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2. Lava flow hazard map of Piton de la Fournaise volcano

Author

Andrea Di Muro, Allan Derrien, Andrew I. Harris, Aline Peltier, Massimiliano Favalli, Villeneuve Nicolas, Alessandro Fornaciai, Oryaëlle Chevrel, Nicole Richter, and Patrice Boissier

Subjects
geography, geography.geographical_feature_category, Volcano, Lava, Hazard map, Geomorphology, Geology
Abstract

Piton de la Fournaise, situated on La Réunion Island (France), is one of the most active hot spot basaltic shield volcanoes worldwide, experiencing at least two eruptions per year since the establishment of the observatory in 1979. Eruptions are typically fissure-fed and form extensive lava flow fields. About 95 % of some ~250 historical events (since the first confidently dated eruption in 1708) have occurred inside an uninhabited horse-shoe shaped caldera (hereafter referred to as the Enclos) which is open to the ocean on its eastern side. Rarely (12 times since the 18th century), fissures have opened outside of the Enclos where housing units, population centers and infrastructure are at risk. In such a situation, lava flow hazard maps are a useful way of visualizing lava flow inundation probabilities over large areas. Here, we present a lava flow hazard map for Piton de la Fournaise volcano based on: i) vent distribution, ii) statistics of lava flow lengths, iii) lava flow recurrence times, and iv) simulations of lava flow paths across multi-temporal (i.e., regularly updated) topography using the DOWNFLOW stochastic numerical model. A map of the entire volcano highlights that the most probable (up to 12 %) location for future lava flow inundation is within the Enclos, where about 100,000 visitors are present each year. Hazard distribution changes throughout the analysis period due to the high frequency of eruptions that constantly modifies the vent opening distribution as well as the topography and the lava flow dimensional characteristics. Outside of the Enclos, probabilities reach 0.5 % along the well-defined rift zones and, although hazard occurrence in inhabited areas is deemed to be very low (

Published
2021

3. Assessing the effect of lithological setting, block characteristics and slope topography on the runout length of rockfalls in the Alps and on the island of La Réunion

Author

Wegner, Kerstin, Haas, Florian, Heckmann, Tobias, Mangeney, Anne, Durand, Virginie, Villeneuve, Nicolas, Kowalski, Philippe, Peltier, Aline, Becht, Michael, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris, Observatoire Volcanologique du Piton de la Fournaise (OVPF), and Institut de Physique du Globe de Paris

Subjects
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], [SDU.STU.GM]Sciences of the Universe [physics]/Earth Sciences/Geomorphology, ComputingMilieux_MISCELLANEOUS
Abstract

In four study areas within different lithological settings and rockfall activity, lidar data were applied for a morphometric analysis of block sizes, block shapes and talus cone characteristics. This information was used to investigate the dependencies between block size, block shape and lithology on the one hand and runout distances on the other hand. In our study, we were able to show that lithology seems to have an influence on block size and shape and that gravitational sorting did not occur on all of the studied debris cones but that other parameters apparently control the runout length of boulders. Such a parameter seems to be the block shape, as it plays the role of a moderating parameter in two of the four study sites, while we could not confirm this for our other study sites. We also investigated the influence of terrain parameters such as slope inclination, profile curvature and roughness. The derived roughness values show a clear difference between the four study sites and seem to be a good proxy for block size distribution on the talus cones and thus could be used in further studies to analyse a larger sample of block size distribution on talus cones with different lithologies.

Published
2021

5. Imaging the deep interior of Piton de la Fournaise

Author

Peltier, Aline, Finizola, Anthony, Delcher, Eric, Chaput, M., Gailler, Lydie, Francke, J., Froger, J.-L., Villeneuve, Nicolas, Cluzel, Nicolas, Del Manzo, G., Soler, F., Gusset, Rachel, Gonano, E., Jouhannel, Sylvaine, Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris), Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Université de La Réunion (UR)-Institut de Physique du Globe de Paris, and Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC)

Subjects
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], [SDU.STU.VO] Sciences of the Universe [physics]/Earth Sciences/Volcanology, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, [SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography, [SDU.STU.PE] Sciences of the Universe [physics]/Earth Sciences/Petrography, [SDU.STU.GP] Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2019

8. Newspaper reporting of the April 2007 eruption of Piton de la Fournaise, part 2: framing the hazard

Author

Harris, Andrew, Villeneuve, Nicolas, Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris), Observatoire Volcanologique du Piton de la Fournaise (OVPF), Institut de Physique du Globe de Paris (IPG Paris), ANR-16-CE39-0009,LAVA,Lava et la Ville: l'évaluation des risques, de réduction des risques et de gestion des crises de effusive Désastres(2016), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université de La Réunion (UR)-Institut de Physique du Globe de Paris, Institut de Physique du Globe de Paris, Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement et la société-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Université Jean Monnet [Saint-Étienne] (UJM)

