Dike propagation in volcanic edifices: Overview and possible developments

Eruptions are fed by dikes; therefore, better knowledge of dike propagation is necessary to improve our
understanding of how magma is transferred and extruded at volcanoes. This study presents an overview of
dike patterns and the factors controlling dike propagation within volcanic edifices. Largely based on
published data, three main types of dikes (regional, circumferential and radial) are illustrated and discussed.
Dike pattern data from 25 volcanic edifices in different settings are compared to derive semi-quantitative
relationships between the topography (relief, shape, height, and presence of sector collapses) of the volcano,
tectonic setting (presence of a regional stress field), and mean composition (SiO2 content). The overview
demonstrates how dike propagation in a volcano is not a random process; rather, it depends from the
following factors (listed in order of importance): the presence of relief, the shape of the edifice and regional
tectonic control. We find that taller volcanoes develop longer radial dikes, whose (mainly lateral)
propagation is independent of the composition of magma or the aspect ratio of the edifice. Future research,
starting from these preliminary evaluations, should be devoted to identifying dike propagation paths and
likely locations of vent formation at specific volcanoes, to better aid hazards assessment.

Partly fundedwith DPC-INGVfunds (LAVAProject).

Ablay, G.J., Carroll, M.R., Palmer, M.R., Martí, J., Sparks, R.S.J., 1998. Basanite–phonolite
lineages of the Teide-Pico Viejo volcanic complex, Tenerife, Canary Islands. J. Petrol.
39, 905–936.
Acocella, V., 2006. Regional and local tectonics at Erta Ale caldera, Afar (Ethiopia).
J. Struct. Geol. 28, 1808–1820.
Acocella, V., Neri, M., 2003.What makes flank eruptions? The 2001 Etna eruption and its
possible triggering mechanisms. Bull. Volcanol. 65, 517–529. doi:10.1007/s00445-
003-0280-3.
Acocella, V., Tibaldi, A., 2005. Dike propagation driven by volcano collapse: a general
model tested at Stromboli, Italy. Geophys. Res. Lett. 32, L08308. doi:10.1029/
2004GL022248.
Acocella, V., Cifelli, F., Funiciello, R., 2001. The control of overburden thickness on
resurgent domes: insights from analogue models. J. Volcanol. Geotherm. Res. 111,
137–153.
Acocella, V., Neri, M., Scarlato, P., 2006a. Understanding shallow magma emplacement
at volcanoes: orthogonal feeder dikes during the 2002–2003 Stromboli (Italy)
eruption. Geophys. Res. Lett. 33, L17310. doi:10.1029/2006GL026862.
Acocella, V., Porreca, M., Neri, M., Mattei, M., Funiciello, R., 2006b. Fissure eruptions at
Mount Vesuvius (Italy): insights on the shallow propagation of dikes at volcanoes.
Geology 34, 673–676. doi:10.1130/G22552.1.
Acocella, V., Porreca, M., Neri, M., Massimi, E., Mattei, M., 2006c. Propagation of dikes at
Vesuvio (Italy) and the effect of Mt. Somma. Geophys. Res. Lett. 33, L08301.
doi:10.1029/2005GL025590.
Acosta, J., Uchupi, E., Smith, D., Munoz, A., Herranz, P., Palomo, C., Llanes, P., Ballesteros,
M., Zee Working Group, 2003. Comparison of volcanic rifts on La Palma and El
Hierro, Canary Islands and the Island of Hawaii. Marine Geophys. Res. 24, 59–90.
Albarède, F., Luais, B., Fitton, G., Semet, M., Kaminski, E., Upton, B.G.J., Bachelery, P.,
Cheminee, J.-L., 1997. The geochemical regimes of Piton de la Fournaise volcano
(Reunion) during the last 530 000 years. J. Petrol. 38, 171–201.
Allard, P., Behncke, B., D'Amico, S., Neri, M., Gambino, S., 2006. Mount Etna 1993–2005.
Anatomy of an evolving eruptive cycle. Earth Sci. Rev. 78, 85–114. doi:10.1016/j.
earscirev.2006.04.002.
