Bulletin of Volcanology

, Volume 69, Issue 1, pp 41–50 | Cite as

Volcanic structure of the southern sector of Mt. Etna after the 2001 and 2002 eruptions defined by magnetotelluric measurements

Research Article


Two magnetotelluric (MT) surveys were carried out on the Mt. Etna volcano after two of the most intense eruptions of the last 30 years which took place in summer 2001 and winter 2002–2003. Surveying was pursued for two main reasons. First, we sought to contribute to the definition of the first-order structure and physico-chemical state (temperature, fluids, melts) of a volcano that has been extensively explored and monitored by means of various geophysical methods, but where only few electrical and electromagnetic surveys have been performed. Secondly, we acquired MT data in the same sites in the two different surveys with the aim of monitoring the possible changes of the first-order structure, since conditions are expected to vary on an active volcano such as Etna, and are supposed to be linked to the eruptive events. Soundings have been acquired in an E-W 10 km-long profile across the southern flank of Mt. Etna, at a distance of almost 6 km south from the Central Crater. The first survey was carried out three months after the 2001 eruption. Inverse models define a pronounced (4 km thickness) low resistivity section at a depth of about 1 km b.s.l. to the west. To the east, a low resistivity section is still present, but appears deeper, thinner and more resistive, and a shallow low resistivity anomaly also exists. The shallow anomaly to the east is tentatively correlated with altered and clayey volcanic units and/or temporary groundwater storage. The deep anomalies are interpreted as being due to melt storage at shallow depths which was not exhausted during the eruption. This would be confirmed by the abundance of lava erupted within one year from the end of the survey. The few good sites retrieved in the second survey, carried out a few weeks after the eruption of 2002–2003, confirm the picture defined in the first survey, and provide a better definition of the bottom of the deep anomaly located in the sedimentary basement.


Mt. Etna volcano Magnetotellurics Volcanic structure Magma storage Thermal regime Resistivity Groundwater 


