Stress Triggering of the 2005 Eruption of Sierra Negra Volcano, Galápagos

P. M. Gregg, H. Le Mével, Y. Zhan, J. Dufek, D. Geist, W. W. Chadwick

Research output: Contribution to journalArticlepeer-review


Extensive vertical deformation (>4.5 m) observed at Sierra Negra volcano Galápagos, Ecuador, between 1992 and the 2005 eruption led scientists to hypothesize that repeated faulting events relieved magma chamber overpressure and prevented eruption. To better understand the catalyst of the 2005 eruption, thermomechanical models are used to track the stress state and stability of the magma storage system during the 1992–2005 inflation events. Numerical experiments indicate that the host rock surrounding the Sierra Negra reservoir remained in compression with minimal changes in overpressure (~10 MPa) leading up to the 2005 eruption. The lack of tensile failure and minimal overpressure accumulation likely inhibited dike initiation and accommodated the significant inflation without the need for pressure relief through shallow trapdoor faulting events. The models indicate that static stress transfer due to the M w 5.4 earthquake 3 hr prior to the eruption most likely triggered tensile failure and catalyzed the 2005 eruption.

Original languageEnglish (US)
Pages (from-to)13,288-13,297
JournalGeophysical Research Letters
Issue number24
StatePublished - Dec 28 2018


  • eruption triggering
  • finite element model
  • geodesy
  • overpressure
  • thermomechanics
  • volcano dynamics

ASJC Scopus subject areas

  • Geophysics
  • General Earth and Planetary Sciences


Dive into the research topics of 'Stress Triggering of the 2005 Eruption of Sierra Negra Volcano, Galápagos'. Together they form a unique fingerprint.

Cite this