Mbah Rono Discusses Volcanic Ash from Eruptions and Its Dangers

Jakarta, CNBC Indonesia — Volcano expert Surono, familiarly known as Mbah Rono, has revealed the potential dangers of Mount Anak Krakatau’s eruptive activity. According to him, the larger the body of Anak Krakatau grows, the larger its magma chamber becomes.

This condition has the potential to make the eruption power of Anak Krakatau greater in the future.

“The bigger Anak Krakatau gets, automatically its magma chamber also grows bigger. And if it grows bigger, then the potential eruption will be large,” Mbah Rono told CNBC Indonesia on Monday (7/9/2026).

According to him, one of the impacts of Anak Krakatau’s current eruption has already been felt at Soekarno-Hatta Airport due to the spread of volcanic ash. A similar situation could recur in the future, including at Raden Inten Airport.

“It will certainly be affected again in the future. So this becomes a problem — I’m not trying to scare anyone, but something that has been affected now has the potential to be affected again. The same goes for Raden Inten and so on,” he said.

Nevertheless, Mbah Rono stressed that the material reaching these areas is not eruptive material thrown directly from Anak Krakatau; rather, the ash that can disrupt flight activity is fine volcanic ash carried by the wind.

Meanwhile, incandescent material and pyroclastic clouds do not directly reach areas such as airports.

“Material that falls directly — because Anak Krakatau is still building its body — would at most fall around the summit or on its own body, to make Anak Krakatau grow bigger and taller,” said Mbah Rono.

“As for the ash, if there were no vital strategic zones, it wouldn’t be a problem in terms of its direct impact on humans. The risk only becomes high because there are strategic vital objects not far from Anak Krakatau’s reach,” he explained.