From Slab Dynamics to Seismicity: A Global Perspective

Subduction zones host the majority of global earthquakes, spanning shallow megathrust events, outer-rise earthquakes, and deep intraplate seismicity within subducting slabs. Although earthquakes form narrow, coherent belts in map view, their three-dimensional spatial distributions exhibit complex, case-dependent patterns when depth is considered. The physical processes governing these patterns, particularly for deep earthquakes, remain incompletely understood.
In this study, we develop realistic three-dimensional spherical geodynamic models constrained by multiple geophysical datasets to investigate long-term slab dynamics across multiple subduction zones worldwide. By comparing modeled slab deformation with global earthquake distributions, we identify a coherent spatial correlation between the deformation rate predicted by the models and the observed distribution of seismicity within subducting slabs. Regions of strong long-term deformation systematically coincide with zones of concentrated deep seismicity, whereas areas of weak deformation are characterized by sparse earthquake occurrence.
These results indicate that large-scale slab dynamics exert a first-order control on the spatial distribution of deep intraplate seismicity, providing a dynamics-based framework for interpreting global earthquake patterns.