Petrological monitoring of active volcanoes: A review of existing procedures to achieve best practices and operative protocols during eruptions

A questionnaire to survey the common petrological monitoring procedures adopted by volcano monitoring institutions has been developed, aimed at identifying prevailing techniques and rating their suitability in terms of costs versus benefits. The collected information resulted from a sample of eighteen participating institutions, which include countries with some of the most important active volcanic provinces worldwide. The participating institutions also offer insights into volcanoes with a variety of volcanic activity, providing a comprehensive picture of the state of art of petrological monitoring. The final purposes are (i) to promote the advancement that petrologic monitoring brings in the comprehension of the eruptive processes, providing the only “signals” (i.e., rock samples) concerning the physico-chemical properties of the magma feeding the eruption; (ii) to design best practices, and (iii) to define the minimum requirements needed to perform an efficient petrological monitoring during ongoing eruptions. The survey also highlighted the main problems to overcome to have a profitable petrological monitoring infrastructure, including (i) the time required to accomplish both field survey and laboratory works (sampling, sample preparation, and analyses), (ii) the lack of onsite analytical facilities, (iii) the shortage of qualified staff.Starting from the state of the art of petrological monitoring, how it is performed by the different institutions worldwide, and what participants considered as the major problems, we identified the Best Practices in Petrological Monitoring as the best compromise between fast and easy analyses and the relevance of the acquired results.