New Insight Into a Volcanic System: Analogue Investigation of Bubble‐Driven Deformation in an Elastic Conduit

Abstract

Analogue and numerical simulations have been widely used to describe the mechanisms of bubble and slug ascent during volcanic eruptions as well as their formation and explosion mechanisms. Nevertheless, little is known about the mechanical interaction between the fluid and the surrounding medium. In this work, we report the results from analogue experiments designed to show how deformation of the conduit walls induced by the rising slugs is related to the radiation and propagation of seismic and geodetic signals. For the first time, we investigate the dynamics of bubbles in an elastic conduit unveiling the relationship between slugs and crustal strain accumulation around the conduit. Moreover, we discuss the retroactive effects of the deformed conduit wall on the dynamics of a rising slug, particularly, how the flow is affected, and the eventual implications on the intensity of the eruption. Our results show that the combination of an elastic conduit with a large volume of gas may lead to the development of a new type of slug, here defined as a "super slug," characterized by tapering towards the tail and a much higher ascent velocity and inner pressure compared with ordinary slugs. This newly observed behavior could be linked to vigorous explosive events.

Characterizing the physical properties of gelatin, a classic analog for the brittle elastic crust, insight from numerical modeling

“…While most experimenters indicate the size of the tank they are using, the size of the load applied during the Young's modulus measurement is never provided except by Kavanagh et al [16]. In the literature, the minimum size of the tank ranges from 8.6 cm [16] to 80 cm [6], which means that the maximum size of the applied load should be less than 0.4 cm for the smallest tanks and less than 3.8 cm for the largest. We provide a solution to this problem as from our results, it is possible to derive a correction factor to be applied to the value derived using the analytical formula in order to take into account the actual size of the tank (Fig.…”