Beyond Anak Krakatau, Semeru and Merapi Activity Also Warrants Vigilance

Surabaya, VIVA – An expert from the Sepuluh Nopember Institute of Technology (ITS) has called on the public to remain alert to Mount Semeru and Mount Merapi amid activity at a number of volcanoes in Indonesia occurring within a short span of time.

“As for the volcanoes that need to be watched at present, I would say Semeru and Merapi. Both require attention because they are close to densely populated zones,” said Alutsyah Luthfian, an expert from the ITS Department of Geophysical Engineering, in Surabaya, East Java, on Monday.

Fian, as he is known, said that simultaneous activity at several volcanoes does not necessarily indicate a direct relationship, as each volcano has its own system and characteristics.

“Volcanoes each have their own cycles and character. So when several volcanoes become active within a short period, their activity is not necessarily interrelated,” he said.

According to him, the close timing of eruptions is not a sufficient basis for concluding that one volcano’s activity triggered another’s.

To establish a relationship between volcanic activities, he said, a study of geophysical data and the subsurface system conditions of each volcano is required.

“One cannot simply observe that the timing is close and then conclude that one volcano triggered another. The data and conditions of each volcano must be examined,” he said.

Fian said Mount Semeru warrants attention because its eruptive behaviour is not always easy to predict. The volcano is also located near areas with high population concentrations.

“Semeru needs greater vigilance because its eruption behaviour cannot be well predicted. At times, Semeru can erupt violently without any prior warning,” said Fian.

Meanwhile, the activity of Anak Krakatau also continues to require monitoring. According to Fian, Anak Krakatau’s character differs from Semeru and Merapi because it lies in a marine environment.

This condition means the potential for the volcano’s flank to collapse into the sea must be a consideration in mitigation efforts, as a similar event previously triggered the 2018 Sunda Strait tsunami.

Nevertheless, he reminded the public not to immediately link Anak Krakatau’s activity with that of Semeru or other volcanoes.

“Each volcano has its own magmatic system. So we cannot say that because Anak Krakatau is active, Semeru then becomes active as well, or vice versa,” he said.