The launch of a new GVP website is scheduled for Monday, May 20, 2013.
|Subregion Name:||Honshu (Japan)|
|Last Known Eruption:||915 AD|
|Summit Elevation:||1159 m||3,802 feet|
|The dramatic, 11-km-wide, lake-filled Towada caldera formed during as many as six major explosive eruptions over a 40,000-year period ending about 13,000 years ago. Pre-caldera eruptive activity at Towada dates back to about 2 million years ago and produced basaltic-to-dacitic lava cones. Following late-Pleistocene andesitic-to-rhyolitic caldera-forming eruptions, the basaltic Ninokura stratovolcano grew in the SSE section of the caldera. The successive dacitic-to-rhyolitic Goshikiiwa explosive eruptions led to the formation of the roughly 2-km-wide Nakanoumi caldera, whose SW and NE rims form dramatic peninsulas extending into Lake Towada. The andesitic-to-dacitic Ogura-yama lava dome was built over the NE rim of Nakanoumi. The latest eruption of Towada took place in 915 AD, when eruptions from Ogura-yama produced widespread ashfalls and pyroclastic flows.|