Two tiltmeters and an integrating seismometer for the monitoring of volcanic activity, and the results of some trials on Mount Etna

Two types of continuously recording tiltmeter and a new "integrating seismometer" were tested on Etna during the period September to December 1976. The primary object was the investigation of techniques for the surveillance and prediction of volcanic activity, but some information on the internal structure and mechanism of Etna was also obtained. It was concluded that a network of tiltmeters combined with seismic monitoring (using standard and/or integrating seismometers) offers the best dual approach to the problem of determining the true state of dormant volcanoes, and predicting the date and site of possible future eruptions.