Tracing the relationship between the upper plate earthquake cycle and megathrust slip, the Atacama fault system in Northern Chile.

ABSTRACT: Inland-normal faulting is recognised as an important process following large subduction earthquakes. The lack of data limits the understanding of how normal fault reactivation relates to the subduction earthquake cycle. We characterised the palaeoseismology of the Atacama fault system (AFS) in the Chilean subduction zone. Our results showed that upper plate normal faulting earthquakes with M_w 7.0 and recurrence intervals of 35 ± 9 ky generated surface ruptures preserved as fault scarps. The average fault slip rate of 0.07 ± 0.01 m/kyr is three orders of magnitude slower than the convergence velocity, and the recurrence intervals of surface-rupturing earthquakes on the studied faults are much larger than the recurrence of great to giant (M_w > 8.5) subduction earthquake

SUBMITTER: Gonzalez G 

PROVIDER: S-EPMC11759327 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature