Hydrogeology of Stromboli volcano, Aeolian Islands (Italy) from the interpretation of resistivity tomograms, self-potential, soil temperature and soil CO2 concentration measurements

To gain a better insight of the hydrogeology and the location of the main tectonic faults
of Stromboli volcano in Italy, we collected electrical resistivity measurements, soil CO2
concentrations, temperature and self-potential measurements along two profiles. These two
profiles started at the village of Ginostra in the southwest part of the island. The first profile
(4.8 km in length) ended up at the village of Scari in the north east part of the volcano and the
second one (3.5 km in length) at Forgia Vecchia beach, in the eastern part of the island. These
data were used to provide insights regarding the position of shallow aquifers and the extension
of the hydrothermal system. This large-scale study is complemented by two high-resolution
studies, one at the Pizzo area (near the active vents) and one at Rina Grande where flank
collapse areas can be observed. The Pizzo corresponds to one of the main degassing structure
of the hydrothermal system. The main degassing area is localized along a higher permeability
area corresponding to the head of the gliding plane of the Rina Grande sector collapse. We
found that the self-potential data reveal the position of an aquifer above the villages of Scari
and San Vincenzo. We provide an estimate of the depth of this aquifer from these data. The
lateral extension of the hydrothermal system (resistivity ∼15–60 ohm m) is broader than
anticipated extending in the direction of the villages of Scari and San Vincenzo (in agreement
with temperature data recorded in shallow wells). The lateral extension of the hydrothermal
system reaches the lower third of the Rina Grande sector collapse area in the eastern part
of the island. The hydrothermal body in this area is blocked by an old collapse boundary.
This position of the hydrothermal body is consistent with low values of the magnetization
(<2.5 A m−1) from previously published work. The presence of the hydrothermal body below
Rina Grande raises questions about the mechanical stability of this flank of the edifice.

INSU-CNRS, Laboratoire GeoSciences Reunion-IPGP, INGV, DOE (Energy Efficiency and Renewable Energy, Geothermal Technologies
Program, awardDE-FG36–08GO018195)

Aizawa, K. et al. 2005. Hydrothermal system beneath Mt. Fuji volcano
inferred from magnetotellurics and electric self-potential, Earth planet.
Sci. Lett., 235, 343–355, doi:10.1016/j.epsl.2005.03.023.
Aizawa, K., Ogawa, Y. & Ishido, T., 2009. Groundwater flow and hydrothermal
systemswithin volcanic edifices: delineation by electric self-potential
and magnetotellurics, J. geophys. Res., 114, B01208, doi:10.1029/
2008JB005910.
Apuani T., Corazzato C., Cancelli A. & Tibaldi A., 2005. Stability of a
collapsing volcano (Stromboli, Italy): limit equilibrium analysis and numerical
modeling, J. Volc. Geotherm. Res., 144, 191–210, doi:10.1016/
j.jvolgeores.2004.11.028.
Aubert, M. & Yene Atangana, Q., 1996. Self-potential method in hydrogeological
exploration of volcanic areas, Ground Water, 34(6), 1010–1016.
Ball L., Ge, S., Caine, J.S., Revil, A. & Jardani, A., 2010. Constraining
fault-zone hydrogeology through integrated hydrological and geoelectrical
analysis, Hydrogeol. J., 1057–1067, 18, doi:10.1007/s10040–010-
0587-z.
Barberi, F., Civetta, L., Gasparini, P., Innocenti, F., Scandone, R. & Villari,
L., 1974. Evolution of a section of the Africa-Europe plate boundary;
paleomagnetic and volcanological evidence from Sicily, Earth planet.
Sci. Lett., 22(2), 123–132.
Barberi, F., Bertagnini, A., Landi, P. & Principe, C., 1992. A review on
phreatic eruptions and their precursors, J. Volc. Geotherm. Res., 52,
231–246, doi:10.1016/0377–0273(92)90046-G.
