Triggering dynamic slip instability on heterogeneous faults: model and experiment
Abstract
The development of modern GPS and broadband seismology have highlighted in the past decades the abundance of slow earthquakes and creep events (long- and short-term SSEs, VLFs and related repeaters and tremors). More recently, clues are also starting to emerge on how slow events interact with large earthquakes and participate in their nucleation process. Key elements are the inhomogeneity of fault zones, and their ambivalent behaviour in terms of stable or unstable slip, also reflected by the geological structure of subduction-channel fault zones where localized slip patches are found interspersed within lenses of ductile material. To understand the physics of rupture nucleation and the transition from stable to unstable sliding, a number of numerical models of faults were proposed. They alternated stable and unstable segments, and sought an effective stability criterion for this inhomogeneous structure at the larger scale through homogenisation techniques, adopting simplified geometries and friction laws. In laboratory experiments on natural fault materials or analogues, the geometry, fabric and composition can display a much broader variability. This is more realistic but challenging as it is sometimes beyond the quantitative control of the operator. We discuss differences and similarities between models and experiments which explore slip instability under variable degrees of inhomogeneity.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMMR43A..07N
- Keywords:
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- 1839 Hydrologic scaling;
- HYDROLOGYDE: 1859 Rocks: physical properties;
- HYDROLOGYDE: 3902 Creep and deformation;
- MINERAL PHYSICSDE: 3653 Fluid flow;
- MINERALOGY AND PETROLOGY