کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6429900 1634771 2014 16 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The geomagnetic dipole moment variation between 250 and 800 ka BP reconstructed from the authigenic 10Be/9Be signature in West Equatorial Pacific sediments
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات علوم زمین و سیاره ای (عمومی)
پیش نمایش صفحه اول مقاله
The geomagnetic dipole moment variation between 250 and 800 ka BP reconstructed from the authigenic 10Be/9Be signature in West Equatorial Pacific sediments
چکیده انگلیسی


- High-resolution authigenic 10Be/9Be ratio from equatorial ocean sediments.
- Geomagnetic modulation of the 10Be atmospheric production.
- Quantification of Geomagnetic Dipole Moment (GDM) variations.
- 10Be overproduction during Geomagnetic Dipole Lows (GDL).
- Brunhes-Matuyama transition and Brunhes excursions.

The authigenic 10Be/9Be ratio, proxy of the cosmogenic radionuclide 10Be production rate in the atmosphere, was measured in sediments deposited in the West Equatorial Pacific (Gulf of Papua; 10°25 S; 146°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 10Be 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 10Be 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.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Earth and Planetary Science Letters - Volume 385, 1 January 2014, Pages 190-205
نویسندگان
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