Montserrat Volcano Observatory

Daily Report
Report for the period 6 pm 4 November
to 6 pm 5 November 1997

The level of seismic activity remains elevated today although there has been little visible activity at the volcano.

After the substantial collapse down the White River valley yesterday afternoon there was a lull in activity at the volcano for several hours. However, soon after 6pm yesterday another hybrid earthquake swarm began and this swarm is still ongoing. The current earthquake swarm is not as intense as the last one with large events visibly declining in number towards the end of the reporting period. Tremor has been recorded throughout the earthquake swarm and is now dominating the seismic signal. In total there have been 472 hybrid earthquakes, 6 long period earthquakes, 2 volcano-tectonic earthquakes and 7 rockfall events.

There have been several rockfalls down the Galways side of the dome today, but no more pyroclastic flows. There are now two distinct channels cutting into the south west side of the volcano in the Galways area. Prior to yesterday, these two channels were divided by a blocky ridge which was part of the pre-explosion dome complex. This has clearly been removed during the dome collapse. Material produced during the dome collapse on 4 November has substantially extended the delta at O'Garro's.

The north face of the new 22 October dome above Tuitt's has been fairly inactive today. Nevertheless, a new rockfall channel is developing on the upper part of Farrell's plain. This shows that although activity has been concentrated on the south west side of the volcano in the last few days, Tyers Ghaut and the Belham Valley are still under threat.

There has been little ash or steam venting today, the small amount of ash which was produced was again blown west over the Plymouth area.

The MVO considers that the volcano is currently in an extremely dangerous state and more explosions or pyroclastic flows could occur at any time. Areas such as the Belham valley, around Trants and the airport are under a very real threat of being impacted by large pyroclastic flows. Under no circumstances, even for brief periods, should anyone be visiting these areas. Friths, Old Towne and Salem are considered to be unsafe at the present time and residents of these areas are urged to comply with restrictions which are currently being enforced

In the event of an explosion residents should take shelter indoors under a strong roof and avoid driving. Make sure you always have an ash mask to hand because a change in wind direction could bring ash into the inhabited parts of the island at any time. At the present time ash levels in the air remain low at less than 50 micrograms per cubic metre. Stay tuned to Radio Montserrat for further information.

Montserrat Volcano Observatory