Temporal changes of the ¹³⁷Cs concentrations in the surface sediments at Stn. IB2.

Uncertainties of the data based on 1σ counting statistics are less than or equal to the size of the filled circles. The data for 134Cs and 137Cs concentrations in surface sediments used in this figure were obtained from May 2011 to June 2017 as a part of the monitoring project of the Marine Ecology Research Institute under contract with the Japanese Ministry of Education, Culture, Sports, Science and Technology (May 2011−March 2013) and the Secretariat of the Nuclear Regulation Authority (April 2013−present) [17].