Instrumental network

As a main achievement of the project, we have successfully realised the first prototypes of fully automated UV cameras. Field validation of the UV-cameras has been performed during a number of field expeditions at Etna and Stromboli, and at a number of volcanic targets abroad (Chile, Costa Rica, and Indonesia, among others). As for the approved research plan, 4 permanent UV camera systems have then been deployed (2 at Etna and 2 at Stromboli) between May and September 2014, assembling therefore the first permanent network of volcanic SO2 imaging systems worldwide (at least to our knowledge). These new observation systems are now paving the way to a real revolution in volcanic gas research, initialising in timely matter (expected from Annex 1 since month 12) the first efforts of in tandem-analysis of volcanic gas and geophysical data (Task 2). We can now real-time image the degassing regime of each individual basaltic explosion, and compare its gas eruption rate/mass with the magnitude, shape and duration of the thermal (Tamburello et al., 2012), seismic (Tamburello et al., 2012, Pering et al., 2014a) and acoustic (Delle Donne et al., 2014) signals it irradiates. These observations, combined with modelling efforts, are substantially impacting the current models invoked to explain generation and dynamics of basaltic explosions. Our data also allow characterising with unprecedented detail and fine temporal resolution the fluctuations and patterns in passive (quiescent) degassing, to prove for the very first time that short- (seconds) to long-term (minutes) pulsatory degassing behaviour of open-vent volcanoes controls the generation of seismic tremor at open-vent volcanoes (Tamburello et al., 2013; Pering et al., 2014a), with implications on our understanding of modes of gas migration within and release from basaltic magmas. Both Etna and Stromboli have shown significant deviation from regular, quiescent degassing toward both effusive (ongoing on Stromboli by the time of writing) and paroxysmal explosive activity (Etna during summer 2014). The huge mass of information we have acquired with the permanent UV camera systems, during 5 months of continuous gas observations, are now under analysis/interpretation, and their full analysis (with more data acquired during months 25-48) will contribute in phase II of BRIDGE to understand and model the processes leading to transition from quiescent degassing to eruption (Aiuppa et al., in prep.).