Mount Semeru, located in East Java, has once again shown a significant increase in volcanic activity. On Tuesday (14/7/2026) morning, the tallest mountain on Java Island was recorded to have erupted four consecutive times within a period of just three hours. The first eruption began at 05:39 WIB, with the height of the volcanic ash column observed reaching 1,300 meters above the peak, or approximately 4,976 meters above sea level. The ash column was white to gray in color with moderate intensity, drifting toward the north.
The subsequent series of eruptions continued in succession. The second eruption was reported at 06:29 WIB with an ash column height of 800 meters. Just 22 minutes later, at 06:51 WIB, another ash column rose to a height of 1,200 meters. The fourth eruption followed at 07:55 WIB with an ash column 1,000 meters high. Tremors from this last eruption were clearly recorded on the seismograph with a maximum amplitude of 22 mm for 100 seconds.
Responding to this situation, Liswanto, an officer at the Semeru Volcano Observation Post (PGA), urged the public and tourists to stop all activities in the southeastern sector along the Besuk Kobokan riverbed up to a distance of 13 kilometers from the eruption center. Outside this area, residents are also prohibited from carrying out activities within 500 meters of the riverbanks along Besuk Kobokan due to the potential expansion of pyroclastic flows and lahar flows that could reach a distance of 17 kilometers from the summit.
Furthermore, a total exclusion zone has been established within a 5-kilometer radius of the active crater to avoid the danger of ejecting incandescent rocks that could occur at any time. Residents around the slopes are also asked to remain vigilant against secondary threats such as lava flows and cold lahar floods, especially those flowing along the valleys of Besuk Kobokan, Besuk Bang, Besuk Kembar, Besuk Sat, and surrounding tributaries.
As of Tuesday at 09:20 WIB, the activity level of Mount Semeru remained at Alert Level III (Siaga). Throughout 2026 alone, the volcano has been recorded to have erupted 1,486 times. PVMBG also reported that during the early morning monitoring period from 00:00 to 06:00 WIB on the same day, 16 eruption earthquakes, 3 avalanche earthquakes, and 2 gust earthquakes were recorded.
