Spatially resolved SO2 flux emissions from Mt Etna

D'Aleo, Roberto; Bitetto, Marcello; Donne, Dario Delle; Tamburello, Giancarlo; Battaglia, Angélo; Coltelli, M.; Patané, Domenico; Prestifilippo, Michele; Sciotto, Mariangela; Aiuppa, Alessandro

doi:10.1002/2016gl069938

Cited by 36 publications

(47 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Salerno et al, 2009), ranging from a few up to several hundred kg s −1 , depending on the activity (e.g. Edner et al, 1994, D'Aleo et al, 2016. The comparatively low values may be partly due to the fact that mainly the emissions of the NEC were captured, which nonetheless appeared to be the strongest source during the observation period.…”

Section: Retrieved So 2 Emission Ratesmentioning

confidence: 99%

“…This allows us to study high-frequency variations in the emission signals or to investigate individual sources separately (e.g. Tamburello et al, 2013, D'Aleo et al, 2016. As a result, the cameras are often pointed at the vicinity of the source, where the plumes can show turbulent behaviour, mostly as a result of aerodynamic effects and buoyancy.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Improved optical flow velocity analysis in SO2 camera images of volcanic plumes – implications for emission-rate retrievals investigated at Mt Etna, Italy and Guallatiri, Chile

et al. 2018

View full text Add to dashboard Cite

Abstract. Accurate gas velocity measurements in emission plumes are highly desirable for various atmospheric remote sensing applications. The imaging technique of UV SO 2 cameras is commonly used to monitor SO 2 emissions from volcanoes and anthropogenic sources (e.g. power plants, ships). The camera systems capture the emission plumes at high spatial and temporal resolution. This allows the gas velocities in the plume to be retrieved directly from the images. The latter can be measured at a pixel level using optical flow (OF) algorithms. This is particularly advantageous under turbulent plume conditions. However, OF algorithms intrinsically rely on contrast in the images and often fail to detect motion in low-contrast image areas. We present a new method to identify ill-constrained OF motion vectors and replace them using the local average velocity vector. The latter is derived based on histograms of the retrieved OF motion fields. The new method is applied to two example data sets recorded at Mt Etna (Italy) and Guallatiri (Chile). We show that in many cases, the uncorrected OF yields significantly underestimated SO 2 emission rates. We further show that our proposed correction can account for this and that it significantly improves the reliability of optical-flow-based gas velocity retrievals.In the case of Mt Etna, the SO 2 emissions of the northeastern crater are investigated. The corrected SO 2 emission rates range between 4.8 and 10.7 kg s −1 (average of 7.1 ± 1.3 kg s −1 ) and are in good agreement with previously reported values. For the Guallatiri data, the emissions of the central crater and a fumarolic field are investigated. The retrieved SO 2 emission rates are between 0.5 and 2.9 kg s −1 (average of 1.3 ± 0.5 kg s −1 ) and provide the first report of SO 2 emissions from this remotely located and inaccessible volcano.

show abstract

Section: Retrieved So 2 Emission Ratesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Improved optical flow velocity analysis in SO2 camera images of volcanic plumes – implications for emission-rate retrievals investigated at Mt Etna, Italy and Guallatiri, Chile

et al. 2018

View full text Add to dashboard Cite

show abstract

“…A fully autonomous system, similar to that used in other recent work (D'Aleo et al, 2016), was mounted on the roof of the laboratory truck and operated every day from 6 am to 4 pm (Local Time). The UV camera system acquired sequential images of the plume at ∼0.5 Hz using two JAI CM 140 GR cameras.…”

Section: Uv Cameramentioning

confidence: 99%

New Advances in Dial-Lidar-Based Remote Sensing of the Volcanic CO2 Flux

et al. 2017

View full text Add to dashboard Cite

We report here on the results of a proof-of-concept study aimed at remotely sensing the volcanic CO 2 flux using a Differential Adsorption lidar (DIAL-lidar). The observations we report on were conducted in June 2014 on Stromboli volcano, where our lidar (LIght Detection And Ranging) was used to scan the volcanic plume at ∼3 km distance from the summit vents. The obtained results prove that a remotely operating lidar can resolve a volcanic CO 2 signal of a few tens of ppm (in excess to background air) over km-long optical paths. We combine these results with independent estimates of plume transport speed (from processing of UV Camera images) to derive volcanic CO 2 flux time-series of ≈16-33 min temporal resolution. Our lidar-based CO 2 fluxes range from 1.8 ± 0.5 to 32.1 ± 8.0 kg/s, and constrain the daily averaged CO 2 emissions from Stromboli at 8.3 ± 2.1 to 18.1 ± 4.5 kg/s (or 718-1565 tons/day). These inferred fluxes fall within the range of earlier observations at Stromboli. They also agree well with contemporaneous CO 2 flux determinations (8.4-20.1 kg/s) obtained using a standard approach that combines Multi-GAS-based in-plume readings of the CO 2 /SO 2 ratio (≈8) with UV-camera sensed SO 2 fluxes (1.5-3.4 kg/s). We conclude that DIAL-lidars offer new prospects for safer (remote) instrumental observations of the volcanic CO 2 flux.Keywords: volcanic CO 2 , DIAL-lidar, Stromboli, remote sensing, CO 2 flux INTRODUCTION A major step forward in ground-based volcano monitoring has recently arisen from the advent of modern instrumental techniques and networks for volcanic gas observations (Galle et al., 2010;Oppenheimer et al., 2014;Saccorotti et al., 2014;Fischer and Chiodini, 2015). Such technical advances provide improved temporal resolution relative to traditional direct sampling techniques (Symonds et al., 1994;Giggenbach, 1996). As longer-term volcanic gas records increase in number and quality, full empirical evidence is finally emerging for increased CO 2 flux emissions prior to eruption of mafic to intermediate volcanoes (Aiuppa, 2015). Precursory plume CO 2 flux increases have been now detected at several volcanoes, including Etna (Aiuppa et al., 2008;Patanè et al., 2013), Kilauea (Poland et al., 2012), Redoubt (Werner et al., 2013), Turrialba (de Moor et al., 2016a), and Poas (de Moor et al., 2016b).At Stromboli (in Italy), however, CO 2 flux observations have been particularly valuable for interpreting, and eventually predicting, the volcano's behavior (Aiuppa et al., 2010a Stromboli, the "regular" mild strombolian activity is occasionally interrupted by larger-scale vulcanian-style explosions, locally referred as "major explosions" or (in the most extreme events) "paroxysms" (Rosi et al., 2006(Rosi et al., , 2013Andronico and Pistolesi, 2010;Pistolesi et al., 2011;Pioli et al., 2014). These explosions, although short-lived (tens of seconds to a few minutes), represent a real hazard for local populations, tourists and volcanologists, since they produce fallout of coarse pyroclastic materials over w...

