Open access
Date
2023-06Type
- Journal Article
ETH Bibliography
yes
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Abstract
Accelerating aseismic slip events have been commonly observed during the rupture nucleation processes of the earthquake. While that accelerating aseismic slip is usually considered strong evidence for precursory activity, it remains unclear whether all accelerating aseismic slip events are precursory to an incoming earthquake. Two contrasting nucleation models have been introduced to explain the observations associated with the nucleation of unstable slip: the pre-slip and cascade nucleation models. Each of these two-end members, however, has its own limitations. In this study, we employ Discrete Element Method simulations of a 2-D strike-slip fault to simulate various rupture nucleation and triggering processes. Our simulation results manifest that the final seismic event is a product contributed by multiple pre-slip nucleation sites, which may interact, causing clock advance or cascade nucleation rupture processes. We also introduce a strengthening perturbation zone to investigate the role of a single nucleation site in an imminent seismic event. The simulation results reveal a new type of non-precursory aseismic slip, representing the region favoring the generation of the precursory slip process but not correlating to the incoming main event, which differs from the previous interpretation of precursory slip. Furthermore, we include weakening perturbation zones in some simulations to demonstrate how small earthquakes may or may not trigger a nucleation site depending on spatial and temporal conditions. Our simulation results imply that such non-precursory but accelerating aseismic slip events may suggest a fault segment that appears weakly coupled but possesses the potential to be triggered seismically. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000619251Publication status
publishedExternal links
Journal / series
Journal of Geophysical Research: Solid EarthVolume
Pages / Article No.
Publisher
American Geophysical UnionOrganisational unit
09650 - Kammer, David / Kammer, David
03476 - Giardini, Domenico / Giardini, Domenico
Funding
856559 - Fault Activation adn Earthquake Rupture (EC)
Related publications and datasets
Is supplemented by: https://doi.org/10.3929/ethz-b-000577745
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ETH Bibliography
yes
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