Evidence for a new shallow magma intrusion at La Soufrière of Guadeloupe (Lesser Antilles)

Villemant, Benoı̂t; Komorowski, Jean‐Christophe; Dessert, Céline; Michel, A.; Crispi, Olivier; Hammouya, G.; Beauducel, François; Chabalier, J. B. de

doi:10.1016/j.jvolgeores.2014.08.002

Cited by 58 publications

(54 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…After the 1976-1977 eruption, La Soufrière has become increasingly studied and monitored with multi-parameter networks managed by the Observatoire Volcanologique et Sismologique de Guadeloupe (OVSG-IPGP). Monitoring data are provided by continuous seismic, global navigation satellite system (GNSS), and meteorological networks, as well as periodic extensometric surveys of the evolution of the lava dome fractures [30] and routine sampling/analysis of the fumarolic gases and thermal springs (OVSG-IPGP, 1999-2017; [10,12,36]. Recorded data are processed and available online on the WebObs internal server [37,38].…”

Section: Volcanological Background and Recent Activitymentioning

confidence: 99%

“…Seismic data and petro-geochemical investigations indicate that the volcano is fed by an andesitic magma reservoir located at about 6-7 km depth beneath the summit [32,33,[39][40][41]. According to C, He and Cl isotopic ratios of the hydrothermal fluids, persistent degassing of this magma reservoir continuously supplies fluids and heat to a shallower hydrothermal system [10,12,[24][25][26][27][28]42,43]. [6,29], the main faults (blue-green), historical eruptive fractures and craters (black) and collapse structures (purple triangle on trace), the region of highest electrical conductivity (>1 S/m, light purple area) determined by Rosas-Carbajal et al [29], active fumaroles (small and big yellow circles), 10 m DEM from GeoEye image, Latitude Geosystems; c) 1 m resolution orthophoto (GeoEye) of the lava dome showing the main active fumaroles of the summit area (yellow circles) TAS: Tarissan crater; NAPN: Napoléon Nord; NAP: Napoléon 1 NPE1: Napoleon Est 1; NPE2: Napoléon Est 2; CS: Cratère Sud, which is divided into northern (CSN), central (CSC) and southern (CSS) vents; G56: Gouffre-56; LCS: Lacroix Supérieur, that is divided into LCS-1 and LCS-2; BLK1: Breislack fumarole; TY: Morne-Mitan fumarole along the Ty fault; d) aerial photo of La Soufrière lava dome (October 2016) showing vegetation impacted by prolonged H2S-and HCl-rich acid gas emissions, photo taken by A. Anglade, OVSG-IPGP, with a drone from OBSERA and with permission by the Parc National de Guadeloupe).…”

Section: Volcanological Background and Recent Activitymentioning

confidence: 99%

“…Compositional changes in fumarolic exhalations have in fact been recognized as signals of unrest or even precursors of several eruptions at dormant volcanoes (e.g., [2,[7][8][9][10]. However, unequivocal interpretation of these chemical changes is often challenging, owing to the complexity of chemical reactions and buffering effects involved in water-gas-rock interactions (e.g., [1]).…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Spatio-Temporal Relationships between Fumarolic Activity, Hydrothermal Fluid Circulation and Geophysical Signals at an Arc Volcano in Degassing Unrest: La Soufrière of Guadeloupe (French West Indies)

et al. 2019

View full text Add to dashboard Cite

： Over the past two decades, La Soufrière volcano in Guadeloupe has displayed a growing degassing unrest whose actual source mechanism still remains unclear. Based on new measurements of the chemistry and mass flux of fumarolic gas emissions from the volcano, here we reveal spatio-temporal variations in the degassing features that closely relate to the 3D underground circulation of fumarolic fluids, as imaged by electrical resistivity tomography, and to geodetic-seismic signals recorded over the past two decades. Discrete monthly surveys of gas plumes from the various vents on La Soufrière lava dome, performed with portable MultiGAS analyzers, reveal important differences in the chemical proportions and fluxes of H2O, CO2, H2S, SO2 and H2, which depend on the vent location with respect to the underground circulation of fluids. In particular, the main central vents, though directly connected to the volcano conduit and preferentially surveyed in past decades, display much higher CO2/SO2 and H2S/SO2 ratios than peripheral gas emissions, reflecting greater SO2 scrubbing in the boiling hydrothermal water at 80–100 m depth. Gas fluxes demonstrate an increased bulk degassing of the volcano over the past 10 years, but also a recent spatial shift in fumarolic degassing intensity from the center of the lava dome towards its SE–NE sector and the Breislack fracture. Such a spatial shift is in agreement with both extensometric and seismic evidence of fault widening in this sector due to slow gravitational sliding of the southern dome sector. Our study thus provides an improved framework to monitor and interpret the evolution of gas emissions from La Soufrière in the future and to better forecast hazards from this dangerous andesitic volcano.

