- 哦,加拿大:1867-2017 O,Canada:from 1867to 2017(英文版)
- (加)凯伦·史密斯
- 1070字
- 2020-11-18 14:01:52
3 Turn of the Tide 1869
When the water in the sea moves up or down near land, it is called a tide. Low tide is when there is no water, and high tide is when there is much water. This story is about the highest tides in the world.
On October 4, 1869, a very big storm came to Nova Scotia. That night, in a place called Minas Basin, the fishermen tied their boats to the dock. When they returned in the morning, their boats were sitting on the rocks, 21.6 metres below the dock.
The Bay of Fundy in Nova Scotia has the highest tides in the world. The water in the sea rises and falls because the moon, the sun and the spin of the Earth pulls or pushes the water. A tide is like water being pushed on a swing. When the swing goes forward it is the same as high tide. When the swing moves backward it is the same as low tide.
In the Bay of Fundy, the water rises 17 metres, two times every day, from low tide to high tide. This is the same height as a four or five-floor building. This is very unusual because in many other parts of the world the water only rises about 1 metre. The Bay of Fundy is different for two reasons. First, there is much water in this bay. Also, the bay has a shape like a boot. At high tide, all that water runs into the top of the boot where it is wide. Then the water runs to the narrow bottom of the boot. Soon, there is so much water that it must rise up when it gets to the narrow end. The tide can rise to 17 metres high in just two minutes. Then it turns and runs out the top of the boot again.
First Nations(see 1999)say that the tides in the Bay of Fundy happen because a very big whale splashes in the water. The Mi'kmaq, who are a First Nations group, have always lived along the Bay of Fundy and fished in its waters. The tide waters also help give food to the birds and things that live in the sea. The tides move the water at the bottom of the ocean. Many small plants and tiny fish are then carried to the top of the ocean. There, the birds, bigger fish and whales can eat them.
Tidewaters are very strong. Their strength is the same as 8,000 train engines or 25 million horses. The tides can wash away rocks. Sometimes when the tides carry away the rocks, people find fossils underneath.
At a place called Joggins, Nova Scotia, the plants and animals are now hard as rock and part of the cliffs. These fossils in the rock cliffs can be up to 300 million years old. Many are not found anywhere else in the world. There are trees and flowers in the rocks. There are even footprints and the last meals of some reptiles. Every four years the tides wash away more of the cliffs and new fossils are found. One year, the first true reptile was found. This was the ancestor of all the dinosaurs that would walk on the Earth 100 million years later. This reptile was the first fish to grow legs, leave the water, and walk on land.
The tides at the Bay of Fundy have made the rocks look like flower pots. The water at high tide only covers the bottom of the rocks here. The water eats away at the rocks and makes them quite thin. The tops of the rocks stay dry so they stay fat. Trees grow on the top of the rocks here so they look like very large, flower pots. When it is low tide, visitors can walk around the flower pots on the ocean floor. When it is high tide, the water flows around the flower pots and makes them into islands.
The strong tide waters also make something interesting happen in New Brunswick. The Bay of Fundy touches two Canadian provinces: Nova Scotia and New Brunswick. In Saint John, New Brunswick, the tide water has to pass through a narrow place between two rock cliffs. It goes in for six hours. Then, when the tide is at its highest, it turns, or reverses, and goes out in the opposite direction. When this happens the water pushes and pulls in two directions. It makes a waterfall. This place is called the Reversing Falls.
DURING LOW TIDE AT THE BAY OF FUNDY, THERE IS NOT ENOUGH WATER TO KEEP THE BOATS FLOATING
At another place in the bay, the tides make a whirlpool. The water runs in a circle very fast. It is called Old Sow Whirlpool. It looks just like the water running out of a bathtub only it is very big. This whirlpool is 75 metres across.
Another interesting thing that happens are the tidal bores. Usually, the water in a river runs towards the sea. In the Bay of Fundy, however, the tides push their way up the rivers that are near it. The tides from the bay meet the river water flowing in the other direction. The tide is so strong and fast that it can stop the river water from going to the sea for a time. This is called a tidal bore because the tide pushes, or bores, its way through the river. Tidal bores can travel almost 15 km per hour.
Scientists tell us that 160 billion tonnes of sea water come in and out of the bay each day. That is more water than the flow of all the freshwater rivers in the world put together. Some people think that perhaps it is possible to make energy using these tides. At the Minas Passage in Nova Scotia, they are trying to use the movement of the tides to make electricity. They built a large wheel and let the tidal water pass through it to make it turn. As this wheel turns, it makes energy which is used to make electricity. It seems that they may be successful in using the tides to make electricity for people living near the Bay of Fundy.
Many tourists come to visit these places every year because the tides at the Bay of Fundy are famous. They are one of the world's natural wonders.