The geography of Indonesia is dominated by volcanoes that are formed due to subduction zones between the Eurasian plate and the Indo-Australian plate. Some of the volcanoes are notable for their eruptions, for instance, Krakatau for its global effects in 1883, Lake Toba for its supervolcanic eruption estimated to have occurred 74,000 Before Present which was responsible for six years of volcanic winter, and Mount Tambora for the most violent eruption in recorded history in 1815.
Mount Ibu stratovolcano lies along the nortwest coast of Halmahera island, Indonesia. The summit is truncated and contains a nested craters. The inner crater has 1 km wide and 400 m deep, while the outer is 1.2 km wide. A large parasitic cone is located at the northeast of the summit and a smaller one at the southwest. The latter feeds a lava flow down the west flank. A group of maars are located in the western and northern of the volcano.