Bulletin of Volcanology

, Volume 65, Issue 7, pp 517–529 | Cite as

What makes flank eruptions? The 2001 Etna eruption and its possible triggering mechanisms

Research Article


Most flank eruptions within a central stratovolcano are triggered by lateral draining of magma from its central conduit, and only few eruptions appear to be independent of the central conduit. In order to better highlight the dynamics of flank eruptions in a central stratovolcano, we review the eruptive history of Etna over the last 100 years. In particular, we take into consideration the Mount Etna eruption in 2001, which showed both summit activity and a flank eruption interpreted to be independent from the summit system. The eruption started with the emplacement of a ~N-S trending peripheral dike, responsible for the extrusion of 75% of the total volume of the erupted products. The rest of the magma was extruded through the summit conduit system (SE crater), feeding two radial dikes. The distribution of the seismicity and structures related to the propagation of the peripheral dike and volumetric considerations on the erupted magmas exclude a shallow connection between the summit and the peripheral magmatic systems during the eruption. Even though the summit and the peripheral magmatic systems were independent at shallow depths (<3 km b.s.l.), petro-chemical data suggest that a common magma rising from depth fed the two systems. This deep connection resulted in the extrusion of residual magma from the summit system and of new magma from the peripheral system. Gravitational stresses predominate at the surface, controlling the emplacement of the dikes radiating from the summit; conversely, regional tectonics, possibly related to N-S trending structures, remains the most likely factor to have controlled at depth the rise of magma feeding the peripheral eruption.


Central volcanoes Summit and flank eruptions Dikes Tectonics Volcano load Mount Etna 


