抄録
Typhoon 21 (Lan) which occurred on 23 October 2017 and Typhoon 19 (Hagibis) on 12 October 2019 caused storm surges with sea-levels 0.5 m above the mean high tide mark in Ena Bay, Miura Peninsula, Kanagawa Prefecture, Japan. We surveyed the sediments before and after the storm surges at three sites in the lower intertidal zone and examined washed-up infaunal bivalves. These results lead to the following conclusions:
(1) Both typhoons caused sandy storm surge deposits which were up to 14 cm thick and characterized by graded structure and well-developed laminations;
(2) The primary sedimentary structure of the storm surge deposits disappeared by bioturbation within two years;
(3) The composition of the washed-up infaunal bivalve assemblage is quite similar for both typhoons, except for released Meretrix lamarcki, which is predominantly Mactra veneriformis, associated with Cyclina sinensis, and indicates >7 cm of erosion.
