Figure 1.

Varying strength in an estimate of the tide raising forces, derived from Wood (ref. 5, Table 16). Each event, shown by a vertical line, gives a measure of the forcing in terms of the angular velocity of the moon, γ, in arc degrees per day, at the time of the event. Arcs connect events of strong 18.03-year tidal sequences. Centennial maxima are labeled, with the final one, “D”, occurring in A.D. 2151.