Krakatau Ash Shuts 8 Airports; Indonesia Starts Cloud-Seeding

Indonesia's Anak Krakatau volcano has finished the continuous, 25-hour eruption that began at 11:07 p.m. local time on September 4, but the country's Geological Agency, PVMBG, kept the volcano at Level III ("Siaga") alert after recording further Strombolian bursts through the weekend and into September 7.

The main eruption ended at 12:04 a.m. on September 6, PVMBG said, but that has not ended the disruption. Eight airports across western Indonesia, including Jakarta's Soekarno-Hatta International, Halim Perdanakusuma, Lampung's Radin Inten II and Curug's Budiarto, halted operations at various points over the weekend as ash drifted through their airspace. By Monday morning, roughly 240 additional flights had been delayed or cancelled and about 30,000 more passengers were affected at Soekarno-Hatta alone, on top of a cumulative total of more than 1,558 disrupted flights and over 270,000 stranded passengers since the eruption began, according to airport operator data cited by regional outlets.

To speed up recovery, Indonesia's National Disaster Management Agency, BNPB, launched a weather-modification operation on September 7. "Today we are implementing weather modification. The aircraft is ready in Pondok Cabe and we will implement the operation until the evening," BNPB chief Suharyanto said, adding the goal is to induce rainfall so "the volcanic ash can quickly be washed away." Where rain clouds are unavailable, crews are using water-mist dispersal instead, coordinating with the meteorological agency BMKG across Jakarta, Banten and Lampung.

The eruption matters beyond Indonesia because Soekarno-Hatta is Southeast Asia's second-busiest airport, and the ash has forced airlines to divert flights to Semarang and Surabaya while grounding domestic routes across the region. Schools in Jakarta shifted to online classes as ash exposure was reported in Tangerang and nearby areas, though the disaster agency BPBD described exposure in the capital itself as light. Officials have said there is no imminent tsunami risk from the eruption, and no deaths or injuries have been reported by any authority so far.

PVMBG is maintaining a 3-kilometer exclusion zone around the volcano's active crater and has warned residents, tourists and climbers to stay clear, citing continued risk of incandescent rock and heavy ashfall if the volcano erupts again. Indonesia's government communications agency said President Prabowo Subianto is being briefed directly on the response as authorities weigh how long the alert level will stay elevated.