Propagating rift

A propagating rift is a seafloor feature associated with spreading centers at mid-ocean ridges and back-arc basins.

This seafloor feature, left in the wake of the segment migration, appears to be offset by an apparent fault in the oceanic crust.

[5] In some circumstances when the spreading rate is low, morphological depressions can be observed along the 'pseudofaults' and shear zones, creating a distinct a bathymetric signature of propagating rifts.

[11] Under this geometry model, three types of propagating rifts were described: (1) discontinuous, (2) continuous and (3) broad transform-zone.

They were first noted in the 1970s on the Juan De Fuca ridge (spreading center) off northwestern North America where marine magnetic anomalies created during seafloor spreading show offsets not parallel to plate motion directions indicated by the trends of transform faults.

Graphical geometry of a propagating rift. Red arrow indicates spreading direction.
Magnetic anomalies (color) off west coast of North America. Dashed lines are spreading centers. Thin cross lines mark pseudo faults, which are features created by propagating rifts.
Bathymetric signatures of propagating rifts observed at the East Pacific Rise and Galapagos Spreading Center. Yellow-dashed lines indicate morphological depressions created in the wake of propagating rifts.