Crustal thickness can then be derived by subtracting this from the observed base of the drift (post break-up) sequence, normally from the interpretation of seismic reflection data.
[1] Most areas of oceanic crust show characteristic stripes due to periodic magnetic reversals during formation at a mid-oceanic ridge.
This method is dependent on stripes being present and will not work for oceanic crust created during the Cretaceous Quiet Zone.
[2] On normal incidence seismic reflection data recorded to sufficient depths, the Moho can in some areas be directly imaged, allowing the identification of normal thickness oceanic crust.
[3] The combined use of seismic wide-angle reflection and refraction data give a precise location for the COB by determining the P-wave velocities along a profile.