A multi-decadal view of the heat and mass budget of a volcano in unrest: La Soufrière de Guadeloupe (French West Indies)

Abstract

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Alteration‐Induced Volcano Instability at La Soufrière de Guadeloupe (Eastern Caribbean)

“…Our modeling and 3D strength map therefore highlight the importance of monitoring the extent and evolution of hydrothermal alteration, and the formation of low-strength altered layers, at La Soufrière and at other active volcanoes worldwide. Such monitoring can be achieved, for example, using geophysical methods such as electrical tomography (Ahmed et al, 2018;Byrdina et al, 2017;Ghorbani et al, 2018;Rosas-Carbajal et al, 2016) and muon tomography (Lesparre et al, 2012;Rosas-Carbajal et al, 2017), near-surface seismic imaging (Amoroso et al, 2018), thermal and gas monitoring (de Moor et al, 2019;Edmonds et al, 2003;Jessop et al, 2021;Moretti et al, 2020;Tamburello et al, 2019), geological mapping (van Wyk de Vries et al, 2000), deformation monitoring (Moretti et al, 2020), magnetic methods (Finn et al, 2007), and remote and/or ground-based optical and spectroscopic methods (Crowley & Zimbelman, 1997;Darmawan et al, 2018;John et al, 2008;Kereszturi et al, 2020;Mueller et al, 2021). Further, although we document a reduction in strength as a function of alteration (Figure 5c), alteration can also increase strength and potentially promote volcanic instability by creating zones of high pore fluid pressure (Heap, Baumann, et al, 2021;Reid, 2004).…”

Magmatic Processes at La Soufrière de Guadeloupe: Insights From Crystal Studies and Diffusion Timescales for Eruption Onset

“…CE (1690CE ( , 1797CE ( -1798CE ( , 1809CE ( -18121836-1837, 1956and 1976-1977Feuillard et al, 1983;Komorowski et al, 2005;Hincks et al, 2014). The 1976-1977 phreatic eruption resulted in the establishment of a monitoring system including a seismic network, global navigation satellite system receivers (GNSS), meteorological networks, periodic extensometric surveys of lava dome fractures, fumarole gas and thermal spring sampling, and thermal monitoring (Komorowski et al, 2005;Villemant et al, 2005;Villemant et al, 2014;Jessop et al, 2020;.…”

“…Since 1992 there have been twenty felt volcanic earthquakes, with ten of these occurring since 2013, culminating in 2018 with the strongest recorded event since 1976 (M 4.1; Komorowski et al, 2005;OVSG-IPGP, 1999. Recent years have also seen an acceleration in the opening rate of several summit fractures and the area of heated ground at the summit increasing in size (Jessop et al, 2020). Passive ground degassing (CO 2 ) has occurred in areas near the summit vent, as well as on the flanks of the dome (OVSG-IPGP, 1999Jessop et al, 2020).…”

“…Recent years have also seen an acceleration in the opening rate of several summit fractures and the area of heated ground at the summit increasing in size (Jessop et al, 2020). Passive ground degassing (CO 2 ) has occurred in areas near the summit vent, as well as on the flanks of the dome (OVSG-IPGP, 1999Jessop et al, 2020).…”

The Basse-Terre Island of Guadeloupe (Eastern Caribbean, France) and Its Volcanic-Hydrothermal Geodiversity: A Case Study of Challenges, Perspectives, and New Paradigms for Resilience and Sustainability on Volcanic Islands

“…The main features of the ongoing unrest are given by (1) the continuous expansion of the degassing area on top of the lava dome and (2) with the appearance of new fumaroles in July 2014 and February 2016. The expansion was accompanied by an increase of thermal ground release (increased from 1.2 MW to 8 MW), that escalated the heat output due to fumarolic steam release, that notably has been roughly constant from 2010 to 2020 (28 MW; Jessop et al 2021 [50]). Fumarolic emissions are steam dominated and characterized by a deep magmatic gas component (Brombach et al 2000;Villemant et al 2014;and Moretti et al 2020 [19,45,46]).…”