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Fig. 3 | Progress in Earth and Planetary Science

Fig. 3

From: Climatic reconstruction at the Sannai-Maruyama site between Bond events 4 and 3—implication for the collapse of the society at 4.2 ka event

Fig. 3

Time series records of a alkenone SSTs and estimated ATs in Mutsu Bay with age-controlling points represented in solid reversed triangles (Kawahata et al. 2009b); b population (open circle) estimated by Kito (2000) and Biraben (1993, 2005) and the relative abundance of population at Jōmon sites (+) (Crèma et al. 2016); c number of archeological sites in Aomori (Sekine 2014); d relative population size of total Japanese people (solid line) by Saito (2017) and relative female effective population size (dotted line) of mitochondrial DNA haplogroups N9b and M7a, estimated by Peng and Zhang (2011); e alkenone SSTs at MD06-3050 (27° 43.36′ N, 121° 46′ 88 E) in the inner shelf of the East China Sea, off river mouth of the Yangtze river (Kajita et al. 2018); f sunspot numbers (Usoskin et al. 2007); g the summer and winter daily insolation at 55° N in the Northern Hemisphere for the last 8000 years (W m−2) (Berger 1978); and h ESR intensity of fine silt-sized quartz particles in Japan Sea sediments (Nagashima et al. 2013), which is a proxy for the latitudinal shift of westerly jet stream, related to latitudinal shift of the East Asian Monsoon. Thin and thick lines indicate original data and the 3-point running mean, respectively. i δ18O of the Dongge Cave stalagmites as a proxy for the intensity of the Far Eastern Asian Summer Monsoon (Wang et al. 2005). Blue color shadings between Bond events 4 and 3 in h and i represent southward shift of westerly jet and weaker summer monsoon, respectively

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