When a slab slides beneath an overriding plate in a subduction zone, the slab takes on a property called anisotropy, meaning its strength is not the same in all directions. Anisotropy is what causes a...

A new study in Geophysical Research Letters published on October 21, 2025, shows that most shear wave splitting in Alaska’s subduction zone originates inside the sinking slab itself…

When a slab slides beneath an overriding plate in a subduction zone, the slab takes on a property called anisotropy, meaning its strength is not the same in all directions.

Subducting plates are stronger in certain directions than others, which may be a factor in how earthquakes occur and how seismic waves propagate.