Advertisement

Bulletin of Volcanology

, Volume 51, Issue 1, pp 28–40 | Cite as

The intensity of plinian eruptions

  • Steven Carey
  • Haraldur Sigurdsson
Article

Abstract

Peak intensities (magma discharge rate) of 45 Pleistocene and Holocene plinian eruptions have been inferred from lithic dispersal patterns by using a theoretical model of pyroclast fallout from eruption columns. Values range over three orders of magnitude from 1.6 × 106 to 1.1 × 109 kg/s. Magnitudes (total erupted mass) also vary over about three orders of magnitude from 2.0 × 1011 to 6.8 × 1014 kg and include several large ignimbrite-forming events with associated caldera formation. Intensity is found to be positively correlated with the magnitude when total erupted mass (tephra fall, surges and pyroclastic flows) is considered. Initial plinian fall phases with intensities in excess of 2.0 × 108 kg/s typically herald the onset of major pyroclastic flow generation and subsequent caldera collapse. During eruptions of large magnitude, the transition to pyroclastic flows is likely to be the result of high intensity, whereas the generation of pyroclastic flows in small magnitude eruptions may occur more often by reduction of magmatic volatile content or some transient change in magma properties. The correlation between plinian fall intensity and total magnitude suggests that the rate of magma discharge is related to the size of the chamber being tapped. A simple model is presented to account for the variation in intensity by progressive enlargement of conduits and vents and excess pressure at the chamber roof caused by buoyant forces acting on the chamber as it resides in the crust. Both processes are fundamentally linked to the absolute size of the pre-eruption reservoir. The data suggest that sustained eruption column heights (i.e. magma discharge rates) are indicators of eventual eruption magnitude, and perhaps eruptive style, and thus are key parameters to monitor in order to assess the temporal evolution of plinian eruptions.

