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Bulletin of Volcanology

, Volume 70, Issue 6, pp 655–673 | Cite as

The 2005 eruption of Sierra Negra volcano, Galápagos, Ecuador

  • Dennis J. Geist
  • Karen S. Harpp
  • Terry R. Naumann
  • Michael Poland
  • William W. Chadwick
  • Minard Hall
  • Erika Rader
Research Article

Abstract

Sierra Negra volcano began erupting on 22 October 2005, after a repose of 26 years. A plume of ash and steam more than 13 km high accompanied the initial phase of the eruption and was quickly followed by a ~2-km-long curtain of lava fountains. The eruptive fissure opened inside the north rim of the caldera, on the opposite side of the caldera from an active fault system that experienced an mb 4.6 earthquake and ~84 cm of uplift on 16 April 2005. The main products of the eruption were an `a`a flow that ponded in the caldera and clastigenic lavas that flowed down the north flank. The `a`a flow grew in an unusual way. Once it had established most of its aerial extent, the interior of the flow was fed via a perched lava pond, causing inflation of the `a`a. This pressurized fluid interior then fed pahoehoe breakouts along the margins of the flow, many of which were subsequently overridden by `a`a, as the crust slowly spread from the center of the pond and tumbled over the pahoehoe. The curtain of lava fountains coalesced with time, and by day 4, only one vent was erupting. The effusion rate slowed from day 7 until the eruption’s end two days later on 30 October. Although the caldera floor had inflated by ~5 m since 1992, and the rate of inflation had accelerated since 2003, there was no transient deformation in the hours or days before the eruption. During the 8 days of the eruption, GPS and InSAR data show that the caldera floor deflated ~5 m, and the volcano contracted horizontally ~6 m. The total eruptive volume is estimated as being ~150×106 m3. The opening-phase tephra is more evolved than the eruptive products that followed. The compositional variation of tephra and lava sampled over the course of the eruption is attributed to eruption from a zoned sill that lies 2.1 km beneath the caldera floor.

Keywords

Caldera Basalt Galápagos Tephra Lava flow emplacement Volcano deformation Magma chamber processes 

Notes

Acknowledgements

We would like to extend our thanks to the Galápagos National Park and the Charles Darwin Research Station, who made our observation of the Sierra Negra eruption possible, particularly Srs. O. Carvajal, W. Tapia, F. Cruz, and G. Watkins. We are also grateful to individuals who have provided us with images from the early phases of the eruption, including G. Estes, F. Cruz, and A. Voigt. Thanks to J. Normandeau of UNAVCO for his heroic patience in helping us get the GPS receivers working again during the eruption. This work was supported by NSF grants EAR-0207425 to KSH and EAR-0207605, 0538205, and 0004067 (which supported the installation of the GPS network) to DJG. ENVISAT ASAR data are copyrighted 2004–2006 by the European Space Agency, and were obtained via Category-1 Proposal 3493. Thanks to W. Tater for his help with the SEM. We thank B. Cousens and especially S. Rowland for review and J. Stix for his editorial help.

