Mount Semeru, located in East Java, has once again shown an increase in volcanic activity by spewing a thick ash column 1,000 meters above its peak on Tuesday night (7/14/2026). The eruption, which occurred at around 20:15 WIB, adds to the long list of seismic activity from one of Indonesia's most active volcanoes.
A report from the Center for Volcanology and Geological Hazard Mitigation (PVMBG) via the MAGMA Indonesia application noted that the volcanic ash column was observed to be white to gray. This dense ash emission was monitored moving toward the northeast and east sectors, reaching an altitude of around 4,676 meters above sea level.
According to seismograph instrumental data, the eruption was recorded with a maximum amplitude of 23 millimeters and lasted for approximately 135 seconds. PVMBG maintains the activity status of the highest volcano on Java Island at Level III (Alert), given that the potential hazard remains fluid.
Prior to the main eruption at night, seismic observations conducted since noon indicated a fairly high frequency of tremors. A total of 11 eruption earthquakes, one rockfall earthquake, and two emission earthquakes were recorded within the six-hour period leading up to the evening eruption.
In response to this situation, authorities urge local residents and tourists to strictly avoid activities in the southeastern sector along Besuk Kobokan within a 13-kilometer radius from the eruption center. Additionally, residents are asked to stay at least 500 meters away from riverbanks along the channel to guard against the threat of expanding pyroclastic flows and cold lava flows.
