Abstract
The 2004–05 eruption of Mount St Helens exhibited sustained, near-equilibrium behaviour characterized by relatively steady extrusion of a solid dacite plug and nearly periodic shallow earthquakes. Here we present a diverse data set to support our hypothesis that these earthquakes resulted from stick-slip motion along the margins of the plug as it was forced incrementally upwards by ascending, solidifying, gas-poor magma. We formalize this hypothesis with a dynamical model that reveals a strong analogy between behaviour of the magma–plug system and that of a variably damped oscillator. Modelled stick-slip oscillations have properties that help constrain the balance of forces governing the earthquakes and eruption, and they imply that magma pressure never deviated much from the steady equilibrium pressure. We infer that the volcano was probably poised in a near-eruptive equilibrium state long before the onset of the 2004–05 eruption.
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References
Sparks, R. S. J. The causes and consequences of eruptions of andesite volcanoes: opening remarks. Phil. Trans. R. Soc. Lond. A 358, 1435–1440 (2000)
Lahr, J. C., Chouet, B. A., Stephens, C. D., Power, J. A. & Page, R. A. Earthquake classification, location, and error analysis in a volcanic environment: implications for the magmatic system of the 1989–1990 eruptions at Redoubt Volcano, Alaska. J. Volcanol. Geotherm. Res. 62, 137–151 (1994)
Neuberg, J. Characteristics and causes of shallow seismicity in andesite volcanoes. Phil. Trans. R. Soc. Lond. A 358, 1533–1546 (2000)
Mullineaux, D. R. & Crandell, D. R. in The 1980 Eruptions of Mount St. Helens, Washington (eds Lipman, P. L. & Mullineaux, D. R.) 3–15 (USGS Professional Paper 1250, US Geological Survey, Washington DC, 1981)
Swanson, D. A. & Holcomb, R. T. in Lava Flows and Domes (ed. Fink, J.) 3–24 (Springer, Berlin, 1990)
Mastin, L. G. Explosive tephra emissions at Mount St. Helens, 1989–1991; the violent escape of magmatic gas following storms?. Geol. Soc. Am. Bull. 106, 175–185 (1994)
Moran, S. C. Seismicity at Mount St. Helens, 1987–1992: Evidence for repressurization of an active magmatic system. J. Geophys. Res. 99, 4341–4354 (1994)
Dzurisin, D., Vallance, J. W., Gerlach, T. M., Moran, S. C. & Malone, S. D. Mount St. Helens reawakens. Eos 86, 25; 29. (2005)
Schilling, S. P., Carrara, P. E., Thompson, R. A. & Iwatsubo, E. Y. Posteruption glacier development within the crater of Mount St. Helens, Washington, USA. Quat. Res. 61, 325–329 (2004)
Walder, J. S., LaHusen, R. G., Vallance, J. W. & Schilling, S. P. Crater glaciers on active volcanoes: hydrological anomalies. Eos 86, 521; 528. (2005)
Pallister, J. S., Reagan, M. & Cashman, K. A new eruptive cycle at Mount St. Helens?. Eos 86, 499 (2005)
Tuffen, H. & Dingwell, D. Fault textures in volcanic conduits: evidence for seismic trigger mechanisms during silicic eruptions. Bull. Volcanol. 67, 370–387 (2005)
Moore, P. L., Iverson, N. R. & Iverson, R. M. Frictional properties of the Mount St. Helens gouge. In A Volcano Rekindled: The First Year of Renewed Eruption at Mount St. Helens, 2004–2005 (eds Sherrod, D. A. & Scott, W. E.) (USGS Professional Paper, US Geological Survey, submitted).
Blundy, J. & Cashman, K. Ascent-driven crystallization of dacite magmas at Mount St. Helens, 1980–1986. Contrib. Mineral. Petrol. 140, 631–650 (2001)
McGee, K. A., Doukas, M. P. & Gerlach, T. M. Quiescent hydrogen sulfide and carbon dioxide degassing from Mount Baker, Washington. Geophys. Res. Lett. 28, 4479–4482 (2001)
Newman, S. & Lowenstern, J. A. VolatileCalc: a silicate melt-H2O–CO2 solution model written in Visual Basic for Application (VBA) with Microsoft® Excel. Comput. Geosci. 28, 597–604 (2002)
Rutherford, M. J. Experimental petrology applied to volcanic processes. Eos 74, 49; 55. (1993)
Yang, X., Davis, P. M. & Dieterich, J. H. Deformation from inflation of a dipping finite prolate spheroid in an elastic half space as a model for volcanic stressing. J. Geophys. Res. 93, 4249–4257 (1988)
Melnik, O. E. & Sparks, R. S. J. Nonlinear dynamics of lava dome extrusion. Nature 402, 37–41 (1999)
Mason, R. M., Starostin, A. B., Melnik, O. E. & Sparks, R. S. J. From Vulcanian explosions to sustained explosive eruptions: the role of diffusive mass transfer in conduit flow dynamics. J. Volcanol. Geotherm. Res. 153, 148–165 (2006)
Chouet, B. Long-period volcano seismicity: its source and use in eruption forecasting. Nature 380, 309–316 (1996)
Denlinger, R. P. & Hoblitt, R. P. Cyclic eruptive behavior of silicic volcanoes. Geology 27, 459–462 (1999)
Voight, B. et al. Magma flow instability and cyclic activity at Soufriere Hills Volcano, Montserrat, British West Indies. Science 283, 1138–1142 (1999)
Ozerov, A., Ispolatov, I. & Lees, J. Modeling Strombolian eruptions of Karymsky volcano, Kamchatka, Russia. J. Volcanol. Geotherm. Res. 122, 265–280 (2003)
Mastin, L. G. & Ghiorso, M. S. A Numerical Program for Steady-state Flow of Magma-gas Mixtures through Vertical Eruptive Conduits (USGS Open-File Report 00–209, US Geological Survey, Vancouver, Washington, 2000)
Marone, C. Laboratory-derived friction laws and their application to seismic faulting. Annu. Rev. Earth Planet. Sci. 26, 643–696 (1998)
Press, W. H., Flannery, B. P., Teukolsky, S. A. & Vettering, W. T. Numerical Recipes (Cambridge Univ. Press, Cambridge, UK, 1986)
Acknowledgements
We are indebted to many colleagues in the USGS Volcano Hazards Program and the Pacific Northwest Seismic Network who contributed to hazard assessment and study of the ongoing eruption at MSH.
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Supplementary Notes
This file contains Supplementary Figures, Supplementary Methods, Supplementary mathematics (Equations), and Supplementary Notes, as well as legends for the Supplementary Movies listed below. (PDF 1733 kb)
Supplementary Movie 1
MSH DEM sequence. This movie shows a sequence of vertical shaded relief images illustrating dome growth and accompanying glacier deformation at Mount St. Helens, 2004-2005. Images were produced from digital elevation models (DEMs) constructed from stereoscopic aerial photographs taken roughly once a month. (MPG 9361 kb)
Supplementary Movie 2
MSH timelapse photo sequence. This movie shows a sequence of terrestrial photographs depicting dome growth at Mount St. Helens, 2004-2005. The movie was compiled from selected digital photographs taken about once every three minutes by an automated camera positioned near the mouth of the MSH crater. (MPG 9981 kb)
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Iverson, R., Dzurisin, D., Gardner, C. et al. Dynamics of seismogenic volcanic extrusion at Mount St Helens in 2004–05. Nature 444, 439–443 (2006). https://doi.org/10.1038/nature05322
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DOI: https://doi.org/10.1038/nature05322
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