Using high-resolution geochemistry to monitor variations in magma dynamics during eruption

Volcano monitoring makes it possible to indirectly visualise magma plumbing systems and follow the onset and evolution of eruptions. While geophysical data provide real-time information on magma transfer and storage, the petrology of erupted products is crucial to assess magma composition and eruptive style. However, erupted magmas often carry recycled crystals which affect bulk rock compositions, masking variations in erupted melts. Here, we explore the use of high-resolution geochemistry to resolve subtle variations in melt composition on the scale of days to years. We investigate recent basaltic eruptions in a variety of geodynamic settings and with distinct eruptive frequencies, including Mount Etna in Sicily (Italy) and Cumbre Vieja in La Palma (Canary Islands, Spain). We demonstrate that targeted laser ablation mass spectrometry can rapidly determine variations in the chemical composition of melts within the plumbing system, which may add petrological insight to volcano monitoring efforts.