The sediments that form the upper layer of the oceanic crust vary significantly in thickness. As the crust ages, it accumulates more and more sediment, and when it is near a continental shelf, it can receive large deposits of continental sediment deposited by turbidity currents forming abyssal plains. Because of their soft, unconsolidated nature, the uppermost sediments tend to have very low shear velocities.

These low velocities create significant delays in the arrival times of seismic waves moving through them, and these delay times can provide a significant source of error for body‐wave tomography. For surface‐wave tomography, these soft sediments...

You do not have access to this content, please speak to your institutional administrator if you feel you should have access.