There was a further episode of volcano-tectonic earthquakes and volcanic tremor last evening, the ninth such episode since Saturday. The latest tremor episode was the most intense to date. The earthquake swarm started at around 3:10 pm, and lasted until just before the tremor started at 7:10 pm. The tremor episode ended at about 9:00 pm. No ashfall was reported during or after the episode. A small pyroclastic flow occurred at 11:27. Between mid-night to 4:00 am a few flood signals were registered on most seismic stations. Rockfall activity remained at a moderate level throughout, with steam venting dominating from about 3:30 am to dawn.
A late afternoon flight to inspect the volcano revealed that there has been little recent changes at the surface of the dome and also along the Galways side of the crater.
The temporary revision of the volcanic risk map was removed yesterday, and the map reverts back to the November edition. No access is allowed to zones A and B, which include Tar River, Long Ground, Galway's, St Patrick's, Kinsale and the upper slopes of the volcano. People making short visits to the area of zone C south of Fort Ghaut are warned that further flash floods in the ghaut are possible if there is heavy rain on the upper slopes; people should remain alert and listen to Radio Montserrat, and be prepared to move quickly if necessary. The map will be published in a few days.
Last night's activity continues the recent trend, with earthquake swarms and tremor repeating every 13 or 14 hours. The next episode is expected before noon today, and may produce some ash. The dome is potentially unstable, and so large pyroclastic flows are still possible. Residents are reminded to wear ash masks if there is ash in the air. The Tar River and upper Galway's areas are extremely dangerous, and should not be entered under any circumstances. Zone E, which includes Corkhill and the airport, remains safe at this time.