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Yamada, Ryuji*; Kimura, Takashi*; Kariya, Yoshihiko*; Sano, Masaki*; Tsushima, Akane*; Li, Z.*; Nakatsuka, Takeshi*; Kokubu, Yoko; Inoue, Kimio*
Sabo Gakkai-Shi, 73(5), p.3 - 14, 2021/01
We discuss the applicability of dating methods for determining landslide chronologies in relation to the type of samples and the sampling location. Case studies are carried out with fossil wood samples buried in the colluvial soil of large-scale landslides occurred in two areas of the Japanese Alps region. Ages are determined by accelerator mass spectrometry radiocarbon dating and dendrochronological analysis using the oxygen isotope composition of tree ring cellulose. Most of ages for Dondokosawa rock avalanche are concordant with the period of AD 887 Ninna (Goki-Shichido) earthquake. Ages for Ohtsukigawa debris avalanche are not concentrated in a specific period. In order to obtain accurate age of large-scale landslide, utilizing buried large diameter tree trunk or branches with the good preservation condition has a lot of advantages because it allows us to compare the landslide chronology with historical records of heavy rainfall and large earthquakes.
Amano, Hikaru
Proc. of the 5th Int. Seminar for Liquid Scintillation Analysis, p.55 - 76, 1993/00
no abstracts in English
Iimoto, Takeshi*; Maedera, Ikuhiko*; Nunokawa, Jun*; Matsuzawa, Hajime*; Kurokawa, Sumihiko*; Yanagawa, Yukihide*; Someya, Seiichi*; Hashimoto, Makoto; Seya, Natsumi; Okawa, Yasuhisa; et al.
no journal, ,
no abstracts in English
Tanaka, Kazuya; Takahashi, Yoshio*
no journal, ,
Tree barks were collected in Fukushima. Stable Cs was adsorbed on the barks and measured using XAFS to investigate its adsorption structure. XAFS analysis indicated that Cs was adsorbed on the barks as a outer-sphere complex.
Niizato, Tadafumi; Sasaki, Yoshito; Namba, Kenji*; Tsukada, Hirofumi*; Vasyl, Y.*
no journal, ,
We determined the 
Cs aggregated transfer coefficients for trees from the Cs activities of tree organs and soil layers collected in the off-site localities on the path of the radioactive plumes (southern and southwestern plume), and assessed the contamination status of each tree type. As a result, it was revealed that although the Japanese red pine has no distinct difference, but the Japanese cedar has a large change in aggregated transfer coefficients due to the plume.
Niizato, Tadafumi; Sasaki, Yoshito
no journal, ,
An understanding of the environmental dynamics of radiocesium in the forested area of Fukushima provides scientific basis on the estimation of radiocesium transfer to the forest products and the radiocesium activity prediction. Long-term field monitoring results show the very low radiocesium transfer flux and aboveground tree compartments include 5% of radiocesium in the investigated site.
Niizato, Tadafumi; Sasaki, Yoshito; Ito, Satomi; Watanabe, Takayoshi; Amamiya, Hiroki*
no journal, ,
An understanding of long-term environmental dynamics of radiocesium in forested area, which is released by the TEPCO's Fukushima Dai-ichi Nuclear Power Plant accident, is a key issue for predicting the future forest products radioactivity. In this paper we present the radiocesium uptake from forest floor in an evergreen Japanese cedar and a deciduous Japanese konara oak forests of the Abukuma Mountains, Fukushima. An investigation was conducted from 2015 to 2019. According to the International Biological Programme, IBP, annual radiocesium uptake from forest floor to the stand is estimated as follows; annual radiocesium increment associated with tree growth plus annual loss through litterfall, stemflow, and throughfall. The rate of annual radiocesium uptake to the total inventory of the stands associated with tree growth were estimated to be 0.1 and 0.06% in Japanese konara oak and Japanese cedar stands, respectively. The sum of radiocesium uptake including the loss of radiocesium amount by litterfall, stemflow, and throughfall were 1.37 and 3.13% in the konara oak and the cedar stands, respectively. The rate of radiocesium uptake estimated are lower than the elemental uptake in deciduous tree stands near Kyoto by IBP. This indicate that the radiocesium uptake by the konara oak and the cedar stands is limited and no significant increase in radiocesium concentration of tree tissues is expected in the study stands.
