The potential for using GPS for volcano monitoring

It is therefore important to develop a system capable of monitoring the eruptive state of volcanoes that does not depend on visual ash-cloud sighting. Numerous geological techniques are being developed for this purpose, some of which depend on making careful measurements of ground movements at volcanoes. Ground deformation preceding volcanic eruptions occurs at relatively high strain rates, which can change on time scales of hours and perhaps minutes in the days directly before eruption. Geodesy using the global positioning system (GPS) is perhaps the most promising technique for autonomously monitoring volcanic ground deformation with daily and sub-daily time resolution. -from Authors