Explosive
eruption
Tilt, in microradians
3000
Extrusion of
new lobe
Explosive
eruption and
extrusion of
second lobe
2000
Explosive
200 eruption
100
1000
0
0
JANUARY
FEBRUARY
MARCH
APRIL
1982
VOLCANO DEFORMATION–Geodetic Monitoring Techniques
By Daniel Dzurisin
U.S. Geological Survey graphics