Barberi, F., Rosi, M. & Sodi, A., 1993. Volcanic hazard assessment at
Stromboli based on review of historical data, Acta Vulcanol., 3, 173–187.
Bonaccorso, A., Calvari, S., Garf`ı, G., Lodato, L. & Patan`e, D., 2003. Dynamics
of the December 2002 flank failure and tsunami at Stromboli
volcano inferred by volcanological and geophysical observations, Geophys.
Res. Lett., 30(18), 1941, doi:10.1029/2003GL017702.
Byrdina, S. et al. 2009. Dipolar self-potential anomaly associated with carbon
dioxide and radon flux at Syabru-Bensi hot springs in central Nepal,
J. geophys. Res., 114, B10101, doi:10.1029/2008JB006154.
Carapezza, M.L. & Federico C., 2000. The contribution of fluid geochemistry
to the volcano monitoring of Stromboli, J. Volc. Geotherm. Res., 95,
227–245.
Carapezza, M.L., Ricci, T., Ranaldi, M. & Tarchini, L., 2009. Active degassing
structures of Stromboli and variations in diffuse CO2 output
related to the volcanic activity, J. Volc. Geotherm. Res., 182, 231–245.
Cardiff, M., Barrash,W., Kitanidis, P.K., Malama, B., Revil, A., Straface, S.
& Rizzo, E., 2009. A potential-based inversion of unconfined steady-state
hydraulic tomography, Ground Water, 47(2), 259–270.
Carrera, J., Alcolea, A., Medina, A., Hidalgo, J. & Slooten, L.J., 2005.
Inverse problem in hydrogeology, Hydrogeol. J., 13(1),206–222.
Chouet, B. et al., 2003. Source mechanisms of explosions at Stromboli
Volcano, Italy, determined from moment–tensor inversions of very-longperiod
data. J. geophys. Res., 108(B1), 2019. doi:10.1029/2002JB001919.
Coppo, N. et al., 2008. Multiple caldera collapses inferred from the shallow
electrical resistivity signature of the Las Canadas caldera, Tenerife,
Canary Islands, J. Volc. Geotherm. Res, 170(3–4), 153–166.
Corwin,R.F.&Hoover,D.B., 1979. The Self-Potential method in geothermal
exploration, Geophysics, 44, 226–245.
Cruz, J.V. & Franc¸a, Z., 2006. Hydrogeochemistry of thermal and mineral
water springs of the Azores archipelago (Portugal), J. Volc. Geoth. Res.,
151 (4), 382–398.
Domenico, P.A. & Schwartz, F.W., 1990. Physical and Chemical Hydrogeology,
2nd edn, John Wiley and Sons, New York, NY, 824pp.
Etiope, G., Beneduce, P., Calcara, M., Favali, P., Frugoni, F., Schiattarella,
M. & Smriglio, G., 1999. Structural pattern and CO2-CH4 degassing of
Ustica island, Southern Tyrrhenian basin, J. Volc. Geotherm. Res., 88,
291–304.
Facca, G. & Tonani F., 1967. The self-sealing geothermal field, Bull. Volcanol.,
30, 271–273, doi:10.1007/BF02597674.
Finizola, A., Sortino, S., L´enat, J.-F. & Valenza, M., 2002. Fluid circulation
at Stromboli volcano (Aeolian Islands, Italy) from self-potential and CO2
surveys, J. Volc. Geotherm. Res., 116, 1–18.
Finizola, A., Sortino, S., L´enat, J.-F., Aubert, M., Ripepe, M. & Valenza,
M., 2003. The summit hydrothermal system of Stromboli. New insights
from self-potential, temperature, CO2 and fumarolic fluid measurements.
Structural and monitoring implications, Bull. Volcanol., 65, 486–
504.
Finizola, A. et al., 2006. Hydrogeological insights at Stromboli volcano
(Italy) from geoelectrical, temperature, and CO2 soil degassing investigations,
Geophys. Res. Lett., 33, L17304, doi:10.1029/2006GL026842.
