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

E Giampiccolo, O Cocina + Show 2 more

Open Access

https://doi.org/10.1038/s41598-020-63371-3

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Journal: Scientific Reports	Publication Date: Apr 14, 2020
Citations: 32	License type: open-access

Affiliation: Osservatorio Astrofisico di Catania

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 VP and VP/VS 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.

Highlights

Earthquake and volcanoes are expression of dramatic changes in the dynamics of the earth interior, connected at a scale that ranges from plate tectonics to local[1,2]
Long term processes of deep magma recharge and storage within the upper crust[7,8], sudden dyke intrusions and eruptions[9,10,11], flank collapses with abnormal velocities [e.g.12,13 and references therein] represent the standard evolution of Mt
The 2018 episode of recrudescence is an exemplary case of strato-volcano dynamics

Summary

Introduction

Earthquake and volcanoes are expression of dramatic changes in the dynamics of the earth interior, connected at a scale that ranges from plate tectonics to local[1,2]. The association with high VP/VS anomalies suggests the existence of wide volumes over-pressured by fluids within the sedimentary units around the volcano. In addition to these robust elements of the volcano structure, peculiar transient changes in VP and VP/VS are revealed during the 2018 episode (Fig. 4) by the time lapse imaging (see the Data and Method section for technical details).

Results

Conclusion