Amma-Miyasaka, M., Nakagawa, M., 2002. Origin of anorthite and olivine megacrysts in
island-arc tholeiites: petrological study of 1940 and 1962 ejecta from Miyake-Jima
volcano, Izu-mariana arc. J. Volcanol. Geotherm. Res. 117, 263–283.
Anderson, E.M., 1936. The dynamics of the formation of cone-sheets, ring dykes and
cauldron subsidence. Proc. Roy. Soc. Edin. 56, 128–157.
Barberi, F., Varet, J., 1970. The Erta Ale Volcanic Range (Danakil depression, northern
Afar, Ethiopia). Bull. Volcanol. 34, 848–917.
Barberi, F., Civetta, L., Varet, J., 1980. Sr isotopic composition of Afar volcanics and its
implications for mantle evolution. Earth Planet. Sci. Lett. 50, 247–259.
Barrat, J.A., Fourcade, S., Jahn, B.M., Chemirke, J.L., Capdevila, R.,1998. Isotope (Sr, Nd, Pb,
O) and trace-element geochemistry of volcanics from the Erta' Ale range (Ethiopia).
J. Volcanol. Geotherm. Res. 80, 85–100.
Behncke, B., Neri, M., 2003. Cycles and trends in the recent eruptive behaviour of Mount
Etna (Italy). Can. J. Earth Sci. 40, 1405–1411. doi:10.1139/E03-052.
Behncke, B., Neri,M., Nagay, A., 2005. Lava flowhazard at Mount Etna (Italy): newdata from
a GIS-based study. In Kinematics and dynamics of lava flows, edited by Manga, M.,
Ventura, G., Spec. Pap. Geol. Soc. Am., 396-13,187–205. doi:10.1130/0-8137-2396-5.189.
Billi, A., Acocella, V., Funiciello, R., Giordano, G., Lanzafame, G., Neri, M., 2003.
Mechanism for ground surface fracturing and incipient slope failure associated
with the 2001 eruption of Mt. Etna, Italy: analysis of ephemeral field data.
J. Volcanol. Geotherm. Res. 122, 281–294.
Bousquet, J.C., Lanzafame, G., 2001. Nouvelle interprétation des fractures des éruptions
latérales de l'Etna: conséquences pour son cadre tectonique. Bull. Soc. Geol. Fr. 172,
455–467.
Calvari, S., Spampinato, L., Lodato, L., Harris, A.J.L., Patrick, M.R., Dehn, J., Burton, M.R.,
Andronico, D., 2005. Chronology and complex volcanic processes during the 2002–
2003 flank eruption at Stromboli volcano (Italy) reconstructed from direct
observations and surveys with a handheld thermal camera. J. Geophys. Res. 110.
doi:10.1029/2004JB003129.
Carracedo, J.C., Rodriguez Badiola, E., Guillou, H., Paterne, M., Scaillet, S., Perez Torrado,
F.J., Paris, R., Fra-Paleo, U., Hansen, A., 2007. Eruptive and structural history of Teide
volcano and rift zones of Tenerife, Canary Islands. GSA Bull. 119, 1027–1051.
Carter, A., van Wyk de Vries, B., Kelfoun, K., Bachelery, P., Briole, P., 2007. Pits, rifts and
slumps: the summit structure of Piton de la Fournaise. Bull. Volcanol. doi:10.1007/
s00445-006-0103-4.
Cayol, V., Cornet, F.H., 1998. Three-dimensional modelling of the 1983–1984 eruption at
piton de la Fournaise Volcano, Reunion Island. J. Geophys. Res. 103, 18025–18037.
Chadwick, W.W., Howard, K.A., 1991. The pattern of circumferential and radial eruptive
fissures on the volcanoes of Fernandina and Isabela islands, Galapagos. Bull.
Volcanol. 53, 259–275.
Chadwick, J.R., Dieterich, J.H., 1995. Mechanical modeling of circumferential and radial
dike intrusion on Galapagos volcanoes. J. Volcanol. Geotherm. Res. 66, 37–52.
