Overview
- Indonesia kept the alert at Level IV after at least 10 eruptions on Wednesday, with 956 residents moved to shelters in East Java.
- Rescuers escorted roughly 170–178 climbers from the Ranu Kumbolo area, with officials reporting all are safe.
- Pyroclastic flows raced down Semeru’s flanks with runouts reported up to about 13 km, while ash blanketed nearby villages.
- Plume-height reports diverged, from about 2 km above the summit in ground observations to detached ash near 17.9 km a.s.l. in VAAC satellite analyses.
- An 8 km exclusion zone remains in effect with specific warnings along the Besuk Kobokan valley, and a red aviation alert led airlines to monitor routes without canceling flights.