Keywords

Tephra Pyroclastic Flow Eruption Column Eruptive Style Plinian Eruption 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Aramaki S (1984) Formation of the Aira Caldera, Southern Kyushu, ∼22,000 years ago. J Geophys Res 89:8485–8501Google Scholar
  2. Blake S (1981) Volcanism and the dynamics of open magma chambers. Nature 289:783–785Google Scholar
  3. Bloomfield K, Rubio G, Wilson L (1977) Plinian eruptions of Nevado de Toluca volcano, Mexico. Geol Rund 66:120–146Google Scholar
  4. Bond A, Sparks RSJ (1976) The Minoan eruption of Santorini, Greece. J Geol Soc Lond 132:1–16Google Scholar
  5. Carey S, Sigurdsson H (1985) The May 18 eruption of Mount St. Helens 2. Modelling of dynamics of the plinian phase. J Geophys Res 90:2948–2958Google Scholar
  6. Carey S, Sigurdsson H (1986) The 1982 eruptions of El Chichon volcano, Mexico (2): Observations and numerical modelling of tephra fall distribution. Bull Volcanol 48:127–141Google Scholar
  7. Carey S, Sigurdsson H (1987) Temporal variations of column height and magma discharge rate during the 79 AD eruption of Vesuvius. Bull Geol Soc Amer 99:303–314Google Scholar
  8. Carey S, Sparks RSJ (1986) Quantitative models of fallout and dispersal of tephra from volcanic eruption columns. Bull Volcanol 48:109–125Google Scholar
  9. Cornell W, Carey S, Sigurdsson H (1983) Computer simulation of transport and deposition of the Campanian Y-5 ash. J Volcanol Geotherm Res 17:89–109Google Scholar
  10. Druitt T, Sparks RSJ (1984) On the formation of calderas during ignimbrite eruptions. Nature 310:679–681Google Scholar
  11. Elder JW (1979a) Magma traps: Part I, Theory. J Pure Appl Geophys 117:3–14Google Scholar
  12. Elder JW (1979b) Magma traps: Part II, Application. J Pure Appl Geophys 117:15–33Google Scholar
  13. Fedotov SA (1985) Estimates of heat and pyroclast discharge by volcanic eruptions based upon the eruption cloud and steady plume observations. J Geodynam 3:275–302Google Scholar
  14. Fierstein J, Hildreth W (1986) Ejecta dispersal and dynamics of the 1912 eruptions at Novarupta, Katmai National Park, Alaska. EOS Trans Am Geophys Union 67(44): 1246Google Scholar
  15. Gorshkov GS (1959) Gigantic eruption of the volcano Bezymianny. Bull Volcanol 20:77–109Google Scholar
  16. Harris D, Rose WI, Roe R, Thompson M (1981) Radar observation of ash eruptions. US Geol Surv Prof Pap 1250:323–334Google Scholar
  17. Hayakawa Y (1985) Pyroclastic geology of Towada Volcano. Bull Earth Res Instit Univ Tokyo 60:507–592Google Scholar
  18. Hoblitt RP (1986) Observations of the eruptions of July 22 and August 7, 1980 at Mount St. Helens, Washington. US Geol Surv Prof Pap 1335:1–44Google Scholar
  19. Katsui Y (1959) On the Shikotsu Pumice-fall Deposit, Special Reference to the Activity just before the Depression of the Shikotsu Caldera. Bull Volcanol Soc Japan 4(2):33–48Google Scholar
  20. Kobayashi T, Hayakawa Y, Aramaki S (1983) Thickness and grain-size distribution of the Osumi pumice fall deposit from the Aira caldera. Bull Volcanol Soc Japan 28(2): 129–139Google Scholar
  21. Lirer L, Pescatore T, Booth B, Walker GPL (1973) Two plinian pumice-fall deposits from Somma Vesuvius, Italy. Bull Geol Soc Am 84:759–772Google Scholar
  22. Naranjo J, Sigurdsson H, Carey S, Fritz W (1986) Eruption of Nevado del Ruiz, Colombia, on 13 November 1985: Tephra fall and lahars. Science 233:961–963Google Scholar
  23. Newhall C, Self S (1982) The volcanic explosivity index (VEI): an estimate of explosive magnitude for historical volcanism. J Geophys Res 87:1231–1238Google Scholar
  24. Pescatore T, Sparks RSJ, Brazier S (1987) Reverse grading in the Avellino plinian deposit of Vesuvius. Bull Volcanol (in press)Google Scholar
  25. Pollard D, Muller O (1976) Effect of gradients in regional stress and magma pressure on the form of sheet intrusions in cross section. J Geophys Res 81:975–984Google Scholar
  26. Robson G, Barr K (1964) The effect of stress on faulting and minor intrusions in the vicinity of a magma body. Bull Volcanol 27:315–330Google Scholar
  27. Rose WI, Newhall C, Bornhorst T, Self S (1987) Quaternary silicic pyroclastic deposits of Atitlan caldera, Guatemala. J Volcanol Geotherm Res 33:57–80Google Scholar
  28. Rowley P, Kuntz M, Macleod N (1981) Pyroclastic flow deposits: The 1980 eruptions of Mount St. Helens, Washington. US Geol Surv Prof Pap 1250:489–512Google Scholar
  29. Settle M (1978) Volcanic eruption clouds and the thermal power output of explosive eruptions. J Volcanol Geotherm Res 3:309–324Google Scholar
  30. Shaw HR (1980) The fracture mechanisms of magma transport from the mantle to the surface. In: Hargraves RB (ed) Physics of magmatic processes, pp 201–232Google Scholar
