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

Abstract

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.