硫黄鳥島

The 1 x 2.7 km island of Io-Torishima, located north of the largest island of the Ryukyus, Okinawa, is composed of two andesitic volcanoes. Torishima (Bird Island) is a common name for offshore islands in Japan. Kusuku lava dome occupies the center of the inner of two sommas on the SE-most volcano. The summit crater of the NW-most volcano, Iodake, contains a small lake, solfataras, and sulfur deposits that were mined in the past. Historical eruptions dating back to 1664 have consisted of mild-to-moderate explosive activity.