HR: 0800h
AN: SH31A-0235    [Abstracts]
TI: High-resolution measurement of beryllium-10 content in the Dome Fuji shallow ice core during the Maunder Minimum
AU: * Miyahara, H
EM: miyahara@eps.s.u-tokyo.ac.jp
AF: Department of Earth and Planetary Sciences, School of Science, The University of Tokyo, 7- 3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
AU: Yokoyama, Y
EM: yokoyama@eps.s.u-tokyo.ac.jp
AF: Department of Earth and Planetary Sciences, School of Science, The University of Tokyo, 7- 3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
AU: Yokoyama, Y
EM: yokoyama@eps.s.u-tokyo.ac.jp
AF: Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Sciences and Technology, 2-15 Natushima-cho, Yokosuka, 237-0061, Japan
AU: Matsuzaki, H
EM: hmatsu@malt.rcnst.u-tokyo.ac.jp
AF: Department of Nuclear Engineering and Management, School of Engineering, The University of Tokyo, 2-11-16, Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan
AU: Horiuchi, K
EM: kh@cc.hirosaki-u.ac.jp
AF: Department of Earth and Environmental Sciences, Hirosaki University, 1 bunkyo-cho, Hirosaki, 036-8560, Japan
AU: Motoyama, H
EM: motoyama@pmg.nipr.ac.jp
AF: National Institute of Polar Research, 9-10, Kaga 1-chome,Itabashi-ku, Tokyo, 173-8515, Japan
AB: The production rate of the beryllium-10 in the atmosphere is basically proportional to the intensity of incoming galactic cosmic rays which show 11 year periodicity associated with the state of solar magnetic field. In order to examine the feasibility of detecting the 11 year solar cycle in the Dome Fuji shallow ice core covering over 3000 years, we measured the Be-10 content with high temporal resolution of 0.7-1.0 years. The Be-10/Be-9 ratio is measured by the Accelerator Mass Spectrometer (AMS) at the Micro Analysis Laboratory, Tandem accelerator (MALT), at the University of Tokyo. We report the preliminary data of the Be-10 concentration in the Dome Fuji shallow ice core around the 17th and the 18th century including the era of the Maunder Minimum. The average content of Be-10 in the ice core for this period is about 10⁵ atoms/g. The 11 year periodicity is clearly detected with amplitude of about 30 %. We compare the obtained Be-10 data with the sunspot data and the other beryllium-10 data to evaluate the validity of our measurement and to examine the accuracy of the dating of the ice sheets for this period. Based on the results, we discuss the variation of solar cycle and the magnetic polarity during the Maunder Minimum.
DE: 0724 Ice cores (4932)
DE: 1650 Solar variability (7537)
DE: 2104 Cosmic rays
DE: 4918 Cosmogenic isotopes (1150)
DE: 7536 Solar activity cycle (2162)
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2007 Fall Meeting