Pontificia Universidad Católica de Chile

The interplay of tectonic forces in subduction zones leads to intense seismic activity and deformations. However, the stress interactions between fault systems, such as the megathrust, splay faults, and crustal faults near the trench, remain poorly understood. These synchronous/asynchronous processes can produce transient slip and stress accumulation on the megathrust that can manifest as earthquake clustering, surrounding asperities. This proposal aims to unravel the puzzle of the Chile megathrust seismic cycle by investigating fault traction rates and fault system interactions of the megathrust with upper plate crustal faults using numerical methods. The objectives are to develop and implement 2D and 3D quasi-dynamic models to simulate the effects of geometric variations, vertical stress anomalies, and the presence of crustal faults adjacent to the megathrust. These models will incorporate rate and state frictional laws spatially distributed on the faults. The fault frictional properties will be consistent with the state of the art regarding expected geochemical processes, temperature models and confining pressure at depth.