  1. Aloisi M, Cocina O, Neri G, Orecchio B, Privitera E (2002) Seismic tomography of the crust underneath the Etna volcano, Sicily. Phys Earth Planet Int 134:139–155CrossRefGoogle Scholar
  2. Behncke B, Neri M (2003) The July-August 2001 eruption of Mt. Etna (Sicily). Bull Volcanol 65:461–476CrossRefGoogle Scholar
  3. Bonaccorso A, Ferrucci F, Patanè D, Villari L (1996) Fast deformation processes and eruptive activity at Mount Etna (Italy). J Geophys Res 101:17467–17480CrossRefGoogle Scholar
  4. Bruno N, Caltabiano T, Giammanco S, Romano R (2001) Degassing of SO2 and CO2 at Mount Etna (Sicily) as an indicator of pre-eruptive ascent and shallow emplacement of magma. J Volc Geoth Res 110:137–153CrossRefGoogle Scholar
  5. Catalano S, Torrisi S, Ferlito C (2004) The relationship between Late Quaternary deformation and volcanism of Mt. Etna (eastern Sicily): new evidence from the sedimentary substratum in the Catania region. J Volcanol Geotherm Res 132:311–334CrossRefGoogle Scholar
  6. Chiarabba C, Amato A, Boschi E (2000) Recent seismicity and tomographic modeling of the Mount Etna plumbing system. J Geophys Res 105(B5):10923–10938CrossRefGoogle Scholar
  7. Della Monica G, Di Maio R, Scandone R, Cecere G, Del Negro C, De Martino P, Santochirico F (2004) Electrical modelling of the shallow structural setting of the Cisternazza-Montagnola area (Mt. Etna). Quad Geofis 35:39–44Google Scholar
  8. Del Negro C, Currenti G (2003) Volcanomagnetic signals associated with 2001 flank eruption of Mt.Etna (Italy). Geophys Res Lett 30(7):1357–1360CrossRefGoogle Scholar
  9. Di Maio R, Mauriello P, Patella D, Petrillo Z, Piscitelli S, Siniscalchi A (1998) Etna: self-Potential, geoelectric and magnetotelluric measurements. In: P. Gasparini (ed) Data related to eruptive activity, unrest phenomena and other observations on the Italian active volcanoes–1993–1995. Acta Volcanol 10:187–193Google Scholar
  10. Gamble T, Goubau W, Clarke J (1979) Magnetotellurics with a remote-reference. Geophysics 44:53–68CrossRefGoogle Scholar
  11. Hirn A, Nicolich R, Gallart J, Laigle M, Cernobori L, ETNASEIS Scientific Group (1997) Roots of Etna volcano in faults of great earthquakes. Earth Planet Sci Lett 148:171–191CrossRefGoogle Scholar
  12. Ingham M (1992) Audiomagnetotelluric soundings on White Island volcano. J Volc Geoth Res 50:301–306CrossRefGoogle Scholar
  13. Jones AG (1992) Electrical conductivity of the continental lower crust. In: Fountain DM, Arculus RJ, Kay RW (eds) Continental lower crust. Elsevier, Amsterdam pp, 81–143Google Scholar
  14. Kagiyama T, Utada H, Yamamoto T (1999) Magma ascent beneath Unzen Volcano, SW Japan, deduced from the electrical resistivity structure. J Volc Geoth Res 89:35–42CrossRefGoogle Scholar
  15. Larsen JC, Mackie R, Manzella A, Fiordelisi A, Rieven S (1996) Robust smooth magnetotelluric transfer function. Geophys J Int 124:801–819CrossRefGoogle Scholar
  16. La Torraca GA, Madden TR, Korringa J (1986) An analysis of the magnetotelluric impedance for three dimensional conductivity structures. Geophysics 51:1819–1829CrossRefGoogle Scholar
  17. Loddo M, Patella D, Quarto R, Ruina G, Tramacere A, Zito G (1989) Application of gravity and deep dipole geoelectrics in the volcanic area of Mt. Etna (Sicily). J Volc Geoth Res 39:17–39CrossRefGoogle Scholar
  18. Massonnet D, Briole P, Arnaud A (1995) Deflation of Mount Etna monitored by spaceborne radar interferometry. Nature 375:567–570CrossRefGoogle Scholar
  19. Mauriello P, Patella D, Petrillo Z, Siniscalchi A, Iuliano T, Del Negro C (2004) A geophysical study of the Mount Etna volcanic area. In: Bonaccorso A, Calvari S, Coltelli M, Del Negro C, Falsaperla S (eds) Mt. Etna: volcano laboratory. AGU geophys Mon 143:273–291Google Scholar
  20. Mogi T, Nakama S (1993) Magnetotelluric interpretation of the geothermal system of the Kuju volcano, southwest Japan. J Volcanol Geotherm Res 56:297–308CrossRefGoogle Scholar
  21. Muller A, Haak V (2004) 3-D modeling of the deep electrical conductivity of Merapi volcano (Central Java): integrating magnetotellurics, induction vectors and the effects of steep topography. J Volcanol Geotherm Res 138:205–222CrossRefGoogle Scholar
  22. Murru M, Montuori C (1999) The location of magma chamber at Mt. Etna, Italy, mapped by b-values. Geophys Res Lett 26(16):2553–2556CrossRefGoogle Scholar
  23. Ogawa YN, Matsushima H, Oshima H, Takakura S, Utsugi M, Hirano K, Igarashi M, Doi T (1998) A resistivity cross-section of Usu volcano, Hokkaido, Japan, by audiomagnetotellurics soundings. Earth Planet Space 50(4):339–346Google Scholar
  24. Oskooi B, Pedersen LB, Smirnov M, Árnason K, Eysteinsson H, Manzella A (2005) The deep geothermal structure of the Mid-Atlantic ridge deduced from MT data in SW Iceland. Phys Earth Planet Int 150:183–195CrossRefGoogle Scholar
  25. Revil A, Finizola A, Sortino F, Ripepe M (2004) Geophysical investigation at Stromboli volcano, Italy: implications for ground water flow. Geophys J Int 157:426–440CrossRefGoogle Scholar
  26. Rodi W, Mackie RL (2001) Nonlinear conjugate gradients algorithm for 2-D magnetotelluric inversion. Geophysics 66:174–187CrossRefGoogle Scholar
  27. Scarlato P, Poe BT, Freda C, Gaeta M (2004) High-pressure and high-temperature measurements of electrical conductivity in basaltic rocks from Mount Etna, Sicily, Italy. J Geophys Res 109:B02210 DOI 10.1029/2003JB002666CrossRefGoogle Scholar
  28. Sharp ADL, Davis PM, Gray F (1980) A low velocity zone beneath Mount Etna and magma storage. Nature 287:587–591CrossRefGoogle Scholar
  29. Schnegg PA (1997) Electrical structure of Plaine des Sables caldera, Piton de la Fournaise volcano (Réunion island). Ann Geofis 40:305–317Google Scholar
  30. Smith T (1995) Understanding telluric distorion matrices. Geophys J Int 122:219–226CrossRefGoogle Scholar
  31. Swift JR (1967) A magnetotelluric investigation of an electrical conductivity anomaly in the southwestern United States. PhD Thesis, MIT, BostonGoogle Scholar
  32. Tanguy JC, Condomines M, Kieffer G (1997) Evolution of the Mount Etna magma: constraints on the present feeding system and eruptive mechanism. J Volc Geoth Res 75:225–250Google Scholar
  33. Vozoff K (1991) The magnetotelluric method. In: Nabighiam MN (ed) Electromagnetic methods in applied geophysics. SEG, Tulsa, 2B, pp 641–711Google Scholar
  34. Wannamaker PE (1999) Affordable magnetotellurics: interpretation of MT sounding profiles from natural environments. In: Oristaglio M, Spies B (eds) Three-dimensional electromagnetics. SEF, Tulsa, pp 349–374Google Scholar
  35. Weaver JT, Agarwal AK, Lilley FEM (2000) Characterization of the magnetotelluric tensor in terms of its invariants. Geophys J Int 141:321–336CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  1. 1.CNR-Istituto di Geoscienze e GeorisorsePisaItaly
  2. 2.Dipartimento di Geologia, Paleontologia e GeofisicaUniversità di PadovaPadovaItaly

Personalised recommendations