Which process triggers a Plinian eruption when magma viscosity and gas content are critically high?

💡 Explanation

When magma viscosity and gas content are high, exsolution of volatiles forms bubbles which rapidly expand, causing fragmentation of the magma and a Plinian eruption because of the sudden pressure release. Therefore, volatile exsolution is responsible, rather than crystallization, convection disruption or shear thinning which typically influence slower or effusive eruptions.

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