Dyke intrusion and stress-induced collapse of volcano flanks: The example of the 2018 event at Mt. Etna (Sicily, Italy)

E Giampiccolo; O Cocina; P De Gori; C Chiarabba

doi:10.1038/s41598-020-63371-3

Dyke intrusion and stress-induced collapse of volcano flanks: The example of the 2018 event at Mt. Etna (Sicily, Italy)

Sci Rep. 2020 Apr 14;10(1):6373. doi: 10.1038/s41598-020-63371-3.

Authors

E Giampiccolo¹, O Cocina², P De Gori³, C Chiarabba³

Affiliations

¹ INGV, Sezione di Catania - Osservatorio Etneo. Piazza Roma, 2 - 95125, Catania, Italy.
² INGV, Sezione di Catania - Osservatorio Etneo. Piazza Roma, 2 - 95125, Catania, Italy. ornella.cocina@ingv.it.
³ INGV, Osservatorio Nazionale Terremoti. Via di Vigna Murata, 605 - 00143, Roma, Italy.

Abstract

Magmatic intrusions, eruptions and flank collapses are frequent processes of volcano dynamics, inter-connected at different space and time scales. The December 2018 recrudescent episode at Mt. Etna is an exemplary case where a sudden intrusive event culminated with a short eruption, intense seismicity and a shallow large strike-slip earthquake at the edge of the eastern sliding flank. Here, we show that high resolution velocity models and transient changes of V_P and V_P/V_S resolve the magma intrusion through a dyke and local stress increase at the base of the unstable flank, inducing the collapse. Episodic brittle faulting occurs at the edge of the sliding sector, locally contributed by high fluid pressure. The feedback between magma ascent, stress changes and flank collapse is driving the volcano dynamics, with processes ranging from long term to transient episodes.