Equatorial Pacific Flow Shifts EastwardCore-surface flow has historically been predominantly westward. Motion in the liquid outer core continuously changes, and those changes alter the magnetic field generated by the moving iron. Madsen and his co-authors hypothesise that changes in Earth’s deeper interior triggered the inferred flow changes beneath the Pacific. Their scientific importance comes from the role of outer-core motion in generating Earth’s magnetic field. That field changes as core flow evolves.