  1. Acocella V, Cifelli F, Funiciello R (2001) The control of overburden thickness on resurgent domes: insights from analogue models. J Volcanol Geotherm Res 111:137–153CrossRefGoogle Scholar
  2. Acocella V, Cifelli R, Funiciello R, Minore L (2002) Analogue models of dike emplacement. Proceedings EGS meeting Nice, France, April 2002, Abstract vol, p 112Google Scholar
  3. Adams N.K, de Silva S.L, Self S, Salas G, Schubring S, Parmenter JL, Arbesman K (2001) The physical volcanology of the 1600 eruption of Huaynaputina, southern Peru. Bull Volcanol 62:493–518CrossRefGoogle Scholar
  4. Alfano GB, Friedlaender I (1929) La storia del Vesuvio. Verlag Dr Karl Höhn, Ulm a.D., p 67Google Scholar
  5. Andronico D, Lodato L, Neri M (2002) Analysis of the 20th century effusive activity at Mount Etna to assess the potential effusive hazard. Proceedings EGS Meeting Nice, France, April 2002Google Scholar
  6. Behncke B, Neri M (2003) The July–August 2001 eruption of Mount Etna (Sicily). Bull Volcanol (in press)Google Scholar
  7. Bonaccorso A, Aloisi M, Mattia M (2002) Dike emplacement forerunning the Etna July 2001 eruption modeled through continuous tilt and GPS data. Geophys Res Lett (in press). DOI 10.1007/s00445-003-0274-1Google Scholar
  8. Bonafede M, Danesi S (1997) Near-field modifications of stress induced by dyke injection at shallow depth. Geophys J Int 130:435–448Google Scholar
  9. Borgia A, Ferrari L, Pasquarè G (1992) Importance of gravitational spreading in the tectonic and volcanic evolution of Mt. Etna. Nature 357:231–235Google Scholar
  10. Borgia A, Lanari R, Sansosti E, Tesauro M, Berardino P, Fornaro G, Neri M, Murray JB (2000) Actively growing anticlines beneath Catania from the distal motion of Mount Etna's decollement measured by SAR interferometry and GPS. Geophys Res Lett 27:3409–3412Google Scholar
  11. Bousquet JC, Lanzafame G (1986) Déformations compressives quaternaires au bord sud de l'Etna. C R Acad Sci Paris 303:235–240PubMedGoogle Scholar
  12. Bousquet JC, Lanzafame G (2001) Nouvelle interprétation des fractures des éruptions latérales de l'Etna: conséquences pour son cadre tectonique. Bull Soc Géol Fr 172:455–467Google Scholar
  13. Bottari A, Lo Giudice E, Patanè G, Romano R, Sturiale C (1975) L'eruzione etnea del gennaio-marzo 1974. Riv Miner Siciliana 154:175–198Google Scholar
  14. Calvari S, Groppelli GL, Pasquarè G (1994) Preliminary geological data on the south-western walls of Valle del Bove, Mt. Etna (Sicily). Acta Vulcanol 5:15–30Google Scholar
  15. Chadwick JR, Dieterich JH (1995) Mechanical modeling of circumferential and radial dike intrusion on Galapagos volcanoes. J Volcanol Geotherm Res 66:37–52CrossRefGoogle Scholar
  16. Coltelli M, Garduño VH, Neri M, Pasquarè G, Pompilio M (1994) Geology of the northern wall of Valle del Bove, Etna (Sicily). Acta Vulcanol 5:55–68Google Scholar
  17. Corsaro R, 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 72:1–19Google Scholar
  18. Cristofolini R, Lentini F, Patanè G, Rasà R (1979) Integrazione di dati geologici, geofisici, e metrologici per la stesura di un profilo crostale in corrispondenza dell'Etna. Boll Soc Geol It 98:239–247Google Scholar
  19. Cronin SJ, Bebbington M, Lai CD (2001) A probabilistic assessment of eruption recurrence of Taveuni volcano, Fiji. Bull Volcanol 63:274–288CrossRefGoogle Scholar
  20. Decker RW (1987) Dynamics of Hawaiian volcanoes: an overview. US Geological Survey Professional Paper 1350:997–1018Google Scholar
  21. Di Geronimo I, Ghisetti F, Lentini F, Mezzani L (1978) Lineamenti neottettonici della Sicilia orientale. Mem Soc Geol It 19:543–549Google Scholar
  22. Dvorak JJ, Nakamura A (1987) A hydraulic model to explain variations in summit tilt rate at Kilauea and Mauna Loa volcanoes. US Geol Surv Prof Pap 1350:1281–1296Google Scholar
  23. Ferrari L, Garduño VH, Neri M (1991) I dicchi della valle del Bove, Etna: un metodo per stimare le dilatazioni di un apparato vulcanico. Mem Soc Geol It 47:495–508Google Scholar
