Cyclic extrusion of a lava dome based on a stick-slip mechanism

Costa, A., Wadge, G. and Melnik, O. (2012) Cyclic extrusion of a lava dome based on a stick-slip mechanism. Earth and Planetary Science Letters, 337-38. pp. 39-46. ISSN 0012-821X doi: 10.1016/j.epsl.2012.05.011

Abstract/Summary

Lava dome eruptions are sometimes characterised by large periodic fluctuations in extrusion rate over periods of hours that may be accompanied by Vulcanian explosions and pyroclastic flows. We consider a simple system of nonlinear equations describing a 1D flow of lava extrusion through a deep elastic dyke feeding a shallower cylindrical conduit in order to simulate this short-period cyclicity. Stick-slip conditions depending on a critical shear stress are assumed at the wall boundary of the cylindrical conduit. By analogy with the behaviour of industrial polymers in a plastic extruder, the elastic dyke acts like a barrel and the shallower cylindrical portion of the conduit as a die for the flow of magma acting as a polymer. When we applied the model to the Soufrière Hills Volcano, Montserrat, for which the key parameters have been evaluated from previous studies, cyclic extrusions with periods from 3 to 30 h were readily simulated, matching observations. The model also reproduces the reduced period of cycles observed when a major unloading event occurs due to lava dome collapse.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/29054
Item Type	Article
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Environmental Systems Science Centre
Publisher	Elsevier
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