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

Abstract

The volcanic-hydrothermal geo-diversity of the Basse-Terre Island of Guadeloupe archipelago (Eastern Caribbean, France) is a major asset of the Caribbean bio-geoheritage. In this paper, we use Guadeloupe as a representative of many small island developing states (SIDS), to show that the volcanic-hydrothermal geodiversity is a major resource and strategic thread for resilience and sustainability. These latter are related to the specific richness of Guadeloupe’s volcanic-geothermal diversity, which is de facto inalienable even in the wake of climate change and natural risks that are responsible for this diversity, i.e., volcanic eruptions. We propose the interweaving the specificity of volcanic-geothermal diversity into planning initiatives for resilience and sustainability. Among these initiatives research and development programs focused on the knowledge of geodiversity, biodiversity and related resources and risks are central for the long-term management of the water resource, lato sensu. Such a management should include a comprehensive scientific observatory for the characterization, exploration, and sustainable exploitation of the volcanic-hydrothermal geodiversity alongside planning for and mitigating geophysical risks related to sudden volcanic-induced phenomena and long-term systemic drifts due to climate change. The results of this exercise for Guadeloupe could typify innovative paths for similar SIDS around their own volcanic-hydrothermal geodiversity.

Monitoring Hydrothermal Activity Using Major and Trace Elements in Low-Temperature Fumarolic Condensates: The Case of La Soufriere de Guadeloupe Volcano

“…Water-rock interaction processes were also deduced following the behavior of halogens, which presented similar relative concentrations in host rocks [60] and condensates (i.e., higher concentrations of Cl and I compared to Br), suggesting incipient isochemical dissolution. This behavior was expected at La Soufriere volcano, where water-rock exchanges producing extensive hydrothermal alteration have already been recognized [11,42,53,55,64,66,67].…”

“…Fumarolic dry gases discharged from La Soufriere primarily have a magmatic origin [42,50]. However, they evolve due to interactions with the hydrothermal system fed by huge amounts of meteoric waters, which, on the La Soufriere summit, reach up to 10 my −1 (5-7 my −1 since 2015; [55] and references therein). The main fumarolic emissions (Figure 1c) are in punctual areas, along with fractures (such as Cratère Sud, hereafter "CS") and open pits (such as Gouffre 56 and Tarissan) caused by past phreatic explosions (Figure 1c).…”

Whole-rock oxygen isotope ratios as a proxy for the strength and stiffness of hydrothermally altered volcanic rocks

“…This unrest is manifest as the expansion of the hot outgassing area at the top of the current lava dome (which formed in CE 1530), the appearance of steam-dominated fumaroles and acid chloride-sulfate springs, an increase in summit and flank displacement rates, an increase in the heat output from the dome, an abundance of shallow seismicity, and, in April 2018, the largest felt tectonic earthquake since the last eruption in 1976-1977 (Brombach et al, 2000;Villemant et al, 2005Villemant et al, , 2014Moretti et al, 2020;Jessop et al, 2021;Heap et al, 2021a;Moune et al, 2022). The link between the stability of the volcano and a combination of hydrothermal alteration resulting from hydrothermal circulation and chemical weathering due to the tropical environment has been underscored in several contributions (Komorowski et al, 2005;Le Friant et al, 2006;Salaün et al, 2011, Rosas-Carbajal et al, 2016Peruzzetto et al, 2019;Heap et al, 2021a;Moretti et al, 2021;Metcalfe et al, 2021;Moune et al, 2022). As a result, La Soufrière de Guadeloupe represents an ideal natural laboratory to study the influence of hydrothermal alteration on rock physical and mechanical properties and volcano stability.…”

Gas Monitoring of Volcanic-Hydrothermal Plumes in a Tropical Environment: The Case of La Soufrière de Guadeloupe Unrest Volcano (Lesser Antilles)

“…At first sight, our dataset does not show clear compositional changes of fumarolic gases in response to seasonal or/and meteorological variations, contrary to previous observations (e.g., Faber et al, 2003;Keely et al, 2013). In fact, an increase of the normalised water table level seems to have no impact on the gas composition and/or the gas fluxes measured with MultiGas, even during its highest peak in May 2017 or during its sudden increase as a result of the passage of hurricane Maria (September 2017; Figure 4), when 440 mm of rainfall in 24 h were recorded by the OVSG rain gauge in Savane à Mulets (Moretti et al, 2021). On the other hand, the gas ratios seem to be more influenced when the normalised water table level decreases.…”