@article{oai:repo.qst.go.jp:00048917,
 author = {Kobayashi, Shingo and Shinomiya, Takayuki and Ishikawa, Takahiro and Imaseki, Hitoshi and Iwaoka, Kazuki and Kitamura, Hisashi and Kodaira, Satoshi and Kobayashi, Keisuke and Oikawa, Masakazu and Miyaushiro, Norihiro and Takashima, Yoshio and Uchihori, Yukio and 小林 進悟 and 四野宮 貴幸 and 石川 剛弘 and 今関 等 and 岩岡 和輝 and 北村 尚 and 小平 聡 and 小林 圭輔 and 及川 将一 and 宮後 法博 and 高島 良生 and 内堀 幸夫},
 journal = {Journal of Environmental Radioactivity},
 month = {May},
 note = {A low 134Cs/137Cs ratio anomaly in the north-northwest (NNW) direction from the Fukushima Dai-ichi Nuclear Power Station (FDNPS) is identified by a new analysis of the 134Cs/137Cs ratio dataset which we had obtained in 2011e2015 by a series of car-borne surveys that employed a germanium gamma-ray spectrometer. We found that the 134Cs/137Cs ratio is slightly lower (0.95, decay-corrected to March 11, 2011) in an area with a length of about 15 km and a width of about 3 km in the NNW direction from the FDNPS than in other directions from the station. Furthermore, the area of this lower 134Cs/137Cs ratio anomaly corresponds to a narrow contamination band that runs NNW from the FDNPS and it is nearly parallel with the major and heaviest contamination band in the west-northwest. The plume trace with a low 134Cs/137Cs ratio previously found by other researchers within the 3-km radius of the FDNPS is in a part of the area with the lower 134Cs/137Cs ratio anomaly that we found. Our result suggests that this lower 134Cs/137Cs ratio anomaly is the area which was contaminated before March 13, 2011 (UTC) in association with the hydrogen explosion of Unit 1 on March 12, 2011 at 06:36 (UTC) and it was less influenced by later subsequent plumes.},
 pages = {84--94},
 title = {Low 134Cs/137Cs ratio anomaly in the north-northwest direction from the Fukushima Dai-ichi Nuclear Power Station},
 volume = {178-179},
 year = {2018}
}