Generating long period and tremor-like seismicity without fluids in volcanic materials

Rowley, Peter; Benson, Phil; Bean, Chris

Abstract

Volcano seismicity is routinely used in the remote monitoring and forecasting of activity at volcanoes around the world. The nature of this seismicity varies, but long period (LP) seismicity is generally interpreted as an indicator of fluid migration, and as a potential precursor of increased activity at the surface. We employ acoustic-emission to monitor rock deformation experiments using weak volcaniclastic sediments at a range of strain rates. These produce microseismic events which are spectrally indistinguishable from long-period and tremor seismicity observed in natural volcanic settings, with the effect most noticeable at low (visco-elastic creep) strain rates.

Given the ubiquitous nature of slow edifice deformation, and the frequent occurrence of such low cohesion materials in the upper edifice of volcanoes, we suggest low frequency seismicity in volcanic settings does not require fluid movement; It may also be an indicator that strain is being accommodated by weak material within the edifice.

• Presentation Conference Type: Poster
• Conference Name: Volcanic and Magmatic Studies Group
• Start Date: Jan 6, 2020
• End Date: Jan 9, 2020
• Deposit Date: Jan 27, 2020
• Publicly Available Date: Jan 29, 2020
• Public URL: https://uwe-repository.worktribe.com/output/5251754