Speaker
Fusa Miyake
(Nagoya University)
Description
$^{14}$C content in tree rings and $^{10}$Be concentration records in ice core provide information about past cosmic ray intensities. Some studies reported a large annual increase in the $^{14}$C content from AD 774 to 775. Also quasi-decadal $^{10}$Be data in the Dome Fuji ice core show a sharp peak in a corresponding period of the AD 775 event. However, annual $^{10}$Be variations in the Dome Fuji core or in other cores have not been revealed. We measured $^{10}$Be concentration in the Dome Fuji ice core with quasi-annual resolution for the period approximately from AD 763 to 794. We found a clear $^{10}$Be increase around AD 775 on a background variation. Since the quasi-annual $^{10}$Be and Na$^{+}$ ion data show a good agreement in our measurement period, the background variation in $^{10}$Be concentration is considered as a climatic noise. It is possible that the quasi-annual $^{10}$Be increase is occurred by the AD 775 cosmic ray event.
| Registration number following "ICRC2015-I/" | 627 |
|---|---|
| Collaboration | -- not specified -- |
Primary author
Fusa Miyake
(Nagoya University)
Co-authors
Ms
Asami Suzuki
(Nagoya University)
Dr
Hideaki Motoyama
(NIPR)
Dr
Hiroyuki Matsuzaki
(University of Tokyo)
Dr
Kazuho Horiuchi
(Hirosaki University)
Dr
Kazuya Takahashi
(RIKEN)
Dr
Kimiaki Masuda
(STEL, Nagoya University)
Dr
Yoichi Nakai
(RIKEN)
Dr
Yuko Motizuki
(RIKEN)
