High spatial and temporal resolution SO2 flux measurements in Southern Italian volcanoes
About the Event:
Volatiles carry crucial information on pre- to sin-eruptive processes at active volcanoes. Measurements of gas emission rates (crater plumes, fumaroles, diffuse soil degassing) therefore improve our understanding of degassing processes and subsurface magmatic and hydrothermal conditions, and contribute to eruption forecasting. Recent technological developments in spectroscopy have allowed, over the last 40 years, the remote sensing of magmatic volatile emissions from quiescent and erupting degassing volcanoes. These data-sets have contributed to discovering cyclic gas flux components due to periodic magma supply and replenishment in magma storage zones, and/or timescales of magma migration (and degassing) within the feeding conduit systems of volcanoes. In spite of these relevant achievements, a number of magmatic degassing processes have remained elusive to measure, as they occur at a faster rate than the time resolution of most available spectroscopic techniques.
In the last few years, we took advantage of a cutting-edge technology – the dual UV camera system – to image SO2 emissions from the southern Italian volcanoes with improved high temporal (seconds) and spatial (meters) resolution. At La Fossa crater (Vulcano island, Italy) fumarolic field, the dual-UV camera allowed the simultaneous imaging of multiple-source emissions, discriminating between SO2 contributions from the four main fumarolic areas. The UV camera-derived individual fumarole SO2 fluxes have been used in tandem with MultiGAS derived gas/SO2 molar ratios to accurately assess CO2, H2O, and H2S fluxes. On Stromboli, the UV camera-derived data allowed the first simultaneous estimate of the SO2 flux contribution from the three main forms of degassing at Stromboli (passive degassing, explosive degassing and puffing) and a systematic in tandem UV camera-geophysical observations. At Mount Etna, the SO2 flux time series highlighted a periodic degassing behaviour for the North-east vent, with characteristic periods in the 60-250 s range correlated with seismic tremor amplitude. A network of UV cameras at Stromboli and Etna volcanoes allowed to follow the degassing dynamics during their eruptions on 2014. We demonstrated that our vent-resolved SO2 flux time series can allow capturing shifts in activity and degassing modes from one vent to another and contributing to our understanding of the shallow plumbing system structure.
About the Speaker:
Dr Giancarlo Tamburello is a researcher at the Istituto Nazionale di Geofisica e Vulcanologia Sez. Bologna, Italy. His research focuses on the study of the volcanic gas geochemistry, volcanic gas-based monitoring and forecasting of volcanic eruptions using real-time in situ and remote techniques. He has a degree in Geological Sciences from Palermo University where he undertook geochemical mapping and SO2 flux measurements in the fumarolic field of Vulcano Island and later gained his PhD developing the application of UV cameras to study volcanoes. Giancarlo created the popular program Ratiocalc which permits the simple and rapid processing of large datasets for monitoring volcanic gas compositions. He later developed a protocol for UV camera measurements and a user-friendly program (Vulcamera) for measuring volcanic SO2 fluxes at high time resolution (1-25 Hz). Giancarlo has used the SO2 camera for flux measurements at several volcanoes worldwide (Vulcano, Etna, Stromboli, Lascar, Lastarria, Putana, Copahue, Poàs, Turrialba, Mutnosvky, Gorely, Merapi, Ibu, Dukono) in tandem with MultiGAS deriving gas/SO2 molar ratios to accurately assess also CO2, H2S, H2O, and H2 fluxes. Giancarlo is also interested in the emission of mercury from active volcanoes and geothermal areas.