Corazzato, C., Francalanci, L., Menna, M., Petrone, M.C., Renzulli, A., Tibaldi, A., Vezzoli,
L., 2008. What controls sheet intrusion in volcanoes? Structure and Petrology of the
Stromboli sheet complex, Italy. J. Volcanol. Geotherm. Res. 173, 26–54.
Corsaro, R.A., Neri, M., Pompilio, M., 2002. Paleo-environmental and volcano-tectonic
evolution of the south-eastern flank of Mt. Etna during the last 225 ka inferred from
volcanic succession of the «Timpe», Acireale, Sicily. J. Volcanol. Geotherm. Res. 113,
289–306.
Day, S.J., Heleno da Silva, S.I.N., Fonseca, J.F.B.D., 1999. A past giant lateral collapse and
present-day flank instability of Fogo, Cape Verde Islands. J. Volcanol. Geotherm. Res.
94, 191–218.
Decker, R.W., 1987. Dynamics of Hawaiian volcanoes: an overview. U.S. Geological Surv.
Prof. Pap. 1350, 997–1018.
Delaney, P.T., Pollard, D.D., Ziony, J.I., McKee, E.H., 1986. Field relations between dikes
and joints — emplacement processes and paleostress analysis. J. Geophys. Res. 91,
4920–4938.
Desmarais, E.K., Segall, P., 2007. Transient deformation following the 30 January 1997
dike intrusion at Kilauea volcano, Hawaii. Bull. Volcanol. 69, 253–363.
Dieterich, J.H., 1988. Growth and persistence of Hawaiian volcanic rift zones. J. Geophys.
Res. 93, 4258–4270.
Donnelly-Nolan, J.M., 1990. Post 11000 year volcanism at Medicine Lake volcano,
cascade Range, Northern California. J. Geophys. Res. 95, 19693–19704.
Doucelance, R., Escrig, S., Moreira, M., Gariépy, C., Kurz, M.D., 2003. Pb–Sr–He isotope
and trace element geochemistry of the Cape Verde Archipelago. Geochim.
Cosmochim. Acta 67, 3717–3733.
Driscoll, B.O., Troll, V.R., Reavy, R.J., Turner, P., 2006. The Great Eucrite intrusion of
Ardnamurchan, Scotland, reevaluating the ring-dike concept. Geology 34, 189–192.
Ebinger, C.J., Casey, M., 2001. Continental breakup in magmatic provinces: an Ethiopian
example. Geology 29, 527–530.
Ferrari, L., Garduno, V.H., Neri, M., 1991. I dicchi della Valle del Bove, Etna: un metodo
per stimare le dilatazioni di un apparato vulcanico. Mem. Soc. Geol. It. 47, 495–508.
Fiske, R.S., Jackson, E.D., 1972. Orientation and growth of Hawaiian volcanic rifts: the
effect of regional structure and gravitational stresses. Proc. R. Soc. Lond. 329,
299–326.
Geshi, N., Shimano, T., Chiba, T., Nakada, S., 2002. Caldera collapse during the 2000
eruption of Miyakejima volcano, Japan. Bull. Volcanol. 64, 55–68.
Gudmundsson, A., 1995. Infrastructure and mechanics of volcanic systems in Iceland.
J. Volcanol. Geotherm. Res. 64, 1–22.
Gudmundsson, A., 1998. Magma chambers modeled as cavities explain the formation of
rift zone central volcanoes and their eruption and intrusion statistics. J. Geophys.
Res. 103, 7401–7412.
Gudmundsson, A., 2002. Emplacement and arrest of sheets and dykes in central
volcanoes. J. Volcanol. Geotherm. Res. 116, 279–298.
Gudmundsson, A., 2003. Surface stresses associated with arrested dykes in rift zones.
Bull. Volcanol. 65, 606–619.
Gudmundsson, A., 2006. How local stresses control magma-chamber ruptures, dyke
injections, and eruptions in composite volcanoes. Earth Sci. Rev. 79, 1–31.
