Mount Semeru, located in East Java, has once again shown significant volcanic activity. On Tuesday (14/7/2026) morning, the highest volcano on the island of Java was reported to have experienced a series of four consecutive eruptions within a span of just three hours.
The Semeru Volcano Observation Post (PGA) recorded the first eruption at 05:39 WIB with a volcanic ash column rising up to 1,300 meters above the summit. The subsequent eruptions followed consecutively at 06:29 WIB (ash column height of 800 meters), 06:51 WIB (1,200 meters), and ended with the fourth eruption at 07:55 WIB with the ash column reaching 1,000 meters.
All of this eruptive activity was recorded on a seismograph with a maximum amplitude of 22 millimeters and an average duration of about 100 seconds. As of 09:20 WIB, the activity level of Mount Semeru remains at Alert Status or Level III. With this series of events, the total number of eruptions of Mount Semeru throughout 2026 has been recorded at 1,486 times.
Responding to this increased threat, Semeru PGA officer Liswanto urged residents and tourists to stay away from the southeastern sector along the Besuk Kobokan river flow up to a distance of 13 kilometers from the summit. The public is also prohibited from carrying out activities within a 500-meter radius of the riverbanks along Besuk Kobokan to anticipate the potential expansion of pyroclastic flows and cold lahar flows.
Furthermore, authorities emphasized a total ban on activities within a 5-kilometer radius of the active crater to avoid the risk of ejected incandescent rocks. Residents around river basins, such as Besuk Kobokan, Besuk Bang, Besuk Kembar, and Besuk Sat, are asked to remain vigilant against potential cold lahar floods, especially when the summit area receives rainfall.
