9:00 AM - 9:15 AM
[SVC44-01] Toward an integrated understanding of magmatic-volcanic processes in subduction zones
Of the different aspects, “source” and “transportation” of heat and material are key for the integrated understanding. For instance, “heat source” for arc magmatism has long been enigmatic and remains unresolved. Numerical modeling for mantle convection with fluid generation and migration shows that inflow of an uncooled mantle from back-arc encounters fluids to cause flux melting. However, the temperature estimate for the uncooled mantle has an uncertainty of ~200 degrees, and the estimate for fluid amount varies from 0.1 to several percent (weight percent of fluid added to the melting source) for the same single arc. The fluid carries elements characteristic to arc magmatism. Therefore, the uncertainty in the fluid amount causes a large difficulty in understanding transport and budget of elements, including water. Accordingly, water contents in primary magmas that are supplied to volcanic eruption systems are poorly constrained; in fact, there are discrepancies in the water content among models, experimental estimates, and observations.
In this presentation, we overview the relevant studies, including the discrepancies, concerning “heat and material” aspects of magmatic-volcanic processes in subduction zones. If a volcano is the result of successive processes as above, there is a possibility to resolve the whole chain once at least one the factors are independently constrained. We try to provide some perspective of these issues based on the latest studies, to provoke discussions.