Is there a relationship between large earthquakes (>M 6) that occur along major fault zones and nearby volcanic eruptions?
Sometimes, yes. A few historic large regional earthquakes (>M 6) are considered by scientists to be related to a subsequent eruption or to some type of unrest at a nearby volcano. The exact triggering mechanism for these historic examples is not well understood, but the volcanic activity probably occurs in response to a change in the local pressure surrounding the magma reservoir system as a consequence of (1) severe ground shaking caused by the earthquake; or (2) a change in the “strain” or pressure in the Earth’s crust in the region surrounding where the earthquake occurred.
