静岡県下田市の海食台にある巨礫への2017年台風第21号（typhoon Lan）の高波の影響

抄録

There are many coarse to very coarse boulders, which include a tsunami boulder caused by the AD 1854 Ansei-Tokai earthquake, on a wave-cut bench at Shimoda, Shizuoka, Central Japan. This area experienced storm surge during 2017 typhoon 21 (Lan). Significant wave height of 14.65 m was observed during the typhoon at Irozaki located 10 km southwest of the study area. Comparison of locations of these boulders before and after the typhoon shows that the storm surge could not move coarse to very coarse boulders. This observation supports the interpretation that the tsunami boulder was rolled by a tsunami associated with the AD 1854 Ansei-Tokai earthquake.