Mount Anak Krakatau Spews Lava Fountains Status Remains at Alert Level III

Serang, en.SERU.co.id – Mount Anak Krakatau in the Sunda Strait has been erupting continuously since Friday night September 5, 2026, producing a lava fountain. Despite the increased activity, the Center for Volcanology and Geological Hazard Mitigation (PVMBG) confirmed the volcano currently shows no potential to trigger a tsunami. Its status remains at Level III (Alert) and the public is advised to stay at least 3 kilometers away from the active crater.

According to a PVMBG report, the eruption began at 11.07 p.m. WIB on Friday and continued through the observation period of 00.00–06.00 WIB on Saturday, September 5, 2026.

“The visual condition of Mount Anak Krakatau was briefly clear before it became covered by fog. Meanwhile, crater smoke was not observed,” said volcano observer Rioboniek Situmorang.

This latest eruption also produced lava ejections interpreted as a lava fountain. Booms and rumbling sounds were even heard from the Pasauran PGA Observation Post.

Seismic monitoring recorded one eruption earthquake with a maximum amplitude of 70 millimeters and a duration of 21,600 seconds.

Booms Heard Hundreds of Kilometers Away

Sounds of booms believed to be linked to Mount Anak Krakatau’s activity were also reported in several areas, including Bandung in West Java.

Head of PVMBG at the Ministry of Energy and Mineral Resources Rita Susilowati explained that eruption sounds can travel very far because of the acoustic energy released during volcanic activity. In some cases, the sound can propagate hundreds of kilometers.

“That phenomenon is not impossible. Certain types of eruptions, especially explosive ones, can generate large amounts of acoustic energy,” she said, quoted from detikcom on Saturday, September 5, 2026.

She cited the explosive eruption of Mount Kelud on February 13, 2014, as an example. At that time the eruption column reached about 17 kilometers, and the booming sounds were heard across parts of Central Java as far as Yogyakarta.

Nevertheless, Rita stressed that her agency cannot yet confirm with absolute certainty the source of the booms heard in various regions. Based on the timing and observed activity, PVMBG strongly suspects the sounds are related to the eruption of Mount Anak Krakatau.

Sound propagation is also influenced by atmospheric conditions. Differences in temperature, wind direction and wind speed determine how far acoustic energy can travel. Further analysis from the relevant weather authority is needed for that aspect.

PVMBG Confirms No Current Tsunami Potential

Amid the rising activity at Mount Anak Krakatau, PVMBG confirmed that the volcano currently shows no signs of a major collapse that could generate a tsunami.

Rita said Anak Krakatau’s activity continues to be monitored through two observation stations located in Pasauran and Kalianda.

“The body of Mount Anak Krakatau that has been rebuilding since the December 22, 2018, eruption is still relatively small. It does not have the potential to collapse on a scale that could trigger a tsunami,” Rita said.

For context, the tsunami on December 22, 2018, occurred after part of Mount Anak Krakatau’s body collapsed into the sea. The collapse displaced a large volume of water and generated tsunami waves that struck the coastal areas of Banten and Lampung.

At present Anak Krakatau is still forming a new lava dome. However, based on PVMBG’s monitoring results, the growth of the volcano’s body does not yet indicate a tsunami threat.

PVMBG has set the activity level of Mount Anak Krakatau at Level III or Alert. The public, visitors, tourists and climbers are asked not to approach Mount Anak Krakatau and not to conduct any activities within a three-kilometer radius of the active crater. (aan/mzm)