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

Abstract

Results velocity images. The 3D velocity images obtained present strong heterogeneities in V P and V P /Vs, shown as perturbations in horizontal layers (Fig. 2) and absolute velocity in vertical sections (Fig. 3). The main morphological features in the 3D images are:

The Christmas 2018 Eruption at Mount Etna: Enlightening How the Volcano Factory Works Through a Multiparametric Inspection

“…This distinguishing characteristic should be related to bypassing of the shallow central conduit and re-equilibration of olivine rims at the M2 thermodynamic conditions in a spatially different position of the volcano edifice (Figure 8d). This inference definitely agrees with development of the eruptive activity along the southeastern flank of the volcano, which has been accounted for as due to a dike intrusion departing from the central conduit system (e.g., Bonforte et al, 2019;Cannavò et al, 2019;De Novellis et al, 2019;Giampiccolo et al, 2020;Pezzo et al, 2020). Timing for re-equilibration to M2 conditions suggests that this lateral intrusion into the volcano southeastern flank started from the M1b level just a few days before the eruption.…”

Seismological constraints on the 2018 Mt. Etna (Italy) flank eruption and implications for the flank dynamics of the volcano

“…The sliding discussed in this paper, as highlighted by the distribution of seismicity and by most of the flank deformations observed (e.g. Bonforte et al, 2019; De Novellis et al, 2019), is likely to have been triggered by the brief event of intrusive nature, perhaps aided by hydrothermal weakening (Giampiccolo et al, 2020).…”

Supplemental Material: Flank sliding: A valve and a sentinel for paroxysmal eruptions and magma ascent at Mount Etna, Italy

“…In order to constrain the eastern flank sliding plane geometry, we use the seismic VP tomography model obtained by Giampiccolo et al (2020). The detachment is assumed to be located at the volcanic-sedimentary interface (Palano, 2016) with a geometry constrained by isovelocity (VP = 3.5 km/s) surface ( Figure S14).…”

“…Figure S14. 3D W-E-profiles showing the P-wave iso-velocity surfaces, V P =3.5 Km/s (a) and V P =5.0 Km/s (b) coming from recent tomographic data (Giampiccolo et al, 2020) and representing the volcanicsedimentary deposit interface and the top of the carbonate basement, respectively. c) a 3D view of both 3.5 and 5.0 Km/s P-wave iso-velocity surfaces where we identified a sharp east-dipping scarp in the sedimentary basement (in red) and the eastern flank sliding plane (in blue).…”