What type of volcano is Mount Merapi?
Mount Merapi is a stratovolcano – a tall, conical volcano composed of one layer of hardened lava, tephra (fragmented material produced by a volcanic eruption) and volcanic ash. These volcanoes are characterized by a steep profile and periodic, explosive eruptions. Explosive volcanoes such as Merapi erupt suddenly and with terrifying force. These volcanoes form when cooled magma creates a lava plug blocking a crater. The plug traps hot gas and magma under the ground, where they build up until the pressure becomes too great, at which point hot gas and magma explodes out of the volcano in a shower of dust, ashes, cinders and volcanic bombs.
