Brades, Montserrat ---- Visual observations suggest that the growth of the lava dome has reduced or even paused during the period. Pyroclastic activity has been limited to intermittent small flows in the Tar River Valley. Fumarolic activity has been evident especially around the region of the collapse scar at the head of Tyres Ghaut left by the 8 January 2007 partial collapse event, and overnight on 28-29 March venting became audible as a low roaring sound.

Otherwise there has been little sign of activity on the volcano. As the dome stands, a significant proportion of the dome material remains in the sector above Tyres Ghaut to the NW. The amount of material here is sufficient for pyroclastic flows and surges to impact the lower Belham Valley.

Seismicity remained very low throughout the period. The seismic network recorded just 16 rockfall signals, 3 long-period rockfall signals, 5 long-period earthquakes and 8 volcano tectonic earthquakes. The only significant feature of the week was the occurrence of a sequence of 4 volcano-tectonic earthquakes between 1:00 and 1:20 (local time) today. These could represent the adjustment of the shallow system in response to stress induced by magma movement in the conduit.

The sulphur dioxide (SO2) flux rate during the most of period has remained low, ranging from a minimum of 67 tonnes per day t/d to a maximum of 287 t/d with an average value of 158 t/d. This is in line with the emissions during the last 3 months and remains well below the long-term average for the eruption, which stands at around 500 t/d.

The alert level remained at 4.

Source: mvo.ms