Montserrat Volcano Observatory

Daily Report
Report for the period 16:00 31 December
to 16:00 1 January 1997
The current alert level is ORANGE

The Soufriere Hills Volcano still threatens the evacuated areas. Activity since yesterday has mainly been rockfalls from the October 1 dome as it continues to grow. The activity could escalate at any time without warning. Large pyroclastic flows into the Tar River Valley area are most likely but a sudden collapse of the Galway's Wall is still a real possibility. Either of these could uncover fresh lava in the dome which might then lead to a lateral blast or a vertical eruption. These would have serious consequences for much of the evacuated area. There is no access to zone A/B. Restricted access is allowed to zone C/D but only for essential purposes and by people who can leave rapidly. There is normal occupation of all other zones.

Visibility has been relatively poor for much of today. Rockfalls continue from the October 1 dome, mainly down the eastern and north-eastern faces. The rockfall activity increased noticeably this afternoon. Many of these rockfalls generated small ash clouds which drifted to the west and south west. The largest of the ash clouds reached a height of about 4,500 feet above sea level.

Seismic activity is still dominated by bands of seismic tremor, hybrid earthquakes and rockfalls. The time between the bands of tremor has lengthened, from 5 hours yesterday to around 10 hours by this afternoon. The size of the signals has remained fairly constant. Other seismic activity was at a similar level to yesterday, with 35 hybrid events, 21 rockfalls and 5 small volcano-tectonic earthquakes recorded. The signals from the rockfalls were larger during the afternoon, consistent with the increase in rockfall activity seen from the dome. Many of the hybrid events occurred in a swarm between 11:00 and 12:00 today.

MVO would like to wish everyone a Happy New Year.

Montserrat Volcano Observatory