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

[摘要] The cosmic-ray flux incident upon the Earth during the late Pleistocene, 20-60 kyr B.P., was studied by measuring the cosmogenic radionuclide Be-10 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 Be-10 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 Be-10 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 Be-10 nor to the paleomagnetic data. The relationship between Be-10 concentration and the dipole held intensity (M/M-o) as measured in the sediments is consistent with theoretical models. (C) 2000 Elsevier Science B.V. All rights reserved.

[发布日期] 2000-10-01

[效力级别]  Proceedings Paper