Mass Eruption Rates of Tephra Plumes During the 2011–2015 Lava Fountain Paroxysms at Mt. Etna From Doppler Radar Retrievals
Real-time estimation of eruptive source parameters during explosive volcanic eruptions is a major challenge in terms of hazard evaluation and risk assessment as these inputs are essential for tephra dispersal models to forecast the impact of ash plumes and tephra deposits. In this aim, taking advant...
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doaj-e7a79400c19349c69b318207f42284d82020-11-24T20:57:16ZengFrontiers Media S.A.Frontiers in Earth Science2296-64632018-06-01610.3389/feart.2018.00073371219Mass Eruption Rates of Tephra Plumes During the 2011–2015 Lava Fountain Paroxysms at Mt. Etna From Doppler Radar RetrievalsValentin Freret-Lorgeril0Franck Donnadieu1Franck Donnadieu2Simona Scollo3Ariel Provost4Patrick Fréville5Yannick Guéhenneux6Claude Hervier7Michele Prestifilippo8Mauro Coltelli9Université Clermont Auvergne, CNRS, IRD, OPGC, Laboratoire Magmas et Volcans, Clermont-Ferrand, FranceUniversité Clermont Auvergne, CNRS, IRD, OPGC, Laboratoire Magmas et Volcans, Clermont-Ferrand, FranceUniversité Clermont-Auvergne, CNRS, UMS 833, OPGC, Aubière, FranceInstituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo, Sezione di Catania, Catania, ItalyUniversité Clermont Auvergne, CNRS, IRD, OPGC, Laboratoire Magmas et Volcans, Clermont-Ferrand, FranceUniversité Clermont-Auvergne, CNRS, UMS 833, OPGC, Aubière, FranceUniversité Clermont-Auvergne, CNRS, UMS 833, OPGC, Aubière, FranceUniversité Clermont-Auvergne, CNRS, UMS 833, OPGC, Aubière, FranceInstituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo, Sezione di Catania, Catania, ItalyInstituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo, Sezione di Catania, Catania, ItalyReal-time estimation of eruptive source parameters during explosive volcanic eruptions is a major challenge in terms of hazard evaluation and risk assessment as these inputs are essential for tephra dispersal models to forecast the impact of ash plumes and tephra deposits. In this aim, taking advantage of the 23.5 cm wavelength Doppler radar (VOLDORAD 2B) monitoring Etna volcano, we analyzed 47 paroxysms produced between 2011 and 2015, characterized by lava fountains generating tephra plumes that reached up to 15 km a.s.l. Range gating of the radar beam allows the identification of the active summit craters in real-time, no matter the meteorological conditions. The radar echoes help to mark (i) the onset of the paroxysm when unstable lava fountains, taking over Strombolian activity, continuously supply the developing tephra plume, then (ii) the transition to stable fountains (climax), and (iii) the end of the climax, therefore providing paroxysm durations. We developed a new methodology to retrieve in real-time a Mass Eruption Rate (MER) proxy from the radar echo power and maximum Doppler velocity measured near the emission source. The increase in MER proxies is found to precede by several minutes the time variations of plume heights inferred from visible and X-Band radar imagery. A calibration of the MER proxy against ascent models based on observed plume heights leads to radar-derived climax MER from 2.96 × 104 to 3.26 × 106 kg s−1. The Total Erupted Mass (TEM) of tephra was computed by integrating over beam volumes and paroxysm duration, allowing quantitative comparisons of the relative amounts of emitted tephra among the different paroxysms. When the climactic phase can be identified, it is found to frequently release 76% of the TEM. Calibrated TEMs are found to be larger than those retrieved by satellite and X-band radar observations, deposit analyses, ground-based infrared imagery, or dispersion modeling. Our methodology, potentially applicable to every Doppler radar, provides mass load parameters that represent a powerful all-weather tool for the quantitative monitoring and real-time hazard assessment of tephra plumes at Etna or any other volcano with radar monitoring.https://www.frontiersin.org/article/10.3389/feart.2018.00073/fullEtnaparoxysmal activityLava fountainsDoppler radarmass eruption ratetotal erupted mass |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Valentin Freret-Lorgeril Franck Donnadieu Franck Donnadieu Simona Scollo Ariel Provost Patrick Fréville Yannick Guéhenneux Claude Hervier Michele Prestifilippo Mauro Coltelli |
