Caldera Batur

Batur Volcano is located in north east Bali. Batur is one of the most impressive calderas in the world. It is 13.8 km by 10 km in size. Within the caldera is Batur volcano and a lake. The volcano rises 700 m above the surrounding terrain, and consists of a main cone with three summit craters flanked by a small parasitic cone (Butus) on its SW slope.

Batur volcanic field is located 300 km north of the Java trench and 150 km above the north-dipping Benioff zone. The crust beneath Bali is about 20-km thick.

Two catastrophic caldera-forming eruptions have occurred at the volcano. Eruptions began at the volcano 500,000 years ago, with the building of a basaltic to andesitic
stratovolcano (Penulisan volcano) in the northwestern sector of the volcanic field. This was followed by formation of an 800-m high basaltic to dacitic parasitic cone (Abang volcano) also formed on the SE flank of the main field.

The first caldera was formed 29,300 years ago and was associated with eruption of dacitic ignimbrite (Ubud Ignimbrite). An andesitic to dacitic lava–dome complex (Bunbulan lava–dome complex) and a small tuff cone (Payang tuff cone) formed within the caldera after the first caldera forming event. A second caldera-forming eruption occurred 20,150 year ago and was accompanied by eruption of andesitic to dacitic ignimbrite.

Batur is a currently active stratovolcano, which has formed in the smallest and youngest caldera.

Historical activity at the volcano includes 25 mild to moderate strombolian eruptions, with lava flows in 1849, 1888, 1904, 1905, 1921, 1926, 1963, 1968 and 1974.
Ref:www.volcanolive.com