GNGTS 2016 - Atti del 35° Convegno Nazionale

GNGTS 2016 S essione 1.3 253 same manufacturer. Sensors operate in the range −40 °C to 100 °C, with a resolution of 0.03 °C and an accuracy of ±0.2 °C. Temperatures were measured every 4 min and their hourly averages were stored in the permanent memory of the logger. The two selected sites are the top of the Bottoniera line craters in the Mt. Etna, and the middle rim of the cone of La Fossa Vulcano Island. The monitored data were compared to meteorological parameters (rainfall, barometric pressure, air temperature) from local weather stations. The theoretical bases and the simplified heat balance applied to calculate the heat flux from the monitored data have been described in Aubert (1999) and Aubert et al. (2008). Results. For the Vulcano island case study (Fig. 2) the time variations of different data- series were compared in near real time, since the multidisciplinary approach to some evidences came by the direct collaboration with other groups of researchers actively involved in the geophysycal monitoring of this quiescent system (Cannata et al. , 2012; Madonia et al. , 2013; Milluzzo et al. , 2010). During periods of higher thermal release, the main fumaroles emissions always showed anomalous contents ofmagmatic gases (see for example theCO 2 content in graph d) as highlighted by the periodical sampling of fumaroles release systematically carried out. Moreover the rate of volcano-seismic release during the monitoring period increased in the same periods. See for example the red curve in Figs. 2a and 2b (from Diliberto, 2013). Fig. 3 – a) Image from the WEB showing an instance of the recent eruption, with the TBL monitoring station on the opposite flank with respect to the direction of last falls and flows emitted by the New South East Crater. b) Heat flux variations (validated data) in the steam heated soil; cumulated volume of erupted material (red triangles, values on the right axis); monthly averages of air temperature at the closest weather station (Blue curve, values on the right axis.). c) Total Radiant Energy (T RE, scale on the right axis) retrieved for lava fountain episodes and strombolian explosions occurred at the New South East Crater (data from Bombrum et al. , 2016); Surface Heat flux calculated at BTL monitoring station (HF Daily averages, scale on the left axis). d) IR image of the exposed surface around the monitoring stations, showing the actual temperature range.