Subjects
[SHS.INFO]Humanities and Social Sciences/Library and information sciences, Front-page, Images, Hazard-communication, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, The press, Short-term memory, Volcanic eruption, Headlines
Abstract

International audience; An analysis of the front pages of 120 consecutive editions of the local newspaper for the island of La Réunion (France), “Le Journal de L’Ile de La Réunion”, published before, during and after the April 2007 eruption of Piton de la Fournaise reveals that its front page is an ideal vehicle for maximizing information delivery and recall during a volcanic eruption. Supported by flash tests, and by cross-checking with a content analysis of information given within the newspaper, we find that the front page is an effective gauge for the hazard frame which, for the case examined here, involved six volcanic hazards (pit-crater collapse, lava flows, gas, air fall, ocean entry lava flow and bench collapse), as well as the issue of evacuation. We found that crater collapse and lava flow hazards were framed using their natural colors and clear imagery of the phenomenon, tied to context-setting explanations within the newspaper. However, for lava flows in particular there was an element of spectacle and promotion of sightseeing, with photographs always featuring sightseers invariably taking photographs. After the end of the eruption reporting became almost entirely focused on tourists and sightseeing. Gas and ash fall hazard were framed using images and words of the victims, so that it became worrying and frightening, and associated with panic. As a result, the volcano itself became portrayed as a monster, and the situation for the impacted population became “apocalyptic” and “hellish”. This probably contributed to the evacuation measures being described as confused and pointless, with the morale of the impacted population suffering accordingly. The ocean entry and bench collapse had no frame at all, and became associated with the dead, exotic fish that were collected; this hazard thus being framed as an interesting curiosity rather than a volcanic hazard. The front page-tracking model followed here could guide future educative measures during volcanic crises by quickly identifying, on the basis of front page analysis, hazards that are appropriately conveyed versus those that are poorly portrayed. Responses to rectify a poor frame can include reactive scientific advertising, a route that is used commonly by businesses seeking to boost sales by taking timely advantage of a developing newspaper frame, and distribution of appropriately designed and timed press releases.

Published
2018

9. Integrating field, textural, and geochemical monitoring to track eruption triggers and dynamics: a case study from Piton de la Fournaise

Author

Gurioli, Lucia, Muro, Andrea, Vlastélic, Ivan, Moune, Séverine, Thivet, Simon, Valer, Marina, Villeneuve, Nicolas, Boudoire, Guillaume, Peltier, Aline, Bachèlery, Patrick, Ferrazzini, Valérie, Métrich, Nicole, Benbakkar, Mhammed, Cluzel, Nicolas, Constantin, Christophe, Devidal, Jean-Luc, Fonquernie, Claire, Hénot, Jean-Marc, Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Observatoire Volcanologique du Piton de la Fournaise (OVPF), Institut de Physique du Globe de Paris (IPG Paris), Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), ANR-10-LABX-0006,CLERVOLC,Clermont-Ferrand centre for research on volcanism(2010), ANR-16-IDEX-0001,CAP 20-25,CAP 20-25(2016), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement et la société-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Université Jean Monnet [Saint-Étienne] (UJM), Institut de Physique du Globe de Paris, and Université de La Réunion (UR)-Institut de Physique du Globe de Paris

Subjects
[SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology
Abstract

The 2014 eruption at Piton de la Fournaise (PdF), La Réunion, which occurred after 41 months of quiescence, began with surprisingly little precursory activity and was one of the smallest so far observed at PdF in terms of duration (less than 2 days) and volume (less than 0.4 × 106 m3). The pyroclastic material was composed of golden basaltic pumice along with fluidal, spiny iridescent and spiny opaque basaltic scoria. Density analyses performed on 200 lapilli reveal that while the spiny opaque clasts are the densest (1600 kg m−3) and most crystalline (55 vol. %), the golden pumices are the least dense (400 kg m−3) and crystalline (8 vol. %). The connectivity data indicate that the fluidal and golden (Hawaiian-like) clasts have more isolated vesicles (up to 40 vol. %) than the spiny (Strombolian-like) clasts (0–5 vol. %). These textural variations are linked to primary pre-eruptive magma storage conditions. The golden and fluidal fragments track the hotter portion of the melt, in contrast to the spiny fragments and lava that mirror the cooler portion of the shallow reservoir. Exponential decay of the magma ascent and output rates through time revealed depressurization of the source during which a stratified storage system was progressively tapped. Increasing syn-eruptive degassing and melt–gas decoupling led to a decrease in the explosive intensity from early fountaining to Strombolian activity. The geochemical results confirm the absence of new input of hot magma into the 2014 reservoir and confirm the emission of a single shallow, differentiated magma source, possibly related to residual magma from the November 2009 eruption. Fast volatile exsolution and crystal–melt separation (second boiling) were triggered by deep pre-eruptive magma transfer and stress field change. Our study highlights the possibility that shallow magma pockets can be quickly reactivated by deep processes without mass or energy (heat) transfer and produce hazardous eruptions with only short-term elusive precursors.

