The control of magma crystallinity on the fluctuations in gas composition at open vent basaltic volcanoes.

Julia Woitischek, Marie Edmonds, Andrew W Woods
Author Information
  1. Julia Woitischek: Department of Earth Sciences, University of Cambridge, Downing St, Cambridge, CB2 3EQ, UK. jw943@cam.ac.uk.
  2. Marie Edmonds: Department of Earth Sciences, University of Cambridge, Downing St, Cambridge, CB2 3EQ, UK.
  3. Andrew W Woods: Department of Earth Sciences, University of Cambridge, Downing St, Cambridge, CB2 3EQ, UK.

Abstract

Basaltic open vent volcanoes are major global sources of volcanic gases. Many of these volcanoes outgas via intermittent Strombolian-type explosions separated by periods of passive degassing. The gas emitted during the explosions has high molar CO/SO and SO/HCl ratios, while during the passive degassing these ratios are lower. We present new laboratory experiments in a model volcanic conduit, which suggest that these differences in gas geochemistry are a consequence of gas migration through crystal-rich magma. We show that gas may flow along channels through the particle-laden liquid and, at a critical depth, the gas may displace an overlying crystal-rich plug en masse, producing a growing slug of gas. Owing to the friction on the walls of the conduit, this plug becomes progressively sheared and weakened until gas enriched in the least soluble volatiles breaks through, causing an explosion at the surface. When the gas slug bursts, liquid is drawn up in its wake, which exsolves the more soluble volatile components, which then vent passively at the surface until the next explosive slug-bursting event.

