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Séminaire

Mapping fault slip along the Chaman plate boundary from space

 

22 avril 2021
11h 12h
Le séminaire sera en distanciel

The Chaman fault system, a 700 km long transpressive fold and fault belt, marks the boundary between the Indian plate and Eurasia. The space and time partitioning of the ~3 cm/yr of relative motion across the whole fault system is currently unclear, with evidences of aseismic slip, large historical earthquakes albeit a generally low seismic activity in the region. We address the question of the distribution of deformation along and across this major plate boundary with InSAR time series covering the area from 2015-2020. After detailing our original method for InSAR time series analysis with a Kalman Filter, we first consider the Chaman fault itself and evaluate the seismic to aseismic slip contribution. We characterise various aseismic slip modes, including continuous creep, post seismic slip following Mw 5-5.6 earthquakes, and potential micro-slip events (Mw ~2.8). Second, we consider the different parallel strike-slip faults within the fault zone and assess the partitioning of slip between major structures, unravelling an unknown fault that accommodates most of today’s relative motion.