Government Information Service

The Volcanic Explanation
For The 24 Hour Period Ending 7 AM On Wednesday April 16, 1997
A Presentation Of The Government Information Services
In Conjunction With The MVO.

The current alert level is ORANGE


The level of activity was slightly higher yesterday (Tuesday) but was fairly quiet overnight. A swarm of hybrid earthquakes and some minor rockfalls started early this morning.

There were 76 hybrid, 1 volcano-tectonic and 5 long period earthquakes, and a total of 28 rockfalls. Visibility has been good during the past 24 hours. The Easter scar is almost filled by a new growth on the dome. This extrusion is very steep on the southern side facing Galways Wall and is unstable. There were pyroclastic flows between 12:30 pm and 3 pm which generated an ashcloud which rose to 6,000 ft and caused light ash to fall in the safe zone. The small pyroclastic flows on the northeast side did not travel beyond the dome of the dome. There has been steaming from the dome during the reporting period.

EDM measurements taken of the northern triangle show a shortening of the line between Windy Hill and Farrells. These results will be verified by further measurements.

Rocks collected from the White River Valley will be sent away for analysis. They do not appear to be different from the samples in the Tar River Valley.

The volcano remains active and dangerous, with a very large dome which could collapse at any time. People should exercise extreme caution and remain vigilant at all times. Ash levels are high and everyone is urged to wear their dust masks in ashy areas.

Government Information Service