On July 28, 2021 at 06:20 UTC (13:20 local time) a violent eruption began at the Indonesian volcano Sinabung, North Sumatra. The aviation color code was raised to red.
According to the Sinabung Volcano Observatory, the eruption lasted about 12 minutes.
Two clouds of volcanic ash were observed from the ground: one up to 7 km (23,000 ft) above sea level, moving west-southwest, and a second up to 5.5 km (18,000 ft), moving south.
Pyroclastic flow was observed across the east-southeast slope, reaching a distance of about 1 km (0.62 miles) from the summit.