| Summary: | Tides are an ever-present reality in many coastal regions of the world, and their causes and influence have long been matters of intrigue. In few places do tides play a greater role in the economics and character of a region and its people than around the shores of the Bay of Fundy in eastern Canada. Indeed, the Bay of Fundy presents a wonderful natural laboratory for the study of tides and their effects. However, to understand these phenomena more fully, some large perspectives are called for on the general physics of the tides and their operation on an oceanic scale. The geologic history of the region too provides key insights into how and why the most dramatic tides in the world have come to be in the Bay of Fundy. Tidal characteristics along the eastern Canadian seaboard result from a combination of diurnal (daily) and semidiurnal (twice daily) tides, the latter mostly dominant. Tidal ranges in the upper Bay of Fundy commonly exceed 15 m, in large part a consequence of tectonic forces that initiated the Bay during the Triassic. The existence and position of the Bay is principally determined by a half-graben, the Fundy Basin, which was established at the onset of the opening of the Atlantic Ocean. Due to the proportions of the Bay of Fundy, differences in tidal range through the Gulf of Maine-Bay of Fundy-Georges Bank system are governed by near resonance with the forcing North Atlantic tides. Although Fundy tide curves are sinusoidal, tide prediction calls for consideration of distinct diurnal inequalities. Overlapping of the cycles of spring and perigean tides every 206 days results in an annual progression of 1.5 months in the periods of especially high tides. Depending on the year, these strong tides can occur at all seasons. The strongest Fundy tides occur when the three elements – anomalistic, synodical, and tropical monthly cycles – peak simultaneously. The closest match occurs at intervals of 18.03 years, a cycle known as the Saros. Tidal movements at Herring Cove, in Fundy National Park, illustrate ...
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