Published
2018

12. A comparison of cooling-limited and volume-limited flow systems: Examples from channels in the Piton de la Fournaise April 2007 lava-flow field

Author

Rhéty, Maéva, Harris, Andrew, Villeneuve, Nicolas, Gurioli, Lucia, Médard, Etienne, Chevrel, Magdalena Oryaëlle, Bachèlery, Patrick, Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris, Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), and Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)

Subjects
[SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, [SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography
Abstract

International audience; Channel-fed lava-flow systems lack detailed thermal and textural studies through the boundary between channelized and dispersed flow, and out to the flow front. Here chemical, textural, and morphological analyses were made to define cooling and crystallization rates down the entire system, especially through the zone of dispersed flow. We compare two channel systems active during the 2007 eruption of Piton de la Fournaise, one of which was cooling limited and one of which as volume limited. In the cooling-limited case, rapid changes in rheology occurred across the zone of dispersed flow, where viscosity increased from 1000 to 1600 Pa s over the last 100 m of the channel system. This was due to an increase in cooling rate from 78C km 21 over the first 500 m of the system, to 428C km 21 over the last 100 m, and an increase in microcryst content from 13% to 25%. In the volume-limited case, the exponentially increasing segment of the down-flow cooling and viscosity trend is absent. Instead, lava arriving at the flow front is still relatively hot (11618C compared with a near-vent temperature of 11678C) and is thus of relatively low viscosity (1125 Pa s). In the volume-limited case, because the channel was still in extension when supply to the system was cut, the zone of dispersed flow was extremely short. However, because lava behind the stalled flow front was still hot and fluid, breakouts from the static front resulted in a complex flow front morphology. Plain Language Summary When lava flows stop they either do so because they have cooled to such an extent that they, essentially, freeze and thus can no longer move, or because the supply of lava is cut; effectively the tap is turned off. We term the former ''cooling-limited'' flows, and the latter ''volume limited.'' We show here the differences in terms of rates of down-flow cooling and crystallization between the two flow types and point to the differences in appearance of the two. For the cooling-limited case, the channel feeds a zone of lava flow with well-formed, frozen flow fronts. For the volume-limited case, the channel extends all the way to the flow front, which is—itself—a mess because of fluid lava inside the stalled flow that then escapes through the stationary front. We show this through a study of lava flows emplaced during the largest historical eruption of Piton de la Fournaise, on the French island of R eunion; this being the eruption of April 2007.

Published
2017

15. Simulating the thermorheological evolution of channel-contained lava: FLOWGO and its implementation in EXCEL

Author

Harris, Andrew J.L., Rhéty, Maéva, Gurioli, Lucia, Villeneuve, Nicolas, Paris, Raphael, Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris, Observatoire Volcanologique du Piton de la Fournaise (OVPF), Institut de Physique du Globe de Paris, A. J. L. Harris, T. De Groeve, F. Garel, S. A. Carn, Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris), and Institut de Physique du Globe de Paris (IPG Paris)

Subjects
[SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2016

16. Retrieving 65 years of volcano summit deformation from multi-temporal Structure from Motion: the case of Piton de la Fournaise (La Réunion Island)

Author

Derrien, Allan, Villeneuve, Nicolas, Peltier, Aline, and Beauducel, François

Abstract

“An edited version of this paper was published by AGU. Copyright 2015 American Geophysical Union.”The structure from motion photogrammetry technique enables use of historical airborne photography to achieve high-resolution 3-D terrain models. We apply this method on Piton de la Fournaise volcano (La R.union), which allows a unique opportunity to retrieve high-resolution (1.5–0.11m) digital elevation models and precise deformation maps of the volcano since 1950. Our results provide evidence that the summit volume increased throughout the study period, at a stable rate of 2.2Mm3/yr between 1950 and 2015, with an acceleration up to 8.0Mm3/yr prior to themajor 2007 eruption that was accompanied by summit caldera collapse. At the same time, summit deformation was asymmetric, with 9.2 Å} 2.5m of eastward seaward displacement and 1.3 Å} 2.5m to the west during 1950–2015. Our results reveal a temporal evolution in the volcano magma influx rate and deformation. Tracking these fluxes and the long-lived preferential eastern motion is crucial to mitigate risks associated to flank destabilization.

