Is There an Influence of the Pole Tide on Volcanism? Insights From Mount Etna Recent Activity

S. Lambert (1) , G. Sottili

1 SYRTE - Systèmes de Référence Temps Espace

We investigate a possible link between polar motion and (i) seismic energy release and (ii) timing and intensity of eruptions at Mount Etna (Italy) for which a dense observational database is available. Our study suggests that the seismicity around Mount Etna increases during the largest excursions of the Earth rotation pole, which result from the constructive interference of the climate-driven seasonal and Chandler wobbles. To a lesser extent, a similar link is detected between the pole tide and the erupted volume of magma. We infer that, by creating periodic changes in the state of stress in the crust through a variable centrifugal force and a periodic vertical displacement (pole tide), variations in polar motion influence eruption timing and magnitude and the rate of seismic energy release from volcanoes. This study provides new evidences on the sensitivity of volcanoes to external forcing.

Keywords: Earth rotation; volcanism; seismicity; polar motion; Chandler wobble; Mount Etna

Domains: Sciences of the Universe [physics]; Volcanology

S. Lambert, G. Sottili. Is There an Influence of the Pole Tide on Volcanism? Insights From Mount Etna Recent Activity. Geophysical Research Letters, 2019, 46, pp.13,730-13,736. ⟨10.1029/2019GL085525⟩. ⟨insu-03713102⟩