WHAT TO VISIT

THE BAY OF FUNDY - ONE OF THE MARINE WONDERS OF THE WORLD

Highest Tides

 

By George Ferguson

 

http://www.tourismnewbrunswick.ca/en-CA/HNThingsToDo/HNNaturalWonders/HNNWBayOfFundy.htm

http://www.bayoffundy.com/tides.aspx

http://www.bayoffundytourism.com/tides

 

The enormous tides of the Bay of Fundy are truly one of the world's great natural wonders.

One hundred billion tonnes of water flows into and out of the Bay on an average tide, twice a day, creating rip-currents, seething up-wellings, swirling whirlpools and a tidal range reaching 16m (53 ft) at the head of the Bay. The volume of water receding & flowing is estimated to be 2000 times greater than the daily discharge of the Gulf of St. Lawrence (Thurston, 1994). The immense energy of the tides powers a highly productive, rich and diverse natural ecosystem, in turn shaping the environment, the economy and the culture of the Fundy region.

 

 

Tides are considered the heartbeat of the oceans of our planet. They are defined as the response of the oceans to the periodic fluctuations in the cosmic forces of the moon, and the sun, and the perpetual spinning rotation of the Earth (Pinet, 1998).This response is in the form of long, gently-swelling waves that are generated throughout the seas and oceans of the world. These equilibrium tides propagate from place to place and are reflected and dissipated just as other long waves. Thus it is that the tide observed at a particular place is not produced locally, but is the sum of tide waves arriving from all over the ocean, each modified by its experiences along the way. The average tidal range of all oceans around the globe is lm (3 ft).

And further galactic forces come into play. During each phase of a new moon or a full moon, when earth, sun and moon are aligned, higher tides result. These are referred to as "spring tides" a term derived from the springing up of the water. Conversely, twice each month when the sun and moon are at right angles to the earth and opposing each other, the tidal ranges are slighter and are defined as "neap tides" (Pinet, 1998).The tides along the Atlantic coast are principally semi-diurnal, meaning there are two significant high tides every 24 hours. Along the Nova Scotia Atlantic coast, the tidal range is 1.5m - 2.5m (4 - 8 ft) and the tide arrives and departs at approximately the same time everywhere. However, due to the unique funnel shape and prodigious depth of the Bay of Fundy, the water moves back and forth in sync with the oceanic tides outside. This movement leads to a large increase in the tidal range towards the head of the Bay. Tidal measurements in the Minas Basin are the highest recorded in the world 16m (53 ft).

(Imagine bobbing in a small boat on water that is deeper than a five-story building and in exactly the same place in less than six hours . . . you can walk on the ocean floor).

And still there are other impelling forces at work in the mighty tides of Fundy. The elementary laws of physics establish that liquid in a basin has a characteristic period of "oscillation" and once set in motion, the liquid will rhythmically slosh back and forth (Cutnell and Johnson, 1995). The speed at which it oscillates depends on the length and depth of the basin. The surface rises first at one end, then at the other, while the level in the middle remains constant. The natural period of oscillation in the Bay of Fundy is approximately 12 hours. And by reason of the contours of the Bay, Fundy's oscillation corresponds with, and is reinforced by, the rhythm of the tides in the Atlantic ocean resulting in "resonance" - the second oscillation induced by the arrival of the ocean tide, of the same speed as the first, resulting in a higher tidal range (Thurston, 1994).

Along the interior Fundy coast, the phenomenal tides have left conspicuous evidence of their power and might: At Hopewell Rocks the tidal currents have carved and sculpted towering statues of red sandstone. Topped by evergreens, they resemble huge flowerpots and stand as one of many Fundy marvels. At St. Martin's, the endless tidal action has carved out spelunker perfect sea caves. And with each receding tide, vast nutrient-rich mudflats are exposed in the Minas Basin.

The highest- profile phenomenon produced by the tides is the world-famous Reversing Falls at Saint John, where the majestic Saint John River plunges over cascading falls and a narrow passage on its way to the ocean. Twice each day the huge river must yield to the superior power of the Bay. As the tides slowly rise above the level of the river, the falls reverse, and the Saint John River flows upstream (Pinet, 1998).

A similar spectacle occurs at the head of the Bay of Fundy in the form of Tidal Bores. Chignecto Bay and Minas Basin form two arms at the head of the Bay, fed respectively by the Peticodiac River and the Salmon River. At high tide, the extraordinary volume of water in the Bay floods into the rivers. As the river banks narrow, the compressing waters rise in a spectacular surge and a visible standing wave, sometimes lm (3 ft) in height, as the maelstrom of roaring, churning water races upstream at speeds close to 15 km per hour (10 mph). Witnesses have likened the sound to that of an approaching railway train, and first-time viewers are usually struck with awe and fear (Thurston, 1994).

In broad overview, the stupendous Fundy tides are a titanic catalyst to a succession of extraordinary scientific, environmental and ecological wonders. Individually, they are microcosms of the perfectly evolving elements of nature. Collectively, they meld in concert to form a macrocosm considered one of the world's most natural and unspoiled. And underlining the fragility of nature is the certainty that with the continuous passage of time, the surging, monumental tides will ultimately destroy themselves as they slowly erode and disintegrate this unique basin.  

 

 

High Tide in Chance Harbour, NB
Tide Height:  7 meters (23ft)

Low Tide in Chance Harbour, NB
Tide Height:  .75 meters (2.4 ft)

Explore one of the world's most dramatic and dynamic coastlines

Visit Atlantic Canada's Bay of Fundy! Home to the highest tides in the world, the Bay of Fundy is a 270km (170 mile long) ocean bay that stretches between the provinces of New Brunswick and Nova Scotia on Canada's east coast. Each day 100 billion tonnes of seawater flows in and out of the Bay of Fundy during one tide cycle more than the combined flow of the world's freshwater rivers!

Hopewell Rocks, situated at the head of the Bay of Fundy, is one of New Brunswick's most outstanding Provincial Parks and is the tourism icon used to showcase New Brunswick and the spectacular Bay of Fundy. The sandstone and conglomerate "flowerpot rock" formations, carved by giant tides that regularly exceed the height of a four and a half story building, are a geological wonder that has attracted visitors from the world over. A walk on the ocean floor at low tide, allows visitors to view the uniquely shaped rocks, while a totally different perspective of the rocks is available only on a high tide sea kayaking excursion.

With ocean tides the height of a four story building and a discharge of water that exceeds that of every brook, stream and river on planet earth in a single day, it is little wonder that The Bay of Fundy is recognized as

"A Marine Wonder of the World."

World's Highest Tides Ecozone

The World's Highest Tides Ecozone presents an extraordinary tidal landscape. This includes the upper basins of the Bay of Fundy, where the peak tidal range is around 15 m (50 ft) - five times higher than typical tides on the rest of the Atlantic coast! The world's highest tides can be experienced as three different phenomena: tidal bores and rapids, horizontal tidal effects, and vertical tidal effects.

How to See the Tides

In the World's Highest Tides Ecozone, visitors can see two high and two low tides each 24-hour period. The time between a high tide and a low tide is, on average, six hours and 13 minutes. As such, you can reasonably expect to see at least one high and one low tide during daylight hours. High and low tide times move ahead approximately one hour each day, and tide times vary slightly for different locations around the Bay. Check with the community you are planning to visit for accurate high and low tide times.

 

Where to See the Greatest Vertical Tidal Effect

The tidal range is normally measured as a vertical distance: the change in the ocean's elevation from high tide to low tide. In the World's Highest Tides Ecozone, the tide's vertical change can be 15 m (50 ft) or more. The best way to see vertical tides is to visit small harbours around the Bay that empty at low tide and then completely fill about six hours later at high tide. Fishing boats that bob in the water alongside wharves at high tide sit on the ground below at low tide. Wharves along the Fundy coast in Nova Scotia (Halls Harbour, Parrsboro, and Advocate) and New Brunswick (Alma and St. Martins) are good locations for viewing extreme vertical tides. At Hopewell Cape, NB, visitors at low tide can walk on the ocean floor among the incredible rock formations that the tides have carved. As the tide comes in, visitors can see these formations become small islands. The best way to see the tide's vertical change is to visit a site at high tide and then return to the same site six hours later at low tide.

 

Low tide, Hopewell Cape, NB

Hall's Harbour, NS low tide

Where to See the Greatest Horizontal Tidal Effect

The tidal range can also be observed as a horizontal change. In some parts of the Bay, the tide retreats as much as five km (three mi.) at low tide, leaving vast areas of the ocean floor exposed. In Chignecto Bay and the Minas Basin, a fascinating inter-tidal zone of beaches, rock ledges, and sand flats is exposed at low tide. At low tide, visitors are able to walk on the ocean floor. The ocean floor is accessible at low tide through local parks and beaches in communities all around the Bay of Fundy's coast. However, visitors who venture onto the inter-tidal zone in Chignecto Bay and the Minas Basin at low tide must be very cautious, as the tide can move extremely fast when it turns and starts to come in again. At Evangeline Beach (NS), Dorchester Cape (NB), and Mary's Point (NB), huge flocks of up to 100,000 migratory shorebirds converge to feast on the inter-tidal zone's fertile mud and sand flats. Each summer, this area exposed at low tide becomes a critical feeding area for birds on their inter-continental migratory flight. Care must be taken not to disturb migratory birds during their feeding period.

