What would you do with the g measurement to get your location? Can g deltas be matched to sea floor contour maps? Otherwise it seems like subs would have to be following g-mapped routes.
Same as if you were navigating based on a physical contour map of the ocean floor, except that getting an accurate depth like that in deep waters isn’t possible, and in shallow waters requires sonar.
Large low-shear-velocity provinces, for anyone else wondering: https://en.wikipedia.org/wiki/Large_low-shear-velocity_provi...