Analysis of magma flux and eruption intensity during the 2021 explosive activity at La Soufrière, St Vincent, West Indies

Sparks, R. J. Steve, Aspinall, Willy P., Barclay, Jenni ORCID:, Renfrew, Ian ORCID:, Contreras-Arratia, Rodrigo and Stewart, Robert (2024) Analysis of magma flux and eruption intensity during the 2021 explosive activity at La Soufrière, St Vincent, West Indies. In: Geological Society Special Publication. Geological Society Special Publications, 539 (1). Geological Society of London, pp. 63-79.

[thumbnail of SP539-2022-286]
PDF (SP539-2022-286) - Accepted Version
Available under License Creative Commons Attribution.

Download (2MB) | Preview


Real-time Seismic Amplitude Measurement signals and eruption cloud height measurements were used to estimate peak intensities of 40 explosive events during the 8–22 April 2021 activity of La Soufrière vol-cano. We estimated magma supply rates and erupted volumes in each explosion, characterized uncertainty by stochastic modelling and identified four eruptive stages. Stage 1 included an intense period of 9.5 hours with 11 explosive events with peak eruption intensity between 2000 and 4000 m 3 s −1 and magma supply rate reaching 828 m 3 s −1. Twelve high-intensity explosions (c. 4000 m 3 s −1) occurred in Stage 2 with average magma supply rate of 251 m 3 s −1. Stage 3 involved both declining intensity and magma supply rate and lengthening repose periods between explosions. Stage 4 involved three much weaker explosions. The total erupted volume of magma is estimated at 38.5 × 10 6 m 3 (90% credible interval: [22.0.. 61.9] × 10 6 m 3) consistent with indepen-dent estimates from analysis of tephra deposits and volcano subsidence sourced at c. 6 km depth. The 150-fold increase in magma supply rate, from the preceding effusive phase to Stage 1 of the explosive phase, is attributed to replacement of very high-viscosity degassed magma occupying the shallow conduit system with new, lower-viscosity, volatile-rich magma from the magma chamber.

Item Type: Book Section
Additional Information: Issue: The 2020-21 Eruption of La Soufrière Volcano, St Vincent
Faculty \ School: Faculty of Science > School of Environmental Sciences
University of East Anglia Research Groups/Centres > Theme - ClimateUEA
UEA Research Groups: Faculty of Science > Research Groups > Geosciences
Faculty of Science > Research Groups > Centre for Ocean and Atmospheric Sciences
Related URLs:
Depositing User: LivePure Connector
Date Deposited: 03 May 2023 13:30
Last Modified: 30 Jan 2024 04:02
DOI: 10.1144/SP539-2022-286


Downloads per month over past year

Actions (login required)

View Item View Item