  24. Fiske RS, Jackson ED (1972) Orientation and growth of Hawaiian volcanic rifts: the effect of regional structure and gravitational stresses. Proc R Soc Lond 329:299–326Google Scholar
  25. Froger JL, Merle O, Briole P (2001) Active spreading and regional extension at Mount Etna imaged by SAR interferometry. Earth Planet Sci Lett 187:245–258CrossRefGoogle Scholar
  26. Garduño VH, Neri M, Pasquarè G, Borgia A, Tibaldi A (1997) Geology of the NE Rift of Mount Etna, Sicily (Italy). Acta Vulcanol 9:91–100Google Scholar
  27. Gillot PY, Kieffer G, Romano R (1994) The evolution of Mount Etna in the light of potassium-argon dating. Acta Vulcanol 5:81–87Google Scholar
  28. Geshi N, Shimano T, Chiba T, Nakada S, (2002) Caldera collapse during the 2000 eruption of Miyakejima volcano, Japan. Bull Volcanol 64:55–68CrossRefGoogle Scholar
  29. Gudmundsson A (1987) Lateral magma flow, caldera collapse and a mechanism of large eruptions in Iceland. J Volcanol Geotherm Res 34:65–78Google Scholar
  30. Gudmundsson A (1995) The geometry and growth of dykes. In: Baer G, Heimann A (eds), Physics and chemistry of dykes 23–33. Balkema, RotterdamGoogle Scholar
  31. 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 103:7401–7412Google Scholar
  32. Gudmundsson A (2002) Emplacement and arrest of sheets and dykes in central volcanoes. J Volcanol Geotherm Res 116:279–298CrossRefGoogle Scholar
  33. Gudmundsson A, Brenner SL (2001) How hydrofractures become arrested. Terra Nova 13:456–462CrossRefGoogle Scholar
  34. Gudmundsson A, Fjeldskaar I, Brenner SL (2002) Propagation pathways and fluid transport of hydrofractures in jointed and layered rocks in geothermal fields. J Volcanol Geotherm Res 116:257–278CrossRefGoogle Scholar
  35. Holcomb RT (1987) Eruptive history and long-term behaviour of Kilauea volcano. US Geol Surv Prof Pap 1350:261–350Google Scholar
  36. Jonsson S, Zebker H, Cervelli P, Segall P, Garbeil H, Mouginis-Mark P, Rowland S (1999) A shallow-dipping dike fed the 1995 flank eruption at Fernandina volcano, Galapagos, observed by satellite radar interferometry. Geophys Res Lett 26:1077–1080CrossRefGoogle Scholar
  37. Kieffer G (1985) Évolution structurale et dynamique d'un grand volcan polygénique: stade d'édification et activité actuelle de l'Etna. PhD Thesis, Univ Clermont-Ferrand II, 497 ppGoogle Scholar
  38. Labaume P, Bousquet JC, Lanzafame G, (1990) Early deformations at a submarine compressive front: the Quaternary Catania foredeep south Mt. Etna, Sicily. Tectonophysics 177:349–366Google Scholar
  39. Lanzafame G, Leonardi A, Neri M, Rust D (1997a) Late overthrust of the Appenine-Maghrebian Chain at the NE periphery of Mt. Etna, Italy. C R Acad Sci Paris 324:325–332Google Scholar
  40. Lanzafame G, Neri M, Coltelli M, Lodato L, Rust D (1997b) North-South compression in the Mt. Etna region (Sicily): spatial and temporal distribution. Acta Vulcanol 9:121–133Google Scholar
  41. Lanzafame G, Neri M, Acocella V, Billi A, Funiciello R, Giordano G (2003) July–August 2001 Etna eruption: deformative pattern and its significance. Journal of the Geological Society of London (in press)Google Scholar
  42. Lo Giudice E, Rasà R (1992) Very shallow earthquakes and brittle deformation in active volcanic areas. The Etnean region as an example. Tectonophysics 202:257–268Google Scholar
  43. Lockwood JP, Dvorak JJ, English TT, Koyanagi RY, Okamura AT, Summers ML, Tanigawa WR (1987) Mauna Loa 1974–1984. A decade of intrusive and extrusive activity. US Geol Surv Prof Pap 1350:537–570Google Scholar
  44. McClelland L, Simkin T, Summers M, Nielsen E, Stein TC (1989) Global volcanism, 1975–1985. Prentice Hall, Englewood Cliffs, 657 ppGoogle Scholar
  45. McGuire WJ (1982) Evolution of the Etna volcano: information from the southern wall of the Valle del Bove caldera. J Volcanol Geotherm Res 13:241–271Google Scholar
  46. McGuire WJ, Pullen AD (1989) Location and orientation of eruptive fissures and feeder-dykes at Mount Etna: influence of gravitational and regional stress regimes. J Volcanol Geotherm Res 38:325–244Google Scholar
