Recent seismic and magnetotelluric imaging studies have identified regions of melt and fluid in the mantle wedge that underlie subduction-generated volcanoes. At the same time, magma pathways in the crust have been observed “lighting up” with increases in seismic events between, prior to, and during eruptions, and some magma storage regions “breathe” geodetically between eruptions. New evidence has emerged from petrologic and geochemical studies documenting timescales of magma assembly, transport and run-up to eruption.

Despite these myriad observations of magma on the move, connections between the mantle melting region, the crustal magmatic system and eruption dynamics are poorly understood. We currently have no unifying models that allow us to understand the connections among magma generation, storage, transport, and eruption from the hydration of the mantle wedge above the subducting slab to the volcano at the surface. By considering the mantle melting region and tectonic setting as parts of the volcanic system, SZ4D will provide a fundamentally new way to interrogate and develop long-term forecasts of volcanic system behavior.