Heat flux-based strategies for the thermal monitoring of sub-fumarolic areas: Examples from Vulcano and La Soufrière de Guadeloupe

Autor: Elodie Brothelande, Anthony Finizola, Aline Peltier, Salvatore Alparone, Fabio Di Gangi, Salvatore Inguaggiato, Vincenzo Milluzzo, Stéphanie Barde-Cabusson, Salvatore Gambino, Eric Delcher, Fabio Vita, Tullio Ricci, Damien Gaudin
Přispěvatelé: Istituto Nazionale di Geofisica e Vulcanologia - Sezione di Roma (INGV), Istituto Nazionale di Geofisica e Vulcanologia, Department of Earth and Environmental Sciences [München], Ludwig-Maximilians-Universität München (LMU), Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris, Istituto Nazionale di Geofisica e Vulcanologia - Sezione di Catania (INGV), Institute of Earth Sciences Jaume Almera, Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Rosenstiel School of Marine and Atmospheric Science (RSMAS), University of Miami [Coral Gables], Instituto Nazionale di Geofisica e Vulcanologie Sezione di Palermo, Eni Angola, Observatoire Volcanologique du Piton de la Fournaise (OVPF), Institut de Physique du Globe de Paris, ANR-08-RISK-0002,DOMOSCAN,Quantification de la dynamique et suivi spatio-temporelle du système hydrothermal de la Soufrière de Guadeloupe(2008)
Rok vydání: 2017
Předmět:
Zdroj: Digital.CSIC. Repositorio Institucional del CSIC
instname
Journal of Volcanology and Geothermal Research
Journal of Volcanology and Geothermal Research, Elsevier, 2017, 343, pp.122-134. ⟨10.1016/j.jvolgeores.2017.06.021⟩
ISSN: 0377-0273
Popis: Gaudin, D. et. al.
Although it is relatively easy to set-up, the monitoring of soil temperature in sub-fumarolic areas is quite rarely used to monitor the evolution of hydrothermal systems. Indeed, measurements are highly sensitive to environmental conditions, in particular daily and seasonal variations of atmospheric temperatures and rainfalls, which can be only partially filtered by the established statistical analysis. In this paper, we develop two innovative processing methods, both based on the computation of the heat flux in the soil. The upward heat flux method (UHF), designed for dry environments, consists in computing both the conductive and convective components of the heat flux between two thermocouples placed vertically. In the cases of wet environments, the excess of total heat method (ETH) allows the integration of rain gauges data in order to correct the heat balance from the superficial cooling effect of the precipitations. The performances of both processing techniques are faced to established methods (temperature gradient and coefficient of determination) on soil temperature time series from two test volcanoes. At La Fossa di Vulcano (Italy), the UHF method undoubtedly detects three thermal crises between 2009 and 2012, enabling to quantify not only the intensity but also the precise timing of the heat flux increase with respect to corresponding geochemical and seismic crises. At La Soufrière de Guadeloupe (French Lesser Antilles), despite large rainfalls dramatically influencing the thermal behavior of the soil, a constant geothermal heat flux is retrieved by the ETH method, confirming the absence of fumarolic crisis during the observation period (February–August 2010). Being quantitative, robust, and usable in almost any context of sub-fumarolic zones, our two heat flux-based methods increase the potential of soil temperature for the monitoring, but also the general interpretation of fumarolic crises together with geochemical and seismological observations. A spreadsheet allowing direct computation of UHF and ETH is provided as supplemental material.
The research leading to these results has received funding from the ANR Domoscan, Programme Transverse en Recherches Volcanologiques (PTRV). This is the IPGP contribution number: 3819.
Databáze: OpenAIRE
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