悪石島

Akusekijima is a small stratovolcano in the southern Ryukyu Islands. Most of the island is surrounded by steep cliffs, and beaches are found only on the SW and SE sides. The andesitic-dacitic volcano consists of two older somma volcanoes, Biroyama and Nakadake. Mitake lava dome forms the high point of the small 2.5 x 3.2 km wide island. The dacitic Omune lava flow on the NE flank was K-Ar dated at less than 80,000 BP; its youthful morphology and lack of overlying tephra layers suggests it could be as young as the Holocene (Furuyama et al., 2002). The lava flow, the youngest product of the volcano, forms a low-angle plateau overlying cliffs forming the northern coast.