Gudmundsson, A., Nilsen, K., 2006. Ring faults in composite volcanoes: structures,
models, and stress fields associated with their formation. J. Geol. Soc. Lond. 269,
83–108.
Gudmundsson, A., Oskarsson, N., Gronvold, K., Saemundsson, K., Sigurdsson, O.,
Stefansson, R., Gislason, S.R., Einarsson, P., Brandsdottir, B., Larsen, G., Johannesson,
H., Thordarson, T., 1992. The 1991 eruption of Hekla, Iceland. Bull. Volcanol. 54,
238–246.
Kennedy, B., Styx, J., 2007. Magmatic processes associatedwith caldera collapse at Ossipee
ring dyke, New Hampshire. Bull. Geol. Soc. Am. 119, 3–17. doi:10.1130/B25980.1.
Komorowski, J.C., et al., 2002. The January 2002 flank eruption of Nyiragongo volcano
(DRC): Chronology, evidence for a tectonic rift trigger and impact of lava flows on
the city of Goma. Acta Vulcanol. 14, 25–57.
Kondo, H., Tanaka, K., Mizuochi, Y., Ninomiya, A., 2004. Long-term changes in the
distribution and chemistry of middle Miocene to Quaternary volcanism in the
Chokai-Kurikoma area across the northeast Japan Arc. Island Arc 13, 18–46.
Knopf, A., 1936. Igneous geology of the Spanish Peaks region, Colorado. Geol. Soc. Am.
Bull. 68, 1727–1784.
Krassilnikov, A.S., Head, J.W., 2003. Novae on Venus: geology, classification, evolution.
J. Geophys. Res. 108, 5108. doi:10.1029/2002JE001983.
Hayashi, S., Kasahara, M., Tanaka, K., Hamaguchi, H., Zana, N., 1992. Major chemistry of
recent eruptive products from Nyamuragire volcano, Africa (1976–1989). Tectonophysics
209, 273–276.
Holcomb, R.T., 1987. Eruptive history and long-term behavior of Kilauea volcano. U.S.
Geol. Survey Prof. Pap. 1350, 261–350.
Ida, Y., 1995. Magma chamber and eruptive processes at Izu-Oshima volcano, Japan:
buoyancy control of magma migration. J. Volcanol. Geotherm. Res. 66, 53–67.
La Femina, P.C., Condor, C.B., Hill, B.E., Strauch, W., Saballos, J.A., 2004. Magma-tectonic
interactions in Nicaragua: the 1999 seismic swarm and eruption of Cerro Negro
volcano. J. Volcanol. Geotherm. Res. 137, 187–199.
Lanzafame, G., Neri, M., Acocella, V., Billi, A., Funiciello, R., Giordano, G., 2003. Structural
features of the July–August 2001 Mount Etna eruption: evidence for a complex
magmatic system. J. Geol. Soc. Lond. 160, 531–544.
Lockwood, J.P., Lipman, P.W., 1987. Holocene eruptive history of Mauna Loa volcano. U.S.
Geol. Surv. Prof. Pap. 1350, 509–535.
Macdonald, K.C., 1998. Linkages between faulting, volcanism, hydrothermal activity and
segmentation on fast spreading centres. In: Buck, W.R., Delaney, P.T., Karson, J.A.,
Lagabrielle, Y. (Eds.), Faulting and Magmatism at Mid-Ocean Ridges. Am. Geophys.
Un., Washington, pp. 27–58.
Marinoni, L.B., Gudmundsson, A., 2000. Dykes, faults and paleostresses in the Teno and
Anaga massifs of Tenerife (Canary Islands). J. Volcanol. Geotherm. Res. 103, 83–103.
Mattioli, G.S., Dixon, T.H., Farina, F., Howell, E.S., Jansma, P.E., Smith, A.L., 1998. GPS
measurement of surface deformation around Soufriere Hills volcano, Montserrat,
from October 1995 to July 1996. Geophys. Res. Lett. 25, 3417–3420.
McGuire, W.J., Pullen, A.D., 1989. Location and orientation of eruptive fissures and
feeder-dykes at Mount Etna: influence of gravitational and regional stress regimes.
