20-May-91 |
120
|
Series of small hydrothermal
"burps" |
21-May-91 |
144
|
Small hydrothermal
explosion; steam clouds and small amounts of
tephra ejected 300 to 500 meters |
26-May-91 |
134
|
Small amounts of tephra
ejected 100-200 meters |
3-Jun-91 |
135
|
Ash ejection lasting
for 30 minutes |
7-Jun-91 |
1500
|
Low frequency volcanic
quakes; magma nearing the surface |
8-Jun-91 |
1776
|
Explosion-type earthquake
|
9-Jun-91 |
1895
|
Violent eruption;
pyroclastic flows to 5 kilometers |
12-Jun-91 |
1565
|
Intense seismic activity
and explosions followed by 3 major explosions, ash,
pumice, and ejected fragments |
13-Jun-91 |
1706
|
Violent eruption triggering
heavy ashfalls |
14-Jun-91 |
1905
|
Fourth major eruption;
vertical ash cloud 25 kilometers; pyroclastic flows
15 kilometers from source |
15-Jun-91 |
1843
|
Two explosions, pyroclastic
flows moving between 70 to 80 km/hr; vertical ash
cloud 40km high |
16-Jun-91
|
856 |
Activities
decline both in frequency and magnitude |