Saturday, Feb 23, 2013
A swarm of earthquakes occurred over the the past days in an area a few km south of the island at about 10 km depth. [more]
Saturday, Dec 22, 2012
Although no explosive eruptions occurred at Otake crater in November, very small eruptions occurred there intermittently. The maximum plume height was 500 m above the crater rim during this period (max. 700 m in October). Weak volcanic glows in the crater were sometimes recorded at night with high-sensitivity cameras. ... [more]
Suwanose-jima volcanoSuwanose-jima (諏訪之瀬島) volcano is Japan's and one of the world's most active volcanoes. It has been in a state of near-continuous strombolian-type eruption since 1949.
The volcano forms the 8 km long spindle-shaped island of the same name in northern Ryuku Islands, Japan. The remote island is home to about 50 residents only.
Suwanose-jima consists of an andesitic stratovolcano with 2 historically active summit craters. Intermittent to continuous strombolian activity began from On-take (Otake), the NE summit crater, in 1949 and has been going on since. After 1996, occasional periods of inactivity have become more frequent.
Background:The summit of Suwanose-jima volcano is truncated by a large breached crater extending to the sea on the east flank that was formed by edifice collapse.
The largest historical eruption took place in 1813-14, when thick scoria deposits blanketed residential areas, and the SW crater produced 2 lava flows that reached the western coast. At the end of the eruption the summit of On-take collapsed forming a large debris avalanche and creating the horseshoe-shaped Sakuchi caldera, which extends 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.
(Source: Smithsonian / GVP information)
A typical 2 year log of activity from Smithsonian's Monthy reports is presented here, illustrating the pulsating, but essentially persistant strombolian activity observed at Suwanose-jima volcano ...more