JMA reported that the eruption at Suwanosejima's Ontake Crater continued during 2-9 October. Crater incandescence was visible nightly, and blocks were ejected as far as 600 m from the crater. Explosions at 0304, 2141, and 2359 on 2 October, at 0112 on 3 October, and 1326 on 6 October produced ash plumes that rose as high as 1 km above the crater rim and drifted SW and W. An explosion was recorded at 0428 on 3 October, though emission details were unknown. The Alert Level remained at 2 (on a 5-level scale) and the public was warned to stay at least 1 km away from the crater.

Geological Summary. The 8-km-long island of Suwanosejima in the northern Ryukyu Islands consists of an andesitic stratovolcano with two active summit craters. The summit is truncated by a large breached crater extending to the sea on the E flank that was formed by edifice collapse. One of Japan's most frequently active volcanoes, it was in a state of intermittent Strombolian activity from Otake, the NE summit crater, between 1949 and 1996, after which periods of inactivity lengthened. The largest recorded eruption took place in 1813-14, when thick scoria deposits covered residential areas, and the SW crater produced two lava flows that reached the western coast. At the end of the eruption the summit of Otake collapsed, forming a large debris avalanche and creating an open collapse scarp extending to the eastern coast. The island remained uninhabited for about 70 years after the 1813-1814 eruption. Lava flows reached the eastern coast of the island in 1884. Only about 50 people live on the island.

Source: Japan Meteorological Agency (JMA)