横当島

Yokoatejima is a 3.5-km-long island NW of Amami Oshima Island at the SW end of the Tokara island chain. Two peaks, the higher Higashimine on the east and Nishimine on the west, form the andesitic island. Higashimine has a steep-walled, well-preserved summit crater. An arcuate ridge east of Yokoatejima appears to be part of 7 x 10 km submarine caldera, with Yokoatejima and Kaminonejima to the NNE being post-caldera cones (Nakano et al., 2001-). Yokoatesho (Yokoate Reef) and Kaminone Kaikyu (Kaminone Knoll) lie to NNW and NE of Yokoatejima, respectively. Documents from the end of the Edo Period mention ash plumes from Yokoatejima.