What makes Niagara Falls so spectacular is the combination of their height and volume. Number of tourists who visit the Falls every year: 12 million. The American Falls measure about m ft. The Bridal Veil Falls measure about 15m 50 ft. Once the water flows over the Falls, it travels down the Niagara River to Lake Ontario, where it then flows into the St.
Lawrence River and finally into the Atlantic Ocean. Fish travel over Niagara Falls and most survive because of their ability to flow with the water. At one time, P. Energy from the Niagara River has been harnessed for hydro-electric power generation as far back as the mid-eighteenth century. Power generation facilities along the Niagara River supply more than one-quarter of all power used in New York State and Ontario.
Under an international treaty, the flow of water over Niagara Falls is reduced during the night to allow more of the water to flow into intakes used for power generation. It was captured by the British during the War of It was a brief and violent encounter and a geological moment lasting only weeks, maybe even only days. In this moment the Falls of the youthful Niagara River intersected an old riverbed and one that had been buried and sealed during the last Ice Age.
The Falls turned into this buried gorge and tore out the glacial debris that filled it and scoured the old river bottom clean. It was probably not a falls at all now but a huge churning rapids. The Falls then re-established at about the area of the Whirlpool Rapids Bridge upriver to our right and resumed carving its way through solid rock to its present location. The Niagara is a fairly young river and only 12, years old, a microsecond in geological time.
The Niagara Escarpment which was created by erosion is much older. The glaciers pressed down on the land during the last ice age and laid down layers of sediment then the slow process of erosion of ice and water ate at the surface of the escarpment.
The mighty river plunges over a cliff of dolostone and shale. Niagara Falls is the second largest falls on the globe next to Victoria Falls in southern Africa. All the outflow empties into the Niagara river and eventually cascades over the Falls. At the bottom of the Falls the water travels 15 miles over many gorges until it reaches the fifth Great Lake-Ontario. Approximately years ago the river encountered an obstacle that caused it to split into two channels, thus Goat Island was formed named after John Stedman whose goat herds froze to death in the winter of This was the original sediment left from a vanished Lake Tonawanda an Indian name.
On the eastern part of the island the American Falls took shape and the Horseshoe Falls is on the western side where the river angles some 90 degrees. The water flow on the American side of the Falls is much less in strength because of Goat Island whereas the Horseshoe Falls has no obstruction to divert it.
It should be noted that a third much narrower falls exists. Man has not been able to completely control the flow of the water over the falls and even modern engineers have tried. Much of the water today is fed through underground channels and pipes to nearby hydro electric power stations. The tremendous volume of water never stops flowing.
0コメント