Basaltic Plinian eruptions at Las Sierras-Masaya volcano driven by cool storage of crystal-rich magmas
Abstract Although rare, basaltic Plinian eruptions represent a considerable volcanic hazard. The low viscosity of crystal-poor basaltic magma inhibits magma fragmentation; however, Las Sierras-Masaya volcano, Nicaragua, has produced multiple basaltic Plinian eruptions. Here, we quantify the geochemi...
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Published in | Communications earth & environment Vol. 3; no. 1; pp. 1 - 17 |
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Main Authors | , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
London
Nature Publishing Group
29.10.2022
Nature Portfolio |
Subjects | |
Online Access | Get full text |
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Summary: | Abstract
Although rare, basaltic Plinian eruptions represent a considerable volcanic hazard. The low viscosity of crystal-poor basaltic magma inhibits magma fragmentation; however, Las Sierras-Masaya volcano, Nicaragua, has produced multiple basaltic Plinian eruptions. Here, we quantify the geochemistry and volatile concentrations of melt inclusions in samples of the Fontana Lapilli and Masaya Triple Layer eruptions to constrain pre-eruptive conditions. Combining thermometry and geochemical modelling, we show that magma cooled to ~1000 °C prior to eruption, crystallising a mush that was erupted and preserved in scoriae. We use these data in a numerical conduit model, which finds that conditions most conducive to Plinian eruptions are a pre-eruptive temperature <1100 °C and a total crystal content >30 vol.%. Cooling, crystal-rich, large-volume basaltic magma bodies may be hazardous due to their potential to erupt with Plinian magnitude. Rapid ascent rates mean there may only be some minutes between eruption triggering and Plinian activity at Masaya. |
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ISSN: | 2662-4435 2662-4435 |
DOI: | 10.1038/s43247-022-00585-5 |