Thirty seven (37) earthquakes were located during the period. These all occurred beneath the Soufriere Hills volcano except for one beneath the South Soufriere Hills; all were at depths of 0 to 3 km (0 to 2 miles). The level of seismicity has generally decreased since midnight, with background tremor dropping to a relatively low level and individual long-period events decreasing both in frequency and amplitude on the Gages seismometer. A low level of tremor is still being recorded on the Long Ground and Bethel seismometers. This decrease in seismic activity is thought to indicate some slowing of upward magma movement, and is now at a similar level to that recorded 3 days ago.
Further rationalisation of the EDM network took place today. The line from Whites to Castle Peak was measured and showed a small amount of shortening. GPS measurements were again made overnight at stations at Harris' Lookout, Radio Antilles Aerial and St. George's Hill. Data processed today indicate that the line between St. Georges Hill and Harris' Lookout increased in length by just over 1 cm between 3 and 4 December. An additional GPS station will be installed at Roache's Yard tomorrow in order to remeasure some lines across the volcano.
Visual observations of the crater area were not made today due to low cloud cover. However, some observations were made by scientists in the Long Ground area and further growth of the most prominent part of the lava dome was noted. Parts of the lava dome were seen to be glowing from the airport early this morning.