show abstract

Section: Volcanological Background and Recent Activitymentioning

confidence: 99%

Section: Volcanological Background and Recent Activitymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Spatio-Temporal Relationships between Fumarolic Activity, Hydrothermal Fluid Circulation and Geophysical Signals at an Arc Volcano in Degassing Unrest: La Soufrière of Guadeloupe (French West Indies)

et al. 2019

View full text Add to dashboard Cite

show abstract

“…The last magmatic eruption occurred in AD 1530 when the present lava dome formed, and the last phreatic eruption occurred in 1976. Recent field measurements in its vents (Allard et al, 2014) and sources (Villemant et al, 2014) show a significant regain of activity in the 2006-2012 period. More recently, new vents appeared during our muon tomography experiments.…”

Section: Introductionmentioning

confidence: 99%

Improvement of density models of geological structures by fusion of gravity data and cosmic muon radiographies

Jourde

Gibert

Marteau

2015

Geosci. Instrum. Method. Data Syst.

View full text Add to dashboard Cite

Abstract. This paper examines how the resolution of smallscale geological density models is improved through the fusion of information provided by gravity measurements and density muon radiographies. Muon radiography aims at determining the density of geological bodies by measuring their screening effect on the natural flux of cosmic muons. Muon radiography essentially works like a medical X-ray scan and integrates density information along elongated narrow conical volumes. Gravity measurements are linked to density by a 3-D integration encompassing the whole studied domain. We establish the mathematical expressions of these integration formulas -called acquisition kernels -and derive the resolving kernels that are spatial filters relating the true unknown density structure to the density distribution actually recovered from the available data. The resolving kernel approach allows one to quantitatively describe the improvement of the resolution of the density models achieved by merging gravity data and muon radiographies. The method developed in this paper may be used to optimally design the geometry of the field measurements to be performed in order to obtain a given spatial resolution pattern of the density model to be constructed. The resolving kernels derived in the joined muon-gravimetry case indicate that gravity data are almost useless for constraining the density structure in regions sampled by more than two muon tomography acquisitions. Interestingly, the resolution in deeper regions not sampled by muon tomography is significantly improved by joining the two techniques. The method is illustrated with examples for the La Soufrière volcano of Guadeloupe.

show abstract

“…Again from Guadeloupe, a recent retrospective Bayesian Belief Network analysis of the unrest of La Soufrière volcano in 1976 Komorowski et al 2015) demonstrates that a formal evidence-based case could have been made to support the authorities' concerns about public safety and the decision to evacuate in 1976. Development of such novel probabilistic formalism for decision-making could help to reduce scientific uncertainty and better assist public officials in making urgent evacuation decisions or policy choices (Woo 2011) should the mild but sustained and slightly increasing seismic and fumarolic unrest that began in 1992, and further developed in 1998, evolve into renewed eruptive activity (OVSG-IPGP 2015;Villemant et al 2014;Allard et al 2014). …”

Section: Risk and Crisis Communication For Island Communitiesmentioning

confidence: 99%

Challenges of Volcanic Crises on Small Islands States

Komorowski

Morin

Jenkins

et al. 2016

Advances in Volcanology

View full text Add to dashboard Cite

Island communities frequently display specific risk-related characteristics that are attributable to the island locations of volcano-affected communities, in terms of exposure, vulnerability and living with the volcanic risk. This chapter examines volcanic crisis response and communication in island communities. We analyse lessons from volcanic crises in 1976 at La Soufrière (Guadeloupe, France), in 2005 and 2006 at Karthala (Grande Comore, Comoros), and in 1995 at Fogo (Cape Verde). Our analysis underscores the strong influence of deep-seated causes (historical, political, cultural, social, economic, and environmental) on the success and failure of volcanic risk communication, all of which are affected by island characteristics. The case studies demonstrate the intensity of politics that manifests in these instances-perhaps because of, rather than despite, the smallness and tightness of the communities, amongst other island characteristics. Consequently, improved information and less uncertainty would not straightforwardly lead to better communication or more harmonious acceptance of decision-making processes and of decisions.

show abstract

Evidence for a new shallow magma intrusion at La Soufrière of Guadeloupe (Lesser Antilles)

Abstract: Insights from long-term geochemical monitoring of halogenrich hydrothermal fluids. V illemant B. (1*) , K omorowski J C. (2,3) , Dessert C. (2,3) , M ichel A. (2) , C rispi O. (3) , H ammouya G. (3) , Beauducel F. (2,3) , De C habalier J.B. (2,3)

Cited by 58 publications

References 65 publications

Spatio-Temporal Relationships between Fumarolic Activity, Hydrothermal Fluid Circulation and Geophysical Signals at an Arc Volcano in Degassing Unrest: La Soufrière of Guadeloupe (French West Indies)

Spatio-Temporal Relationships between Fumarolic Activity, Hydrothermal Fluid Circulation and Geophysical Signals at an Arc Volcano in Degassing Unrest: La Soufrière of Guadeloupe (French West Indies)

Improvement of density models of geological structures by fusion of gravity data and cosmic muon radiographies

Challenges of Volcanic Crises on Small Islands States

Contact Info

Product

Resources

About