The 2002–2003 eruption of Stromboli (Italy): Evaluation of the volcanic activity by means of continuous monitoring of soil temperature, CO₂ flux, and meteorological parameters

Abstract

[1] From December 2002 to July 2003, Stromboli volcano was characterized by a new effusive stage of eruption after a period of extraordinary strombolian activity. Signals recorded in two continuous monitoring stations during the eruption, which have already been presented in very recent papers, evidenced anomalies in the CO 2 flux just before the onset of the eruption. A more detailed analysis carried out on the data subset acquired during the eruption, integrated by daily field observations of the scientific personnel working at the volcanological observatory in Stromboli, showed that CO 2 flux and soil temperature are strictly related to volcanic events. Furthermore, the relative minima and maxima of the two parameters showed a strong correlation with wind speed and direction. This fact was especially true at the summit station, whereas at the coastal sites seasonal and meteorological effects masked the volcanic signal. The analysis of the wind data, particularly the relationships between wind speed and direction, air and soil temperature, and local circulation of atmospheric air masses revealed that during the eruption, in the summit area of Stromboli air movements were not only related to atmospheric circulation but were also significantly affected, and in certain cases caused, by volcanic activity. This conclusion was reached by observing several anomalies, such as the discrepancies in the wind direction between the two stations, higher air temperatures at the summit site, and inversion of direction for wind before and after the reopening of the conduit in a major explosion on 5 April 2003. The relationships found between volcanic activity, soil temperatures, CO 2 fluxes, and wind speed and direction indicate that soil temperature measurements, in an open conduit volcano such as in this case, could be used to monitor the level of volcanic activity, along with CO 2 flux. Furthermore, the possible volcanic origin of a peculiar type of air circulation identified in the summit area of Stromboli suggests that the separation between volcanic and atmospheric signals might not be obvious, requiring monitoring over a wide area, rather than a single location.

Geochemical evidence of the renewal of volcanic activity inferred from CO2 soil and SO2 plume fluxes: the 2007 Stromboli eruption (Italy)

“…on active volcanoes have proven to be the best sites for monitoring diffuse CO 2 flux from the soil (Finizola et al 2002;Werner and Cardellini 2006;Mazot et al 2011). On Stromboli, the most extensive and intense soil degassing areas, which are sometimes associated with thermal anomalies, are located at the summit area (Pizzo Sopra la Fossa) and on structural zones (Carapezza and Federico 2000;Finizola et al 2003;Brusca et al 2004).…”

Anomalous Diffuse CO2 Emission prior to the January 2002 Short-term Unrest at San Miguel Volcano, El Salvador, Central America

“…3), it is evident that the observed changes of diffuse CO 2 emission rate on the eastern flank of San Miguel volcano should be related to either a sharp increase of CO 2 pressure within the volcanichydrothermal system or degassing from an uprising fresh gas-rich magma within the shallow plumbing system of the volcano as it was explained for the observed changes on CO efflux prior to the Stromboli 2002-2003 eruptive events (CARAPEZZA et al, 2004;BRUSCA et al, 2004). As an alternative procedure to isolate the joint impulseresponse function of the CO 2 efflux and determine the effects of variations in the hydrothermal system on diffuse CO 2 efflux, we used multivariate regression analysis (MRA) to delineate the relations between CO 2 efflux and external factors and then use these relations to filter out the effects of these factors on the measured efflux history.…”

“…Extensive work on diffuse CO 2 degassing has been performed at volcanic and geothermal areas over the last 13 years, suggesting that even during periods of quiescence, volcanoes release large amounts of carbon dioxide in a diffuse form (BAUBRON et al, 1990;ALLARD et al, 1991;FARRAR et al, 1995;CARTAGENA et al, 2004;CHIODINI et al, 1996CHIODINI et al, , 1998HERNA´NDEZ et al, 1998, 2001bGERLACH et al, 1998;SOREY et al, 1998;GIAMMANCO et al, 1998;PE´REZ et al, 1996ROGIE et al, 2001;SALAZAR et al, 2001). However, few works related to continuous monitoring of the diffuse CO 2 degassing have been published (ROGIE et al, 2001;SALAZAR et al,2002SALAZAR et al, , 2004MORI et al, 2002;GRANIERI et al, 2003;CARAPEZZA et al, 2004;BRUSCA et al, 2004).…”

Tunable diode laser measurements of hydrothermal/volcanic CO<sub>2</sub> and implications for the global CO<sub>2</sub> budget

“…The alternative extrapolation approach used to quantify CO 2 emissions from "unmeasured" volcanoes assumes that the distribution of volcanic CO 2 fluxes obeys a power law (Brantley and Koepenick, 1995), as other geophysical parameters do (Marret and Allmendinger, 1991;Turcotte, 1992). If volcanic emissions follow a power-law distribution, then the number of volcanoes (N) with an emission rate ≥ f are given by:…”

“…In the power-law assumption, the global volcanic CO 2 flux (f tot ) was extrapolated to 88-132 Mt yr −1 (Brantley and Koepenick, 1995) using the relation:…”