Depth of Magma Storage Under Iceland Controlled by Magma Fluxes

Abstract The compositions of volcanic materials are sensitive to physical conditions in the underlying magmatic system. When basaltic melts saturated olivine‐plagioclase‐augite prior eruption, their can be used estimate pressure at which they last equilibrated. We developed PyOPAM, an open‐source tool that runs Python, and use this refreshed liquid‐barometer investigate relationship between final depths magma storage flux. first tested PyOPAM using 312 experimental glasses compiled from literature found 1 σ uncertainty is 1.13 kbar (±3 km). was then applied a data set 13,400 analyses Iceland, where suspected controls on flux well constrained. Of these, 3807 return robust estimates, constraining pre‐eruptive for 23 30 Icelandic systems. Our results indicate pressures Iceland linked melt‐flux mantle. This finding consistent with previous models linking spreading rates global mid‐ocean ridge In addition, we provide clear evidence flux, rather than rate alone, key control distribution melt centers. Increased associated shoaling depths, indicating mantle fluxes dictate long‐term stabilization extensive regions shallower 10 km. Quantitative relationships test computational transcrustal