The launch of a new GVP website is scheduled for Monday, May 20,
2013. |Subregion Name:||Lesser Sunda Islands (Indonesia)| |Last
Known Eruption:||1967 ± 20 years| |Summit Elevation:||2850
m||9,350 feet| |The massive Tambora stratovolcano forms the
entire 60-km-wide Sanggar Peninsula on northern Sumbawa Island.
The largely trachybasaltic-to-trachyandesitic volcano grew to
about 4000 m elevation before forming a caldera more than 43,000
years ago. Late-Pleistocene lava flows largely filled the early
caldera, after which activity changed to dominantly explosive
eruptions during the early Holocene. Tambora was the source of
history's largest explosive eruption, in April 1815. Pyroclastic
flows reached the sea on all sides of the peninsula, and heavy
tephra fall devastated croplands, causing an estimated 60,000
fatalities. The eruption of an estimated more than 150 cu km of
tephra formed a 6-km-wide, 1250-m-deep caldera and produced
global climatic effects. Minor lava domes and flows have been
extruded on the cald