Oceanic lithosphere contains a record of plate-spreading rates, but the oldest oceanic plates have been subducted into the mantle. Measurements of seismic wave velocities in the subducted part of the Cocos Plate beneath central Mexico reveal an anisotropy that was created when the plate formed, preserving an archive of ancient plate-spreading rates on Earth.
- Teh-Ru Alex Song
- YoungHee Kim