Finizola, A. et al., 2010. Adventive hydrothermal circulation on Stromboli
volcano (Aeolian Islands, Italy) revealed by geophysical and geochemical
approaches: Implications for general fluid flow models on volcanoes, J.
Volc. Geotherm. Res., 196, 111–119.
Fitterman, D.V., Stanley W.D. & Bisdorf, R.J., 1988. Electrical structure of
Newberry volcano, Oregon, J. geophys. Res., 93, 10 119–10 134.
Francalanci, L., 1987. Evoluzione vulcanologica emagmatologica dell’isola
di Stromboli (Isole Eolie) : Relazioni tra magmatismo calc-alcalino e
shoshonitico, Tesi di Dottorato, PhD thesis. Dipartimento di Scienze della
Terra, Firenze.
G´elis, C., Revil, A., Cushing, M.E., Jougnot, D., Lemeille, F., Cabrera,
J., De Hoyos, A. & Rocher, M., 2010. Potential of electrical resistivity
tomography to detect fault zones in limestone and argillaceous formations
in the experimental site of Tournemire, France, Pure appl. Geophys.,
167(11), 1405–1418, doi:10.1007/s00024–010-0097-x.
Gillot, P.Y., 1984. Datation par la m´ethode du potassium argon des roches
volcaniques r´ecentes (pl´eistoc`enes et holoc`enes). Contribution `a l’´etude
chronostratigraphique et magmatologique des provinces volcaniques de
Campanie, des ˆıles ´eoliennes, de Pantelleria (Italie du Sud) et de la
R´eunion (Oc´ean Indien), PhD thesis, Paris.
Gillot, P.Y. & Keller, J., 1993. Radiochronological dating of Stromboli, Acta
Vulcanol., 3, 69–77.Hornig-Kjarsgaard, I., Keller, J., Koberski, U., Stadlbauer, E., Francalanci,
L. & Lenhart, R., 1993. Geology, stratigraphy and volcanological evolution
of the island of Stromboli, Aeolian arc, Italy., Acta Vulcanol., 3,
21–68.
Ingebritsen, S. E. & Sorey, M. L., 1988. Vapor-dominated zones within
hydrothermal systems: Evolution and natural state, J. geophys. Res., 93,
13,635– 13,655, doi:10.1029/JB093iB11p13635.
Ingebritsen, S. E., Geiger, S., Hurwitz, S. & Driesner, T., 2010. Numerical
simulation of magmatic hydrothermal systems, Rev. Geophys., 48,
RG1002, doi:10.1029/2009RG000287.
Jackson, D.B. & Kauahikaua, J., 1987. Regional SP anomalies at Kilauea,
Volcanism in Hawaii. USGS Prof. paper 1350, ch. 40, pp. 947–959.
Keller, J., Hornig-Kjarsgaard, I., Koberski, U., Stadlbauer, E. & Lenhart, R.,
1993. Geological map of the island of Stromboli, Acta Vulcanol., 3.
Krivochieva, S. & Chouteau,M., 2003. Integrating TDEM and MT methods
for characterizing and delineation of the Santa Catarina aquifer (Chalco
Sub-basin, Mexico), J. appl. Geophys., 52(1), 23–43.
Komori, K., Kagiyama, T., Hoshizumi H, Takakura, S. & Mimura, M.,
2010. Vertical mapping of hydrothermal fluids and alteration from bulk
conductivity: simple interpretation on the USDP-1 site, Unzen Volcano,
SW Japan, J. Volc. Geotherm. Res., 198, 339–347.
Loke, M.H., & Barker, R.D., 1996. Practical techniques for 3D resistivity
surveys and data inversion, Geophys. Prospect., 44, pp. 499–523.
L´opez, D. L. & Williams, S. N., 1993. Catastrophic volcanic collapse:
Relation to hydrothermal processes, Science, 260, 1794–1796,
doi:10.1126/science.260.5115.1794.
