A year of lava fountaining at Etna: Volumes from SEVIRI

Abstract

International audienceWe present a new method that uses cooling curves, apparent in high temporal resolution thermal data acquired by geostationary sensors, to estimate erupted volumes and mean output rates during short lava fountaining events. The 15 minute temporal resolution of the data allows phases of waxing and peak activity to be identified during short (150-to-810 minute-long) events. Cooling curves, which decay over 8-to-21 hour-periods following the fountaining event, can also be identified. Application to 19 fountaining events recorded at Etna by MSG's SEVIRI sensor between 10 January 2011 and 9 January 2012, yields a total erupted dense rock lava volume of ∼28 × 106 m3, with a maximum intensity of 227 m3 s−1being obtained for the 12 August 2011 event. The time-averaged output over the year was 0.9 m3 s−1, this being the same as the rate that has characterized Etna's effusive activity for the last 40 years

Coupled Short- and Medium-Term Geophysical Signals at Etna Volcano: Using Deformation and Strain to Infer Magmatic Processes From 2009 to 2017

“…As anticipated, this accords with the previous source modeling obtained by the analysis of the strain changes . For the lava fountains of NSEC, several geochemical and geophysical studies (Aiuppa et al, 2010;Bonaccorso et al, 2011a,b;Calvari et al, 2011;Ganci et al, 2012;Corsaro et al, 2017) supported the interpretation that these events were violent releases of bubble-rich magma layers previously decoupled from the melt and trapped at shallow depths close to sea level. The observed behavior for the NSEC lava fountains is a cyclic process of charge/discharge.…”

Ten years of soil CO2 continuous monitoring on Mt. Etna: Exploring the relationship between processes of soil degassing and volcanic activity

“…At the beginning of the new year (during the night between 11 and 12 January 2011), a huge paroxystic phase began at the new Pit Crater, accompanied by a lava fountain and a lava flow which lasted for several hours. The violence of this paroxysm erupted a volume of magma close to 1.55 Â 10 6 m 3 in only 4 h [Ganci et al, 2012]. Although the type of activity of this eruption is similar to the paroxysms that occurred during 2007, the volume of magma erupted was four times higher than in 2007 [Harris et al, 2011].…”

“…During the first 4 months of 2012, a further seven paroxysms with similar features followed (5 January; 9 February; 4 and 18 March; 1, 12, and 24 April), reaching a total of 25 paroxysms since the first in 2011. Ganci et al [2012], using a comparable method, estimated the total amount of lava erupted for all the 18 events in 2011, including the first of the 2012 (5 January), at about 25.4 Â 10 6 m 3 . This is remarkable if we consider that the huge amount of lava erupted over these 19 episodes was emitted in the equivalent of less than 9 days, and that this value might have been underestimated as the weather conditions during the events on 18 February and 19 September did not permit any measurement survey.…”

“…Norm increase-decrease cycles can be put in relationship with the eruptive activity and the volumes of erupted magma [Harris et al, 2011;Ganci et al, 2012], even if, as explained in section 6, a simple direct relationship cannot be expected between them. Nevertheless, it is notable that the eruptions during 2011-2012, although very short in duration, produced a quantity of erupted lava of approximately 25 Â 10 6 m 3 (the time amounting to only about 9 days in total, calculated until the first paroxysm in January 2012), which is more comparable with the 2006 eruption (in total 39 Â 10 6 m 3 ) than with the small 2007 eruptions (in total 2.5 Â 10 6 m 3 ).…”

Assessing Performance of the RSTVOLC Multi-Temporal Algorithm in Detecting Subtle Hot Spots at Oldoinyo Lengai (Tanzania, Africa) for Comparison with MODLEN

“…RST VOLC runs, in fact, also on geostationary satellite data [58], which are the most suited to detect short-lived eruptive events [59,60]. Furthermore, it is ready to be implemented on VIIRS (the Visible Infrared Imaging Radiometer Suite), providing information in MIR and TIR bands with a higher spatial resolution (i.e., 375 m) than MODIS, enabling a better subtle hot spot identification at Lengai.…”