Secular variation of seismo-volcanic phenomena in the azores

By studying the past behaviour of Azorean volcanoes, sunspot and Earth tide correlations have been discovered, and may certainly help in prediction. Some evidence has also been found that buckling of the thin roof of magma chambers may be the mechanism responsible for the eruptions, including the accompanying seismic swarms. If this is the case, geodetic control of the adjacent regions will probably be decisive in forecasting future activity.