Global Volcanism Program | Image GVP-10418
An "X" marks the approximate location of Iriomote-jima submarine volcano, the southernmost Ryukyu Islands volcano. The submarine volcano is located north of the NE tip of 30-km-wide Iriomote-jima island (lower left) and WSW of the northern tip of the island of Ishigaki-shima (right-center). A major submarine eruption that was volumetrically one of the largest in Japan during historical time took place at this volcano on October 31, 1924. It produced pumice rafts that were carried by currents along both coasts of Japan as far north as Hokkaido.
NASA Space Shuttle image STS66-117-19, 1994 (http://eol.jsc.nasa.gov/).
This image is made available as a Public Domain Work, but proper attribution is appreciated.