Vertical distributions of global fallout Cs and C were investigated in a Japanese forest soil in 2001. Even 38 years after the fallout, Cs was still observed mostly in the uppermost 5 cm. A preferential accumulation of Cs was found in a 1-cm-thick transition layer between organic-rich A and underlying B horizons. This unique observation indicated that Cs migrated through the A horizon at a rate of 0.20% y and the transition layer acted as a barrier for Cs migration to deeper layers. The vertical distributions of Cs and C were significantly correlated, suggesting a coupled downward migration of Cs and organic matter on a time scale of decades, along the same physical pathways.
[CLARIVATE ANALYTICS], [WEB OF SCIENCE], [HIGHLY CITED PAPER & CUP LOGO] and [HOT PAPER & FIRE LOGO] are trademarks of Clarivate Analytics, and/or its affiliated company or companies, and used herein by permission and/or license.