Sedimentation process of ashfall during a Vulcanian eruption as revealed by high-temporal-resolution grain size analysis and high-speed camera imaging

Progress in Earth and Planetary Science - Tập 7 - Trang 1-16 - 2020
T. Miwa1, Y. Iriyama1, M. Nagai1, F. Nanayama2
1National Research, Institute for Earth Science and Disaster Resilience, Tsukuba, Japan
2Geological Survey of Japan, AIST, AIST No.7, Tsukuba, Japan

Tóm tắt

We here examined the sedimentation process of falling ash particles during a short-lived Vulcanian eruption at Sakurajima volcano, Japan, using high-speed camera imaging of airborne ash particles, as well as grain size analyses of ash samples collected at high temporal resolution. Ashfalls from a sequence of two Vulcanian eruptions at 10:44 and 11:26 JST (Japan Standard Time) on 26 March 2016 were investigated. The field site for imaging and sampling was located approximately 3.5 km from the vent. The ash particles collected exhibit bimodal grain size distributions (GSDs). The median particle size of the main subpopulation decreased throughout the ashfall owing to size-dependent segregation of ash particles from a single source released from a constant height. The volume fraction of the subordinate subpopulation is interpreted to represent a component of ash aggregates and shows an increase in its volume fraction after the eruption onset. High-speed camera imaging reveals that the mean particle density decreased over time as the ashfall continued. These data suggest an increasing contribution of low-density aggregates during the course of the ashfall. The temporal changes in the density of airborne ash particles and in the GSD of ash samples demonstrate that the sedimentation process during a Vulcanian eruption at Sakurajima volcano is characterized by sedimentation of ash particles from transient eruption plumes at constant height, in which ash aggregation increases over time. Moreover, time series analysis of the ash falling rate shows that secondary thickening occurred during these Vulcanian eruptions and that this can be triggered by the settling of ash aggregates.

