Bulletin of Volcanology

, Volume 51, Issue 1, pp 1–15 | Cite as

The thickness, volume and grainsize of tephra fall deposits

  • David M. Pyle


An improved empirical method for the plotting of field data and the calculation of tephra fall volumes is presented. The widely used “area” plots of ln(thickness) against ln(isopach area) are curved, implying an exponential thinning law. Use of ln(thickness)−(area)1/2 diagrams confirm the exponential dependence of many parameters (e.g. thickness, maximum and median clast size) with distance from source, producing linear graphs and allowing volumes to be calculated without undue extrapolation of field data. The agreement between theoretical models of clast dispersion and observation is better than previously thought. Two new quantitative parameters are proposed which describe the rates of thinning of the deposit (b t the thickness half-distance) and the maximum clast size (b c the clast half-distance). Many deposits exhibit different grainsize and thickness thinning rates, with the maximum clast size diminishing 1–3 times slower than the thickness. This implies that the entrained grainsize population influences the morphologic and granulometric patterns of the resulting deposit, in addition to the effects of column height and wind-speed. The grainsize characteristics of a deposit are best described by reference to the half-distance ratio (b c /b t ). A new classification scheme is proposed which plots the half-distance ratio against the thickness half-distance and may be contoured in terms of the column height.


Grainsize Field Data Classification Scheme Tephra Sedimentology 
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.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Booth B, Croasdale R, Walker GPL (1978) A quantitative study of five thousand years of volcanism on Sao Miguel, Azores. Phil Trans R Soc London A288:271–319Google Scholar
  2. Brazier S, Sparks RSJ, Carey SN, Sigurdsson H, Westgate JA (1983) Bimodal grainsize distribution and secondary thickening in air-fall ash layers. Nature 301:115–119Google Scholar
  3. Carey SN, Sigurdsson H (1982) Influence of particle aggregation on deposition of distal tephra from the May 18, 1980 eruption of Mt. St. Helens volcano. J Geophys Res 87:7061–7072Google Scholar
  4. Carey SN, 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
  5. Carey SN, Sparks RSJ (1986) Quantitative models of the fall-out and dispersal of tephra from volcanic eruption columns. Bull Volcanol 48:109–125Google Scholar
  6. Cole JW, Stephenson TM (1972) Calculation of the volume of a tephra deposit: Appendix in Cole JW Distribution of High-Alumina Basalts in the Taupo Volcanic Zone. Geol Dep Victoria University Wellington Publication 1:13–15Google Scholar
  7. Cornell W, Carey SN, Sigurdsson H (1983) Computer simulation of transport and deposition of the Campanian Y5 ash. J Volcanol Geotherm Res 17:89–109Google Scholar
  8. Fisher RV (1964) Maximum size, median diameter and sorting of tephra. J Geophys Res 69:341–355Google Scholar
  9. Froggatt PC (1982) Review of methods of estimating rhyolitic tephra volumes: applications to the Taupo volcanic zone, New Zealand. J Volcanol Geotherm Res 14:301–318Google Scholar
  10. Hayakawa Y (1985) Pyroclastic geology of Towada volcano. Bull Earthq Res Inst Univ Tokyo 60:507–592Google Scholar
  11. Hildreth W (1987) New perspectives on the eruption of 1912 in the Valley of Ten Thousand Smokes, Katmai National Park, Alaska. Bull Volcanol 49:680–693Google Scholar
  12. Kittleman LR (1973) Mineralogy, correlation and grainsize distributions of Mazama tephra and other post-glacial pyroclastic layers; Pacific Northwest. Geol Soc Am Bull 84:2957–2980Google Scholar
  13. Kobayashi T, Hayakawa Y, Aramaki S (1983) Thickness and grainsize distribution of the Osumi pumice fall deposit from the Aira caldera. Bull Volcanol Soc Japan 28:129–139Google Scholar
  14. Lirer L, Pescatore T, Booth B, Walker GPL (1973) Two plinian pumice-fall deposits from Somma-Vesuvius, Italy. Geol Soc Am Bull 84:759–772Google Scholar
  15. Ninkovich D, Sparks RSJ, Ledbetter MT (1978) The exceptional magnitude and intensity of the Toba eruption, Sumatra: an example of the use of deep-sea tephra layers as a geological tool. Bull Volcanol 41:286–298Google Scholar
  16. Porter SC (1973) Stratigraphy and chronology of late Quaternary tephra along the south rift zone of Mauna Kea volcano, Hawaii. Bull Geol Soc Am 84:1923–40Google Scholar
  17. Rose WI, Bonis S, Stoiber RE, Keller M, Bickford T (1973) Studies of volcanic ash from two recent Central American eruptions. Bull Volcanol 37:338–364Google Scholar
  18. Rose WI, Wunderman RL, Hoffman MF, Gale L (1983) A volcanologist's review of atmospheric hazards of volcanic activity: Fuego and Mt St Helens. J Volcanol Geotherm Res 17:133–157Google Scholar
  19. Sapper K (1905) In den Vulkangebieten Mittelamerikas und Westindien. Stuttgart, pp 174Google Scholar
