Volcanic sintering: Timescales of viscous densification and strength recovery

Vasseur, Jérémie; Wadsworth, Fabian B.; Lavallée, Yan; Hess, Kai-Uwe; Dingwell, Donald B.

Abstract

[1] Sintering and densification are ubiquitous processes influencing the emplacement of both effusive and explosive products of volcanic eruptions. Here we sinter ash‐size fragments of a synthetic National Institute of Standards and Technology viscosity standard glass at temperatures at which the resultant melt has a viscosity of ∼108–109 Pa.s at 1bar to assess sintering dynamics under near‐surface volcanic conditions. We track the strength recovery via uniaxial compressive tests. We observe that volcanic ash sintering is dominantly time dependent, temperature dependent, and grain size dependent and may thus be interpreted to be controlled by melt viscosity and surface tension. Sintering evolves from particle agglutination to viscous pore collapse and is accompanied by a reduction in connected porosity and an increase in isolated pores. Sintering and densification result in a nonlinear increase in strength. Micromechanical modeling shows that the pore‐emanated crack model explains the strength of porous lava as a function of pore fraction and size.

Citation

Vasseur, J., Wadsworth, F. B., Lavallée, Y., Hess, K., & Dingwell, D. B. (2013). Volcanic sintering: Timescales of viscous densification and strength recovery. Geophysical Research Letters, 40(21), 5658-5664. https://doi.org/10.1002/2013gl058105

• Journal Article Type: Article
• Acceptance Date: Oct 22, 2013
• Online Publication Date: Nov 15, 2013
• Publication Date: Nov 16, 2013
• Deposit Date: Mar 20, 2018
• Publicly Available Date: Jun 12, 2018
• Journal: Geophysical Research Letters
• Print ISSN: 0094-8276
• Electronic ISSN: 1944-8007
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 40
• Issue: 21
• Pages: 5658-5664
• DOI: https://doi.org/10.1002/2013gl058105
• Public URL: https://durham-repository.worktribe.com/output/1337118