Development of a method for reconstruction of cosmic-ray variations using terrestrial carbonate deposits

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K13488
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Musashino Art University
• Principal Investigator: Miyahara Hiroko 武蔵野美術大学, 造形学部, 准教授 (00532681)
• Co-Investigator(Renkei-kenkyūsha): HORIUCHI Kazuho 弘前大学, 理工学研究科, 助教 (00344614)
• Research Collaborator: ZHOU Limin East China Normal University, Professor ; XU Hongyang East China Normal University, Professor ; SAKASHITA Wataru 筑波大学, 生命環境系, 研究員
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 宇宙線 / 宇宙線生成核種 / 太陽活動 / 炭酸塩堆積物 / ベリリウム10

Outline of Final Research Achievements

In this study, we conducted basic analysis of beryllium-10 content in carbonate sediments to explore methods which enable the reconstruction of past cosmic ray variations with one year resolution. Characteristics of tufa deposits and travertine sediments, concentrations in the rainy and dry seasons, and the secular variation were analyzed. In addition, beryllium-9 and trace elements were analyzed. As a result, beryllium-10 calibrated with beryllium-9 and trace element shows variations that are consistent with cosmic ray variations measured by neutron monitors.

Free Research Field

宇宙線物理学, 太陽物理学