One (1) volcano-tectonic earthquake was located during this period at a depth of 1km beneath the volcano. Seven (7) long-period events were recorded by most of the seismometers in the network. The broadband tremor which started on the morning of 28 December continued until approximately 05:00 this morning, but then occurred only intermittently during today. This tremor is still only being recorded on the Gages seismometer and is probably due to steam emission from English's crater. A regional earthquake was recorded at 10:37 this morning; this had a magnitude of 5.0 and was located approximately 95 km NE of St. Lucia at a depth of 85 km. A 2nd regional earthquake of estimated magnitude 3.9 occurred at 15:02 today and was located about 260 km from Montserrat.
EDM lines were measured today to Castle Peak from Long Ground and White's and to Gages Wall from Amersham and Dagenham. None of the lines measured yesterday showed any change. GPS measurements were made overnight at St George's Hill, Reid's Hill and Tar River. All three GPS stations were then removed to be returned to the USA. Installation of permanent GPS receivers is expected to take place in mid January.
Visual observations were made today from the helicopter and from White's Yard and Harris' Lookout. From measurements at White's, the upper surface of the eastern part of the lava dome has risen by a further 1m (3ft) in the last 24 hours. Several significant rock falls were witnessed by scientists, but material is still confined to the crater area.. The latest spine is still clearly visible in the west part of the crater. A rock fall in the dome area at about 17:30 yesterday evening produced a small ash plume which was clearly seen from the observatory as it drifted over Gages to the west. Attempts were made today to collect rock from the new dome area using a bucket device suspended beneath the helicopter. Unfortunately, conditions became hazardous and the bucket had to be ditched.