Lava discharge during Etna's January 2011 fire fountain tracked using MSG-SEVIRI

Abstract

International audienceEtna's January 2011 eruption provided an excellent opportunity to test the ability of Meteosat Second Generation satellite's Spinning Enhanced Visible and InfraRed Imager (SEVIRI) sensor to track a short-lived effusive event. The presence of lava fountaining, the rapid expansion of lava flows, and the complexity of the resulting flow field make such events difficult to track from the ground. During the Etna's January 2011 eruption, we were able to use thermal data collected by SEVIRI every 15 min to generate a time series of the syn-eruptive heat flux. Lava discharge waxed over a ~1-h period to reach a peak that was first masked from the satellite view by a cold tephra plume and then was of sufficient intensity to saturate the 3.9-μm channel. Both problems made it impossible to estimate time-averaged lava discharge rates using the syn-eruptive heat flux curve. Therefore, through integration of data obtained by ground-based Doppler radar and thermal cameras, as well as ancillary satellite data (from Moderate Resolution Imaging Spectrometer and Advanced Very High Resolution Radiometer), we developed a method that allowed us to identify the point at which effusion stagnated, to allow definition of a lava cooling curve. This allowed retrieval of a lava volume of ~1.2 × 106 m3, which, if emitted for 5 h, was erupted at a mean output rate of ~70 m3 s−1. The lava volume estimated using the cooling curve method is found to be similar to the values inferred from field measurements

Enhanced volcanic hot-spot detection using MODIS IR data: results from the MIROVA system

“…Previous studies have shown that the duration of the cooling curve and its integrated thermal energy can be correlated with the volume or thickness of the observed lava flows (Gouhier et al 2012;Ganci et al 2012a;. For example, Gouhier et al (2012) proposed a method to estimate lava-flow volume based on the cooling curves recorded by the SEVIRI sensor after a paroxysmal event at Mt Etna.…”

“…Geostationary Operational Environmental Satellite (GOES), Spinning Enhanced Visible and InfraRed Imager (SEVIRI); GOES-class sensors, according to the classification of Harris 2013) enable us to estimate the thermal output every 15-30 min, and is thus crucial for tracking short-term variations in major effusive activity (e.g. Ganci et al 2012a;Gouhier et al 2012). However, the low spatial resolution characterizing these sensors (i.e.…”

Rheological control on the radiant density of active lava flows and domes

“…During the last decade the availability of field-and remotelybased thermal images, has increased the use of thermal data in observing volcanic activity (e.g., Ramsey and Harris, 2012), particularly in studying the relationships with lava discharge rates (e.g., Wright et al, 2001;Harris et al, 2005Harris et al, , 2007aHarris et al, ,b, 2010Coppola et al, 2009Coppola et al, , 2010Dragoni and Tallarico, 2009;Harris and Baloga, 2009;Harris and Rowland, 2009;Hirn et al, 2009;Vicari et al, 2009;Ganci et al, 2012b;Garel et al, 2012;Gouhier et al, 2012). This kind of thermal analysis has been also used to detect and quantify extraterrestrial volcanism allowing to point out all the work done on Io, the innermost Galilean moon of Jupiter (e.g.…”

Paroxysmal Explosions, Lava Fountains and Ash Plumes at Etna Volcano: Eruptive Processes and Hazard Implications

“…The first phase lasted from 11 January 2011 to 24 April 2012, and comprised 25 LF events displaying similar features. These are: duration of the Strombolian phase preceding the paroxysmal episode (hours to days); duration of the LF event (hours); maximum height of the LF (800-1,500 m); extension of the lava flow field associated with the explosive event (1-4 km; Behncke et al, 2014); and erupted volume of pyroclastics and lava flows (∼2.5 × 10 6 m 3 ; Calvari et al, 2011;Gouhier et al, 2012;Bonaccorso and Calvari, 2013). The first eruptive pause lasted from April 2012 to February 2013 (Table 1).…”