Lorenz, V. & Kurszlaukis, S., 2007. Root zone processes in the phreatomagmatic
pipe emplacement model and consequences for the evolution of
maar-diatreme volcanoes, J. Volc. Geotherm. Res., 159(1–3), 4–32.
Lowell, R.P.,Cappellen, P.V.&Germanovich,L.N., 1993. Silica precipitation
in fractures and the evolution of permeability in hydrothermal upflow
zones, Science, 260, 192–194, doi:10.1126/science.260.5105.192.
Marsella, M., Proietti, C., Sonnessa, A., Coltelli, M., Tommasi, P. &
Bernardo, E., 2009. The evolution of the Sciara del Fuoco subaerial
slope during the 2007 Stromboli eruption: relation between
deformation processes and effusive activity. J. Volc. Geotherm. Res,
doi:10.1016/j.jvolgeores.2009.02.002.
Michael H.A., Mulligan A.E., & Harvey C.F., 2005. Seasonal oscillations
in water exchange between aquifers and the coastal ocean, Nature, 436,
1145–1148, doi:10.1038/nature03935.
Nappi, G., Capaccioni B., Biagiotti F., & Vaselli O., 1999. Upper pyroclastic
sequence of the Scari formation: A paroxistic eruption from Stromboli
volcano (Aeolian Island, Italy), Acta Vulcanol., 11, 259–264.
Okuma, S., Stotter, C., Supper, R.,Nakatsuka, T., Furukawa, R.&Motschka,
K., 2009. Aeromagnetic constraints on the subsurface structure of Stromboli
Volcano, Aeolian Islands, Italy, Tectonophysics, 478, 19–33.
Onizawa, S., Matsushima, N., Ishido, T., Hase, H., Takakura, S. & Nishi, Y.,
2009. Self-potential distribution on active volcano controlled by threedimensional
resistivity structure in Izu-Oshima, Japan, Geophys. J. Int.,
178, 1164–1181, doi:10.1111/j.1365–246X.2009.04203.x
Pasquar`e, G., Francalanci, L., Garduno, V.H. & Tibaldi, A., 1993. Structure
and geologic evolution of the Stromboli volcano, Aeolian Islands, Italy,
Acta Vulcanol., 3, 79–89.
Petrinovic, I.A.Π˜nol, F.C., 2006. Phreatomagmatic and phreatic eruptions
in locally extensive settings of Southern Central Andes: the Tocomar
Colcanic Center (24◦10 S–66◦34 W), Argentina, J. Volc. Geotherm. Res.,
158(1–2), 37–50.
Revil A., 1999. Ionic diffusivity, electrical conductivity, membrane and
thermoelectric potentials in colloids and granular porous media: a unified
model, J. Coll. Interface Sci., 212, 503–522.
Revil, A. & Glover, P.W.J., 1998. Nature of surface electrical conductivity in
natural sands, sandstones, and clays, Geophys. Res. Lett., 25(5), 691–694.
Revil, A. & Leroy, P., 2001. Hydroelectric coupling in a clayey material,
Geophys. Res. Lett., 28(8), 1643–1646.
Revil, A., Hermitte, D., Spangenberg, E. & Coch´em´e, J.J., 2002. Electrical
properties of zeolitized volcaniclastic materials, J. geophys.Res., 107(B8),
2168, doi: 10.1029/2001JB000599.
Revil, A., Naudet, V., Nouzaret, J., & Pessel, M., 2003. Principles
of electrography applied to self-potential electrokinetic sources and
hydrogeological applications, Water Resour. Res., 39(5), 1114, doi:
10.1029/2001WR000916.
Revil, A., Naudet, V. & Meunier J. D., 2004a. The hydroelectric problem
of porous rocks: Inversion of the water table from self-potential data,
Geophys. J. Int., 159, 435–444.
