World's Highest Tides
The Guinness Book of World Records states the world's highest tides to be in the Minas Basin, N.S., with the maximum tidal range recorded at 16.8 meters (54.6 ft). Tide Times.
Parrsboro, the largest seaport on the Minas Basin, affords the best view of this tidal phenomenon. At this point the tide floods and ebbs over 3.2 kilometers (2 mi.) of tidal flat from the low water mark to the head of the harbour. Each phase of the cycle takes approximately 5 hrs and 40 min. which results in each succeeding high or low water mark range an average 14m. (45.5 ft.) while the harbour heights are about 7.5 m (24 ft.).
The initial cause of tidal action is the pull or attraction on the world's oceans by the moon, sun, planets and stars. They exert their gravitational influence most in relatively narrow bands around the earth at about 45 degrees north and south latitude. This is so because those are the areas tipped closest and farthest away from these celestial bodies. Although the gravitational pull on the earth by these bodies and particularly by the moon is strong, it is not enough to actually lift water but it can greatly influence its direction of flow,a thus creating ocean tides. Along the Atlantic coast of Nova Scotia ocean tides account for a general rise and fall of from one of two meters. Sometimes this figure can be higher if there is a celestial alignment which would combine the gravitational influence of these bodies on the earth. However, for the Bay of Fundy Region, there are two other principal factors (geographical shape and tidal resonance) which change these two meter tides to the world record breaking sixteen meter and above variety.
The pull of the ocean by the celestial bodies at the mouth of the funnel shaped Bay of Fundy creates a wave of water that continues to double up on itself as it travels to the Bay's head and then falls back. The entire trip happens to take about thirteen hours by which time the moon is ready for another pull. The timing of this cycle creates a rhythmic rocking or "sloshing effect" to the water in the Bay which amplifies the tides to such unusual heights. It is estimated that for the Fundy tides there may be as many as two hundred different factors that all in some way influence the timing and heights of tides.
The Mighty Fundy Tide
- The tides in Nova Scotia's Bay of Fundy are the highest in the world. Twice a day 115 billion tones of water move in and out of the 160 mile long v-shaped pocket of sea-water.
- The rise and fall is 20, 30, often 40 feet in some places. During periods of high winds and a full moon, some Bay of Fundy tides have risen as high as fifty feet. The record variance between high and low has been measured as 54 feet in a place called Burncoat Head on the Minas Basin.
- The Glooscap Trail, named for the Micmac Indian God, follows the shoreline of Chignecto Bay, the Minas Channel, the Minas Basin, and Cobequid Bay where long stretches of mud flats are exposed during low tides and where curious backward waves called tidal bores occur during the rise.
- Further along the mouth of the Bay of Fundy in St. Mary's Bay, at Digby, in the Annapolis Basin and along the coast of the North Mountain are other, if less dramatic, examples of the amazing Fundy tides.
- As a natural phenomenon, the Bay of Fundy tide is not a sudden and dramatic event, but rather a gradual, remarkable occurrence. In some places in Cobequid Bay, the high tide comes in as fast as one inch per minute, fair warning for adventurous beachcombers who stray too far from shore.
- Ships and fishing boats that use the Bay of Fundy Ports like Delaps Cove, Parker's Cove, Hampton, Parrsboro, and Hall's Harbour are found flush and even with adjacent wharves during high tides, but become stranded, high and dry, 20 feet down when the tides recedes eight hours later.
- Rivers running into the Minas Basin, Cobequid Bay and Chignecto Bay often experience a tidal bore -- a wave of water that moves upstream against the current, making it seem like the river is running backwards.
- Tidal bores regularly occur in the Macaan River and River Hebert near Amherst, the Chigonois and Salmon River near Truro, the Shubenacadie River and the Meander River near Windsor.
- The Salmon River on the outskirts of Truro is the most popular place to watch the tidal bore. Tide times are well posted and there is parking near the viewing sites.
- Unlike the gradual tide change, a tidal bore occurs in a matter of minutes. It passes in seconds. As the high tide reaches its peak, a small wave of water (the wave increases in height with wind direction and the phases of the moon) suddenly appears at the mouth of the river and works its way up stream. At some places in the stream, the bore causes white water turbulence as the river fights to push back the advancing tide.
- But the mighty Fundy tide always wins and soon the mud-covered river sides are engulfed in water, the river fills its banks and the advancing bore disappears gradually upstream. A remarkable and unusual sight -- found nowhere else in North America, part of the magic and mystery of the amazing Fundy tides.