Abstract
The three-day eruption at Novarupta in 1912 consisted of three discrete episodes. Episode I began with plinian dispersal of rhyolitic fallout (Layer A) and contemporaneous emplacement of rhyolitic ignimbrites and associated proximal veneers. The plinian column was sustained throughout most of the interval of ash flow generation, in spite of progressive increases in the proportions of dacitic and andesitic ejecta at the expense of rhyolite. Accordingly, plinian Layer B, which fell in unbroken continuity with purely rhyolitic Layer A, is zoned from >99% to ∼15% rhyolite and accumulated synchronously with emplacement of the correspondingly zoned ash flow sequence in Mageik Creek and the Valley of Ten Thousand Smokes (VTTS). Only the andesiterichest flow units that cap the flow sequence lack a widespread fallout equivalent, indicating that ignimbrite emplacement barely outlasted the plinian phase. On near-vent ridges, the passing ash flows left proximal ignimbrite veneers that share the compositional zonation of their valley-filling equivalents but exhibit evidence for turbulent deposition and recurrent scour. Episode II began after a break of a few hours and was dominated by plinian dispersal of dacitic Layers C and D, punctuated by minor proximal intraplinian flows and surges. After another break, dacitic Layers F and G resulted from a third plinian episode (III); intercalated with these proximally are thin intraplinian ignimbrites and several andesite-rich fall/flow layers. Both CD and FG were ejected from an inner vent <400 m wide (nested within that of Episode I), into which the rhyolitic lava dome (Novarupta) was still later extruded. Two finer-grained ash layers settled from composite regional dust clouds: Layer E, which accumulated during the D-F hiatus, includes a contribution from small contemporaneous ash flows; and Layer H settled after the main eruption was over. Both are distinct layers in and near the VTTS, but distally they merge with CD and FG, respectively; they are largely dacitic but include rhyolitic shards that erupted during Episode I and were kept aloft by atmospheric turbulence. Published models yield column heights of 23–26 km for A, 22–25 km for CD, and 17–23 km for FG; and peak mass eruption rates of 0.7–1x108, 0.6–2x108, and 0.2–0.4x108 kg s-1, respectively. Fallout volumes, adjusted to reflect calculated redistribution of rhyolitic glass shards, are 8.8 km3, 4.8 km3, and 3.4 km3 for Episodes I, II, and III. Microprobe analyses of glass show that as much as 0.4 km3 of rhyolitic glass shards from eruptive Episode I fell with CDE and 1.1 km3 with FGH. Most of the rhyolitic ash in the dacitic fallout layers fell far downwind (SE of the vent); near the rhyolite-dominated ignimbrite, however, nearly all of Layers E and H are dacitic, showing that the downwind rhyolitic ash is of ‘co-plinian’ rather than co-ignimbrite origin.
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References
Abe K (1992) Seismicity of the great eruption of Mount Katmai, Alaska, in 1912. Bull Seism Soc Am 82:175–191
Carey SN, Sigurdsson H (1982) Influence of particle aggregation on deposition of distal tephra from the May 18, 1980, eruption of Mount St. Helens volcano. J Geophys Res 87:7061–7072
Carey S, Sparks RSJ (1986) Quantitative models of the fallout and dispersal of tephra from volcanic eruption columns. Bull Volcanol 48:109–125
Carey SN, Sigurdsson H, Sparks RSJ (1988) Experimental studies of particle-laden plumes. J Geophys Res 93:15314–15328
Curtis GH (1968) The stratigraphy of the ejecta from the 1912 eruption of Mount Katmai and Novarupta, Alaska. Geol Soc Am Mem 116:153–210
Federman AN, Scheidegger KF (1984) Compositional heterogeneity of distal tephra deposits from the 1912 eruption of Novarupta, Alaska. J Volcanol Geotherm Res 21:233–254
Fierstein J, Nathenson M (1992) Another look at the calculation of fallout tephra volumes. Bull Volcanol 54:156–167
Fisher RV, Schmincke H-U (1984) Pyroclastic rocks. Springer-Verlag, Berlin, Heidelberg, New York, Tokyo, 472 pp
Freundt A, Schmincke H-U (1986) Emplacement of small-volume pyroclastic flows at Laacher See (East-Eifel, Germany). Bull Volcanol 48:39–59
Froggatt PC (1982) Review of methods of estimating rhyolitic tephra volumes; applications to the Taupo Volcanic Zone, New Zealand. J Volcanol Geotherm Res 14:301–318