References

  1. Allan JF, Simkin R (2000) Fernandina Volcano’s evolved, well-mixed basalts: mineralogical and petrological constraints on the nature of the Galapagos plume. J Geophys Res 105:6017–6031CrossRefGoogle Scholar
  2. Amelung F, Jonsson S, Zebker H, Segall P (2000) Widespread uplift and ‘trapdoor’ faulting on Galapagos volcanoes observed with radar interferometry. Nature 407:993–996CrossRefGoogle Scholar
  3. Blackburn EA, Wilson L, Sparks RSJ (1976) Mechanisms and dynamics of Strombolian activity. J Geol Soc London 132:429–440CrossRefGoogle Scholar
  4. Bruce PM, Huppert HE (1989) Thermal control of basaltic fissure eruptions. Nature 342:665–667CrossRefGoogle Scholar
  5. Capaccioni B, Cuccoli F (2005) Spatter and welded air fall deposits generated by fire-fountaining eruptions: cooling of pyroclasts during transport and deposition. J Volcanol Geotherm Res 145:263–280CrossRefGoogle Scholar
  6. Cashman KV (1993) Relationship between plagioclase crystallization and cooling rate in basaltic melts. Contrib Mineral Petrol 113:126–142CrossRefGoogle Scholar
  7. Chadwick WW, Geist DJ, Johnsson S, Poland M, Johnson DJ (2006) A volcano bursting at the seams: inflation, faulting, and eruption at Sierra Negra Volcano, Galápagos. Geology 34:1025–1028CrossRefGoogle Scholar
  8. Geist D (2002) Volcanic evolution in the Galapagos: the dissected shield of Volcan Ecuador. Geochem Geophys Geosyst 3(10): 1061. DOI  10.1019/2002GC000355
  9. Geist DJ, Naumann TR, Standish JJ, Kurz MD, Harpp KS, White WM, Fornari DJ (2005) Wolf Volcano, Galapagos Archipelago: melting and magmatic evolution at the margins of a mantle plume. J Petrol 46:2197–2224Google Scholar
  10. Geist D, Chadwick W, Johnson D (2006) Results from new GPS and gravity monitoring networks at Fernandina and Sierra Negra volcanoes, Galapagos, 2000–2002. J Volcanol Geotherm Res 150:79–97CrossRefGoogle Scholar
  11. Ghiorso MS, Sack RO (1995) Chemical mass transfer in magmatic processes: IV. a revised and internally consistent thermodynamic model for the interpolation and extrapolation of liquid-solid equilibria in magmatic systems at elevated temperatures and pressures. Contrib Mineral Petrol 119:197–212CrossRefGoogle Scholar
  12. Goff F, McMurtry GM, Counce D, Simac JA, Roldan-Manzo AR, Hilton DR (2000) Contrasting hydrothermal activity at Sierra Negra and Alcedo volcanoes, Galapagos Archipelago, Ecuador. Bull Volcanol 62:34–52CrossRefGoogle Scholar
  13. Harpp KS, Fornari DJ, Geist DJ, Kurz MD (2003) Genovesa Submarine Ridge: a manifestation of plume-ridge interaction in the Northern Galápagos Islands. Geochem Geophys Geosys 4 DOI  10.1029/2003GC000531
  14. Head JW, Wilson L (1987) Lava fountain heights at Pu’u O’o, Kilauea, Hawaii: indictators of amount and variations of exsolved magma volatiles. J Geophys Res 92:13,715–713,719Google Scholar
  15. Helz RT, Kirschenbaum H, Marinenko JW (1989) Diapiric transfer of melt in Kilauea Iki lava lake, Hawaii: a quick, efficient process of igneous differentiation. Geol Soc Am Bull 101:578–594CrossRefGoogle Scholar
  16. Hon KA, Gansecki C, Kauahikaua J (2003) The transition from ‘a’a to pahoehoe crust on flows emplaced during the Pu’u ‘O’o-Kupaianaha eruption. US Geol Surv Prof Pap 89-103Google Scholar
  17. Hon K, Kauahikaua J, Denlinger R, Mackay K (1994) Emplacement and inflation of pahoehoe sheet flows: observations and measurements of active lava flows on Kilauea volcano, Hawaii. Geol Soc Am Bull 106:351–370CrossRefGoogle Scholar
  18. Jellinek AM, Kerr RC (2001) Magma dynamics, crystallization, and chemical differentiation of the 1959 Kilauea Iki lava lake, Hawaii, revisited. J Volcanol Geotherm Res 110:235–263CrossRefGoogle Scholar
  19. Jonsson S, Zebker H, Amelung F (2005) On trapdoor faulting at Sierra Negra volcano, Galapagos. J Volcanol Geotherm Res 144:59–71CrossRefGoogle Scholar
  20. Jurado-Chichay Z, Rowland SK (1995) Channel overflows of the Phue Bay flow, Mauna Loa, Hawai’i: examples of the contrast between surface and interior lava. Bull Volcanol 57(2):117–126Google Scholar
  21. Marsh BD (1996) Solidification fronts and magmatic evolution. Mineral Mag 60:5–40CrossRefGoogle Scholar
  22. Marsh BD (2002) On bimodal differentiation by solidification front instability in basaltic magmas, part 1: basic mechanics. Geochim Cosmochim Acta 66:2211–2229CrossRefGoogle Scholar
  23. Naumann TR, Geist D (2000) Physical volcanology and structural development of Cerro Azul Volcano, Isabela Island, Galapagos: implications for the development of Galapagos-type shield volcanoes. Bull Volcanol 61:497–514Google Scholar
  24. Okada Y (1985) Surface deformation due to shear and tensile faults in a half-space. Bull Seism Soc Am 75:1135–1154Google Scholar
