Bay of Fundy

 

The Bay of Fundy is a bay on the Atlantic coast of North America, on the northeast end of the Gulf of Maine between the Canadian provinces of New Brunswick and Nova Scotia, with a small portion touching the U.S. state of Maine. Some sources believe the name "Fundy" is a corruption of the French word "Fendu", meaning "split", while others believe it comes from the Portuguese fondo, meaning "funnel". The bay was also named Baie Française (French Bay) by explorer/cartographer Samuel de Champlain during a 1604 expedition led by Pierre Dugua, Sieur de Monts which resulted in a failed settlement attempt on St. Croix Island.

The Bay of Fundy is known for its high tidal range. Rivaled by Ungava Bay in northern Quebec and the Severn Estuary in the UK, it has one of the highest vertical tidal ranges in the world.

Portions of the Bay of Fundy, Shepody Bay and Minas Basin, form one of six Canadian sites in the Western Hemisphere Shorebird Reserve Network, and is classified as a Hemispheric site. It is owned by the provinces of New Brunswick and Nova Scotia, and the Canadian Wildlife Service, and is managed in conjunction with Ducks Unlimited Canada and the Nature Conservancy of Canada.

In July 2009, the Bay of Fundy was named as a finalist for the New 7 Wonders of Nature contest that ends in November of 2011.

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 metres (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.

Geology

The Bay of Fundy lies in a rift valley called the Fundy Basin; as the rift began to separate from mainland North America, volcanic activity occurred, forming volcanoes and flood basalts. These flood basalts poured out over the landscape, covering much of southern Nova Scotia. Sections of the flood basalts have been eroded away, but still form a basaltic mountain range known as North Mountain. As a result, much of the basin floor is made of tholeiitic basalts giving its brown colour. The rift valley eventually failed (see aulacogen) as the Mid-Atlantic Ridge continued to separate North America, Europe, and Africa.

Sub-basins

The upper part of the bay splits into Chignecto Bay in the northeast and the Minas Basin in the east. Chignecto Bay is further subdivided into Cumberland Basin and Shepody Bay and the extreme eastern portion of Minas Basin is called Cobequid Bay. Some of these upper reaches exhibit exposed red bay muds, for which the Bay of Fundy is noted (for their appearance and biological productivity).

Cape Chignecto defines Chignecto Bay whereas Cape Split defines the Minas Channel, leading to the Minas Basin. The Minas Channel connects the Minas Basin with the main body of the bay. The channel is 5.6 kilometers across and approximately 106.7 meters deep. The tides that flow through the channel are very powerful. They are as powerful as 8000 train engines or 25 million horses.

The lower part of the bay is also home to four important sub-basins: Passamaquoddy Bay and Back Bay on the New Brunswick shore, Cobscook Bay on the Maine shore, and the Annapolis Basin on the Nova Scotia shore.

The bay is home to several islands, the largest of which is Grand Manan Island at the boundary with the Gulf of Maine. Other important islands on the north side of the bay include Campobello Island, Moose Island, and Deer Island in the Passamaquoddy Bay area. Brier Island and Long Island can be found on the south side of the bay while Isle Haute is in the upper bay off Cape Chignecto. Smaller islands and islets also exist in Passamaquoddy Bay, Back Bay, and Annapolis Basin. The Five Islands, in the Minas Basin, are particularly scenic.

The Bay of Fundy is also home to another interesting geologic feature, the Hopewell Rocks formation. This formation is where the “famous flower-pot rocks” are located on a short, one kilometer long portion of Shepody Bay. These rocks are shaped by the tides, the strength of the rocks, and the presence of the joints in the rocks. The rock in the cliffs the stacks are being cut from are arkosic sandstone and coarse poorly sorted conglomerates. The tides that are eroding away the cliffs are between 10.7 meters and 14.7 meters high on average.