Earthquake nucleation on rough faults

Harbord, Christopher W.A.; Nielsen, Stefan B.; De Paola, Nicola; Holdsworth, Robert E.

Abstract

Earthquake nucleation is currently explained using rate and state stability analysis, which successfully models the behavior of laboratory simulated faults with constant thickness gouge layers. However, roughness is widely observed on natural faults and its influence on earthquake nucleation is little explored. Here we conduct frictional sliding experiments with different roughness on granite samples at upper crustal conditions (30–200 MPa). We observe a wide range of behaviors, from stable sliding to stick slip, depending on the combination of roughness parameters and normal stress. Stick slip is repeatedly observed in velocity-strengthening regimes, and increases in normal stress stabilize slip; these features are not fully predicted by current stability analysis. We derive a new instability criterion that matches our observations, based on fracture energy considerations and the size of weak patches created by fault roughness.

Citation

Harbord, C. W., Nielsen, S. B., De Paola, N., & Holdsworth, R. E. (2017). Earthquake nucleation on rough faults. Geology, 45(10), 931-934. https://doi.org/10.1130/g39181.1

• Journal Article Type: Article
• Acceptance Date: Jun 28, 2017
• Online Publication Date: Aug 8, 2017
• Publication Date: Oct 1, 2017
• Deposit Date: Jun 28, 2017
• Publicly Available Date: Jul 3, 2017
• Journal: Geology
• Print ISSN: 0091-7613
• Electronic ISSN: 1943-2682
• Publisher: Geological Society of America
• Peer Reviewed: Peer Reviewed
• Volume: 45
• Issue: 10
• Pages: 931-934
• DOI: https://doi.org/10.1130/g39181.1
• Public URL: https://durham-repository.worktribe.com/output/1356459