The Role of Tectonic Stress in Triggering Large Silicic Caldera Eruptions

Haley E. Cabaniss, Patricia M. Gregg, Eric B. Grosfils

Research output: Contribution to journalArticle

Abstract

We utilize 3-D temperature-dependent viscoelastic finite element models to investigate the mechanical response of the host rock supporting large caldera-size magma reservoirs (volumes >102 km3) to local tectonic stresses. The mechanical stability of the host rock is used to determine the maximum predicted repose intervals and magma flux rates that systems may experience before successive eruption is triggered. Numerical results indicate that regional extension decreases the stability of the roof rock overlying a magma reservoir, thereby promoting early-onset caldera collapse. Alternatively, moderate amounts of compression (≤10 mm/year) on relatively short timescales (<104 years) increases roof rock stability. In addition to quantifying the affect of tectonic stresses on reservoir stability, our models indicate that the process of rejuvenation and mechanical failure is likely to take place over short time periods of hundreds to thousands of years. These findings support the short preeruption melt accumulation timescales indicated by U series disequilibrium studies.

Original languageEnglish (US)
Pages (from-to)3889-3895
Number of pages7
JournalGeophysical Research Letters
Volume45
Issue number9
DOIs
StatePublished - May 16 2018

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Keywords

  • Collapse calderas
  • eruption triggers
  • external eruption triggers
  • flux rates
  • numerical model
  • repose periods

ASJC Scopus subject areas

  • Geophysics
  • Earth and Planetary Sciences(all)

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