Chronology of the Eruption
The first block and ash flows carried material from the crater region into the upper Tar River valley by late March,1996. The first pyroclastic flow in early April, travelled about 1.5 miles from the dome, to the road which crosses the Tar River valley. This led to the third evacuation of the area. On "Mothers Day", mid-March, pyroclastic flows reached the sea for the first time.
In late July, the amount of seismic activity increased. This corresponded with the occurrence of high numbers of VT earthquakes for the first time since dome growth began. These were also accompanied by a major increase in magma production rate, and a switch in dome activity to the eastern side of the crater. The rate of deformation on the eastern side increased to about 6mm per day. A high rate of magma production (of about 10 cubic metres per second) led to major collapse and resulted in pyroclastic flows into the Tar River valley. This started a period of intense seismic activity, with repetitive episodes of tremor, and hybrid and VT earthquakes, which lasted until mid-August.