Revil A., Finizola A., Sortino F. & Ripepe M., 2004b. Geophysical investigations
at Stromboli volcano, Italy. Implications for ground water flow
and paroxysmal activity, Geophys. J. Int., 157, 426–440.
Revil, A. et al., 2008. Inner structure of La Fossa di Vulcano (Vulcano
Island, southern Tyrrhenian Sea, Italy) revealed by high resolution electric
resistivity tomography coupled with self-potential, temperature, and soil
CO2 diffuse degassing measurements, J. geophys. Res., 113, B07207,
doi:10.1029/2007JB005394.
Revil, A., Johnson, T. C. & Finizola, A., 2010. Three-dimensional resistivity
tomography of Vulcan’s forge, Vulcano Island, southern Italy, Geophys.
Res. Lett., 37, L15308, doi:10.1029/2010GL043983.
Richards, K., Revil, A., Henderson, F., Batzle, M. & Haas, A., 2010. Pattern
of shallow ground water flow at Mount Princeton Hot Springs, Colorado,
using geoelectrical methods, J. Volc. Geotherm. Res., 198, 217–232.
Romagnoli, C., Casalbore, D., Chiocci, F.L. & Bosman, A., 2009a. Offshore
evidence of large-scale lateral collapses on the eastern flank of Stromboli,
Italy, due to structurally-controlled, bilateral flank instability, Mar. Geol.,
262, 1–13, doi:10.1016/j.margeo.2009.02.004.
Romagnoli, C., Kokelaar, P., Casalbore, D. & Chiocci, F.L., 2009b. Lateral
collapses and active sedimentary processes on the northwestern flank of
Stromboli volcano, Italy, Mar. Geol., 265, 101–119.
Rosi, M., 1980. The Island of Stromboli, Rend. Soc. It. Miner. Petrol., 36,
345–368.
Segre, A.G., 1968. Notizie sulla morfologia submarina di Stromboli, Stromboli,
11, 45–49.
Sinclair, A.J., 1974. Selection of threshold values in geochemical data using
probability graphs, J. Geochem. Explor., 3, 129–149.
Tibaldi, A., 2001. Multiple sector collapses at Stromboli volcano, Italy: how
they work, Bull. Vulcanol., 63, 112–125.
Tinti, S., Bortolucci, E. & Romagnoli, C., 1999. Modeling a possible
Holocenic landslide-induced tsunami at Stromboli volcano. Italy, Phys.
Chem. Earth, 24(5), 423–429.
Tinti, S., Bortolucci, E. & Romagnoli, C., 2000. Computer simulations of
tsunamis due to sector collapse at Stromboli. Italy, J. Volc. Geotherm.
Res., 96, 103–128.
Tinti, S., Pagnoni, G., Zaniboni, F. & Bortolucci, E., 2003. Tsunami generation
in Stromboli island and impact on the south-east Tyrrhenian coasts,
Nat. Hazards Earth Syst. Sci., 3, 299–309.
Tinti, S., Maramai, A.,·Armigliato, A., Grazian,i L., Manucci, A., Pagnoni,
G.&Zaniboni, F. 2006. Observations of physical effects from tsunamis of
December 30, 2002 at Stromboli volcano, southern Italy, Bull. Volcanol.,
68, 450–461, doi:10.1007/s00445–005-0021-x.
Tinti, S., Zaniboni, F., Pagnoni, G. & Manucci A., 2008. Stromboli Island
(Italy): Scenarios of Tsunamis Generated by Submarine Landslides, Pure
appl. geophys., 165, 2143–2167, doi:10.1007/s00024–008-0420-y.
Waxman, M.H. & Smits, L.J.M., 1968. Electrical conductivities in oil bearing
shaly sands, Soc. Pet. Eng. J., 8, 107–122.
Weinstein, Y., 2007. A transition from strombolian to phreatomagnatic activity
induced by a lava flow damming water in a valley, J. Volc. Geotherm.
Res, 159(1–3), 267–284.