Seismic Expression of Magma-Induced Crustal Strains and Localized Fluid Pressures during Initial Eruptive Stages, Soufrière Hills Volcano, Montserrat

V. Miller, B. Voight, C. J. Ammon, E. Shalev, Glenn Thompson

Research output: Contribution to journalArticlepeer-review

Abstract

We explore volcanotectonic earthquake activity during the early stages of volcanic activity (1995–96) at Soufrière Hills volcano. We focus on several zones of temporally-confined seismic activity that comprise assemblages of small scale structural elements, >2–4 km distant from the volcano, at depths 2–4 km below sea level, and consider seismicity in relation to regional tectonics and heterogeneity of stiffness and strength as revealed by the SEA-CALIPSO tomography experiment. The clustered seismicity and relatively aseismic zones are interpreted to reflect a broad weakened tectonic zone of ESE trend that crosses Montserrat, and the ascent of a magmatic dike of NNE trend, which altered the stress distribution to promote localized fault movements and caused localized dilatation with changes in pore-fluid pressures, to either weaken or strengthen the rock mass depending on the local polarity of strain.

Original languageAmerican English
JournalGeophysical Research Letters
Volume37
DOIs
StatePublished - Oct 1 2010
Externally publishedYes

Keywords

  • volcano-tectonic
  • location
  • Montserrat
  • seismicity

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