IAVCEI 2013 Scientific Assembly - July 20 - 24, Kagoshima, Japan
Forecasting Volcanic Activity - Reading and translating the messages of nature for society

4A2_3E-O11

Room A1

Date/Time: July 24 11:30-11:45

Full bandwidth remote sensing for total parameterization of volcanic plumes
Sebastien Valade1 , Andrew Harris1 , Georgina Sawyer1 , Franck Donnadieu1 , Philippe Labazuy1 , Karim
Kelfoun1 , Maxime Bombrun2 , Vincent Barra2 , Claude Hervier3 , Maurizio Ripepe4 , Dario Delle Donne4 ,Giorgio Lacanna4 , Mike Burton5 , Laure Chevalier1 , Thomas Stachowicz1
1LMV, Universite Blaise Pascal, 63000 Clermont-Ferrand, France, 2 LIMOS, Universite Blaise Pascal,
63117 Aubiere, France, 3 OPGC, Universite Blaise Pascal, 63117 Aubiere, France, 4 Universita diFirenze, Dipartimento di Scienze della Terra, 50121 Firenze, Italy, 5 INGV, Via della Faggiola 32, 56126
Pisa, Italy
E-mail: s.valade@opgc.univ-bpclermont.fr

If we are to adequately track the emission, ascent and dispersion of a volcanic plume, we first need to measure
a number of source condition parameters. These include mass flux, exit velocity, particle size distribution, andplume density or ash concentration. Because of the difficulty of close approach to an active volcanic vent, suchmeasurements need to be remote. Moreover, these need to span a broad range of the electromagnetic spectrum
in order to fully parameterize the volcanic plume. With this in mind, we designed in 2012 an experiment involving
the full range of modern ground-based remote sensing capabilities, from microwave to ultraviolet wavelengths.
Stromboli (Italy) was selected for this test deployment, both for its ease of access and reliability as particle emitter.
Our aim was to: characterize explosive eruption dynamics at the highest possible spatio-temporal resolution, test
the combined deployment of a complete instrument package, and evaluate its potential for operational plumetracking with a special emphasis on extracting source condition parameters. The equipment package deployed
involved the following instruments, beginning with the longest wavelength: (i) 1 Doppler radar (VOLDORAD2,23.5 cm wavelength) sampling at 10 Hz, used to quantify the ejection velocities and mass fluxes, (ii) 2 thermal
infrared cameras (FLIR Systems, 8-14 micrometers) sampling at 200 Hz and 30 Hz, used to track the near-ventemission and the plume ascent and dispersion, (iii) 1 very high frame rate camera (Photron Fastcam SA3, visible
and near-infrared) sampling up to 2000 Hz, used to characterize the highest velocities for particles carried by
the gas phase, (iv) 2 stereoscopic cameras (IP Basler, visible and near infrared) sampling at 25 Hz, used toreconstruct 3-D particle trajectories and further constrain their sizes, (v) 1 SO2 camera (310 and 330 nm) and 1
OP-FTIR, used to quantify the mass of gas. In addition, a permanent seismic and infrasonic array was used tocharacterise the seismic and acoustic signal associated with explosive activity, and in-situ sampling of particles
landing in well-defined areas was done to carry geochemical, density, vesicle, and crystal analysis of the ejecta.
The ongoing work involves creating code to process and integrate all data sets so as to output the source terms ina rapid-to-real-time frame. We here give special emphasis on the mutual feedback between infrared cameras andDoppler radar, where the first provide particle size distribution to the second to constrain the mass flux.

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