Tài liệu tham khảo

Andronico D, Cioni R (2002) Contrasting styles of Mount Vesuvius activity in the period between the Avellino and Pompeii Plinian eruptions, and some implications for assessment of future hazards. Bull Volcanology 64(6):372–391. https://doi.org/10.1007/s00445-002-0215-4 Bagheri G, Rossi E, Biass S, Bonadonna C (2016) Timing and nature of volcanic particle clusters based on field and numerical investigations. J Volcanology Geothermal Res 327:520–530. https://doi.org/10.1016/j.jvolgeores.2016.09.009 Blott SJ, Pye K (2001) GRADISTAT: a grain size distribution and statistics package for the analysis of unconsolidated sediments. Earth Surface Processes Landforms 26(11):1237–1248. https://doi.org/10.1002/esp.261 Bonadonna C, Genco R, Gouhier M, Pistolesi M, Cioni R, Alfano F, Hoskuldsson A, Ripepe M (2011) Tephra sedimentation during the 2010 Eyjafjallajökull eruption (Iceland) from deposit, radar, and satellite observations. J Geophysical Res Solid Earth 116(B12). https://doi.org/10.1029/2011JB008462 Bonadonna C, Mayberry GC, Calder ES, Sparks RSJ, Choux C, Jackson P, Lejeune AM, Loughlin SC, Norton GE, Rose WI, Ryan G (2002) Tephra fallout in the eruption of Soufrière Hills Volcano, Montserrat. Geological Soc London Memoirs 21(1):483–516. https://doi.org/10.1144/GSL.MEM.2002.021.01.22 Brazier S, Sparks RSJ, Carey SN, Sigurdsson H, Westgate J (1983) Bimodal grain size distribution and secondary thickening in air-fall ash layers. Nature 301(5896):115–119. https://doi.org/10.1038/301115a0 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 Geophysical Res 87(B8):7061–7072. https://doi.org/10.1029/JB087iB08p07061 Chojnicki KN, Clarke AB, Adrian RJ, Phillips JC (2014) The flow structure of jets from transient sources and implications for modeling short-duration explosive volcanic eruptions. Geochemistry Geophysics Geosystems 15(12):4831–4845. https://doi.org/10.1002/2014gc005471 Chojnicki KN, Clarke AB, Phillips JC, Adrian RJ (2015a) Rise dynamics of unsteady laboratory jets with implications for volcanic plumes. Earth Planetary Sci Lett 412(0):186–196. https://doi.org/10.1016/j.epsl.2014.11.046 Chojnicki KN, Clarke AB, Phillips JC, Adrian RJ (2015b) The evolution of volcanic plume morphology in short-lived eruptions. Geology 43(8):707–710. https://doi.org/10.1130/G36642.1 Clarke AB (2013) Unsteady explosive activity: Vulcanian eruptions. In: Fagents SA, Gregg TKP, Lopes RMC (eds) Modeling volcanic processes: the physics and mathematics of volcanism. Cambridge University Press, England, pp 129–152. https://doi.org/10.1017/CBO9781139021562.007 Costa A, Folch A, Macedonio G (2010) A model for wet aggregation of ash particles in volcanic plumes and clouds: 1. Theoretical formulation. Journal of Geophysical Research 115(B9). https://doi.org/10.1029/2009JB007175 Dellino P, Mele D, Bonasia R, Braia G, La Volpe L, Sulpizio R (2005) The analysis of the influence of pumice shape on its terminal velocity. Geophysical Res Lett 32(21). https://doi.org/10.1029/2005GL023954 Evans JR, Huntoon JE, Rose WI, Varley NR, Stevenson JA (2009) Particle sizes of andesitic ash fallout from vertical eruptions and co-pyroclastic flow clouds, Volcán de Colima, Mexico. Geology 37(10):935–938. https://doi.org/10.1130/G30208A.1 Eychenne J, Le Pennec JL, Troncoso L, Gouhier M, Nedelec JM (2012) Causes and consequences of bimodal grain-size distribution of tephra fall deposited during the August 2006 Tungurahua eruption (Ecuador). Bull Volcanology 74(1):187–205. https://doi.org/10.1007/s00445-011-0517-5 Folch A (2012) A review of tephra transport and dispersal models: evolution, current status, and future perspectives. J Volcanology Geothermal Res 235:96–115. https://doi.org/10.1016/j.jvolgeores.2012.05.020 Folk RL, Ward WC (1957) Brazos River bar: a study in the significance of grain size parameters. J Sedimentary Petrology 27(1):3–26. https://doi.org/10.1306/74D70646-2B21-11D7-8648000102C1865D Gilbert J, Lane S, Sparks R, Koyaguchi T (1991) Charge measurements on particle fallout from a volcanic plume. Nature 349(6310):598–600. https://doi.org/10.1038/349598a0 Hammer J, Cashman K, Hoblitt R, Newman S (1999) Degassing and microlite crystallization during pre-climactic events of the 1991 eruption of Mt. Pinatubo, Philippines. Bull Volcanology 60(5):355–380. https://doi.org/10.1007/s004450050238 Iguchi M, Tameguri T, Ohta Y, Ueki S, Nakao S (2013) Characteristics of volcanic activity at Sakurajima volcano’s Showa crater during the period 2006 to 2011 (Special Section, Sakurajima Special Issue). Bull Volcanological Soc Jpn 58(1):115–135. https://doi.org/10.18940/kazan.58.1_115 Iguchi M, Yokoo A, Tameguri T (2010) Intensity of volcanic explosions at Showa crater of Sakurajima volcano. Annuals of Disaster Prevention Research Institute of Kyoto University 53:233–240 Imura R (1991) Pyroclastic deposits of Suwanosejima