  47. Merle O, Borgia A (1996) Scaled experiments of volcanic spreading. J Geophys Res 101:13805–13817Google Scholar
  48. Monaco C, Tapponier P, Tortorici L, Gillot PY (1997) Late Quaternary slip rates on the Acireale-Piedimonte normal faults and tectonic origin of Mt. Etna (Sicily). Earth Planet Sci Lett 147:125–139CrossRefGoogle Scholar
  49. Monaco C, Tortorici L (2000) Active faulting in the Calabrian arc and eastern Sicily. J Geodyn 29:407–424CrossRefGoogle Scholar
  50. Murray JB (1994) Elastic model of the actively intruded dyke feeding the 1991–1993 eruption of Mt. Etna, derived from ground deformation measurements. Acta Vulcanol 4:97–99Google Scholar
  51. Murray JB, Pullen AD (1984) Three dimensional model of feeder conduit of the 1983 eruption of Mount Etna volcano, from ground deformation measurements. Bull Volcanol 47:1145–1163Google Scholar
  52. Murru M, Montuosi C, Wiss M, Privitera E (1999) The locations of magma chambers at Mt. Etna, Italy, mapped by b-values. Geophys Res Lett 26:2553–2556Google Scholar
  53. Neri M, Garduño VH, Pasquarè G, Rasà R (1991) Studio strutturale e modello cinematico della Valle del Bove e del settore nord-orientale etneo. Acta Vulcanol 1:17–24Google Scholar
  54. Patanè D, Chiarabba C, Cocina O, De Gori P, Moretti M, Boschi E (2002) Tomographic images and 3D earthquake locations of the seismic swarm preceding the 2001 Mt. Etna eruption: evidence for a dyke intrusion. Geophys Res Lett 29 NO10, 101029/2001 GLO14391Google Scholar
  55. Pollard DD, Delaney PT, Duffield WA, Endo ET, Okamura AT (1983) Surface deformation in volcanic rift zones. Tectonophysics 94:541–584Google Scholar
  56. Pollard DD, Aydin A (1984) Propagation and linkage of oceanic ridge segments. J Geophys Res 89:10017–10028Google Scholar
  57. Research Staff of the Istituto Nazionale di Geofisica e Vulcanologia — Catania, Italy (2001) Multidisciplinary approach yields insight into Mt. Etna eruption. EOS, Trans AGU 52:653–656Google Scholar
  58. Rittmann, A (1973): Structure and evolution of Mount Etna. Philos Trans R Soc Lond 274 A:5–16Google Scholar
  59. Romano R (1982) Succession of the volcanic activity in the Etnean area. Mem Soc Geol It 23:27–48Google Scholar
  60. Rubin AM, Pollard DD (1987) Origins of blade-like dikes in volcanic rift zones. US Geol Surv Prof Pap 1350:1449–1470Google Scholar
  61. Rubin AM (1992) Dike-induced faulting and graben subsidence in volcanic rift zones. J Geophys Res 97:1839–1858Google Scholar
  62. Rust D, Neri M (1996) The boundaries of large-scale collapse on the flanks of Mount Etna, Sicily. In: McGuire WC, Jones AP, Neuberg J (eds) Volcano instability on Earth and other planets. Geol Soc Lond Spec Publ 110:193–208Google Scholar
  63. Sumner JM (1998) Formation of clastogenic lava flows during fissure eruption and scoria collapse: the 1986 eruption of Izu-Oshima volcano, eastern Japan. Bull Volcanol 60:195–212CrossRefGoogle Scholar
  64. Takada A (1997) Cyclic flank-vent and central-vent eruption patterns. Bull Volcanol 58:539–556CrossRefGoogle Scholar
  65. Tanguy H, Kieffer G (1993) Les éruptions de l'Etna et leurs mécanismes. Mem Soc Geol Fr 163:239–252Google Scholar
  66. Tazieff H, Le Guern F (1971) Signification tectonique et mécanisme de l'éruption d'avril-mai-juin 1971 de l'Etna. C R Acad Sci Paris 272:3252–3255Google Scholar
  67. Tedesco D (2002) The January 2002 eruption of Mount Nyiragongo, DRC: dynamics andhazard. Proc EGS meeting Nice, France, April 2002 Abstract vol, p 111Google Scholar
  68. Thorwarth M, Dahm T (2002) Three-D stress field around a rising fluid-filled crack. Proc EGS meeting, Nice, France, April 2002. Abstract vol, p 308Google Scholar

Copyright information

© Springer-Verlag 2003

Authors and Affiliations

  1. 1.Dip. Scienze Geologiche Roma TRERomaItaly
  2. 2.Istituto Nazionale di Geofisica e VulcanologiaCataniaItaly

Personalised recommendations