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Title2021 Monitoring of Artificial Radionuclides in Seawater and Seabed soil around Japan
Author 1Japan Coast Guard
Author 2 
Author 3 
Author 4 
Authors 5- 
SubjectOceans
Subject_sub1 
Subject_sub2 
AbstractThis dataset comprises 34 data records and is derived from radioactivity surveys by Japan Coast Guard, former Maritime Safety Agency, in 2021. The radioactivity surveys aim to monitor artificial radionuclides in seawater and seabed soil around Japan, because the artificial radionuclides were released into the environment through past nuclear tests and accidents at nuclear facilities. The study of seawater commenced in 1959, while the study of seabed soil began in 1974, with both continuing to the present day.
Temporal coverage2021
Spatial coverage26.66333333N~45.33500000N, 126.42500000E~143.00500000E
File formatDelimited
LanguageEnglish
Discovery metadata record 
PublisherCenter for Research in Radiation, Isotopes, and Earth System Sciences, University of Tsukuba
Publication year2024
Publication date29th of May
Digital Object Identifier (DOI)10.34355/JCG.HOD.00239 Data Download (21KB)
Short DOI 
Citation textJapan Coast Guard. (2024). 2021 Monitoring of Artificial Radionuclides in Seawater and Seabed soil around Japan [Dataset]. Center for Research in Radiation, Isotopes, and Earth System Sciences, University of Tsukuba. https://doi.org/10.34355/JCG.HOD.00239
Serial at center00239
Serial at each Univ./InstituteJCGHOD0002
Key word 1Sr-90
Key word 2Cs-137
Key word 3Cs-134
Key word 4Co-60
Key word 5 
RemarksSamples collection for this survey was conducted by Japan Coast Guard. The samples comprise 24 seawater and 10 seabed soil specimens. Of 24 samples in seawater, 8 were in coastal water, 16 were in the offing; and all samples in seabed were collected from the sampling sites in coastal water. The analytes were as follows: Co-60, Sr-90, Ru-106, Cs-134, and Cs-137 in seawater; Co-60, Sr-90, Cs-134, and Cs-137 in seabed soil. The concentrations of radioactivity are shown two significant figures with the estimated error coefficient in the dataset. When measured value was smaller than threshold or a detection limit which is defined as a value of three times the coefficient of error, it was noted as 'Not Detected'. Due to 'Not Detected' at all sampling sites, Co-60, Ru-106, and Cs-134 in seawater, as well as Co-60 in seabed soil, were omitted from the dataset.

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