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The Volcanic Explanation
For The 24 Hour Period Ending 7 AM On Wednesday April 23, 1997
A Presentation Of The Government Information Services
In Conjunction With The MVO.

The current alert level is AMBER

The alert level dropped to AMBER at 6 am this morning because of the continued lower level of activity at the Soufriere Hills Volcano.

The activity over the past 24 hours has been very similar to that of late with the seismic network recording earthquake, rockfall and pyroclastic flow activity. There have been volcano-tectonic, long period and hybrid earthquakes recorded over the reporting period. In addition there were two regional earthquakes recorded in the Trinidad & Tobago area early yesterday morning.

The rockfall signals numbered about 100 over the 24 hours under review and some of these led to pyroclastic flows over the Galways Wall and down the White River Valley. These flows have generated an ash cloud in the form of a continuous plume which reached heights of about 5000 feet. The wind blew this to the west and northwest and light ash is expected to fall in the St George's Hill, Cork Hill and Old Towne areas.

During yesterday (Tuesday) a GPS and total station survey of the northern triangle was undertaken to see if there has been any movement of the northern flanks of the volcano, these results are being processed today and results will be announced later.

Scientists are currently assessing the possibility of mudflows down various ghauts if there is excessive rain during the upcoming hurricane season which starts on June 1st.

The dome is under cloud this morning (Wednesday) and therefore there are no clear views of the dome, however it is expected to get clearer as the day progresses.

At AMBER alert, Zone A remains a "no go" area, Zone B is for limited short visits by residents with a rapid means of exit and Zone C is for daytime occupation only. All other zones are as normal.

Although the alert level has been lowered, residents are warned that activity could escalate at any time and that they should remain vigilant at all times.

Government Information Service