Geomagnetic modulation of the late Pleistocene cosmic-ray flux as determined by 10Be from Blake Outer Ridge marine sediments

Autor: L. R. McHargue, Douglas J. Donahue, Paul E. Damon, D. Biddulph, George S. Burr, C.P Sonett
Rok vydání: 2000
Předmět:
Zdroj: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 172:555-561
ISSN: 0168-583X
Popis: The cosmic-ray flux incident upon the Earth during the late Pleistocene, 20–60 kyr B.P., was studied by measuring the cosmogenic radionuclide 10 Be from a marine sediment core at site CH88-10P on the Blake Outer Ridge. The paleointensity of the geomagnetic field for this core was determined by various methods. The variance in the concentration of 10 Be in the authigenic fraction of the sediments from Blake Ridge closely correlates with the inverse of the variance in the paleointensity of the geomagnetic field. The 10 Be signal lags, up to 1000 years of sedimentation, the measured paleointensity of the sediments. In contrast, the data from several other elements, some climatically sensitive, and from beryllium show relationship neither to 10 Be nor to the paleomagnetic data. The relationship between 10 Be concentration and the dipole field intensity ( M / M o ) as measured in the sediments is consistent with theoretical models.
Databáze: OpenAIRE