Objetivo The primary scientific objectives of this project are twofold, 1) to improve understanding of the mechanisms which generate the geomagnetic field in the core by careful study of geomagnetic excursions (brief changes in direction and intensity of the geomagnetic field) and, 2) to better understand the correlation between geomagnetic-field intensity, production rate of cosmogenic nuclides, and climate variations.This project will involve a detailed study of two such geomagnetic excursions, the Blake and the Jamaica, in three sediment cores at varying latitude. It will assess the exact magnetic-field behaviour during the excursions, in terms of direction, intensity, and duration. By combining already existing oxygen isotope stratigraphies for these cores with precise estimates of the sedimentation rates from 230Thxs measurements (an approach termed Th-normalization) the exact duration of these excursions will be constrained. Measurements of the flux of cosmogenic nuclides (10Be) to the sediments during the magnetic excursions will also be performed to assess the relationship between field intensity and cosmogenic production rates.Th-normalization is required to calculate the exact fluxes of 10Be to the sediments, because the concentration of 10Be is dependent on sedimentation rate. As the project develops, absolute palaeointensities from lava flows will also be measured and combined with the relative palaeointensity from the sediments to construct a detailed record of the absolute palaeointensity for the last 100-200 kyr. This work will provide the first direct correlation of geomagnetic-field intensity with the production rate of cosmogenic nuclides, both measured in the same discrete samples. Furthermore, to investigate the relationship between the Earth's magnetic field and climate variations, the palaeointensity record obtained in this study will be compared with existing climate records from the Vostok ice-core. Ámbito científico natural sciencesearth and related environmental sciencesgeologysedimentology Palabras clave Geomagnetic excursions climate changes cosmogenic nuclides isotope geochemistry palaeointensity Programa(s) FP6-MOBILITY - Human resources and Mobility in the specific programme for research, technological development and demonstration "Structuring the European Research Area" under the Sixth Framework Programme 2002-2006 Tema(s) MOBILITY-2.1 - Marie Curie Intra-European Fellowships (EIF) Convocatoria de propuestas FP6-2002-MOBILITY-5 Consulte otros proyectos de esta convocatoria Régimen de financiación EIF - Marie Curie actions-Intra-European Fellowships Coordinador THE CHANCELLORS, MASTERS, AND SCHOLARS OF THE UNIVERSITY OF OXFORD Aportación de la UE Sin datos Dirección University Offices, Wellington Square OXFORD Reino Unido Ver en el mapa Enlaces Sitio web Opens in new window Coste total Sin datos