J. Volcanol. Geotherm. Res. 38, 325–344.
Morita, Y., Nakao, S., Hayashi, Y., 2006. A quantitative approach to the dike intrusion
process inferred from a joint analysis of geodetic and seismological data for the
1998 earthquake swarm of the east coast of Izu Peninsula, central Japan. J. Geophys.
Res. 111, B06208. doi:10.1029/2005JB003860.
Munro, D.C., Rowland, S.K., 1996. Caldera morphology in the western Galapagos and
implications for volcano eruptive behaviour and mechanism of caldera formation.
J. Volcanol. Geotherm. Res. 72, 85–100.
Nakamura, K., 1977. Volcanoes as possible indicators of tectonic stress orientation:
principle and proposal. J. Volcanol. Geotherm. Res. 2, 1–16.
Nakano, S., Tsuchiya, N., 1992. Geology of the Chokaisan and Fukura district. with
geological sheet map at 1:50,000. Geol. Surv. Japan 138 pp. (in Japanese with
English abstract 7p).
Nairn, I.A., Kobayashi, T., Nakagawa, M., 1998. The ∼10 ka multiple vent pyroclastic
eruption sequence at Tongariro Volcanic Centre, Taupo Volcanic Zone, New
Zealand. Part 1. Eruptive processes during regional extension. J. Volcanol.
Geotherm. Res. 86, 19–44.
Naumann, T., Geist, D., Kurz, M., 2002. Petrology and geochemistry of Volcán Cerro Azul:
petrologic diversity among the western Galápagos volcanoes. J. Petrol. 43, 859–883.
Neal, C.A., Lockwood, J.P., 2003. Geologic map of the summit region of Kilauea Volcano,
Hawaii. USGS map MI-2759.
Neri, M., Acocella, V., 2006. The 2004–05 Etna eruption: implications for flank
deformation and structural behaviour of the volcano. J. Volcanol. Geotherm. Res.
158, 195–206. doi:10.1016/j.jvolgeores.2006.04.022.
Neri, M., Acocella, V., Behncke, B., 2004. The role of the Pernicana fault system in the
spreading of Mt. Etna (Italy) during the 2002–2003 eruption. Bull. Volcanol. 66,
417–430. doi:10.1007/s00445-003-0322-x.
Neri, M., Acocella, V., Behncke, B., Maiolino, V., Ursino, A., Velardita, R., 2005.
Contrasting triggering mechanisms of the 2001 and 2002–2003 eruptions of
Mount Etna (Italy). J. Volcanol. Geotherm. Res. 144, 235–255.
Neri, M., Guglielmino, F., Rust, D., 2007. Flank instability on Mount Etna: Radon, radar
interferometry, and geodetic data from the southwestern boundary of the unstable
sector. J. Geophys. Res. 112, B04410. doi:10.1029/2006JB0047.
Neri, M., Lanzafame, G., Acocella, V., 2008. Dike emplacement and related hazard in
volcanoes with sector collapse: the Stromboli 2007 eruption. J. Geol. Soc. Lond.
in press.
Newhall, C.G., Dzurisin, D., 1988. Historical unrest at large calderas of the world. U.S.
Geological Survey. 1109 pp.
Nostro, C., Stein, R.S., Cocco, M., Belardinelli, M.E., Marzocchi, W., 1998. Two-way
coupling between Vesuvius eruptions and southern Apennine earthquakes, Italy, by
elastic stress transfer. J. Geophys. Res. 103, 24487–24504.
Ode, H., 1957. Mechanical analysis of the dike pattern of the Spanish Peaks area,
Colorado. Geol. Soc. Am. Bull. 68, 567–575.
Ozerov, A.Yu., Ariskin, A.A., Kyle, Ph., Bogoyavlenskaya, G.E., Karpenko, S.F., 1997.
Petrological–geochemical model for genetic relationships between basaltic and
andesitic magmatism of Klyuchevskoi and Bezymyannyi volcanoes, Kamchatka.
Petrology 5, 550–569.
