Ten years of soil CO2 continuous monitoring on Mt. Etna: Exploring the relationship between processes of soil degassing and volcanic activity

[1] The measurement of soil CO2 flux variations is a well−established practice in many volcanic areas around the world. Until recently, however, most of these were made using direct sampling methods. These days, a variety of automatic devices providing real-time data now make the continuous monitoring of volcanic areas possible. A network of automatic geochemical monitoring stations (EtnaGas network) was developed by INGV Palermo and installed at various sites on the flanks of Mt. Etna. Here, we present a large set of soil CO2 flux data recorded by the network, dating back 10 years, a period in which several noteworthy eruptive phenomena occurred. Our statistical analysis strongly suggests that anomalous measurements of soil CO2 flux are attributable to volcanic origin and in almost all cases precede volcanic activity. Here, we present the actual data series recorded by EtnaGAS and an interpretative model of the expected behavior of soil CO2 flux (in terms of increase-decrease cycles), which corresponded well with the volcanic activity during this period. Through the use of a comparative approach, incorporating both volcanological and geochemical data, the global soil CO2 flux trends are put into a coherent framework, highlighting close links between the time flux variations and volcanic activities. These insights, made possible from 10 years of uninterrupted data, confirm the importance of continuous monitoring of volcanic soil degassing, and may contribute in the forecasting of imminent eruptive activity or the temporal evolution of an in-progress eruption, therefore facilitating Civil Defense planning in volcanic areas under high-hazard conditions.

[1]  G. Pecoraino,et al.  Geochemical Characterization and Temporal Changes in Parietal Gas Emissions at Mt. Etna (Italy) During the Period July 2000-July 2003 , 2005 .

[2]  R. Symonds,et al.  Magmatic gas scrubbing: implications for volcano monitoring , 2001 .

[3]  M. Burton,et al.  Etna 2004–2005: An archetype for geodynamically‐controlled effusive eruptions , 2005 .

[4]  Paolo Papale,et al.  On the oxidation state and volatile behavior in multicomponent gas–melt equilibria , 2004 .

[5]  R. Clocchiatti,et al.  Primitive magmatism of Mt Etna: Insights from mineralogy and melt inclusions , 1996 .

[6]  M. Liuzzo,et al.  Continuous monitoring of soil CO2 flux on Mt. Etna: The 2004–2005 eruption and the role of regional tectonics and volcano tectonics , 2008 .

[7]  M. Camarda,et al.  CO2 flux measurements in volcanic areas using the dynamic concentration method: Influence of soil permeability , 2006 .

[8]  P. Zettwoog,et al.  Eruptive and diffuse emissions of CO2 from Mount Etna , 1991, Nature.

[9]  Luigi Marini,et al.  Soil CO2 flux measurements in volcanic and geothermal areas , 1998 .

[10]  Placido Montalto,et al.  Patterns in the recent 2007–2008 activity of Mount Etna volcano investigated by integrated geophysical and geochemical observations , 2010 .

[11]  Simona Scollo,et al.  Monitoring ash emission episodes at Mt. Etna : The 16 November 2006 case study , 2009 .

[12]  M. Camarda,et al.  In situ Permeability Measurements Based on a Radial Gas Advection Model: Relationships Between Soil Permeability and Diffuse CO2 Degassing in Volcanic Areas , 2006 .

[13]  Mimmo Palano,et al.  Feeding system and magma storage beneath Mt. Etna as revealed by recent inflation/deflation cycles , 2008 .

[14]  F. Greco,et al.  Multidisciplinary investigation on a lava fountain preceding a flank eruption: The 10 May 2008 Etna case , 2011 .

[15]  A. Harris,et al.  Thirty years of satellite‐derived lava discharge rates at Etna: Implications for steady volumetric output , 2011 .

[16]  Sergio Gurrieri,et al.  Anomalous soil CO2 degassing in relation to faults and eruptive fissures on Mount Etna (Sicily, Italy) , 1998 .

[17]  W. Marzocchi,et al.  Continuous monitoring of CO 2 soil diffuse degassing at Phlegraean Fields (Italy): influence of environmental and volcanic parameters , 2003 .

[18]  Paolo Papale,et al.  Forecasting Etna eruptions by real-time observation of volcanic gas composition , 2007 .

[19]  A. Sobolev,et al.  Melt inclusion record of the conditions of ascent, degassing, and extrusion of volatile‐rich alkali basalt during the powerful 2002 flank eruption of Mount Etna (Italy) , 2006 .

[20]  Placido Montalto,et al.  Relationship between soil CO2 flux and volcanic tremor at Mt. Etna: Implications for magma dynamics , 2010 .

[21]  C. Federico,et al.  Diffuse degassing of carbon dioxide at Somma Vesuvius volcanic complex (Southern Italy) and its relation with regional tectonics , 2004 .

[22]  W. L. Powers,et al.  FIELD CHAMBER MEASUREMENTS OF CO2 FLUX FROM SOIL SURFACE , 1974 .

[23]  Mike Burton,et al.  Continuous soil radon monitoring during the July 2006 Etna eruption , 2006 .

[24]  B. Behncke,et al.  Complex magma dynamics at Mount Etna revealed by seismic, thermal, and volcanological data , 2009 .

[25]  S. Gurrieri,et al.  Fault-controlled Soil CO2 Degassing and Shallow Magma Bodies: Summit and Lower East Rift of Kilauea Volcano (Hawaii), 1997 , 2006 .

[26]  I. S. Diliberto,et al.  Tectonic control over large-scale diffuse degassing in eastern Sicily (Italy) , 2002 .

[27]  Philippe Labazuy,et al.  A year of lava fountaining at Etna: Volumes from SEVIRI , 2012 .

[28]  A. Schmidt,et al.  Carbon isotopic composition of soil CO2 efflux, a powerful method to discriminate different sources feeding soil CO2 degassing in volcanic-hydrothermal areas , 2008 .

[29]  Boris Behncke,et al.  Cycles and trends in the recent eruptive behaviour of Mount Etna (Italy) , 2003 .

[30]  Gaetana Ganci,et al.  The initial phases of the 2008–2009 Mount Etna eruption: A multidisciplinary approach for hazard assessment , 2011 .