Why does the Bay of Fundy cause large tides?

Answer 1

The Bay of Fundy extends north, then northeast from the Gulf of Maine, between New Brunswick and Nova Scotia. The bay narrows to the northeast, into the Minas Basin. At Burntcoat Head, the tidal range is as high as 17 meters (55.8 feet) and even higher in some conditions.

The reason for the extreme shift is a seiche, a 12-hour north-south oscillation of the waters of the bay that is in resonance with the tidal period for the ocean. When the tide enters the bay, it reinforces the normal increase in height. There are 2 high tides and 2 low tides each day. Over a period of six hours, the level of water will rise or fall dramatically, and there is a huge difference between the lowest low tide (tide out, water sloshes away) and the highest high tide (tide in, water sloshes in). The actual speed of the incoming tide is about 10 meters per minute. This does creates a tidal bore (large upriver waves) in some local rivers.

*(Read the detailed explanation at the Bay of Fundy Tourism website - the link is below.)