Seismicity during this period was low, with only two earthquakes being located, at depths in the range 2 - 3 km. One event (a volcano-tectonic earthquake) was located in the Windy Hill area while the second event (a hybrid earthquake) occurred beneath the Soufriere Hills volcano. Persistent low amplitude broadband tremor, with a period of considerably increased amplitude between 08:45 and 11:00 on January 18, characterised the Gages seismic record throughout the period under review. This tremor is probably due to increased steam emission within the crater region. Several signals which probably represent rockfalls from the growing dome were also recorded by some stations of the network. Two instances of moderate ash emissions occurred at 10:15am and 1:30pm today. These resulted in minor ashfalls in upper Gages and Kinsale.
EDM measurements were made today on the Long Ground - White's Yard - Castle Peak triangle. Analysis of the results suggests no change in any of the line lengths since the last occupation two days ago. An attempt to conduct measurements to Gage's wall was aborted due to the ash fall associated with the eruption at 10:15am
Visual observations were made early this morning and mid- afternoon from the helicopter and from the ground at several points around the volcano. The new spine, which was first observed a few days ago, grew significantly overnight. The mid-afternoon flight revealed that a large segment of the new spine had collapsed since the ash emission at 10:15am. Vigorous steaming was observed from the crater area throughout the day.