Thursday, June 20, 2013
Unfortunately the period of excellent visibility experienced over the two previous reporting periods failed to continue and a week of relatively cloudy conditions prevailed. Because of this observations of the dome have been limited and FTIR measurements were not possible. However the limited number of images provided by Caribbean Helicopters have helped to affirm that the dome morphology has changed little, with minor changes to the eastern talus flank by rockfall and mudflow. The pause in activity continues and measurable activity at the Soufrière Hills Volcano has remained low. This is reflected in the triggered seismic event count.

The seismic network recorded 3 volcano-tectonic events, 2 rockfalls and 1 hybrid earthquake.

The recorded sulphur dioxide (SO2) flux rate for the reporting period ranged from a maximum of 1202 tonnes per day (t/d) on 3 February to a minimum of 494 t/d on 4 February. The average flux rate for the period was 881 t/d. This figure is above the long term average for the eruption which stands at 550 t/d.

Fumarolic activity continues and has been very similar to that of the last reporting period although the Gage's fumarole has been mostly obscured by cloud, so observations and thermal images of this feature have not been possible.

The pause in dome growth continues but a possibility of collapse or explosion remains, however as the system cools without the introduction of fresh magma and the pause continues the likelihood of this is believed to decrease.

During periods of heavy precipitation it must be remembered the potential hazard from lahar (mudflow) in the drainage channels around the volcano remains.

The alert level remained at 4.

Category: Weekly reports