volcano for the last 200 years: a reconstruction of volcanic activity using the volcanic sand formation. J Geological Soc Jpn 97(10):865–868. https://doi.org/10.5575/geosoc.97.865 Imura R (1995) Pyroclastic deposit accumulated by small-scale eruptions. Bull Volcanological Soc Jpn 40(3):119–132. https://doi.org/10.18940/kazan.40.3_119 Iriyama Y, Toramaru A, Yamamoto T (2018) Theory for deducing volcanic activity from size distributions in plinian pyroclastic fall deposits. J Geophysical Res Solid Earth 123(3):2199–2213. https://doi.org/10.1002/2017JB014782 James MR, Lane SJ, Gilbert JS (2003) Density, construction, and drag coefficient of electrostatic volcanic ash aggregates. J Geophysical Res 108(B9). https://doi.org/10.1029/2002JB002011 Kobayashi T, Miki D, Sasaki H, Iguchi M, Yamamoto T, Uto K (2013) Geological Map of Sakurajima Volcano, 2nd Ed. 1: 25,000 Koyaguchi T, Ohno M (2001a) Reconstruction of eruption column dynamics on the basis of grain size of tephra fall deposits: 1. Methods. J Geophysical Res 106(B4):6499–6512. https://doi.org/10.1029/2000JB900426 Koyaguchi T, Ohno M (2001b) Reconstruction of eruption column dynamics on the basis of grain size of tephra fall deposits: 2. Application to the Pinatubo 1991 eruption. J Geophysical Res 106(B4):6513–6533. https://doi.org/10.1029/2000JB900427 Kozono T, Iguchi M, Miwa T, Maki M, Maesaka T, Miki D (2019) Characteristics of tephra fall from eruptions at Sakurajima volcano, revealed by optical disdrometer measurements. Bull Volcanology 81(7):41. https://doi.org/10.1007/s00445-019-1300-2 Miura K, Ban M, Ohba T, Fujinawa A (2012) Sequence of the 1895 eruption of the Zao volcano, Tohoku Japan. J Volcanology Geothermal Res 247:139–157. https://doi.org/10.1016/j.jvolgeores.2012.08.005 Miwa T, Geshi N, Shinohara H (2013) Temporal variation in volcanic ash texture during a Vulcanian eruption at the Sakurajima volcano, Japan. J Volcanology Geothermal Res 260:80–89. https://doi.org/10.1016/j.jvolgeores.2013.05.010 Miyabuchi Y, Hanada D, Niimi H, Kobayashi T (2013) Stratigraphy, grain-size and component characteristics of the 2011 Shinmoedake eruption deposits, Kirishima Volcano, Japan. J Volcanology Geothermal Res 258:31–46. https://doi.org/10.1016/j.jvolgeores.2013.03.027 Oishi M, Nishiki K, Geshi N, Furukawa R, Ishizuka Y, Oikawa T, Yamamoto T, Nanayama F, Tanaka A, Hirota A, Miwa T (2018) Distribution and mass of tephra-fall deposits from volcanic eruptions of Sakurajima Volcano based on posteruption surveys. Bull Volcanology 80(4):42. https://doi.org/10.1007/s00445-018-1215-3 Poulidis AP, Takemi T, Iguchi M, Renfrew IA (2017) Orographic effects on the transport and deposition of volcanic ash: a case study of Mount Sakurajima, Japan. J Geophysical Res Atmospheres 122(17):9332–9350. https://doi.org/10.1002/2017JD026595 Schumacher R (1994) A reappraisal of Mount St. Helens’ ash clusters–depositional model from experimental observation. Bull Volcanology 59(3):253–260. https://doi.org/10.1016/0377-0273(94)90099-X Sheridan M, Wohletz K, Dehn J (1987) Discrimination of grain-size subpopulations in pyroclastic deposits. Geology 15(4):367–370. https://doi.org/10.1130/0091-7613(1987)15<367:DOGSIP>2.0.CO;2 Shimbori T (2016) Tephra transport: modeling and forecasting. Bull Volcanological Soc Jpn 61(2):399–427. https://doi.org/10.18940/kazan.61.2_399 Sparks RSJ, Bursik MI, Carey S, Gilbert J, Glaze L, Sigurdsson H, Woods A (1997) Volcanic plumes. Wiley, New Jersey Taddeucci J, Scarlato P, Montanaro C, Cimarelli C, Del Bello E, Freda C, Andronico C, Gudmundsson MT, Dingwell DB (2011) Aggregation-dominated ash settling from the Eyjafjallajökull volcanic cloud illuminated by field and laboratory high-speed imaging. Geology 39(9):891–894. https://doi.org/10.1130/G32016.1 Tournigand P-Y, Taddeucci J, Gaudin D, Peña Fernández JJ, Del Bello E, Scarlato P, Kueppers U, Sesterhenn J, Yokoo A (2017) The initial development of transient volcanic plumes as a function of source conditions. J Geophysical Res Solid Earth 122(12):9784–9803. https://doi.org/10.1002/2017JB014907 Walker GPL (1971) Grain-size characteristics of pyroclastic deposits. J Geology 79(6):696–714. https://doi.org/10.1086/627699 Wilson L, Huang T (1979) The influence of shape on the atmospheric settling velocity of volcanic ash particles. Earth Planetary Sci Lett 44(2):311–324. https://doi.org/10.1016/0012-821X(79)90179-1 Wohletz KH, Sheridan MF, Brown WK (1989) Particle size distributions and the sequential fragmentation/transport theory applied to volcanic ash. J Geophysical Res 94(B11):15703–15721. https://doi.org/10.1029/JB094iB11p15703 Woods AW, Kienle J (1994) The dynamics and thermodynamics of volcanic clouds: theory and observations from the April 15 and April 21, 1990 eruptions of Redoubt Volcano, Alaska. J Volcanology Geothermal Res 62(1–4):273–299. https://doi.org/10.1016/0377-0273(94)90037-X