Bandung, itb.ac.id – Recently volcanic activity in Indonesia is showing its presence in various locations. Indonesia is well known to be rich in volcanoes as part of the Ring of Fire. Yet in recent times an interesting trend emerged with the occurrence of relatively parallel volcanic activity at six volcanoes. Mount Anak Krakatau witnessed an eruption on Friday, April 10, 2020 which was almost simultaneous with five other Indonesian volcanoes.

The simultaneously erupting mountains were (from west to east): Kerinci, Krakatau, Merapi, Semeru, Ibu and Dukono), all of them were in level II, or reported as "warning" based on the latest PVMBG report on Saturday, April 11, 2020. The volcanic eruption activities of the six mountains in Java and Sumatra had caused fear for the people. Volcanist Bandung Institute of Technology (ITB), Dr. Mirzam Abdurrahman, gave his statement on this matter interviewed by ITB's Public Relations.

"There are two possibilities for the six volcanoes to be active simultaneously. First possibility is that the volcanoes have different arcs or plates which interact differently, so the eruption times are possibly the same coincidentally," he said. The volcanoes in Indonesia are considered in four separate arcs, namely Sunda, Banda, Halmahera, and Celebes-Sangihe.

"The analogy is as I'm eating, my neighbors are eating and you're also eating, and it happens coincidentally at the same lunch hour," the ITB Geology Engineering lecturer added. He takes as the former case the example of Mount Krakatoa at Sunda Strait with Mount Ibu and Dukono in Halmahera.

Next to the second possibility, he explained that if volcanoes are in the same arc, there may be other factors that cause them to occur together. Explaining this, he revealed an analogy, "Suppose tectonic phenomena (liken) to those who gather to eat because of an invitation." In other words, this can occur with the same triggers. This is exactly what is happening at the moment on Mount Kerinci, Krakatau, Merapi and Semeru who are coughing together.

From its distribution, Mount Kerinci, Anak Krakatau, Merapi, and Semeru are in the same arc, namely the Sunda Arc, which covers the islands of Sumatra, Java, Bali, NTT, and NTB. Meanwhile Mount Ibu and Dukono are located on the Arc of Halmahera.

Reporter: Irfan Ibrahim

Translator: Moch Akbar Selamat