Citation

Bai L, Baker DR, Polacci M, Hill RJ. Geophys. Res. Lett. 2011; 38(17): n/a-n/a.

Copyright

(Copyright © 2011, American Geophysical Union)

DOI

10.1029/2011GL048540

PMID

unavailable

Abstract

Three-dimensional crystal and bubble sizes and distributions in experimentally produced vesicular crystal-bearing Stromboli basalts and natural scoria were studied with X-ray microtomography (CT) at high (1.85 m) and low (5.46-9.0 m) resolution. The permeabilities from lattice Boltzmann (LB) simulations and experimental measurements are about 1-2 orders of magnitude higher than in aphyric Stromboli basalts at porosity 31.6-55.3%. We propose that the higher permeability in crystal-bearing samples results in highly efficient degassing in shallow, highly porphyritc (HP) magma as opposed to the deeper, aphyric (LP) magma. In paroxysmal explosions, the LP magma flows up in a cylindrical conduit due to the density and viscosity difference between the two magmas. This type of convection can cause the LP magma with exsolved gas to be efficiently transferred through the overlying HP magma, potentially resulting in the more-violent paroxysmal explosions. Copyright 2011 by the American Geophysical Union.