The event lasted 55 minutes. Pyroclastic flow activity increased at 12:35 hrs, the first peak began at 13:04 hrs, and the event waned at 13:30 hrs.

The largest pyroclastic flows moved to the northeast towards the old airport at Trants and moved across the sea. Pyroclastic surges traveling across the sea on the northeast side of the island were visible from Lookout village. Pyroclastic flows also moved down Tyers Ghaut and into the Belham valley, reaching as far as Cork Hill.

The ash column rose to at least 50,000 ft (from pilot reports) and is drifting northeast. Minimal ash fall has been reported in inhabited regions.