Discrete Element Modeling of a Subduction Zone with a Seafloor Irregularity and its Impact on the Seismic Cycle  

作　　者：JIAO Liqing CHAN Chung-Han Luc SCHOLTÈS Aurélia HUBERT-FERRARI Frédéric-Victor DONZÉ Paul TAPPONNIER 

机构地区：[1]SinoProbe Center,Chinese Academy of Geological Sciences,Beijing 100037,China [2]Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China [3]Earthquake-Disaster&Risk Evaluation and Management(E-DREaM)Center,National Central University,Taoyuan,China [4]Department of Earth Sciences,National Central University,Taoyuan,China [5]CNRS,IRD,OPGC,Laboratoire Magma et Volcans,UniversitéClermont Auvergne,Clermont-Ferrand,France [6]Department de Geography,Universitéde Liege,Liege,Belgium [7]Institut des Sciences de la Terre,UniversitéGrenoble Alpes,Grenoble,France [8]National Institute of Natural Hazards,MEMC,Beijing 100085,China

出　　处：《Acta Geologica Sinica(English Edition)》2022年第3期776-790,共15页地质学报（英文版）

基　　金：This work is Earth Observatory of Singapore contribution(No.M4430217.B50.706022);the Ministry of Science and Technology(Grant Nos.MOST 109-2116-M-008-029-MY3,MOST 110-2124-M-002-008,and MOST 110-2634-F-008-008)。

摘　　要：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.

关 键 词：discrete element modeling subduction zone MEGATHRUST splay backthrust faults SEAMOUNT Mentawai 

分 类 号：P738.4[天文地球—海洋地质]