https://phys.org/news/2018-05-volcano-libraries-future-volcanic-crises.html

By analysing the records in the crystals and working back from the time of eruption, they were able to read the magma's history in time and location, which allowed them to interpret how the volcano behaved, and magma built up, in the six months beforehand. Their reconstruction of what was happening deep underneath the ground aligns with observations made at the surface at the same time. This opens up the possibility of studying other, older erupted materials to get a long term record of how the volcano has typically behaved in the run-up to previous eruptions.

The same techniques could potentially be applied to numerous other volcanoes, creating a 'library' of volcano histories and could greatly improve understanding of the critical, pre-eruptive phase of volcano activity, which is key in making accurate forecasts of eruptions.