Interactions between gas slug ascent and exchange flow in the conduit of persistently active volcanoes
| Autor: | Zhipeng Qin, Jenny Suckale, Alison C Rust, Frances Beckett |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
geography
geography.geographical_feature_category 010504 meteorology & atmospheric sciences Flow (psychology) Mechanics 010502 geochemistry & geophysics 01 natural sciences Geophysics Electrical conduit Volcano 13. Climate action Space and Planetary Science Geochemistry and Petrology Gas slug Earth and Planetary Sciences (miscellaneous) Laboratory experiment Geology 0105 earth and related environmental sciences |
| Zdroj: | Qin, Z, Beckett, F M, Rust, A C & Suckale, J 2021, ' Interactions between gas slug ascent and exchange flow in the conduit of persistently active volcanoes ', Journal of Geophysical Research: Solid Earth, vol. 126, no. 9, e2021JB022120 . https://doi.org/10.1029/2021JB022120 |
| Popis: | Many volcanoes around the world are persistently active with continuous degassing for years or even centuries, sometimes exceeding historic records. Such long-term stability contrasts with short-term instability, reflected in eruptive episodes that punctuate passive degassing. These two aspects of persistent activity, long-term stability as opposed to short-term instability, are often conceptualized through two distinct model frameworks: Exchange-flow in volcanic conduits is commonly invoked to explain the long-term thermal balance and sustained passive degassing, while the ascent of large gas slugs is called upon to understand explosive eruptions. While typically considered separately, we propose here that both flow processes could occur jointly in the conduits of persistently active volcanoes and in transient connections between subvolcanic melt lenses. To understand the dynamic interplay between exchange flow and slug ascent, we link analogue laboratory experiments with direct numerical simulations. We find that the two flows superimpose without creating major disruptions when only considering the ascent of a single gas slug. However, the sequential ascent of multiple gas slugs is disruptive to the ambient exchange flow, because it may entail continual buildup of buoyant magma at depth. While our study focuses on the laboratory scale, we propose that the dependence of exchange-flow stability on sequential slug ascent is relevant for understanding why explosive sequences are sometimes followed by effusive eruptions. Taken together, our work suggests that integrating exchange flow and slug ascent could provide a more complete understanding of persistently active volcanoes than either model framework offers in isolation. |
| Databáze: | OpenAIRE |
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