Seismicity during this period continued at a moderate rate, although at a lower level than yesterday. Gages seismometer recorded periods with very small, repetitive long-period events mixed with a period of very low amplitude broadband tremor lasting for about 6 hours during the morning of 9 December. These patterns were not recorded elsewhere, but a large number of moderately sized hybrid events were recorded throughout the seismic network. A total of 19 earthquakes have so far been located for the period up to 04:30 this morning, these being a mixture of hybrid and a few volcano-tectonic earthquakes at depths of 0 to 5 km scattered beneath the Soufriere Hills volcano. A signal was recorded at 12:52 on 9 December at most seismic stations which is interpreted as a significant rock fall event from within the crater area.
EDM measurements were made today on the line from Dagenham to Gages Wall and on the lines from Galway's Plantation and O'Garra's to Chances Peak. None of these lines showed any change from previous occupations.
Visual observations of the crater were made from Chance's Peak early this morning but cloud cover over the volcano prevented any further observations during the day. Rock falls from the September spine this morning suggest that it may be weakening due to the growth of the lava dome around it. Elsewhere, no significant changes in the size or shape of any areas of the dome were noted, although it appears to still be growing at a slow rate.