Published
2016
Full Text
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17. Observatoire INSAR de L’océan indien (OI2), un volcan sous haute surveillance

Author

Froger, Jean-Luc, Cayol, Valérie, Tridon, M., Bato, M. G., Prival, Jean-Marie, Villeneuve, Nicolas, Peltier, P., Augier, A., Rivet, S., Guéhenneux, Yannick, Univ, Réunion, Patrick Bachèlery, D. Laporte, J. Van Baelen, P. Schiano, Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris, Observatoire Volcanologique du Piton de la Fournaise (OVPF), Institut de Physique du Globe de Paris, Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris), and Institut de Physique du Globe de Paris (IPG Paris)

Subjects
[SDU.STU.VO] Sciences of the Universe [physics]/Earth Sciences/Volcanology, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2016

18. Seismological and geodetic network of the volcanological and seismological observatories

Author

Saurel, Jean-Marie, Anglade, André, Kowalski, Philippe, Lemarchand, Arnaud, Clouard, Valérie, Dessert, Céline, Villeneuve, Nicolas, Shapiro, Nicolas, Agrinier, Pierre, Observatoire volcanologique et sismologique de martinique (OVSM), Institut de Physique du Globe de Paris, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Observatoire Volcanologique et Sismologique de Guadeloupe (OVSG), and Observatoire Volcanologique du Piton de la Fournaise (OVPF)

Subjects
[SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2015

19. Validation des données sismologiques des observatoires volcanologiques et sismologiques de l’IPGP (OVSG, OVSM et OVPF)

Author

Lemarchand, Arnaud, Beauducel, François, Bouin, Marie-Paule, Brenguier, Florent, Jacques, Eric, Pardo, Constanza, Aissaoui, El-Madani, Dessert, Céline, Clouard, Valérie, Villeneuve, Nicolas, Ferrazzini, Valérie, Shapiro, Nikolai, Anglade, André, Kowalski, Philippe, Saurel, Jean-Marie, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut des Sciences de la Terre (ISTerre), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel-Université Grenoble Alpes (UGA), Observatoire Volcanologique et Sismologique de Guadeloupe (OVSG), Institut de Physique du Globe de Paris, Observatoire volcanologique et sismologique de martinique (OVSM), Observatoire Volcanologique du Piton de la Fournaise (OVPF), Résif, Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), and Institut de Physique du Globe de Paris (IPG Paris)

Subjects
Volcan, Sismologie, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], RESIF, Système d’information, Antilles, La Réunion
Abstract

Les observatoires volcanologiques et sismologiques de l’Institut de Physique du Globe de Paris assurent le suivi sismologique et volcanologique aux Antilles et à La Réunion: l’OVSG pour la Guadeloupe, l’OVSM pour la Martinique et l’OVPF pour La Réunion. Ces observatoires ont une mission officielle de surveillance qui les oblige à mettre la priorité sur les données temps-réel, en particulier en cas d'interruption des transmissions ou d'une trop faible bande passante des moyens de communication. Les observatoires ont donc développé des méthodes spécifiques pour assurer a posteriori la continuité et la qualité des données validées.Ce poster a été présenté lors des Rencontres Scientifiques et Techniques Résif qui se sont déroulées à La Grande Motte en octobre 2015. Il présente le processus de traitement et de validation des flux de données sismologiques de ces observatoires jusqu’à leur archivage au centre de données de l’IPGP.Ce centre de données constitue le nœud A Volcano du système d’information sismologique de Résif-Epos. Résif-Epos est une infrastructure de recherche nationale dédiée à l’observation et la compréhension de la structure et de la dynamique Terre interne. Résif se base sur des réseaux d’observation de haut niveau technologique, composés d’instruments sismologiques, géodésiques et gravimétriques déployés de manière dense sur tout le territoire français. Les données recueillies permettent d’étudier avec une haute résolution spatio-temporelle la déformation du sol, les structures superficielles et profondes, la sismicité à l’échelle locale et globale et les aléas naturels, et plus particulièrement sismiques, sur le territoire français. Résif s’intègre aux dispositifs européens (EPOS - European Plate Observing System) et mondiaux d’instruments permettant d’imager l’intérieur de la Terre dans sa globalité et d’étudier de nombreux phénomènes naturels.