Low tide, Five Islands, NS

Exploring sea caves at St. Martins, NB

 

What is a tidal bore?

A tidal bore is a tidal phenomenon in which the leading edge of the incoming tide forms a wave (or waves) of water that travel up a river or against the direction of the current.

Bores occur in relatively few locations worldwide, usually in areas with a large tidal range such as the Bay of Fundy, and where incoming tides are funneled into a shallow, narrowing river via a broad bay. The funnel-like shape not only increases the height of the tide, but it can also decrease the duration of the flood tide down to a point where the flood appears as a sudden increase in the water level.

The word bore derives through Old English from the Old Norse word bara, meaning a wave or swell. In the Bay of Fundy region there are several excellent places either to watch a tidal bore from the shore or to ride its waves with an adventure tour company!

Where to See Tidal Bores and Rapids

The Bay of Fundy's tides also cause tidal bores, rapids, and whirlpools. Visitors can also take a thrilling jet-boat ride through Reversing Falls in Saint John (NB) where the incoming tide reverses the river's natural flow and creates extreme tidal rapids. Cape d'Or (NS) and Cape Enrage (NB) are great locations for seeing tidal rapids from shore. Intense tidal whirlpools also occur around the coasts of Deer Island and Campobello Island in New Brunswick.

Tidal bore rafting, Shubenacadie River, NS

The Science of the Tides

Tides are the periodic rise and fall of the sea caused by the gravitational pull of the moon and the sun on the Earth. Fundy's tides are the highest in the world because of an unusual combination of factors: resonance and the shape of the bay. The water in the Bay of Fundy has a natural resonance or rocking motion called seiche. You could compare this to the movement of water in a bathtub. Although the water in a bathtub sloshes from one end to the other and back again in a few seconds, it takes about 13 hours for the water in the bay to rock from the mouth of the bay to the head of the bay and back again. As the ocean tide rises and floods into the bay every 12 hours and 25 minutes, it reinforces the rocking motion. Likewise the seiche in the bay is sustained by the natural resonance of the ocean tides. The bay's shape and bottom topography are secondary factors contributing to Fundy's high tides. The bay becomes narrower and shallower [from 130 m (426 ft) to 40 metres (131 ft)] toward the upper bay, forcing the water higher up onto the shores.

 

 

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At the Hopewell Rocks, Fundy's tides, in combination with other forces of nature, have carved a unique and diverse ecosystem.

Deer Island, New Brunswick - Eastport, Maine

One of the most dramatic demonstrations of the power of the tides is found in the Western Passage of the Passamaquoddy Bay towards the mouth of the Bay of Fundy. "Old Sow" is the largest whirlpool in the western hemisphere, the second largest in the world - second only to the Maelstrom Whirlpool of Norway. Located between Deer Island and Indian Island, this natural wonder can be seen from the shores of Eastport, Maine. It is called "Old Sow" because of the sounds that are heard from the churning waters.

This powerful whirlpool is formed when the rising tide passes both sides of Indian Island, takes a sharp right turn around the southern tip of Deer Island to flood the Western Passage. A current of over 6 knots (11 km/hr or 6.9 mi/hr) has been experienced off Deer Island Point. In addition to the waters pressing through the narrow straight, the waters are forced along the peaks and valleys of the ocean floor - a trench as deep as 122 meters (400 feet), followed by a reduction in water depth to 36 meters (119 feet) and again followed by a depth of over 107 meters (350 feet). The current of inflowing tributaries within the Passamaquoddy Bay add to the already busy waters.

Old Sow is reported to be most active about 3 hours before high tide. This activity continues for about two hours and takes the form of a collection of small gyres, troughs, spouts and holes and on the rare occasion will form one large funnel. This area, which has been reported to be as wide as 76 meters (250 feet) in diameter, can best be described as turbulent water. However, during spring tides (high water tide caused by a full or new moon) combined with high winds or a tidal surge will increase Old Sow's activity causing more intense funnels and formations.

Tidal electrical power generation

Several proposals to build tidal harnesses for electrical power generation have been put forward in recent decades. Such proposals have mainly involved building barrages which effectively dam off a smaller arm of the bay and extract power from water flowing through them.

One such facility exists, the Annapolis Royal Generating Station consists of a dam and 18-MW power house on the Annapolis River at Annapolis Royal, Nova Scotia, but larger proposals have been held back by a number of factors, including environmental concerns. The Annapolis Royal Generating Station has been studied for its various effects, including an accelerated shoreline erosion problem on the historic waterfront of the town of Annapolis Royal, as well as increased siltation and heavy metal and pesticide contamination upstream due to lack of regular river/tidal flushing. There have also been instances where large marine mammals such as whales have become trapped in the head pond after transiting the sluice gates during slack tide.