Ash ejection was observed at the Indonesian volcano Sirung, East Nusa Tenggara, starting at 08:44 UTC (16:44 LT) on July 21, 2021. The last known eruption of this volcano occurred in 2015, the ash rose to a height of 1.5 km above sea level.
According to the Sirung Volcanic Observatory, the best estimate of the top of the ash cloud is about 2.8 km above sea level, but it may be higher than what can be clearly observed.
The ash cloud is heading north. Its height was estimated by a ground observer.
Seismicity on the volcano did not show significant changes, but the ash ejection may be repeated.
The last eruption at Sirung volcano occurred on July 8, 2015, when the ash plume spread 55 km west of the volcano at an altitude of 1.5 km above sea level.
On May 8, 2012, a 3-hour eruption occurred on Sirung Volcano. The eruption was accompanied by loud sounds and red-hot tephra, which rose 10 m above the crater.
As a result of the explosion, an ash plume was formed, which rose to a height of 3.5 km above sea level and rushed northward, forming ash falls up to 4 mm thick near the crater.