Sustaining persistent lava lakes: Observations from high-resolution gas measurements at Villarrica volcano, Chile

TitleSustaining persistent lava lakes: Observations from high-resolution gas measurements at Villarrica volcano, Chile
Publication TypeJournal Article
Year of Publication2016
AuthorsMoussallam Y., Bani P., Curtis A., Barnie T., Moussallam M., Peters N., Schipper C.I, Aiuppa A., Giudice G., Amigo A., Velasquez G., Cardona C.
JournalEarth and Planetary Science Letters
Volume454
Pagination237-247
Date Published2016/11
Type of ArticleArticle
ISBN Number0012-821X
Accession NumberWOS:000386645700024
Keywordsantarctica; conduit dynamic; dynamics; emissions; erebus volcano; Fire; fluctuations; flux measurements; hawaii; kilauea volcano; magma; Multi-GAS; spectroscopy; Trail By; UAV; UV camera; volcanic degassing
Abstract

Active lava lakes - as the exposed upper part of magmatic columns - are prime locations to investigate the conduit flow processes operating at active, degassing volcanoes. Persistent lava lakes require a constant influx of heat to sustain a molten state at the Earth's surface. Several mechanisms have been proposed to explain how such heat transfer can operate efficiently. These models make contrasting predictions with respect to the flow dynamics in volcanic conduits and should result in dissimilar volatile emissions at the surface. Here we look at high-frequency SO2 fluxes, plume composition, thermal emissions and aerial video footage from the Villarrica lava lake in order to determine the mechanism sustaining its activity. We found that while fluctuations are apparent in all datasets, none shows a stable periodic behaviour. These observations suggest a continuous influx of volatiles and magma to the Villarrica lava lake. We suggest that ascending volatile-rich and descending degassed magmas are efficiently mixed within the volcanic conduit, resulting in no clear periodic oscillations in the plume composition and flux. We compare our findings to those of other lava lakes where equivalent gas emission time-series have been acquired, and suggest that gas flux, magma viscosity and conduit geometry are key parameters determining which flow mechanism operates in a given volcanic conduit. The range of conduit flow regimes inferred from the few studied lava lakes gives a glimpse of the potentially wide spectrum of conduit flow dynamics operating at active volcanoes. (C) 2016 Elsevier B.V. All rights reserved.

DOI10.1016/j.epsl.2016.09.012
Short TitleEarth Planet. Sci. Lett.
Student Publication: 
No