Tilt measurements on volcanoes: more than a hundred years of recordings

Tilt measurements represent one of the earliest methods to detect
ground deformation on volcanoes with the first acquisition being
made on Kilauea (Hawaii) in 1912-13. Tilt is a powerful tool for volcano
monitoring enabling to obtain signals with high precision. Tilt has
proved its worth especially in understanding dike intrusions, fracture
propagation, lava fountains, strombolian activity, dome growing and
volume and amplitude changes in magmatic/hydrothermal systems.
This paper is a review of tilt studies performed worldwide on volcanoes
in the last 105 years. We highlighted the methodologies used
and the improvements and developments made over recent years to
augment the possibility to detect volcanic processes.
We review the results obtained on about 40 volcanic areas in
which tilt measurements have played a major role in volcanic process
knowledge.