[8a-Z25-1~12] 【CS.1】 Code-sharing Session of 2.4 & 7.5

[8a-Z25-11] Distribution of the cosmogenic Be isotopes concentration in seawater in the Eastern South Pacific (Ⅱ)

〇Takeyasu Yamagata^1,2, Hiroyuki Matsuzaki¹, Hisao Nagai² (1.The Univ. of Tokyo, 2.Nuhon Univ.)

Keywords:Accelerator Mass Spectrometry, Cosmogenic Nuclide, Eastern South Pacific

Cosmogenic nuclides ⁷Be (half-life 53.3 days) and ¹⁰Be (half-life 1.36 My) are produced in the upper atmosphere by nuclear interactions between secondary cosmic rays and atmospheric nitrogen and oxygen. The residence time of Be in the ocean is estimated to be 400-1000 years. The depth profile of ¹⁰Be concentration in seawater appeared increases with the depth, which is called a recycle type. In this presentation, to consider the ¹⁰Be circulation in the ocean from the depth distribution of ¹⁰Be concentration in the eastern South Pacific.