Université de Liege, Department de Geography, Liege, Belgium
Université Grenoble Alpes, Institut des Sciences de la Terre, Grenoble, France
Institute of Crustal Dynamics, China Earthquake Administration, Beijing, China
Abstract. Seafloor irregularities influence rupture behavior along the subducting slab and in the overriding plate, thus affecting earthquake cycles. Whether seafloor irregularities increase the likelihood of large earthquakes in a subduction zone remains contested, partially due to focus put either on fault development or on rupture pattern. Here, we simulate a subducting slab with a seafloor irregularity and the resulting deformation pattern of the overriding plate using the discrete element method. Our simulations illustrate the rupture along three major fault systems: megathrust, splay and backthrust faults. Our results show different rupture dimensions of earthquake events varying from tens to ca. 140 km. Our results suggest that the recurrence interval of megathrust events with rupture length of ca. 100 km is ca. 140 years, which is overall comparable to the paleoseismic records at the Mentawai area of the Sumatran zone. We further propose the coseismic slip amounts decrease and interseismic slip amounts increase from the surface downwards gradually. We conclude that the presence of seafloor irregularities significantly affects rupture events along the slab as well as fault patterns in the overriding plate.
How to cite. Jiao, L., Chan, C.-H., Scholtès, L., Hubert-Ferrari, A., Donzé, F.-V., and Tapponnier, P.: Discrete element modeling of a subduction zone with a seafloor irregularity and its impact on the seismic cycle, Solid Earth Discuss. [preprint], https://doi.org/10.5194/se-2020-41, 2020.
Received: 25 Mar 2020 – Discussion started: 07 Apr 2020
Seafloor geometry plays an important role in earthquake behaviors in a tectonic subducting system. Here, we simulate a subducting slab with a seafloor irregularity to perform the resulting deformation pattern of the overriding plate and spatial and temporal patterns of the seismicity activity in the subducting system. Our model is overall comparable to paleoseismic records, matches seismicity patterns, and fulfils the domain definition of a subduction system.
Seafloor geometry plays an important role in earthquake behaviors in a tectonic subducting...