Tangential
strain
0.6
Radial
strain
0.4
0.6
0.4
0.2
0.2
– 4d
– 2d
– 0.2
– 0.4
2d
4d
– 2d
Distance
0.6
Tilt
– 4d
– 0.4
Volumetric
strain
0.4
– 2d
– 0.2
– 0.4
2d
4d
Distance
0.6
0.4
0.2
0.2
– 4d
– 0.2
2d
4d
Distance
– 4d
– 2d
– 0.2
– 0.4
2d
4d
Distance
VOLCANO DEFORMATION–Geodetic Monitoring Techniques
By Daniel Dzurisin
U.S. Geological Survey graphics