  20. Sarna-Wojcicki AM, Shipley S, Waitt RB, Dzurisin D, Wood SH (1981) Areal distribution, thickness, volume and grain-size of air-fall ash from the six major eruptions of 1980. US Geol Surv Prof Pap 1250:577–600Google Scholar
  21. Self S (1976) The recent volcanology of Terceira, Azores. J Geol Soc London 132:645–666Google Scholar
  22. Self S, Sparks RSJ (1978) Characteristics of widespread pyroclastic deposits formed by the interaction of silicic magma and water. Bull Volcanol 41:196–212Google Scholar
  23. Self S, Sparks RSJ, Booth B, Walker GPL (1974) The Heimay strombolian scoria deposit, Iceland. Geol Mag 111:539–548Google Scholar
  24. Settle M (1978) Volcanic eruption clouds and the thermal output of explosive eruptions. J Volcanol Geotherm Res 3:309–324Google Scholar
  25. Sigurdsson H (1982) Tephra from the 1979 Soufriere explosive eruption. Science 216:1106–1108Google Scholar
  26. Sigurdsson H, Carey SN, Cornell W, Pescatore T (1985) The eruption of Vesuvius in A.D. 79. Nat Geogr. Res 1:332–387Google Scholar
  27. Sorem RK (1982) Volcanic ash clusters: tephra rafts and scavengers. J Volcanol Geotherm Res 13:63–71Google Scholar
  28. Sparks RSJ (1986) The dimensions and dynamics of volcanic eruption columns. Bull Volcanol 48:3–15Google Scholar
  29. Sparks RSJ, Huang TC (1980) The volcanological significance of deep-sea ash layers associated with ignimbrites. Geol Mag 117:425–436Google Scholar
  30. Sparks RSJ, Walker GPL (1977) The significance of vitric-enriched air-fall ashes associated with crystal-enriched ignimbrites. J Volcanol Geotherm Res 2:329–341Google Scholar
  31. Sparks RSJ, Wilson L, Sigurdsson H (1981) The pyroclastic deposits of the 1875 eruption of Askja, Iceland. Phil Trans R Soc London A299:241–273Google Scholar
  32. Suzuki T, Katsui Y, Nakamura T (1973) Size distribution of the Tarumai Ta-b pumice-fall deposit. Bull Volc Soc Japan 18:47–67Google Scholar
  33. Suzuki T (1981) “Thickness-isopach area” curve of tephra. Bull Volc Soc Japan 26:9–23 (In Japanese)Google Scholar
  34. Suzuki T (1983) A theoretical model for dispersion of tephra. In: Shimozuru D, Yokoyama I (eds) Arc volcanism: Physics and Tectonics: 95–113 TERRAPUB, ToykoGoogle Scholar
  35. Thorarinsson S (1954) The eruptions of Hekla 1947–1948. II, 3. The tephra fall from Hekla. Vis Islendinga, Reykjavik, pp 68Google Scholar
  36. Thorarinsson S, Sigvaldason GE (1972) The Hekla eruption of 1970. Bull Volcanol 36:269–288Google Scholar
  37. Thunell R, Federman A, Sparks RSJ, Williams DF (1979) The age, origin and volcanological significance of the Y-5 ash layer in the Mediterranean. Quat Res 12:241–253Google Scholar
  38. Topping WW (1973) Tephrostratigraphy and chronology of Late Quaternary eruptives from the Tongariro volcanic centre, New Zealand. NZ J Geol Geophys 16:397–423Google Scholar
  39. Vucetich CG, Pullar WA (1973) Holocene tephra formations erupted in the Taupo area and interbedded tephras from other volcanic sources. NZ J Geol Geophys 16:745–780Google Scholar
  40. Waitt RB, Dzurisin D (1981) Proximal air-fall deposits from the May 18 eruption: stratigraphy and field sedimentology. US Geol Surv Prof Pap 1250:601–616Google Scholar
  41. Waitt RB, Hansen VL, Sarna-Wojcicki AM, Wood SH (1981) Proximal airfall deposits of eruptions between May 24 and August 7,1980 — stratigraphy and field sedimentology. US Geol Surv Prof Pap 1250:617–630Google Scholar
  42. Walker GPL (1971) Grainsize characteristics of pyroclastic deposits. J Geol 79:696–714Google Scholar
  43. Walker GPL (1973) Explosive volcanic eruptions — a new classification scheme. Geol Rundsch 62:431–446Google Scholar
  44. Walker GPL (1980) The Taupo pumice: product of the most powerful known (ultraplinian) eruption? J Volcanol Geotherm Res 8:69–94Google Scholar
  45. Walker GPL (1981a) Plinian eruptions and their products. Bull Volcanol 44:223–240Google Scholar
  46. Walker GPL (1981b) Characteristics of two phreatoplinian ashes and their water-flushed origin. J Volcanol Geotherm Res 9:395–407Google Scholar
  47. Walker GPL (1981c) The Waimihia and Hatepe plinian deposits from the rhyolitic Taupo Volcanic Centre. NZ J Geol Geophys 24:305–324Google Scholar
  48. Walker GPL, Croasdale R (1971) Two plinian type eruptions in the Azores. J Geol Soc London 127:17–55Google Scholar
  49. Williams H, Goles G (1968) Volume of the Mazama ash-fall and the origin of Crater lake caldera. Ore Dep Geol Miner Ind Bull 62:37–41Google Scholar
  50. Williams SN (1983) Plinian airfall deposits of basaltic composition. Geology 11:211–214Google 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, Walker GPL (1987) Explosive volcanic eruptions-VI. Ejecta dispersal in plinian eruptions: the control of eruption conditions and atmospheric properties. Geophys J R astr Soc 89:657–679Google Scholar
  53. Wilson L, Sparks RSJ, Huang TC, Watkins ND (1978) The control of eruption column heights by eruption energetics and dynamics. J Geophys Res 83:1829–1836Google Scholar

Copyright information

© Springer-Verlag 1989

Authors and Affiliations

  • David M. Pyle
    • 1
  1. 1.Department of Earth SciencesCambridgeUK

Personalised recommendations