Fig. 6

Variations of \({\text{U}}_{{{37}}}^{{{\text{K}}^{\prime } }}\)-SST and the abundance of benthic foraminifer in the present-day Tokyo Bay and Palaeo-Tokyo Bays. The left and right axes show the calculation results after performing culture calibration (Sawada et al. 1996) and global core-top calibration (Müller et al. 1998), respectively. a Variation of \({\text{U}}_{{{37}}}^{{{\text{K}}^{\prime } }}\)-SSTs in Tokyo Bay over the past 4200 years (late of MIS 1) recovered from the sediment core KT12-06-2B (Kajita et al. 2020b). The 11 points’ running average (black line) with standard error ranges (grey lines) is presented. The pre-industrial level obtained by averaging the values from 1850 to 1950 CE is shown by the red dotted line. The benthic foraminiferal assemblage in the surface sediment is at almost the same location as the site of the KT12-06-2B core (K5 site in Kosugi et al. 1991). b–e Variations of \({\text{U}}_{{{37}}}^{{{\text{K}}^{\prime } }}\)-SSTs (this study) and benthic foraminiferal abundances in Palaeo-Tokyo Bays (Kaneko et al. 2018)