Investigation of surge-derived pyroclastic flow formation by numerical modelling of the 25 June 1997 dome collapse at Soufrière Hills Volcano, Montserrat
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Deposits from ash-cloud surges associated with dome collapse can, under certain conditions, be remobilised to form surge-derived pyroclastic flows (SDPFs). Using numerical modelling, we reproduce the emplacement of these flows and investigate the conditions that favour their genesis. We use the new version of the numerical model VolcFlow, which simulates the two components of a pyroclastic flow: the basal avalanche and the overriding ash-cloud surge. The basal avalanche (primary block-and-ash flows and SDPFs) are simulated using three previously published rheological laws: plastic, frictional and frictional velocity-weakening rheologies. Applied to the 25 June 1997 dome collapse at Soufrière Hills Volcano, the models reproduce to different degrees the deposit footprints formed by the block-and-ash flows, the ash-cloud surges and the SDPFs. In the plastic model, SDPFs occur if the ash-cloud surge deposit exceeds a threshold thickness that allows it to remobilise and flow. In the frictional models, SDPFs occur only if ash-cloud surge deposition takes place on a slope exceeding the friction angle of the ash. Results also highlight that SDPFs appeared so clearly in 1997 at Montserrat due to a combination of topographic factors: (i) a bend in the Mosquito Ghaut drainage that allowed the ash-cloud surges to detach, (ii) a depositional area on the watershed between the eastern and western drainage channels and (iii) a network of tributaries that drained all the remobilised mass into Dyer’s River to form a single, large SDPF. Our model could be a promising tool for the future forecasting of hazards posed by surge-derived pyroclastic flows.
KeywordsPyroclastic flows Soufrière Hills Volcano Dome collapse Numerical modelling Rheology Volcanic hazards
We are very grateful to Dr. Adam Stinton and the Montserrat Volcano Observatory for providing the digital elevation model of Montserrat Island and also Dr. Anne Mangeney for discussions about seismic waves.
The development of the numerical code was funded by the Domerapi—ANR (French Agence Nationale de la Recherche) Project (ANR-12-BS06-0012). This research was (partly) supported by the French Government Laboratory of Excellence initiative no. ANR-10-LABX-0006, the Région Auvergne and the European Regional Development Fund. This is Laboratory of Excellence ClerVolc contribution number 336.
- Annen C, Wagner J-J (2003) The impact of volcanic eruptions during the 1990s. Nat Hazard Rev 4(4):169–175. https://doi.org/10.1061/(ASCE)1527-6988(2003)4:4(169) CrossRefGoogle Scholar
- Balachandar S, Eaton JK (2010) Turbulent dispersed multiphase flow. Annu Rev Fluid Mech 42:111–133. https://doi.org/10.1146/annurev.fluid.010908.16524 CrossRefGoogle Scholar
- Brown RJ and Andrews DMG (2015) Deposits of pyroclastic density currents. The Encyclopedia of Volcanoes (Second Edn). Elsevier Inc. https://doi.org/10.1016/B978-0-12-385938-9.00036-5 CrossRefGoogle Scholar
- Charbonnier SJ, Gertisser R (2012) Evaluation of geophysical mass flow models using the 2006 block-and-ash flows of Merapi Volcano, Java, Indonesia: towards a short-term hazard assessment tool. J Volcanol Geotherm Res 231–232:87–108. https://doi.org/10.1016/j.jvolgeores.2012.02.015 CrossRefGoogle Scholar