Published
2015

20. Validation of seismological data from volcanological and seismological French observatories of the Institut de Physique du Globe de Paris (OVSG, OVSM and OVPF)

Author

Lemarchand, Arnaud, Beauducel, François, Bouin, Marie-Paule, Brenguier, Florent, Jacques, Eric, Pardo, Constanza, Aissaoui, El-Madani, Dessert, Céline, Clouard, Valérie, Villeneuve, Nicolas, Ferrazzini, Valérie, Shapiro, Nikolai, Anglade, André, Kowalski, Philippe, Saurel, Jean-Marie, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Institut des Sciences de la Terre (ISTerre), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel-Université Grenoble Alpes (UGA), Observatoire Volcanologique et Sismologique de Guadeloupe (OVSG), Institut de Physique du Globe de Paris, Observatoire volcanologique et sismologique de martinique (OVSM), Observatoire Volcanologique du Piton de la Fournaise (OVPF), Résif, Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), and Institut de Physique du Globe de Paris (IPG Paris)

Subjects
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], RESIF, Volcano, Seismology, Information system, Antilles, La Réunion
Abstract

The volcanological and seismological observatories of the Institut de Physique du Globe de Paris ensure seismological and volcanological monitoring in the Antilles and La Reunion : the OVSG for Guadeloupe, the OVSM for Martinique and the OVPF for La Reunion. These observatories have an official monitoring mission that requires them to give priority to real-time data, especially in case of interruption of transmissions or a too low bandwidth of the communication means. The observatories have then developped specific methodologies to ensure afterward the validated data continuity and quality.This poster was presented at the Scientific and Technical Meetings of Résif held in La Grande Motte in October 2015. It presents the process of processing and validation of seismological data streams from these observatories until their archiving at the IPGP data center.This data center constitutes the A Volcano node of the Résif-Epos seismological information system. Résif-Epos is a national research infrastructure dedicated to the observation and understanding of the structure and dynamics of the Inner Earth. Résif is based on high-tech observation networks, composed of seismological, geodetic and gravimetric instruments deployed in a dense manner throughout France. These data make it possible to study with high spatial and temporal resolution the deformation of the ground, surface and deep structures, seismicity on a local and global scale and natural hazards, and more particularly seismic hazards, on French territory. Résif is integrated into European (EPOS - European Plate Observing System) and global systems of instruments for imaging the Earth's interior as a whole and studying many natural phenomena.

Published
2015

28. Modeling the lava heat flux during severe effusive volcanic eruption an important impact on surface air quality

Author

Durand, Jonathan, Tulet, Pierre, Leriche, Maud, Bielli, Soline, Villeneuve, Nicolas, Di Muro, Andrea, Fillipi, Jean-Baptiste, Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Laboratoire d'aérologie (LAERO), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Sciences pour l'environnement (SPE), Centre National de la Recherche Scientifique (CNRS)-Université Pascal Paoli (UPP), Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'aérologie (LA), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), Université Pascal Paoli (UPP)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Météo-France, Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Piton de la Fournaise, Modeling with MesoNH, Natural hazard, Volcano eruption, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, [SDU.STU.ME]Sciences of the Universe [physics]/Earth Sciences/Meteorology, [SDU.STU.AG]Sciences of the Universe [physics]/Earth Sciences/Applied geology
Abstract

International audience; The April 2007 eruption of Piton de la Fournaise, one of the most active volcanoes in the world, was the strongest eruption in recent decades with 230Mm3 of lava emitted and more 300KT of SO2 degased. The surface concentrations of SO2 have been measured by the ORA (Air Observatory of the Reunion Island) and showed that many stations exceeded the critic threshold for health. These high concentrations led to important health issues, accompanied by environmental and infrastructure degradations. Realized with MesoNH atmospheric model, our simulations show the transport of sulfur and his component between 2 April and 6 April 2007, with a focus on the influence of heat flow from lava. For this purpose, we have implemented ForeFire, a surface model initially realized to simulate forest fire, by adapting it to reproduce the dynamic of a lava flow. Thus, all flows (SO2, heat, vapor, CO2, CO) are triggered depending on its dynamic. With this first approach, our simulations reproduce quite faithfully the surface field observation of SO2 provides by ORA. Various sensitivity analyzes exhibit that volcano sulfur distribution was mainly controlled by the lava heat flow. Without heat flow parameterization, the surface concentrations are multiplied by a factor 30 compared to the reference simulation. Simulations also put in evidence that the 5 April, during the height of the eruption, changes in meteorological conditions, especially weakening of atmospheric boundary layer stability, led to various pollutants to be transported in higher altitude (8000m). The main consequence is the volcanic pollutants are transported off the east coast of Réunion Island.

Published
2014

29. La Réunion Island: A Typical Example of a Basaltic Shield Volcano with Rapid Evolution

Author

Villeneuve, Nicolas, Bachèlery, Patrick, Institut de Physique du Globe de Paris (IPGP), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne (UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Natural hazard, Evolution, Basaltic shield volcanoes, Volcanic geomorphology, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology
Abstract

International audience; La Réunion Island is a volcanic area located in a tropical climate context. Volcanism has built up a 7 km high cone over the last five million years. For the last two or three million years, magmatic, tectonic and weathering processes have been engaged in a gigantic race to shape the island’s morphologies, with dramatic consequences in terms of landforms such as volcanic peaks (the dormant Piton des Neiges and active Piton de la Fournaise), cliffs or “ramparts”, deep gorges and waterfalls which, together with endemic flora and fauna, helped the central part of La Réunion to be recently recognised by UNESCO as a World Heritage Site. Yet, induced natural hazards such as volcanic eruptions and landslides remain a threat for the population.

