The eruption run-up at Mt. Etna volcano: Constraining magma decompression rates and their relationships with the final eruptive energy

•We have estimated magma decompression rates for three recent eruptions at Mt. Etna.•Diffusive volatile element gradients measured along melt embayments were modeled.•Decompression rates correlate positively with the energy of explosive eruptions.•Syn-eruptive degassing contributes to the final magma fragmentation.•Similar magmas at Etna can be erupted with markedly distinct eruptive energies.