Paquet, F., Dauteuil, O., Hallot, E., Moreau, F., 2007. Tectonics and magma dynamics
coupling in a dyke swarm of Iceland. J. Struct. Geol. 29, 1477–1493.
Phillips, W.J., 1974. The dynamic emplacement of cone sheets. Tectonophysics 24,
69–84.
Pinel, V., Jaupart, C., 2000. the effect of edifice load on magma scent beneath a volcano.
Phil. Trans. R. Soc. Lond. 358, 1515–1532.
Pinel, V., Jaupart, C., 2003. Magma chamber behavior beneath a volcanic edifice.
J. Geophys. Res. 108, 2072. doi:10.1029/2002JB001751.
Pinel, V., Jaupart, C., 2004. Magma storage and horizontal dike injection beneath a
volcanic edifice. Earth Planet. Sci. Lett. 221, 245–262.
Platz, T., Foley, S.F., Andrè, L., 2004. Low-pressure fractionation of the Nyitagongo
volcanic rocks, Virunga Province, D.R. Congo. J. Volcanol. Geotherm. Res. 136,
269–295.
Pollard, D.D., 1973. Derivation and evaluation of a mechanical model for sheet
intrusions. Tectonophysics 19, 233–269.
Pollard, D.D., Muller, O.H., 1976. Effect of gradients in regional stress and magma
pressure on form of sheet intrusions in cross-section. J. Geophys. Res. 81, 975–984.
Poland, M.P., Fink, J.H., Tauxe, L., 2004. Patterns of magma flow in segmented silicic
dikes at Summer Coon volcano, Colorado: AMS and thin section analysis. Earth
Planet. Sci. Lett. 219, 155–169.
Poland, M.P., Moats, W.P., Fink, J.H., 2008. A model for radial dike emplacement in
composite cones based on observations from Summer Coon volcano, Colorado, USA.
Bull. Volcanol 70, 861–875. doi:10.1007/s00445-007-0175-9.
Rubin, A.M., Pollard, D.D.,1987. Origin of blade-like dikes in volcanic rift zones. U.S. Geol.
Surv. Prof. Pap. 1350, 1449–1470.
Rubin, A.M., Pollard, D.D., 1988. Dike-induced faulting in rift zones of Iceland and Afar.
Geology 16, 413–417.
Rust, D., Behncke, B., Neri, M., Ciocanel, A., 2005. Nested zones of instability in the
Mount Etna volcanic edifice, Sicily. J. Volcanol. Geotherm. Res. 155, 137–153.
doi:10.1016/j.jvolgeores.2004.11.021.
Sato, M., Hamaguchi, H., 2006. Weak long-lived round deformation related to Iwate
volcanism revealed by Bayesian decomposition of strain, tilt and positioning data.
J. Volcanol. Geotherm. Res. 155, 244–262.
Sigmundsson, F., 2006. Magma does the splits. Nature 442, 251–252.
Skilling, I.P., 1993. Incremental caldera collapse of Suswa volcano, Gregory Rift Valley,
Kenya. J. Geol. Soc. London 150, 885–896.
Soriano, C., Beamud, E., Garcés,M., 2008.Magma flowin dikes fromrift zones of the basaltic
shield of Tenerife, Canary Islands: implications for the emplacement of buoyant
magma. J. Volcanol. Geotherm. Res. 173, 55–68. doi:10.1016/j.jvolgeores.2008.01.007.
Takada, A., 1997. Cyclic flank-vent and central-vent eruption patterns. Bull. Volcanol. 58,
539–556.
Takada, A., Ishizuka, Y., Nakano, S., Yamamoto, T., Kobayashi, M., Suzuki, Y., 2007.
Characteristic and evolution inferred from eruptive fissures of Fuji volcano, Japan.
In: Aramaki, S. (Ed.), Fuji Volcano. Volcanol. Soc., Japan, Tokyo, pp. 183–202.
