Passive vs. active degassing modes at an open-vent volcano (Stromboli, Italy)

Abstract

This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. and we concurrently derived SO 2 masses for more than 130 Strombolian explosions and 50 gas puffs. From this, we show erupted SO 2 masses have a variability of up to one order of magnitude, and range between 2 and 55 kg (average $ 20 kg), corresponding to a time integrated flux of 0.05 7 0.01 kg s À 1 . Our experimental constraints on individual gas puff mass (0.03-0.42 kg of SO 2 , averaging 0.19 kg) are the first of their kind, equating to an emission rate ranging from 0.02 to 0.27 kg s À 1 . On this basis, we conclude that puffing is two times more efficient than Strombolian explosions in the magmatic degassing process, and that active degassing (explosions þpuffing) accounts for $ 23% (ranging from 10% to 45%) of the volcano's total SO 2 flux, e.g., passive degassing between the explosions contributes the majority ( $ 77%) of the released gas. We furthermore integrate our UV camera gas data for the explosions and puffs, with independent geophysical data (infrared radiometer data and very long period seismicity), to offer key and novel insights into the degassing dynamics within the shallow conduit systems of this open-vent volcano.

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

“…In contrast, the temporal resolution of UV spectrometers/cameras is higher, from ∼10 to 20 min (Burton et al, 2009) to 0.5 s (Tamburello et al, 2012), but observations are intrinsically limited to daylight hours and to good meteorological conditions (no clouds). Figure 7 exemplifies the issue related to misalignment between Multi-GAS and UV observations.…”

“…This latter approach has been used at volcanoes for years (Aiuppa, 2015), and at Stromboli involves use of two fully automated Multi-GAS instruments, operating on the volcano's summit to measure the in-plume CO 2 /SO 2 ratio (Figure 2A; Aiuppa et al, 2009Aiuppa et al, , 2010aCalvari et al, 2014). This is combined with SO 2 fluxes, delivered from either the FLAMES network of scanning UV spectrometers (Burton et al, 2009) or from UV camera observations (Tamburello et al, 2012), to obtain the CO 2 flux.…”

“…Concurrently with our lidar observations, a dual-UV camera system (Kantzas et al, 2010;Tamburello et al, 2012;Burton et al, 2014) was used to monitor the temporal variations of the SO 2 flux and plume transport speed. 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).…”

“…Distinct bandpass filters, centerd at either 310 nm (where SO 2 absorbs) or 330 nm (no SO 2 absorption), were mounted on the back on the lenses of the two cameras. Each set of co-acquired images from the two UV cameras was processed using the methodology of Kantzas et al (2010) and integrated into the Vulcamera software (Tamburello et al, 2011(Tamburello et al, , 2012, to calculate an absorbance for each camera pixel. Absorbance was converted into an SO 2 column amount from readings of a co-exposed Ocean optics USB2000+ UV Spectrometer, as outlined in Lübcke et al (2013).…”

Correlation of oscillatory behaviour in Matlab using wavelets

“…Hurrell et al, 2003;Lockwood, 2012;Philander, 1990). Oscillations are also present over much shorter timescales of seconds to hours, for example within geochemical datasets concerning volcanic degassing (Tamburello et al, 2012). The links between fluctuations present in environmental data series can wax and wane dramatically, providing a motivation for the application of wavelet analysis.…”