References

Oppenheimer, C., Bani, P., Calkins, J. A., Burton, M. R. & Sawyer, G. M. Rapid FTIR sensing of volcanic gases released by Strombolian explosions at Yasur volcano, Vanuatu. Appl. Phys. B 85, 453–460 (2006). [DOI: 10.1007/s00340-006-2353-4]
Burton, M., Allard, P., Mure, F. & La Spina, A. Magmatic gas composition reveals the source depth of slug-driven Strombolian explosive activity. Science 317, 227–230 (2007). [DOI: 10.1126/science.1141900]
Liu, E. J. et al. Dynamics of outgassing and plume transport revealed by proximal unmanned areal systems (UAS) measurements at Volcán Villarrica. Chile. Geochem. Geophys. Geosyst. 20, 730–750 (2019). [DOI: 10.1029/2018GC007692]
Oppenheime, R. C., Lomakina, S. A., Kyle, P. R., Kingsbury, N. G. & Boichu, M. Pulsatory magma supply to a phonolite lava lake. Earth Planet. Sci. Let. 284, 392–398 (2009). [DOI: 10.1016/j.epsl.2009.04.043]
Woitischek, J. et al. Strombolian eruptions and dynamics of magma degassing at Yasur Volcano (Vanuatu). J. Volcanol. Geotherm. Res. 398, 106869 (2020). [DOI: 10.1016/j.jvolgeores.2020.106869]
Parfitt, E. A. & Wilson, L. Explosive volcanic eruptions-IX. The transition between Hawaiian-style lava fountaining and Strombolian explosive activity. Geophys. J. Int. 121, 226–232 (1995). [DOI: 10.1111/j.1365-246X.1995.tb03523.x]
Jaupart, C. & Vergniolle, S. The generation and collapse of a foam layer at the roof of a basaltic magma chamber. J. Fluid Mech. 203, 347–380 (1989). [DOI: 10.1017/S0022112089001497]
Jaupart, C. & Vergniolle, S. Laboratory models of Hawaiian and Strombolian eruptions. Nature 331, 58–60 (1988). [DOI: 10.1038/331058a0]
Métrich, N. et al. Magma and volatile supply to post-collapse volcanism and block resurgence in Siwi Caldera (Tanna Island, Vanuatu Arc). J. Petrol. 52, 1077–1105 (2011). [DOI: 10.1093/petrology/egr019]
Métrich, N., Bertagini, A. & Di Muro, A. Conditions of magma storage, degassing and ascent at Stromboli: new insights into the volcano plumbing system with inferences on the eruptive dynamics. J. Petrol. 51, 603–626 (2010). [DOI: 10.1093/petrology/egp083]
Ridolfi, F., Puerini, M., Renzulli, A., Menna, M. & Toulkeridis, T. The magmatic feeding system of El Reventador volcano (Sub-Andeanzone, Ecuador) constrained by texture, mineralogy and thermobarometry of the 2002 erupted products. J. Volcanol. Geotherm. Res. 176, 94–106 (2008). [DOI: 10.1016/j.jvolgeores.2008.03.003]
Reagan, M. K., Gill, J. B., Malavassi, E. & Garcia, M. O. Changes in magma composition at Arenal volcano, Costa Rica, 1968–1985: real-time monitoring of open-system differentiation. Bull. Volcanol. 49, 415–434 (1987). [DOI: 10.1007/BF01046634]
Oppenheimer, J., Rust, A. C., Cashman, K. V. & Sandnes, B. Gas migration regimes and outgassing in particle-rich suspensions. Front. Phys. 3, 60 (2015). [DOI: 10.3389/fphy.2015.00060]
Belien, I. B., Cashman, K. V. & Rempel, A. W. Gas accumulation in particle-rich suspensions and implications for bubble populations in crystal-rich magma. Earth Planet. Sci. Lett. 297, 133–140 (2010). [DOI: 10.1016/j.epsl.2010.06.014]
Oppenheimer, J. et al. Analogue experiments on the rise of large bubbles through a solid-rich suspension: A ’’weak plug’’ model for Strombolian eruptions. Earth Planet. Sci. Lett. 531, 115931 (2020). [DOI: 10.1016/j.epsl.2019.115931]
Parmigiani, A., Huber, C. & Bachmann, O. Mush microphysics and the reactivation of crystal-rich magma reservoirs. J. Geophys. Res. Solid Earth 119, 6308–6322 (2014). [DOI: 10.1002/2014JB011124]
Barth, A., Edmonds, E. & Woods, A. W. Valve-like dynamics of gas flow through a packed crystal mush and cyclic strombolian explosions. Sci. Rep. 9, 821 (2019). [DOI: 10.1038/s41598-018-37013-8]
Ilanko, T., Oppenheimer, C., Burgisser, A. & Kyle, P. Transient degassing events at the lava lake of Erebus volcano, Antarctica: Chemistry and mechanism. GeoReJ. 7, 43–58 (2015).
Lesne, P. et al. Experimental simulation of closed-system degassing in the system basalt-HO-CO-S-Cl. J. Petrol. 52, 1737–1762 (2011). [DOI: 10.1093/petrology/egr027]
Shishkina, T. A., Botcharnikov, R. E., Holtz, F., Almeev, R. R. & Portnyagin, M. V. Solubility of HO- and CO-bearing fluids in tholeiitic basalts at pressures up to 500 MPa. Chem. Geol. 277, 115–125 (2010). [DOI: 10.1016/j.chemgeo.2010.07.014]
Witham, F. et al. SolEx: A model for mixed COHSCl-volatile solubilities and exsolved gas compositions in basalt. Comput. Geosci. 45, 87–97 (2012). [DOI: 10.1016/j.cageo.2011.09.021]
Métrich, N. & Wallace, P. J. Volatile abundances in basaltic magmas and their degassing paths tracked by melt inclusions. Rev. Mineral. Geochem. 69, 362–402 (2008). [DOI: 10.2138/rmg.2008.69.10]
Oppenheimer, C. et al. Mantle to surface degassing of alkali magmas at Erebus volcano, Antarctica. Earth Planet. Sci. Lett. 306, 261–271 (2011). [DOI: 10.1016/j.epsl.2011.04.005]
Menand, T. & Phillips, J. C. Gas segregation in dykes and sills. J. Volcanol. Geotherm. Res. 159, 393–408 (2007). [DOI: 10.1016/j.jvolgeores.2006.08.003]
Shaw, H. R., Wright, T. L., Peck, D. L. & Okamura, R. The viscosity of basaltic magma; an analysis of field measurement in Makaopuhi Lava, Hawaii. Am. J. Sci. 266, 225–264 (1968). [DOI: 10.2475/ajs.266.4.225]
Saar, M. O., Manga, M., Cashman, K. V. & Fremouw, S. Numerical models of the onset of yield strength in crystal-melt suspensions. Earth Planet. Sci. Lett. 187, 367–379 (2001). [DOI: 10.1016/S0012-821X(01)00289-8]
Hoover, S. R., Cashman, K. V. & Manga, M. The yield strength of subliquidus basalts: experimental results. J. Volcanol. Geotherm. Res. 107, 1–18 (2001). [DOI: 10.1016/S0377-0273(00)00317-6]
Sandnes, B., Flekkøy, E. G., Knudsen, H. A., Måløy, K. J. & See, H. Patterns and flow in frictional fluid dynamics. Nat. Commun. 2, 288 (2011). [DOI: 10.1038/ncomms1289]
Varas, G., Ramos, G., Géminard, J. C. & Vidal, V. Flow and fracture in water-saturated, unconstrained granular beds. Front. Phys. 3, 44 (2015). [DOI: 10.3389/fphy.2015.00044]
Rosi, M. et al. Stromboli volcano, aeolian islands (Italy): present eruptive activity and hazards. Geol. Soc. Lond. Mem. 37(1), 473–490 (2013). [DOI: 10.1144/M37.14]
Gaudin, D. et al. Integrating puffing and explosions in a general scheme for Strombolian-style activity. J. Geophys. Res. Solid Earth. 122, 1860–1875 (2017).
Bani, P. et al. Magma dynamics feeding Yasur’s explosive activity observed using thermal infrared remote sensing. Geophys. Res. Lett. 40, 3830–3835 (2013). [DOI: 10.1002/grl.50722]
Pering, T. D. et al. Conduit dynamics and post explosion degassing on Stromboli: a combined UV camera and numerical modeling treatment. Geophys. Res. Lett. 43, 5009–5016 (2016). [DOI: 10.1002/2016GL069001]
Vona, A. et al. The rheology of crystal bearing basaltic magmas from Stromboli and Etna. Geochim. Cosmochim. Acta. 75, 3214–3236 (2011). [DOI: 10.1016/j.gca.2011.03.031]
Del Bello, E. et al. Viscous plugging can enhance and modulate explosivity of strombolian eruptions. Earth Planet. Sci. Let. 423, 210–218 (2015). [DOI: 10.1016/j.epsl.2015.04.034]

Word Cloud

Similar Articles

Cited By