Published
2014

30. Modeling the lava heat flux during severe effusive volcanic eruption: an important impact on surface air quality

Author

Durand, Jonathan, Tulet, Pierre, Filippi, Jean-Baptiste, Villeneuve, Nicolas, Leriche, M., Di Muro, Andrea, Environnement, Géo-ingénierie et Développement (EGID), SERPOL, Laboratoire de l'Atmosphère et des Cyclones (LACy), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France, Feux de Forêt, Sciences pour l'environnement (SPE), Centre National de la Recherche Scientifique (CNRS)-Université Pascal Paoli (UPP)-Centre National de la Recherche Scientifique (CNRS)-Université Pascal Paoli (UPP), Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris, Laboratoire d'aérologie (LAERO), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Institut de Physique du Globe de Paris (IPGP), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; The April 2007 eruption of Piton de la Fournaise, one of the most active volcanoes in the world, was the strongest eruption in recent decades with 230Mm3 of lava emitted and more 300KT of SO2 degased. The surface concentrations of SO2 have been measured by the ORA (Air Observatory of the Reunion Island) and showed that many stations exceeded the critic threshold for health. These high concentrations led to important health issues, accompanied by environmental and infrastructure degradations. Realized with MesoNH atmospheric model, our simulations show the transport of sulfur and his component between 2 April and 6 April 2007, with a focus on the influence of heat flow from lava. For this purpose, we have implemented ForeFire, a surface model initially realized to simulate forest fire, by adapting it to reproduce the dynamic of a lava flow. Thus, all flows (SO2, heat, vapor, CO2, CO) are triggered depending on its dynamic. With this first approach, our simulations reproduce quite faithfully the surface field observation of SO2 provides by ORA. Various sensitivity analyzes exhibit that volcano sulfur distribution was mainly controlled by the lava heat flow. Without heat flow parameterization, the surface concentrations are multiplied by a factor 30 compared to the reference simulation. Simulations also put in evidence that the 5 April, during the height of the eruption, changes in meteorological conditions, especially weakening of atmospheric boundary layer stability, led to various pollutants to be transported in higher altitude (8000m). The main consequence is the volcanic pollutants are transported off the east coast of Réunion Island.

Published
2013

31. Un SIG Volcanologique pour la connaissance de l'aléa éruptif du Piton de la Fournaise, Ile de la Réunion

Author

Saint-Marc, Cécile, Davoine, Paule-Annick, Di Muro, Andrea, Staudacher, Thomas, Boissier, Patrice, Bachèlery, Patrick, Michon, Laurent, Villeneuve, Nicolas, Spatio-temporal information systems (STEAMER), Laboratoire d'Informatique de Grenoble (LIG), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS), Physique des géomatériaux (PG), Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Dipartimento di Scienze Geologiche [Roma TRE], Università degli Studi Roma Tre = Roma Tre University (ROMA TRE), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Magmas et Volcans (LMV), Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National Polytechnique de Grenoble (INPG)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF), IPG PARIS-Centre National de la Recherche Scientifique (CNRS), Università degli Studi Roma Tre, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), and Université de La Réunion (UR)-Institut de Physique du Globe de Paris

Subjects
[SCCO.COMP]Cognitive science/Computer science
Abstract

International audience; Le Piton de la Fournaise, situé sur l'île de la Réunion, est l'un des volcans les plus actifs au monde avec 31 éruptions de 1998 à nos jours. Il fait l'objet d'une surveillance continue et de nombreuses données retraçant les phénomènes éruptifs passés sont disponibles : coulées, fissures, tephras, cônes, séismes, données géochimiques... La connaissance de l'aléa éruptif nécessite de mettre en relation spatialement et temporellement l'ensemble de ces données afin de suivre l'évolution spatio-temporelle de l'activité volcanique. L'objet de la communication est de présenter les différentes étapes d'élaboration du SIG Volcanologique sous ArcGIS, allant de la structuration des données spatiales et temporelles hétérogènes issues de sources variées (capteurs de surveillance, GPS, photo-interprétation, documents anciens), jusqu'à la spatialisation des phénomènes volcaniques, exprimée au moyen de diverses représentations cartographiques, statiques ou animées, 2D ou 3D, en passant par des analyses spatiales et géo traitements plus ou moins complexes. L'enjeu principal est de contribuer à l'étude du fonctionnement du Piton de la Fournaise afin de caractériser l'aléa volcanique à l'Île de la Réunion.

