Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 12 October
to 16:00 13 October 1996
The current alert level is AMBER

The activity at the Soufriere Hills volcano remains at a low level, with only a few small earthquakes being recorded. However the character of the seismicity has changed since yesterday. No views of the dome have been possible today.

Five small rockfalls were recorded by the seismic network during the last 24 hours. In addition, there were two larger long-period earthquakes, which were similar to the long-period earthquake recorded on October 10. These earthquakes are thought to indicate magma movement within the volcano, The new broadband seismic stations which have been installed recently enable us to study such earthquakes in much greater detail. Since noon today, about 20 very small volcano-tectonic earthquakes have occurred. It has been possible to locate only one of these, which occurred at about 3.5 km beneath the crater.

Although the level of seismicity is low, the change in the character of the seismicity could indicate changes in the style of the eruption, and the seismicity will be watched carefully over the next few days.

Visibility has been very poor today, and no views of the crater area have been possible.

GPS measurements have continued on the network which straddles the volcano. The work is still going on this afternoon, and will be finished tomorrow. The measurements will be processed over the next couple of days.

The eastern face of the October 1 dome is quite steep, and large rockfalls and possibly pyroclastic flows may occur during the next few days. The volcano remains highly dangerous, and pyroclastic flows could trigger another explosive eruption with very little warning. Everyone who enters the evacuated zone must remain alert and be ready to move at short notice. Individuals who go beyond the Long Ground area into the Tar River valley are risking death. All residents of Montserrat are urged to become familiar with the new alert system and evacuation procedures.

Montserrat Volcano Observatory