Now showing 1 - 2 of 2
Loading...
Thumbnail Image
Publication
Restricted

Tephra sedimentation during the 2010 Eyjafjallajökull eruption (Iceland) from deposit, radar, and satellite observations

2011, Bonadonna, C., Genco, R., Gouhier, M., Pistolesi, M., Cioni, R., Alfano, F., Hoskuldsson, A., Ripepe, M., Bonadonna, C.; Section of Earth and Environmental Sciences, University of Geneva, Geneva, Switzerland, Genco, R.; Dipartimento di Scienze della Terra, Università di Firenze, Firenze, Italy, Gouhier, M.; Laboratoire Magmas et Volcans, Université Blaise Pascal, Clermont-Ferrand, France, Pistolesi, M.; Dipartimento di Scienze della Terra, Università di Pisa, Pisa, Italy, Cioni, R.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia, Alfano, F.; Section of Earth and Environmental Sciences, University of Geneva, Geneva, Switzerland, Hoskuldsson, A.; Institute of Earth Sciences, University of Iceland, Reykjavik, Iceland, Ripepe, M.; Dipartimento di Scienze della Terra, Università di Firenze, Firenze, Italy, Section of Earth and Environmental Sciences, University of Geneva, Geneva, Switzerland, Dipartimento di Scienze della Terra, Università di Firenze, Firenze, Italy, Laboratoire Magmas et Volcans, Université Blaise Pascal, Clermont-Ferrand, France, Dipartimento di Scienze della Terra, Università di Pisa, Pisa, Italy, Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia, Section of Earth and Environmental Sciences, University of Geneva, Geneva, Switzerland, Institute of Earth Sciences, University of Iceland, Reykjavik, Iceland, Dipartimento di Scienze della Terra, Università di Firenze, Firenze, Italy

The April–May 2010 eruption of the Eyjafjallajökull volcano (Iceland) was characterized by a nearly continuous injection of tephra into the atmosphere that affected various economic sectors in Iceland and caused a global interruption of air traffic. Eruptive activity during 4–8 May 2010 was characterized based on short-duration physical parameters in order to capture transient eruptive behavior of a long-lasting eruption (i.e., total grain-size distribution, erupted mass, and mass eruption rate averaged over 30 min activity). The resulting 30 min total grain-size distribution based on both ground and Meteosat Second Generation-Spinning Enhanced Visible and Infrared Imager (MSG-SEVIRI) satellite measurements is characterized by Mdphi of about 2 and a fine-ash content of about 30 wt %. The accumulation rate varied by 2 orders of magnitude with an exponential decay away from the vent, whereas Mdphi shows a linear increase until about 18 km from the vent, reaching a plateau of about 4.5 between 20 and 56 km. The associated mass eruption rate is between 0.6 and 1.2 × 105 kg s−1. In situ sampling showed how fine ash mainly fell as aggregates of various typologies. About 5 to 9 wt % of the erupted mass remained in the cloud up to 1000 km from the vent, suggesting that nearly half of the ash >7 settled as aggregates within the first 60 km. Particle sphericity and shape factor varied between 0.4 and 1 with no clear correlation to the size and distance from vent. Our experiments also demonstrate how satellite retrievals and Doppler radar grain-size detection can provide a real-time description of the source term but for a limited particle-size range.

Loading...
Thumbnail Image
Publication
Restricted

Adventive hydrothermal circulation on Stromboli volcano (Aeolian Islands, Italy) revealed by geophysical and geochemical approaches: Implications for general fluid flow models on volcanoes

