Tidal Amplitudes

Over most of the Arctic, and the rest of the world, the average difference between water levels at high and low tide – known as the tidal amplitude – is about 2 metres. In the eastern Arctic, and along the southern coast of Greenland, the average tidal amplitude is higher, from 2–4 metres. The highest tidal range (12.3 metres) recorded in the Arctic occurs at Iqaluit. In Churchill, tidal amplitudes average 4.5 metres, but spring tides exceed 5 metres. By contrast, Resolute Bay, False Strait, and Tuktoyaktuk have tidal amplitudes of only 0.5–2 metres. The local variation in tidal range reflects the variation in basin shape. The triangular shape of Frobisher Bay sets the stage for the huge tidal range at Iqaluit. In comparison, the highest tides in the world, in the Minas Basin of the Bay of Fundy, average 12 metres, but sometimes reach 16 metres.