Active volcano Mount Agung erupted on the Indonesian island of Bali.
Mount Agung, also known as Gunung Agung, is an active volcano located on the island of Bali in Indonesia island arc.
It is the highest point on the island of Bali.
Mount Agung is a stratovolcano built by a long history of recurrent eruptions.
A stratovolcano is a tall, conical volcano composed of one layer of hardened lava, tephra, and volcanic ash.
These volcanoes are characterized by a steep profile and periodic, explosive eruptions.
The lava that flows from them is highly viscous, and cools and hardens before spreading very far.
Volcanic activity is common to Indonesia, as the country is situated on the Pacific Ocean's "Ring of Fire" where tectonic plates collide and move often, causing frequent seismic and volcanic activity.
75% of volcanoes, or more than 750, are located along the Ring of Fire and 90% of Earth's earthquakes occur along the plates.
The volcanoes of Java, Bali, and many other Indonesian islands have been formed by interactions between the Australia and Sunda tectonic plates.
At the Sunda-Java Trench, the Australia Plate subducts beneath the Sunda Plate and begins its descent into the mantle.
The Australia Plate begins to melt when it reaches a depth of about 100 miles, and hot and molten materials then begin rising towards the surface and erupt to form the volcanoes of the Indonesian volcanic arc.