Publications des scientifiques de l'IRD

Menabreaz L., Thouveny Nicolas, Bourles D. L., Vidal L. (2014). The geomagnetic dipole moment variation between 250 and 800 ka BP reconstructed from the authigenic Be-10/Be-9 signature in West Equatorial Pacific sediments. Earth and Planetary Science Letters, 385, p. 190-205. ISSN 0012-821X.

Titre du document
The geomagnetic dipole moment variation between 250 and 800 ka BP reconstructed from the authigenic Be-10/Be-9 signature in West Equatorial Pacific sediments
Année de publication
2014
Type de document
Article référencé dans le Web of Science WOS:000331025000021
Auteurs
Menabreaz L., Thouveny Nicolas, Bourles D. L., Vidal L.
Source
Earth and Planetary Science Letters, 2014, 385, p. 190-205 ISSN 0012-821X
The authigenic Be-10/Be-9 ratio, proxy of the cosmogenic radionuclide Be-10 production rate in the atmosphere, was measured in sediments deposited in the West Equatorial Pacific (Gulf of Papua; 10 degrees 25 S; 146 degrees 15 E), in order to reconstruct the geomagnetic dipole moment variations in the 250-800 ka time interval, independently from paleomagnetic methods. The pelagic clayey-carbonate muds continuously deposited between marine isotope stages 8 and 20 were subsampled every 10 cm. The Be-10 production rate record reconstructed for the 250-800 ka interval is described and compared over the same time interval with global paleomagnetic stacks (SINT-2000 and PISO-1500). The highlighted cosmogenic Be-10 overproductions appear to be triggered by the series of Geomagnetic Dipole Lows (GDL) that have occurred since the Brunhes-Matuyama reversal. Calibration using absolute values of the geomagnetic dipole moment drawn from a paleomagnetic database produces a new record of the dipole moment variations over the 250-800 ka time interval. The timing and amplitude of the GDL succession revealed by such records will contribute to improving knowledge of the geodynamo rhythms and rate of changes at millennial to million year scales.
Plan de classement
Géologie et formations superficielles [064] ; Géophysique interne [066]
Description Géographique
PACIFIQUE ; ZONE EQUATORIALE
Localisation
Fonds IRD
Identifiant IRD
PAR00011493
Contact