- 著者
-
吉川 周作
山崎 秀夫
井上 淳
三田村 宗樹
長岡 信治
兵頭 政幸
平岡 義博
内山 高
内山 美恵子
- 出版者
- 日本地質学会
- 雑誌
- 地質學雜誌 (ISSN:00167630)
- 巻号頁・発行日
- vol.107, no.8, pp.535-538, 2001-08-15
- 参考文献数
- 20
- 被引用文献数
-
1
The explosion of a plutonium atomic bomb over Nagasaki city took place on 9 August 1945. After the explosion, a cloud formed, which passed over the Nishiyama district, where 'black rain' fell. Thus, the Nishiyama reservoir, located approximately 3 km from the hypocenter, received the heaviest radioactive fallout from the Nagasaki atomic bomb. Sediment samples were collected from the bottom of the Nishiyama reservoir in 1999 and analyzed for their ^<137>Cs, ^<241>Am and charcoal concentrations. The stratigraphic distribution of ^<137>Cs and charcoal clearly indicate that the 'black rain' horizon is recognized in the Nishiyama reservoir sediments. The 'black rain' horizon contains anthropogenic radionuclides (^<137>Cs and ^<241>Am) and charcoal in high concentrations.