show abstract

“…This capability has also been exploited in respect of multiple vent scenarios, e.g., Fuego (Guatemala) [20] and Mt. Etna, where a shifting of degassing from one vent to another was observed in tandem with a transference of eruptive activity between craters [34].…”

Section: Improving the Spatio-temporal Resolution Of Volcanic Degassingmentioning

confidence: 99%

“…To date, the targets covered by permanent network installations have been rather few, e.g., Etna and Stromboli in Italy and Kīlauea in Hawaii [33][34][35][36][37], potentially as a consequence of the requirement to image the plume, e.g., without cloud cover between the camera and summit area. There is, of course, meteorological cloud cover at the top of volcanoes, which can occlude observations.…”

Section: Improving the Spatio-temporal Resolution Of Volcanic Degassingmentioning

confidence: 99%

Ultraviolet Imaging of Volcanic Plumes: A New Paradigm in Volcanology

et al. 2017

View full text Add to dashboard Cite

Ultraviolet imaging has been applied in volcanology over the last ten years or so. This provides considerably higher temporal and spatial resolution volcanic gas emission rate data than available previously, enabling the volcanology community to investigate a range of far faster plume degassing processes than achievable hitherto. To date, this has covered rapid oscillations in passive degassing through conduits and lava lakes, as well as puffing and explosions, facilitating exciting connections to be made for the first time between previously rather separate sub-disciplines of volcanology. Firstly, there has been corroboration between geophysical and degassing datasets at ≈1 Hz, expediting more holistic investigations of volcanic source-process behaviour. Secondly, there has been the combination of surface observations of gas release with fluid dynamic models (numerical, mathematical, and laboratory) for gas flow in conduits, in attempts to link subterranean driving flow processes to surface activity types. There has also been considerable research and development concerning the technique itself, covering error analysis and most recently the adaptation of smartphone sensors for this application, to deliver gas fluxes at a significantly lower instrumental price point than possible previously. At this decadal juncture in the application of UV imaging in volcanology, this article provides an overview of what has been achieved to date as well as a forward look to possible future research directions.

show abstract

Spatially resolved SO₂ flux emissions from Mt Etna

Cited by 36 publications

References 40 publications

Improved optical flow velocity analysis in SO<sub>2</sub> camera images of volcanic plumes – implications for emission-rate retrievals investigated at Mt Etna, Italy and Guallatiri, Chile

Improved optical flow velocity analysis in SO<sub>2</sub> camera images of volcanic plumes – implications for emission-rate retrievals investigated at Mt Etna, Italy and Guallatiri, Chile

New Advances in Dial-Lidar-Based Remote Sensing of the Volcanic CO2 Flux

Ultraviolet Imaging of Volcanic Plumes: A New Paradigm in Volcanology

Contact Info

Product

Resources

About

Spatially resolved SO2 flux emissions from Mt Etna

Cited by 36 publications

References 40 publications

Improved optical flow velocity analysis in SO&lt;sub&gt;2&lt;/sub&gt; camera images of volcanic plumes – implications for emission-rate retrievals investigated at Mt Etna, Italy and Guallatiri, Chile

Improved optical flow velocity analysis in SO&lt;sub&gt;2&lt;/sub&gt; camera images of volcanic plumes – implications for emission-rate retrievals investigated at Mt Etna, Italy and Guallatiri, Chile

New Advances in Dial-Lidar-Based Remote Sensing of the Volcanic CO2 Flux

Ultraviolet Imaging of Volcanic Plumes: A New Paradigm in Volcanology

Contact Info

Product

Resources

About

Spatially resolved SO₂ flux emissions from Mt Etna

Improved optical flow velocity analysis in SO<sub>2</sub> camera images of volcanic plumes – implications for emission-rate retrievals investigated at Mt Etna, Italy and Guallatiri, Chile

Improved optical flow velocity analysis in SO<sub>2</sub> camera images of volcanic plumes – implications for emission-rate retrievals investigated at Mt Etna, Italy and Guallatiri, Chile