Tedesco, D., Vaselli, O., Papale, P., Carn, S.A., Voltaggio, M., Sawyer, G.M., Durieux, J.,
Kasereka, M., Tassi, F., 2007. January 2002 volcano-tectonic eruption of Nyiragongo
volcano, Democratic Republic of Congo. J. Geophys. Res. 112, B09202. doi:10.1029/
2006JB004762.
Tibaldi, A., 2003. Influence of cone morphology on dikes, Stromboli, Italy. J. Volcanol.
Geotherm. Res. 126, 79–95.
Tibaldi, A., 2005. Volcanism in compressional tectonic settings. Is it possible? Geophys.
Res. Lett. 32. doi:10.1029/2004GL021798.
Tibaldi, A., Bistacchi, A., Pasquare, F.A., Vezzoli, L., 2006. Extensional tectonics and
volcano lateral collapses: insights from Ollague volcano (Chile–Bolivia) and
analogue modelling. Terra Nova 18, 282–289.
Thornber, C.R., Heliker, C., Sherrod, D.R., Kauahikaua, J.P., Miklius, A., Okubo, P.G.,
Trusdell, F.A., Budahn, J.R., Ridley, W.I., Meeker, G.P., 2003. Kilauea East Rift Zone
magmatism: an episode 54 perspective. J. Petrol. 44, 1525–1559.
Troll, V.R., Emeleus, C.H., Donaldson, C.H., 2000. Caldera formation in the Rum Central
Igneous Complex, Scotland. Bull. Volcanol. 62, 301–317.
Ueda, H., Fujita, E., Ukawa, M., Yamamoto, E., Irwan, M., Kimata, F., 2005. Magma
intrusion and discharge process at the initial stage of the 2000 activity of
Miyakejima, Central Japan, inferred from tilt and GPS data. Geophys. J. Int. 161,
891–906.
Vezzoli, L., Acocella, V., 2006. Geological and structural evolution of Easter Island
(Chile). Proceedings of EGU meeting, Vienna (Austria), April 2006, p. 509. Abstract
volume pag.
Walker, G.P.L., 1987. The dike complex of Koolau volcano, Oahu: internal structure of a
Hawaiian rift zone. U.S. Geol. Surv. Prof. Pap. 1350, 961–993.
Walter, T.R., 2003. Buttressing and fractional spreading of Tenerife, an experimental
approach on the formation of rift zones. Geophys. Res. Lett. 30, 1296. doi:10.1029/
2002GL016610.
Walter, T.R., Troll, V.R., Cailleau, B., Belousov, A., Schmincke, H.U., Amelung, F., Bogaard,
P., 2005a. Rift zone reorganization through flank instability in ocean island
volcanoes: an example from Tenerife, Canary Islands. Bull. Volcanol. 67, 281–291.
Walter, T.R., Acocella, V., Neri, M., Amelung, F., 2005b. Feedback processes between
magmatism and E-flank movement at Mt. Etna (Italy) during the 2002–2003
eruption. J. Geophys. Res. 110, B10205. doi:10.1029/2005JB003688.
Walter, T.R., Klugel, A., Munn, S., 2006. Gravitational spreading and formation of new rift
zones on overlapping volcanoes. Terra Nova 18, 26–33.
Witter, J.B., Kress, V.C., Delmelle, P., Stix, J., 2004. Volatile degassing, petrology and
magma dynamics of the Villarrica Lava Lake, Southern Chile. J. Volcanol. Geotherm.
Res. 134, 303–337.
Wright, T.J., Ebinger, C., Biggs, J., Ayele, A., Yirgu, G., Keir, D., Stork, A., 2006. Magma
maintained rift segmentation at continental rupture in the 2005 Afar dyking episode.
Nature 442, 291–294. doi:10.1038/nature04978.
Yamamoto, T., Takada, A., Ishizuka, Y., Miyaji, N., Tajima, Y., 2005. Basaltic pyroclastic
flows of Fuji volcano, Japan: characteristics of their deposits and their origin. Bull.
Volcanol. 67, 622–633.
Yoshida, T., 1984. Tertiary Ishizuchi Cauldron, Southwestern Japan Arc: formation by
ring fracture subsidence. J. Geophys. Res. 89, 8502–8510.