2010, Finizola, A., Ricci, T., Deiana, R., Barde Cabusson, S., Rossi, M., Praticelli, N., Giocoli, A., Romano, G., Delcher, E., Suski, B., Revil, A., Menny, P., Di Gangi, F., Letort, J., Peltier, A., Villasante-Marcos, V., Douillet, G., Avard, G., Lelli, M., Finizola, A.; Laboratoire GéoSciences Réunion, UR, IPGP, UMR 7154, Saint Denis, La Réunion, France, Ricci, T.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia, Deiana, R.; Dipartimento di Geoscienze, Università degli Studi di Padova, Padova, Italy, Barde Cabusson, S.; Dipartimento di Scienze della Terra, Università di Firenze, Firenze, Italy, Rossi, M.; Dipartimento di Geoscienze, Università degli Studi di Padova, Padova, Italy, Praticelli, N.; Dipartimento di Geoscienze, Università degli Studi di Padova, Padova, Italy, Giocoli, A.; Laboratorio di Geofisica, IMAA-CNR, Tito Scalo, Potenza, Italy, Romano, G.; Tito Scalo, Potenza, Italy, Delcher, E.;, Suski, B.; Institut de Géophysique, Université de Lausanne, Lausanne, Switzerland, Revil, A.; Colorado School of Mines, Illinois St. Golden, Colorado, USA; CNRS-LGIT, UMR 5559, Université de Savoie, Equipe Volcan, Le Bourget du Lac, France, Menny, P.; Laboratoire Magmas et Volcans, Université Blaise Pascal, Clermont-Ferrand, France, Di Gangi, F.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia, Letort, J.; Ecole et Observatoire des Sciences de la Terre, Université de Strasbourg, France, Peltier, A.; Institut de Physique du Globe de Paris, UMR 7154, Paris, France, Villasante-Marcos, V.; Instituto Geografico Nacional, Madrid, Spain, Douillet, G.; Ecole et Observatoire des Sciences de la Terre, Université de Strasbourg, France, Avard, G.; Department of Geological Sciences, University of Missouri, USA, Lelli, M.; Istituto di Geoscienze e Georisorse, CNR, Pisa, Italy, Laboratoire GéoSciences Réunion, UR, IPGP, UMR 7154, Saint Denis, La Réunion, France, Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia, Dipartimento di Geoscienze, Università degli Studi di Padova, Padova, Italy, Dipartimento di Scienze della Terra, Università di Firenze, Firenze, Italy, Dipartimento di Geoscienze, Università degli Studi di Padova, Padova, Italy, Dipartimento di Geoscienze, Università degli Studi di Padova, Padova, Italy, Laboratorio di Geofisica, IMAA-CNR, Tito Scalo, Potenza, Italy, Tito Scalo, Potenza, Italy, #PLACEHOLDER_PARENT_METADATA_VALUE#, Institut de Géophysique, Université de Lausanne, Lausanne, Switzerland, Colorado School of Mines, Illinois St. Golden, Colorado, USA; CNRS-LGIT, UMR 5559, Université de Savoie, Equipe Volcan, Le Bourget du Lac, France, Laboratoire Magmas et Volcans, Université Blaise Pascal, Clermont-Ferrand, France, Istituto Nazionale di Geofisica e Vulcanologia, Sezione Palermo, Palermo, Italia, Ecole et Observatoire des Sciences de la Terre, Université de Strasbourg, France, Institut de Physique du Globe de Paris, UMR 7154, Paris, France, Instituto Geografico Nacional, Madrid, Spain, Ecole et Observatoire des Sciences de la Terre, Université de Strasbourg, France, Department of Geological Sciences, University of Missouri, USA, Istituto di Geoscienze e Georisorse, CNR, Pisa, Italy

On March 15th 2007 a paroxysmal explosion occurred at the Stromboli volcano. This event generated a large amount of products,mostly lithic blocks, someofwhich impacted the ground as far as down to 200 m a.s.l., about 1.5 kmfaraway fromthe active vents. Two days after the explosion, a newvapouremissionwas discovered on the north-eastern flank of the volcanic edifice, at 560 m a.s.l., just above the area called “Nel Cannestrà”. This new vapour emission was due to a block impact. In order to investigate the block impact area to understand the appearance of the vapour emission, we conducted on May 2008 a multidisciplinary study involving Electrical Resistivity Tomography (ERT), Ground Penetrating Radar (GPR), Self-Potential (SP), CO2 soil diffuse degassing and soil temperature surveys. This complementary data set revealed the presence of an anomalous conductive body, probably related to a shallow hydrothermal level, at about 10–15 m depth, more or less parallel to the topography. It is the first time that such a hydrothermal fluid flow,with a temperature close to thewater boiling point (76 °C) has been evidenced at Stromboli at this low elevation on the flank of the edifice. The ERT results suggest a possible link between (1) the main central hydrothermal system of Stromboli, located just above the plumbing system feeding the active vents, with a maximum of subsurface soil temperature close to 90 °C and limited by the NeoStromboli summit crater boundary and (2) the investigated area of Nel Cannestrà, at ~500 m a.s.l., a buried eruptive fissure active 9 ka ago. In parallel, SP and CO2 soil diffuse degassingmeasurements suggest in this sector at slightly lower elevation fromthe block impact crater a magmatic and hydrothermal fluid rising system along the N41° regional fault. A complementary ERT profile, on May 2009, carried out from the NeoStromboli crater boundary downto the block impact crater displayed a flank fluid flowapparently connected to a deeper system. The concept of shallow hydrothermal level have been compared to similar ERT results recently obtained onMount Etna and La Fossa cone of Vulcano. This information needs to be taken into account in general fluid flow models on volcanoes. In particular, peripheral thermal waters (as those bordering the northeastern coast of Stromboli) could be contaminated by hydrothermal and magmatic fluids coming from regional faults but also from the summit.