Three Indonesian Volcanoes at Alert Level, Here's the Latest Activity

Jakarta: Three volcanoes in Indonesia, Mount Merapi, Mount Semeru, and Mount Anak Krakatau, are currently at Level III (Alert). Two of them are on Java, while Mount Anak Krakatau is in the Sunda Strait, South Lampung Regency.

According to the Center for Volcanology and Geological Hazard Mitigation (PVMBG), Mount Merapi, located on the border of Central Java and the Special Region of Yogyakarta, is still showing increased activity. Merapi has been at Alert status since November 5, 2020, or for 2,177 days.

Mount Merapi observation post officer Alzwar Nurmanaji recorded 10 hybrid/multiphase earthquakes during the observation period on Wednesday, November 4, 2026, from 00:00 to 06:00 WIB.

"The volcano was clearly visible at times and covered by fog at others, at fog levels 0 to III. White smoke was seen coming from the main crater, with medium to high intensity, rising about 200 meters above the summit," Alzwar said, as quoted from the official website on Wednesday, November 4, 2026.

During the same period, Merapi also recorded 10 rockfall earthquakes, two shallow volcanic earthquakes, and one non-harmonic tremor with an amplitude of 44.0 mm lasting 98.64 seconds.

Meanwhile, Mount Semeru in East Java is also showing high volcanic activity. Mount Semeru observation post officer Agastya Rajendra reported 25 eruption earthquakes on Wednesday, November 4, 2026, during the 00:00–06:00 WIB period.

In addition, there were seven rockfall earthquakes, six emission earthquakes, two harmonic tremors, and three distant tectonic earthquakes. Semeru had previously been at Level IV (Warning) before it was lowered to Level III on November 29, 2025.

In the waters of the Sunda Strait, Mount Anak Krakatau has also been at Level III (Alert) since October 10, 2026. Observation post officer Deny Mardiono said the volcano was clearly visible, and the main crater released white smoke rising 50 to 200 meters above the summit.

Anak Krakatau's seismic activity from early Wednesday morning until the morning included three emission earthquakes, two hybrid/multiphase earthquakes, and five long non-harmonic tremors lasting between 378 and 3,836 seconds.
 

(Yaumil Tianri Rahmi)