Published
2012

32. SO2 degassing at Piton de la Fournaise during the April 2007 eruption

Author

Villeneuve, Nicolas, Tulet, Pierre, Michon, Laurent, Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris, Laboratoire de l'Atmosphère et des Cyclones (LACy), Institut national des sciences de l'Univers (INSU - CNRS)-Météo France-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Météo France

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
Abstract

International audience; Communication about SO2 degassing at Piton de la Fournaise during the April 2007 eruption

Published
2010

33. Insitutional and social responses to hazards related to Karthala volcano, Comoros: Part I: Analysis of the May 2006 eruptive crisis

Author

Morin, Julie, Lavigne, Franck, Bachèlery, Patrick, Finizola, Anthony, Villeneuve, Nicolas, Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris, Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), and Lavigne, Franck

Subjects
Karthala volcano, [SDU.STU.VO] Sciences of the Universe [physics]/Earth Sciences/Volcanology, Crisis management, Grande Comore Island, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, [SHS] Humanities and Social Sciences, [SHS]Humanities and Social Sciences
Abstract

International audience; This paper aims at understanding the failure of the crisis management system during the 2006 eruption of Karthala volcano on Grande Comore Island. Since 2005, the eruptive activity of Karthala volcano had increased, with higher intensity and frequency. These changes should have led Grande Comore to be better prepared for confronting a volcanic threat. But the following analysis demonstrates that the country remained unprepared to face even a minor eruptive event. The weaknesses that led to poor crisis management are detailed and analysed and suggestions for improvement are made.

Published
2009

34. Gravity structure of Piton de la Fournaise volcano and inferred mass transfer during the 2007 crisis

Author

Gailler, L. S., Lenat, J. F., Lambert, M., Levieux, G., Villeneuve, Nicolas, and Froger, J.L.

Subjects
modelling, Piton de la Fournaise, seismic tomographies, volcano-tectonic, mass transfer, gravity anomalies
Abstract

The structure and mass transfers at Piton de la Fournaise volcano are investigated using new on land and offshore measurements. The structures are defined using 2 and 3D modelling. Short-wavelength positive anomalies to the W and NW of the central area are interpreted as shallow piles of thick, dense lava flows which have filled volcano-tectonic depressions, several hundreds of meters deep. This finding provides a new insight into the evolution of the volcano. Conversely, the currently active central zone is associated with a negative short-wavelength anomaly, explained by the presence of thin, highly vesiculated and fractured lava flows building the Central Cone. Low density formations underlying the Rivieres des Remparts and Langevin areas are tentatively interpreted as breccias related to erosion and/or to southward directed mass-wasting. Topographic offshore highs in the continuation of the SE and NE rift zones of Piton de la Fournaise are characterized by negative gravity anomalies and reversed magnetic anomalies. Their interpretation as hyaloclastites and pillow lavas provides a coherent explanation for both types of signals if we admit that they were primarily constructed during the Alizes stage. Two main deeper, dense structures are also found: the Grand Brule complex, and a complex beneath the Plaine des Sables and the Enclos Fouque. Both are identified as hypovolcanic intrusive complexes. The Grand Brule complex (10 x 18 km in plan view) shows a marked NS-elongated geometry, unlike the other comparable complexes on the island. The Plaine des Sables-Enclos Fouque complex, a more or less circular structure 5 km in diameter, is attributed to the Ancient Shield stage. It is centered on the Enclos fault, suggesting that the paleo-center of the Ancient Shield was located about 1.5 km eastward of the previously proposed location. An apparent contradiction was noted between the seismic and gravity images of the internal structure. In particular, a high velocity cylinder beneath the summit was not detected in the gravity models. This contradiction was resolved by considering the relative sensitivity of each method. Finally, the gravity dataset has allowed us to explore the gravity changes that accompanied the major eruptive and volcano-tectonic crisis of April 2007 (350 m collapse of the summit and emission of similar to 120 x 10(6) m(3) of lava). The change in the mass distribution of the edifice was large enough to be detected in the survey data collected in the central area before and after the crisis. However, the accuracy was too low for the precise assessment of the mass transfers.

