Hybrid events (dominant frequency of 3-5 Hz), disappeared in the early evening of the 6 February, 1996. Occasional, small long-period earthquakes (magnitude less than 1), have been recorded by only the nearest seismic station (Gages). There were about 25 seismic signals, of the type that can often be associated with rockfall or small explosions. Some of these events produced observed ashfalls. A strong seismic signal was recorded only at the Gages seismic station at 01:43 on 7 February; this was probably caused by a small mudflow down the Gages Ghaut. The period under review is the most seismically inactive period since mid-January.
Very overcast conditions heavy rainfall throughout the entire day prevented any EDM measurement from being made. No angular measurements to the dome was possible since the crater rim was not visible at any time during the day.
The concentration of magmatic gases in the Gages valley have been somewhat higher than normal during the past week. The presence of sulphur dioxide in the atmosphere has produced a dull light blue haze which was particularly evident during most of the day. The general brown discolouration of leaves observed in villages such as Webbs and Amersham may have been caused by the presence of hydrogen fluoride and hydrogen chloride, which quickly dissolve in rainfall. The concentrations of these gases are still below levels that should be of immediate concern to people living in these areas, unless they draw their drinking water from surface sources. In particular surface water held in galvanised containers should be avoided.