Solid-state sintering can cause explosivity and seismogenic unstable sliding during dome-building eruptions

In contrast, gouge sheared at 900°C, 50 or 100 MPa normal stress and 10-5 to 10-3 s-1 is sintered, exhibits strain-weakening behavior and shows microstructural evidence of strain localization as well as significant lithification. Samples sheared at 900°C for <1 h have measured final porosities and permeabilities comparable to gouge samples hot-pressed at the similar temperature-pressure conditions for 60 h, indicating shearing significantly enhances sintering.

We use results to develop a model that can predict time-temperature-pressure-dependent densification by solid-state sintering under both static conditions and during shear. Finally, we propose that sintering-driven lithification can cause deforming shear zones to transition from aseismic stable sliding to unstable seismogenic sliding, perhaps resulting in the drumbeat seismicity observed at dome-building volcanoes. Included in data repository: - experimental log, including conditions of experiment, date, sample dimensions, UMN Paterson ID number, etc. - mechanical data for all deformation experiments - mechanical data for experiments used for jacket correction - measured porosities, determined by image analysis - BSE images used for image analysis - measured permeabilities, determined using flow-through permeameter - BSE mosaics (in power point, affinity designer, pdf files) for all samples