Published
2009

35. Les risques littoraux à l'île de la Réunion

Author

Lorion, David, Villeneuve, Nicolas, Centre de Recherches et d'Etudes en Géographie de l'Université de la Réunion (CREGUR), Université de La Réunion (UR), and Univ, Réunion

Subjects
Île de la Réunion, Tsunami, Glissement de terrain, [SHS.GEO] Humanities and Social Sciences/Geography, Tourisme, Littoral, Inondation, Catastrophe, [SHS.GEO]Humanities and Social Sciences/Geography, Risque
Abstract

National audience; Jeune île volcanique isolée dans le sud-ouest de l'océan Indien, La Réunion subit chaque année les assauts des houles cycloniques et polaires et les averses torren-tielles des cyclones et des dépressions tropicales. Cette abondance d'eau terrestre et océanique engendre sur l'interface littorale des submersions marines et des inondations de plaines. Certains secteurs littoraux présentent aussi une grande instabilité qui menace ponctuellement les constructions existantes, mais qui peut aussi intéresser l'ensemble des côtes réunionnaises. Le développement écono-mique soutenu par les effets de la départementalisation et la vocation touristique du littoral balnéaire sont à l'origine d'une urbanisation souvent mal contrôlée et d'aménagements ponctuels aux conséquences géomorphologiques bien visibles. Les règles assouplies de la loi littorale outre-mer et la défiscalisation ne permet-tent pas aujourd'hui une meilleure gestion de l'espace littoral. La vulnérabilité s'est donc accrue de manière irraisonnée et les risques littoraux n'ont jamais fait l'objet d'un réel diagnostique. Ils sont même bien absents des ouvrages de vulgarisation des risques naturels.

Published
2007

36. Role of the structural inheritance of the oceanic lithosphere in the magmato-tectonic evolution of Piton de la Fournaise volcano (La Réunion Island)

Author

Michon, Laurent, Saint-Ange, Francky, Bachèlery, Patrick, Villeneuve, Nicolas, Staudacher, Thomas, Laboratoire GéoSciences Réunion (LGSR), Université de La Réunion (UR)-Institut de Physique du Globe de Paris, Centre de Recherche en Géographie de l'Université de La Réunion (CREGUR), Océan Indien : Espaces et Sociétés (OIES), Université de La Réunion (UR)-Université de La Réunion (UR), Observatoire Volcanologique du Piton de la Fournaise (OVPF), Institut de Physique du Globe de Paris, This work was partly funded by the BQR 2004 provided by the University of La Réunion to L.M., Laboratoire des Sciences de la Terre (LSTUR), and Université de La Réunion (UR)

Subjects
[SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics, Piton de la Fournaise, Reunion Island, volcano, Réunion Island, oceanic lithosphere, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, tectonics, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences
Abstract

International audience; La Réunion Island is located east of Madagascar, on the eastern rim of the tectonically inactive Mascarene Basin. This island is composed of three shield volcanoes of which only Piton de la Fournaise is currently active. Although the magmatic activity is restricted to Piton de la Fournaise, a scattered seismicity occurs on the whole 200 km wide volcanic edifice and in the underlying oceanic crust. We carried out a multiscale analysis to understand (1) the origin of the seismicity in the geodynamic context and (2) the role of the oceanic lithosphere in the deformation of Piton de la Fournaise and La Réunion Island. Analysis of the magmatic system suggests that the magma ascent is controlled by large N25–30 and N125–130 fracture zones located below the Enclos depression. We also show that the orientation difference between the eruptive fissures and the related dykes result from a rotation of the main principal stress s 1 from vertical to downslope through the surface. Combining a Digital Elevation Model (DEM) analysis, field observations and the geophysical data reveals that the volcano is affected by large fault zones. The fault distribution indicates the predominance of a main N70–80 trend. Magnetic data show the same N80 orientation characterizing the remnant part of the Alizés volcano. Such parallel alignment suggests a control exerted by the underlying Alizés volcano on Piton de la Fournaise. Furthermore, the alignment between the crustal orientations and the structures determined on the island suggests a control of the crustal structures in La Réunion 's volcano-tectonic activity. Contrary to several volcanic islands such as Hawaii and Tenerife, La Réunion volcanoes lie on an upbending crust. Then, we interpret the reactivation of the crustal faults as resulting from a crustal uplift related to the thermal erosion of the base of the lithosphere and/or to strong underplating. The upward deformation may prevent the spreading of the volcanoes, as no evidence of such a mechanism is observed in the bathymetry and the seismic data around the island.

Published
2007

37. Typologie des éruptions au Piton de la Fournaise: processus et risques volcaniques

Author

Villeneuve, Nicolas, Bachèlery, Patrick, Centre de Recherches et d'Etudes en Géographie de l'Université de la Réunion (CREGUR), Université de La Réunion (UR), Laboratoire des Sciences de la Terre (LSTUR), and Univ, Réunion

Subjects
Ile de La Réuni, magmatisme, risque volcaniq, [SDU.STU.VO] Sciences of the Universe [physics]/Earth Sciences/Volcanology, [SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology, typologie des é, Piton de la Fou, ComputingMilieux_MISCELLANEOUS
Abstract

National audience

Published
2004

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