spellingShingle |
Valentin Freret-Lorgeril Franck Donnadieu Franck Donnadieu Simona Scollo Ariel Provost Patrick Fréville Yannick Guéhenneux Claude Hervier Michele Prestifilippo Mauro Coltelli Mass Eruption Rates of Tephra Plumes During the 2011–2015 Lava Fountain Paroxysms at Mt. Etna From Doppler Radar Retrievals Frontiers in Earth Science Etna paroxysmal activity Lava fountains Doppler radar mass eruption rate total erupted mass |
author_facet |
Valentin Freret-Lorgeril Franck Donnadieu Franck Donnadieu Simona Scollo Ariel Provost Patrick Fréville Yannick Guéhenneux Claude Hervier Michele Prestifilippo Mauro Coltelli |
author_sort |
Valentin Freret-Lorgeril |
title |
Mass Eruption Rates of Tephra Plumes During the 2011–2015 Lava Fountain Paroxysms at Mt. Etna From Doppler Radar Retrievals |
title_short |
Mass Eruption Rates of Tephra Plumes During the 2011–2015 Lava Fountain Paroxysms at Mt. Etna From Doppler Radar Retrievals |
title_full |
Mass Eruption Rates of Tephra Plumes During the 2011–2015 Lava Fountain Paroxysms at Mt. Etna From Doppler Radar Retrievals |
title_fullStr |
Mass Eruption Rates of Tephra Plumes During the 2011–2015 Lava Fountain Paroxysms at Mt. Etna From Doppler Radar Retrievals |
title_full_unstemmed |
Mass Eruption Rates of Tephra Plumes During the 2011–2015 Lava Fountain Paroxysms at Mt. Etna From Doppler Radar Retrievals |
title_sort |
mass eruption rates of tephra plumes during the 2011–2015 lava fountain paroxysms at mt. etna from doppler radar retrievals |
publisher |
Frontiers Media S.A. |
series |
Frontiers in Earth Science |
issn |
2296-6463 |
publishDate |
2018-06-01 |
description |
Real-time estimation of eruptive source parameters during explosive volcanic eruptions is a major challenge in terms of hazard evaluation and risk assessment as these inputs are essential for tephra dispersal models to forecast the impact of ash plumes and tephra deposits. In this aim, taking advantage of the 23.5 cm wavelength Doppler radar (VOLDORAD 2B) monitoring Etna volcano, we analyzed 47 paroxysms produced between 2011 and 2015, characterized by lava fountains generating tephra plumes that reached up to 15 km a.s.l. Range gating of the radar beam allows the identification of the active summit craters in real-time, no matter the meteorological conditions. The radar echoes help to mark (i) the onset of the paroxysm when unstable lava fountains, taking over Strombolian activity, continuously supply the developing tephra plume, then (ii) the transition to stable fountains (climax), and (iii) the end of the climax, therefore providing paroxysm durations. We developed a new methodology to retrieve in real-time a Mass Eruption Rate (MER) proxy from the radar echo power and maximum Doppler velocity measured near the emission source. The increase in MER proxies is found to precede by several minutes the time variations of plume heights inferred from visible and X-Band radar imagery. A calibration of the MER proxy against ascent models based on observed plume heights leads to radar-derived climax MER from 2.96 × 104 to 3.26 × 106 kg s−1. The Total Erupted Mass (TEM) of tephra was computed by integrating over beam volumes and paroxysm duration, allowing quantitative comparisons of the relative amounts of emitted tephra among the different paroxysms. When the climactic phase can be identified, it is found to frequently release 76% of the TEM. Calibrated TEMs are found to be larger than those retrieved by satellite and X-band radar observations, deposit analyses, ground-based infrared imagery, or dispersion modeling. Our methodology, potentially applicable to every Doppler radar, provides mass load parameters that represent a powerful all-weather tool for the quantitative monitoring and real-time hazard assessment of tephra plumes at Etna or any other volcano with radar monitoring. |
topic |
Etna paroxysmal activity Lava fountains Doppler radar mass eruption rate total erupted mass |
url |
https://www.frontiersin.org/article/10.3389/feart.2018.00073/full |
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