRS 6118, Universite de
Rennes 1
Campus de Beaulieu Bat 15
CS 74205, Rennes, 35042cedex, France
AU: Osete, M
EM: mlosete@fis.ucm.es
AF: Departamento de Fisica de la Tierra, Universidad Complutense de Madrid, Ciudad
Universitaria, Madrid, 28040, Spain
AU: McIntosh, G
EM: gregc@fis.ucm.es
AF: Departamento de Fisica de la Tierra, Universidad Complutense de Madrid, Ciudad
Universitaria, Madrid, 28040, Spain
AU: Thiriot, J
EM: thiriot@mmsh.univ-aix.fr
AF: MMSH UMR CNRS 6572, 5 rue du Chateau de l'Horloge
BP 647, Aix-en-Provence, 13094, France
AB:
A first secular variation (SV) curve for the Iberian Peninsula was computed by hierarchical Bayesian method using
a total of 134 archaeomagnetic directions with ages ranging from 775 BC to 1959 A.D. A general agreement is
observed between the Iberian curve and the French and German SV curves, excepted between the 11th and 14th
centuries. The analysis of these three reference curves indicates that SV in western Europe is characterized by
three major directional changes at 125, 200, and 1350 A.D. It is suggested that these cusps are regional
features of the geomagnetic field.
Archeointensity studies were also conducted on 24 Spanish archeomagnetic sites (220 AD to 1959 AD). Intensity
data were obtained using the original Thellier method with anisotropy and cooling rates corrections. Our new 24
data, together with 62 previously published results, were used to recover, by Bayesian modelling, the
geomagnetic field intensity evolution over the past two millennia for western Europe. Our results indicate that the
geomagnetic intensity remains more or less constant between the 1st and 4th centuries, and between the 13th
and 15th centuries, whereas an important decrease occurs during the last 5 centuries. The evolution of the
Earth's magnetic field intensity during High Middle Ages remains uncertain. The available geomagnetic global
models predict reasonably well our data.
DE: 1503 Archeomagnetism
DE: 1521 Paleointensity
SC: Geomagnetism and Paleomagnetism [GP]
MN: 2007 Joint Assembly