  25. Parfitt EA (2004) A discussion of the mechanisms of explosive basaltic eruptions. J Volcanol Geotherm Res 134:77–107CrossRefGoogle Scholar
  26. Parfitt EA, Wilson L (1995) Explosive volcanic eruptions: IX. the transition between Hawaiian-style lava fountaining and Strombolian explosive activity. Geophys J Int 121:226–232CrossRefGoogle Scholar
  27. Parfitt EA, Wilson L, Neal CA (1995) Factors influencing the height of Hawaiian lava fountains: implications for the use of fountain height as an indicator of magma gas content. Bull Volcanol 57:440–450CrossRefGoogle Scholar
  28. Pollard DD, Delaney PT, Duffield WA, Endo ET, Okamura AT (1983) Surface deformation in volcanic rift zones. Tectonophys 94:541–584CrossRefGoogle Scholar
  29. Rader E, Harpp KS, Geist DJ (2006) Eruption dynamics and flow morphology during the 2005 Sierra Negra eruption, Galapagos Islands. EOS Trans AGU Fall Meet Assem Suppl 87:Abstract V23A-0586Google Scholar
  30. Reynolds RW, Geist DJ (1995) Petrology of lavas from Sierra Negra volcano, Isabela Island, Galapagos Archipelago. J Geophys Res 100:24,537–524,553Google Scholar
  31. Reynolds RW, Geist D, Kurz MD (1995) Physical volcanology and structural development of Sierra Negra volcano, Isabela Island, Galapagos Archipelago. Geol Soc Am Bull 107:1398–1410CrossRefGoogle Scholar
  32. Rowland SK, Walker GPL (1990) Pahoehoe and aa in Hawaii: volumetric flow rate controls the lava structure. Bull Volcanol 52(8):615–628Google Scholar
  33. Rowland SK, Munro D (1992) The caldera of Volcan Fernandina: a remote sensing study of its structure and recent activity. Bull Volcanol 55:97–109CrossRefGoogle Scholar
  34. Self S, Keszthelyi L, Thordarson T (1998) The importance of pahoehoe. Ann Rev Earth Planet Sci 26:81–110CrossRefGoogle Scholar
  35. Simkin T, Siebert L (1994) Volcanoes of the world. Geoscience Press, Tucson, AZGoogle Scholar
  36. Sparks RSJ (1978) The dynamics of bubble formation and growth in magmas: a review and analysis. J Volcanol Geotherm Res 3:1–37CrossRefGoogle Scholar
  37. Sumner JM, Blake S, Matela RJ, Wolff JA (2005) Spatter. J Volcanol Geotherm Res 142:49–65CrossRefGoogle Scholar
  38. Teasdale R, Geist D, Kurz M, Harpp K (2005) 1998 eruption at Volcan Cerro Azul, Galapagos Islands: I. syn-eruptive petrogenesis. Bull Volcanol 67:170–185CrossRefGoogle Scholar
  39. Vergniolle S, Brandeis G (1996) Strombolian explosions 1: a large bubble breaking at the surface of a lava column as a source of sound. J Geophys Res 101:20,433–420,447Google Scholar
  40. Vergniolle S, Mangan MT (2000) Hawaiian and Strombolian eruptions. In: Sigurdsson H, Houghton B, McNutt SR, Rymer H, Stix J (eds) Encyclopedia of volcanoes. Academic Press, San Diego, CA, pp 447–461Google Scholar
  41. Wilson L (1980) Relationships between pressure, volatile content and ejecta velocity in three types of volcanic explosion. J Volcanol Geotherm Res 8:297–313CrossRefGoogle Scholar
  42. Wilson L, Head JW (1981) Ascent and eruption of basaltic magma on the Earth and Moon. J Geophys Res 86:2971–3001CrossRefGoogle Scholar
  43. Wolfe EW, Neal CA, Banks NG, Duggan TJ (1988) Geologic observations and chronology of eruptive events. US Geol Surv Prof Pap 1463:1–97Google Scholar
  44. Wylie JJ, Helfrich KR, Dade B, Lister JR, Salzig JF (1999) Flow localization in fissure eruptions. Bull Volcanol 60:432–440CrossRefGoogle Scholar
  45. Yun S, Zebker H, Segall P, Hooper A, Poland M (2005) The 2005 eruption at Sierra Negra volcano unveiled by InSAR observations, EOS Trans AGU Fall Meet Assem Suppl 87(52):Abstract G52A-01Google Scholar
  46. Yun S, Segall P, Zebker H (2006a) Constraints on magma chamber geometry at Sierra Negra Volcano, Galapagos Islands, based on InSAR observations. J Volcanol Geotherm Res 150:232–243CrossRefGoogle Scholar
  47. Yun S, Zebker H, Segall P, Hooper A, Poland M (2006b) 2005 Eruption at Sierra Negra volcano unveiled by InSAR observations. EOS Trans AGU Fall Meet Assem Suppl 87(52):Abstract G52A-01Google Scholar

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Dennis J. Geist
    • 1
  • Karen S. Harpp
    • 2
  • Terry R. Naumann
    • 3
  • Michael Poland
    • 4
  • William W. Chadwick
    • 5
  • Minard Hall
    • 6
  • Erika Rader
    • 2
  1. 1.Department of Geological SciencesUniversity of Idaho 3022MoscowUSA
  2. 2.Geology DepartmentColgate UniversityHamiltonUSA
  3. 3.Geology DepartmentUniversity of AlaskaAnchorageUSA
  4. 4.USGS-HVOHawai’i National ParkUSA
  5. 5.Hatfield Marine Science CenterOregon State UniversityNewportUSA
  6. 6.Instituto GeofisicoEscuela Politecnica NacionalQuitoEcuador

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