Fluid fluxing and accumulation drive decadal and short-lived explosive basaltic andesite eruptions preceded by limited volcanic unrest

Some volcanoes are known for repeatedly producing explosive but short-lived eruptions (half a day) every decade or so. These eruptions are often preceded by limited unrest signals and short run-up times to eruption (a few hours to months), and thus they are difficult to anticipate. Some well-documen...

Full description

Saved in:
Bibliographic Details
Main Authors: Utami, Sri Budhi, Costa, Fidel, Lesage, Ph., Allard, P., Humaida, H.
Other Authors: Asian School of the Environment
Format: Article
Language:English
Published: 2022
Subjects:
Online Access:https://hdl.handle.net/10356/162529
Tags: Add Tag
No Tags, Be the first to tag this record!
Institution: Nanyang Technological University
Language: English
id sg-ntu-dr.10356-162529
record_format dspace
spelling sg-ntu-dr.10356-1625292022-10-29T23:31:13Z Fluid fluxing and accumulation drive decadal and short-lived explosive basaltic andesite eruptions preceded by limited volcanic unrest Utami, Sri Budhi Costa, Fidel Lesage, Ph. Allard, P. Humaida, H. Asian School of the Environment Earth Observatory of Singapore Science::Geology Volcano Monitoring Magma Storage Conditions Some volcanoes are known for repeatedly producing explosive but short-lived eruptions (half a day) every decade or so. These eruptions are often preceded by limited unrest signals and short run-up times to eruption (a few hours to months), and thus they are difficult to anticipate. Some well-documented examples are the 1990 and 2014 eruptions of Kelud volcano in Indonesia, or the 2015 Calbuco eruption in Chile. Here we interrogate the rock record and obtain insights into the processes and pre-eruptive conditions that led to the 1990 Kelud eruption, which we integrate with monitoring data (seismicity, lake temperature and hydro-Acoustics, sulfur emissions) towards a conceptual model for this type of events. Mineral-melt geothermobarometers indicate that the basaltic andesite magma carried a crystal cargo from as deep as 1519 km, and reached volatile saturation at 49 km with 24 wt.% water in the melt. The textures and compositional zoning of orthopyroxene and plagioclase do not support intrusion of more primitive magma as the driver for the eruption, and we instead propose that pre-eruptive fluid accumulation and hightemperature fluid fluxing from depth (likely dominated by CO2) played a major role in priming the eruption to occur. Such pre-eruptive gas accumulation is also supported by mass balance calculation of the emitted excess SO2 gas. Mg-Fe diffusion profiles in reversely zoned pyroxenes constrain timescales of weeks to months before eruption for fluid addition to the reservoir, and such events may be recorded in the monitoring signals, especially in the change of hydroacoustics and water lake temperature, and probably in the seismic swarms.We propose that fluid exsolution and accumulation in the shallow reservoir plays a crucial role in modulating and triggering short-lived explosive eruptions with brief unrest at Kelud and probably other volcanoes worldwide. Ministry of Education (MOE) National Research Foundation (NRF) Published version This research was supported by the Earth Observatory of Singapore via its funding from the National Research Foundation Singapore and the Singapore Ministry of Education under the Research Centres of Excellence initiative. F. Costa was funded by NRFi Award (NRF-NRFI2017-06). 2022-10-26T08:12:35Z 2022-10-26T08:12:35Z 2021 Journal Article Utami, S. B., Costa, F., Lesage, P., Allard, P. & Humaida, H. (2021). Fluid fluxing and accumulation drive decadal and short-lived explosive basaltic andesite eruptions preceded by limited volcanic unrest. Journal of Petrology, 62(11), 1-29. https://dx.doi.org/10.1093/petrology/egab086 0022-3530 https://hdl.handle.net/10356/162529 10.1093/petrology/egab086 2-s2.0-85124624832 11 62 1 29 en NRF-NRFI2017-06 Journal of Petrology © The Author(s) 2021. Published by Oxford University Press. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Science::Geology
Volcano Monitoring
Magma Storage Conditions
spellingShingle Science::Geology
Volcano Monitoring
Magma Storage Conditions
Utami, Sri Budhi
Costa, Fidel
Lesage, Ph.
Allard, P.
Humaida, H.
Fluid fluxing and accumulation drive decadal and short-lived explosive basaltic andesite eruptions preceded by limited volcanic unrest
description Some volcanoes are known for repeatedly producing explosive but short-lived eruptions (half a day) every decade or so. These eruptions are often preceded by limited unrest signals and short run-up times to eruption (a few hours to months), and thus they are difficult to anticipate. Some well-documented examples are the 1990 and 2014 eruptions of Kelud volcano in Indonesia, or the 2015 Calbuco eruption in Chile. Here we interrogate the rock record and obtain insights into the processes and pre-eruptive conditions that led to the 1990 Kelud eruption, which we integrate with monitoring data (seismicity, lake temperature and hydro-Acoustics, sulfur emissions) towards a conceptual model for this type of events. Mineral-melt geothermobarometers indicate that the basaltic andesite magma carried a crystal cargo from as deep as 1519 km, and reached volatile saturation at 49 km with 24 wt.% water in the melt. The textures and compositional zoning of orthopyroxene and plagioclase do not support intrusion of more primitive magma as the driver for the eruption, and we instead propose that pre-eruptive fluid accumulation and hightemperature fluid fluxing from depth (likely dominated by CO2) played a major role in priming the eruption to occur. Such pre-eruptive gas accumulation is also supported by mass balance calculation of the emitted excess SO2 gas. Mg-Fe diffusion profiles in reversely zoned pyroxenes constrain timescales of weeks to months before eruption for fluid addition to the reservoir, and such events may be recorded in the monitoring signals, especially in the change of hydroacoustics and water lake temperature, and probably in the seismic swarms.We propose that fluid exsolution and accumulation in the shallow reservoir plays a crucial role in modulating and triggering short-lived explosive eruptions with brief unrest at Kelud and probably other volcanoes worldwide.
author2 Asian School of the Environment
author_facet Asian School of the Environment
Utami, Sri Budhi
Costa, Fidel
Lesage, Ph.
Allard, P.
Humaida, H.
format Article
author Utami, Sri Budhi
Costa, Fidel
Lesage, Ph.
Allard, P.
Humaida, H.
author_sort Utami, Sri Budhi
title Fluid fluxing and accumulation drive decadal and short-lived explosive basaltic andesite eruptions preceded by limited volcanic unrest
title_short Fluid fluxing and accumulation drive decadal and short-lived explosive basaltic andesite eruptions preceded by limited volcanic unrest
title_full Fluid fluxing and accumulation drive decadal and short-lived explosive basaltic andesite eruptions preceded by limited volcanic unrest
title_fullStr Fluid fluxing and accumulation drive decadal and short-lived explosive basaltic andesite eruptions preceded by limited volcanic unrest
title_full_unstemmed Fluid fluxing and accumulation drive decadal and short-lived explosive basaltic andesite eruptions preceded by limited volcanic unrest
title_sort fluid fluxing and accumulation drive decadal and short-lived explosive basaltic andesite eruptions preceded by limited volcanic unrest
publishDate 2022
url https://hdl.handle.net/10356/162529
_version_ 1749179251393822720