title: Spatial variations of low levels of ¹³⁴Cs and ¹³⁷Cs in seawaters within the Sea of Japan after the Fukushima Dai-ichi Nuclear Power Plant accident.
abstract: Our method based on low background γ-spectrometry enabled the measurement of low radiocesium concentrations in only 20 L of seawater. In May 2011 after deposition of radiocesium, (134)Cs concentration in surface water within the Sea of Japan was confirmed to be significantly small (<0.1-1 mBq/L) by the method. The concentration was not detected (<0.1 mBq/L) below 50 m depth. The Fukushima-derived radiocesium migrated from the surface water of the Sea of Japan without advection to below the thermocline.
authors.affiliation: Low Level Radioactivity Laboratory, Kanazawa University, Nomi, Ishikawa 923-1224, Japan. mutsuo@llrl.ku-unet.ocn.ne.jp
authors.forename: Mutsuo
authors.initials: M
authors.lastname: Inoue
authors.forename: Hisaki
authors.initials: H
authors.lastname: Kofuji
authors.forename: Shinji
authors.initials: S
authors.lastname: Oikawa
authors.forename: Takuma
authors.initials: T
authors.lastname: Murakami
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Seiya
authors.initials: S
authors.lastname: Nagao
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Hamajima
authors.forename: Jun
authors.initials: J
authors.lastname: Misonoo
mesh_terms: D002588:Cesium Radioisotopes / Q000032:analysis*; D062406:Fukushima Nuclear Accident; D007564:Japan; D009792:Oceans and Seas; D011829:Radiation Dosage; D011834:Radiation Monitoring / Q000379:methods*; D011847:Radioactive Fallout / Q000032:analysis*; D012623:Seawater / Q000032:analysis* / Q000737:chemistry*; D062211:Spatio-Temporal Analysis; D014875:Water Pollutants, Radioactive / Q000032:analysis*
chemical_list: D002588:Cesium Radioisotopes; D011847:Radioactive Fallout; D014875:Water Pollutants, Radioactive
keywords: Deposition; Fukushima Dai-ichi Nuclear Power Plant accident; Radiocesium; Riverine discharge; Water circulation