Bay of Fundy - Tides

Tides

The Bay of Fundy is known for its high tidal range. The quest for world tidal dominance has led to a rivalry between the Minas Basin in the Bay of Fundy and the Leaf Basin in Ungava Bay, over which body of water lays claim to the highest tides in the world, with supporters in each region claiming the record.

The Canadian Hydrographic Service finally declared it a statistical tie, with measurements of a 16.8 metre (55.1 feet) tidal range in Leaf Basin for Ungava Bay and 17 meters (55.8 feet) at Burntcoat Head for the Bay of Fundy. The highest water level ever recorded in the Bay of Fundy system occurred at the head of the Minas Basin on the night of October 4–5, 1869 during a tropical cyclone named the “Saxby Gale”. The water level of 21.6 meters (70.9 feet) resulted from the combination of high winds, abnormally low atmospheric pressure, and a spring tide.

Leaf Basin has only been measured in recent years, whereas the Fundy system has been measured for many decades. The tide at Leaf Basin is higher on average than tides at Minas Basin; however, the highest recorded tidal ranges ever measured are at Burntcoat Head and result from spring tides measured at the peak of the tidal cycle every 18 years.

Folklore in the Mi'kmaq First Nation claims that the tides in the Bay of Fundy are caused by a giant whale splashing in the water. Oceanographers attribute it to tidal resonance resulting from a coincidence of timing: the time it takes a large wave to go from the mouth of the bay to the inner shore and back is practically the same as the time from one high tide to the next. During the 12.4-hour tidal period, 115 billion tonnes of water flow in and out of the bay.

The tides in the Bay of Fundy are semidiurnal. Semidiurnal tides are tides that have two highs and two lows each day. The height that the water rises and falls to each day during these tides are approximately equal. There are approximately six hours and thirteen minutes between each high and low tide.