Magma flow instability and cyclic activity at Soufriere Hills volcano, Montserrat, British West Indies

B. Voight, RSJ Sparks, AD Miller, RC Stewart, R.P Hoblitt, A Clarke, J Ewart, WP Aspinall, B Baptie, ES Calder, P Cole, TH Druitt, C Hartford, Richard Herd, P Jackson, AM Lejeune, AB Lockhart, SC Loughlin, R Luckett, L LynchGE Norton, R Robertson, IM Watson, R Watts, SR Young

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266 Citations (Scopus)


Dome growth at the Soufriere Hills volcano (1996 to 1998) was frequently accompanied by repetitive cycles of earthquakes, ground deformation, degassing, and explosive eruptions. The cycles reflected unsteady conduit flow of volatile-charged magma resulting from gas exsolution, rheological stiffening, and pressurization. The cycles, over hours to days, initiated when degassed stiff magma retarded flow in the upper conduit. Conduit pressure built with gas exsolution, causing shallow seismicity and edifice inflation. Magma and gas were then expelled and the edifice deflated. The repeat time-scale is controlled by magma ascent rates, degassing, and microlite crystallization kinetics. Cyclic behavior allows short-term forecasting of timing, and of eruption style related to explosivity potential.
Original languageEnglish
Pages (from-to)1138-1142
Number of pages5
Issue number5405
Publication statusPublished - 19 Feb 1999

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