Griggs RF (1922) The Valley of Ten Thousand Smokes. National Geogr Soc, Washington, 340 pp
Hildreth W (1983) The compositionally zoned eruption of 1912 in the Valley of Ten Thousand Smokes, Katmai National Park, Alaska. J Volcanol Geotherm Res 18:1–56
Hildreth W (1987) New perspectives on the eruption of 1912 in the Valley of Ten Thousand Smokes, Katmai National Park, Alaska. Bull Volcanol 49:680–693
Hildreth W (1991) The timing of caldera collapse at Mount Katmai in response to magma withdrawal toward Novarupta. Geophys Res Lett 18:1541–1544
Hildreth W, Drake R (1992) Volcán Quizapu, Chilean Andes. Bull Volcanol 54:93–125
Imman DL (1952) Measures for describing the size distribution of sediments. J Sediment Petrol 22:125–145
Martin GC (1913) The recent eruption of Katmai volcano in Alaska. National Geog Mag 24:131–181
Nayudu YR (1964) Volcanic ash deposits in the Gulf of Alaska and problems of correlation of deep-sea ash deposits. Marine Geol 1:194–212
Pyle DM (1989) The thickness, volume and grainsize of tephra fall deposits. Bull Volcanol 51:1–15
Pyle DM (1990) New estimates for the volume of the Minoan eruption. In: Hardy D (ed) Thera and the Aegean World III, 2, Earth Sciences, The Thera Foundation London, pp 113–121
Rose WI Jr, Bonis S, Stoiber RE, Keller M, Bickford T (1973) Studies of volcanic ash from two recent Central American eruptions. Bull Volcanol 37:338–364
Rosi M (1992) A model for the formation of vesiculated tuff by the coalescence of accretionary lapilli. Bull Volcanol 54:429–434
Schumacher R (1990) Artificial ash clusters and deposition of fine volcanic ash (abstract). IAVCEI, International Volcanol Congress, Mainz (FRG), Abstracts volume, unpaginated
Schumacher R, Schmincke H-U (1990) The lateral facies of ignimbrites at Laacher See volcano. Bull Volcanol 52:271–285
Sigurdsson H, Carey SN, Cornell W, Pescatore T (1985) The eruption of Vesuvius in AD 79. Nat Geog Res 1:332–387
Sparks RSJ (1976) Grain size variations in ignimbrites and implications for the transport of pyroclastic flows. Sedimentology 23:147–188
Sparks RSJ (1986) The dimensions and dynamics of volcanic eruption columns. Bull Volcanol 48:3–15
Sparks RSJ, Walker GPL (1977) The significance of vitric-enriched air-fall ashes associated with crystal-enriched ignimbrites. J Volcanol Geotherm Res 2:329–341
Thorarinsson S (1954) The tephra fall from Hekla on March 29th, 1947. In: The eruption of Hekla 1947–1948, II. Soc Scient Islandica 1:1–68
Valentine G (1987) Stratified flow in pyroclastic surges. Bull Volcanol 49:616–630
Walker GPL (1971) Grain-size characteristics of pyroclastic deposits. J Geol 79:696–714
Walker GPL (1980) The Taupo pumice: product of the most powerful known (ultraplinian) eruption? J Volcanol Geotherm Res 8:69–94
Walker GPL (1981) Plinian eruptions and their products. Bull Volcanol 44:223–240
Walker GPL, Croasdale R (1971) Two plinian-type eruptions in the Azores. J Geol Soc London 127:17–55
Walker GPL, Wilson L, Bowell ELG (1971) Explosive volcanic eruptions — I. The rate of fall of pyroclasts. Geophys J R Astron Soc 22:377–383
Walker GPL, Wilson CJN, Froggatt PC (1981) An ignimbrite veneer deposit: the trail-marker of a pyroclastic flow. J Volcanol Geotherm Res 9:409–421
Wallmann PC, Pollard DD, Hildreth W, Eichelberger JC (1990) New structural constraints on magma chamber locations at the Valley of Ten Thousand Smokes, Katmai National Park, Alaska. Geology 18:1240–1243
Wilson L (1972) Explosive volcanic eruptions —II. The atmospheric trajectories of pyroclasts. Geophys J R Astron Soc 30:381–392
Wilson L, Huang TC (1979) The influence of shape on the atmospheric settling velocity of volcanic ash particles. Earth Planet Sci Lett 44:311–324
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 Astron Soc 89:657–679
Wilson L, Sparks RSJ, Walker GPL (1980) Explosive volcanic eruptions — IV. The control of magma properties and conduit geometry on eruption column behavior. Geophys J R Astron Soc 63:117–148
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Fierstein, J., Hildreth, W. The plinian eruptions of 1912 at Novarupta, Katmai National Park, Alaska. Bull Volcanol 54, 646–684 (1992). https://doi.org/10.1007/BF00430778
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DOI: https://doi.org/10.1007/BF00430778