- Charbonnier SJ, Germa A, Connor CB, Gertisser R, Preece K, Komorowski JC, Lavigne F, Dixon T, Connor L (2013) Evaluation of the impact of the 2010 pyroclastic density currents at Merapi volcano from high-resolution satellite imagery, field investigations and numerical simulations. J Volcanol Geotherm Res 261:295–315. https://doi.org/10.1016/j.jvolgeores.2012.12.021 CrossRefGoogle Scholar
- Druitt TH, Kokelaar BP (Eds.) (2002) The eruption of Soufrière Hills volcano, Montserrat, from 1995 to 1999. Geological Society, London, Memoirs 21:263–279Google Scholar
- Druitt TH, Calder ES, Cole PD, Hoblitt RP, Loughlin SC, Norton GE, Ritchie LJ, Sparks RSJ, Voight B (2002) Small-volume, highly mobile pyroclastic flows formed by rapid sedimentation from pyroclastic surges at Soufriere Hills Volcano, Montserrat: an important volcanic hazard. Geol Soc Lond Mem 21(1):263–279. https://doi.org/10.1144/GSL.MEM.2002.021.01.12 CrossRefGoogle Scholar
- Dufek J (2016) The fluid mechanics of pyroclastic density currents. Annu Rev Fluid Mech 48:459–485. https://doi.org/10.1146/annurev-fluid-122414-034252 CrossRefGoogle Scholar
- Iverson RM, Vallance JW (2001) New views of granular mass flows. Geology 29(2):115–118. https://doi.org/10.1130/0091-7613(2001)029<0115:NVOGMF>2.0.CO CrossRefGoogle Scholar
- Kelfoun K, Samaniego P, Palacios P, Barba D (2009) Testing the suitability of frictional behaviour for pyroclastic flow simulation by comparison with a well-constrained eruption at Tungurahua volcano (Ecuador). Bull Volcanol 71(9):1057–1075. https://doi.org/10.1007/s00445-009-0286-6 CrossRefGoogle Scholar
- Komorowski JC, Legendre Y, Christopher T, Bernstein M, Stewart R, Joseph E et al (2010) Insights into processes and deposits of hazardous vulcanian explosions at Soufrière Hills Volcano during 2008 and 2009 (Montserrat, West Indies). Geophys Res Lett 37(11):1–6. https://doi.org/10.1029/2010GL042558 CrossRefGoogle Scholar
- Komorowski JC, Jenkins S, Baxter PJ, Picquout A, Lavigne F, Charbonnier S, Gertisser R, Preece K, Cholik N, Budi-Santoso A, Surono (2013) Paroxysmal dome explosion during the Merapi 2010 eruption: processes and facies relationships of associated high-energy pyroclastic density currents. J Volcanol Geotherm Res 261(November 2010):260–294. https://doi.org/10.1016/j.jvolgeores.2013.01.007 CrossRefGoogle Scholar
- Loughlin SC, Calder ES, Clarke A, Cole PD, Luckett R, Mangan MT, Pyle DM, Sparks RSJ, Voight B, Watts RB (2002b) Pyroclastic flows and surges generated by the 25 June 1997 dome collapse, Soufriere Hills Volcano, Montserrat. Geol Soc Lond Mem 21(1):191–209. https://doi.org/10.1144/GSL.MEM.2002.021.01.09 CrossRefGoogle Scholar
- Mangeney A, Staron L, Volfson D, Tsimring L (2007) Comparison between discrete and continuum modeling of granular spreading. WSEAS Trans Math 6(2):373–380Google Scholar
- Ogburn SE, Calder ES (2017) The relative effectiveness of empirical and physical models for simulating the dense undercurrent of pyroclastic flows under different emplacement conditions. Front Earth Sci 5(November). https://doi.org/10.3389/feart.2017.00083
- Pudasaini SP and Hutter K (2007) Avalanche dynamics: dynamics of rapid flows of dense granular avalanches. https://doi.org/10.1007/978-3-540-32687-8
- Voellmy A (1955) Über die Zerstörungskraft von Lawinen. Schweiz Bauzeitung 73(12):159–165Google Scholar
- Woods AW, Sparks RSJ, Ritchie LJ, Batey J, Gladstone C, Bursik MI (2002) The explosive decompression of a pressurized volcanic dome: the 26 December 1997 collapse and explosion of Soufriere Hills Volcano, Montserrat. Geol Soc Lond Mem 21(1):457–465. https://doi.org/10.1144/GSL.MEM.2002.021.01.20 CrossRefGoogle Scholar