Magma decompression rate correlates with explosivity at basaltic volcanoes — Constraints from water diffusion in olivine

Despite the strong theoretical basis for the importance of magma decompression rate in modulating the dynamics of explosive basaltic eruptions, few measurements exist. Here, we quantify magma decompression rate using the incomplete diffusive re-equilibration of water through olivine for two contrasting eruptions at Cerro Negro volcano in Nicaragua: the 1992 VEI 3 and 1995 VEI 2 eruptions. Both eruptions have the same basaltic composition (SiO2 ∼...