  31. Sigurdsson H, Carey S, Cornell W, Pescatore T (1985) The eruption of Vesuvius in A.D. 79. Nat Geograph Res 1(3):332–387Google Scholar
  32. Sigurdsson H, Carey S (1989) The 1815 eruptions of Tambora, Indonesia: generation of co-ignimbrite ash fall during entrance of pyroclastic flows into the ocean. Bull Volcanol 51 (in press)Google Scholar
  33. Sparks RSJ (1986) The dimensions and dynamics of volcanic eruption columns. Bull Volcanol 48:3–15Google Scholar
  34. Sparks RSJ, Wilson L (1976) A model for the formation of ignimbrite by gravitational column collapse. J Geol Soc Lond 132:441–451Google Scholar
  35. Sparks RSJ, Self S, Walker GPL (1973) Products of ignimbrite eruptions. Geology 1:115–118Google Scholar
  36. Sparks RSJ, Wilson L, Hulme G (1978) Theoretical modeling of the generation, movement, and emplacement of pyroclastic flows by column collapse. J Geophys Res 83:1727–1739Google Scholar
  37. Sparks RSJ, Wilson L, Sigurdsson H (1981) The pyroclastic deposits of the 1875 Askja eruption, Iceland. Phil Trans Roy Soc Lond 29:241–273Google Scholar
  38. Sparks RSJ, Moore JG, Rice CJ (1986) The initial giant eruption cloud of the May 18, 1980, explosive eruption of Mount St. Helens. J Volcanol Geotherm Res 28:257–274Google Scholar
  39. Sussman D (1985) Apoyo caldera, Nicaragua: a major Quaternary silicic eruptive center. J Volcanol Geotherm Res 24:249–282Google Scholar
  40. Traineau H, Westercamp, D (1985) Les éruptions ponceuses récentes de la Montagne Pelée (Martinique) Description des dépôts-dynamique éruptifs. IMRG A.F.M.E. 85 SGN 471 IRG: 1–68Google Scholar
  41. Walker GPL (1980) The Taupo pumice: products of the most powerful known (ultraplinian) eruption? J Volcanol Geotherm Res 8:69–94Google Scholar
  42. Walker GPL (1981a) Plinian eruptions and their products. Bull Volcanol 44-2:223–240Google Scholar
  43. Walker GPL (1981b) The Waimihia and Hatepe plinian deposits from the rhyolitic Taupo volcanic center. New Zeal J Geol Geophys 24:305–324Google Scholar
  44. Walker GPL (1984) Downsag calderas, ring faults, caldera sizes, and incremental caldera growth. J Geophys Res 89:8407–8416Google Scholar
  45. Walker GPL, Croasdale R (1973) Two plinian-type eruptions in the Azores. J Geol Soc Lond 127:17–55Google Scholar
  46. Walker GPL, Wright JV, Clough BJ, Booth B (1981) Pyroclastic geology of the rhyolitic volcano of La Primavera, Mexico. Geol Rundsch 70:1100–1118Google Scholar
  47. Walker GPL, Self S, Wilson L (1984) Tarawera 1886, New Zealand- a basaltic plinian fissure eruption. J Volcanol Geotherm Res 21:61–78Google Scholar
  48. Watkins ND, Sparks RSJ, Sigurdsson H, Huang TC, Federman A, Carey S, Ninkovich D (1978) Volume and extent of the Minoan tephra from Santorini Volcano: new evidence from deep-sea cores. Nature 271:122–126Google Scholar
  49. Weertman J (1971) Theory of water-filled crevasses in glaciers applied to vertical magma transport beneath oceanic ridges. J Geophys Res 76:1171–1183Google Scholar
  50. Whitney J, Stormer JC Jr (1986) Model for the intrusion of batholiths associated with the eruption of large volume ash flow tuffs. Science 231:483–485Google Scholar
  51. Williams SN, Self S (1983) The October, 1902 plinian eruption of Santa Maria volcano, Guatemala. J Volcanol Geotherm Res 16:33–56Google Scholar
  52. Wilson L (1980) Relationships between pressure, volatile content and ejecta velocity in three types of volcanic explosions. J Volcanol Geotherm Res 8:297–313Google Scholar
  53. Wilson L, Head J (1981) Ascent and eruption of basaltic magma on the Earth and Moon. J Geophys Res 86:2971–3001Google Scholar
  54. Wilson CJN, Walker GPL (1985) The Taupo eruption, New Zealand I. General aspects. Phil Trans Roy Soc Lond A 314:199–228Google Scholar
  55. Wilson L, Sparks RSJ, Huang TC, Watkins ND (1978) The control of volcanic column heights by eruption energetics and dynamics. J Geophys Res 83:1829–1836Google Scholar
  56. Wilson L, Sparks RSJ, Walker GPL (1980) Explosive volcanic eruptions IV. The control of magma properties and conduit geometry on eruption column behaviour. Geophys J Roy Astrom Soc 63:117–148Google Scholar
  57. Wright JV (1981) The Rio Caliente ignimbrite: analysis of a compound intraplinian ignimbrite from a major late Quarternary Mexican eruption. Bull Volcanol 44-2:189–212Google Scholar

Copyright information

© Springer-Verlag 1989

Authors and Affiliations

  • Steven Carey
    • 1
  • Haraldur Sigurdsson
    • 1
  1. 1.Graduate School of OceanographyUniversity of Rhode IslandNarragansettUSA

Personalised recommendations