The waterfalls of Niagara Falls are located on the Niagara
River which connects two of the five
Great Lakes. Lake Erie and Lake Ontario.
Collectively the waterfalls are named Niagara Falls. They
consist of three different waterfalls. The American Falls and the Bridal Veil
Falls in the USA and the Canadian "Horseshoe" Falls in Canada.
The Niagara River serves as an international border between
the USA & Canada. There are two distinctive cities. Niagara Falls Ontario,
Canada and Niagara Falls New York, United States of America.
Ice Age History of the Niagara River and Whirlpool Rapids
The Niagara River, as is the entire Great Lakes Basin of
which the river is an integral part, is a legacy of the last Ice Age. 18,000
years ago southern Ontario was covered by ice sheets 2-3 kilometers thick. As
they advanced southward the ice sheets gouged out the basins of the Great
Lakes. Then as they melted northward for the last time they released vast
quantities of meltwater into these basins. Our water is "fossil
water"; less than one percent of it is renewable on an annual basis, the
rest leftover from the ice sheets.
The Niagara Peninsula became free of the ice about 12,500
years ago. As the ice retreated northward, its meltwaters began to flow down
through what became Lake Erie, the Niagara River and Lake Ontario, down to the
St. Lawrence River, and, finally, down to the sea. There were originally 5
spillways from Lake Erie to Lake Ontario. Eventually these were reduced to one,
the original Niagara Falls, at Queenston-Lewiston. From here the Falls began
its steady erosion through the bedrock.
However, about 10,500 years ago, through an interplay of
geological effects including alternating retreats and re-advances of the ice,
and rebounding of the land when released from the intense pressure of the ice
(isostatic rebound), this process was interrupted. The glacial meltwaters were
rerouted through northern Ontario, bypassing the southern route. For the next
5,000 years Lake Erie remained only half the size of today, the Niagara River
was reduced to about 10% of its current flow, and a much-reduced Falls stalled
in the area of the Niagara Glen.
About 5,500 years ago the meltwaters were once again routed
through southern Ontario, restoring the river and Falls to their full power.
Then the Falls reached the Whirlpool.
It was a brief and violent encounter, a geological moment
lasting only weeks, maybe even only days. In this moment the Falls of the
youthful Niagara River intersected an old riverbed, one that had been buried
and sealed during the last Ice Age. The Falls turned into this buried gorge,
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. When
it was all over it left behind a 90-degree turn in the river we know today as
the Whirlpool, and North America's largest series of standing waves we know
today as the Whirlpool 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.
Straddling the Canadian-United States International Border
and both in the Province of Ontario and the State of New York, Niagara Falls
attracts some 12 Million tourists to her majestic awesome beauty each year.
The Niagara is a fairly young river, only 12,000 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.
One fifth of all the fresh water in the world lies in the
four Upper Great Lakes-Michigan, Huron,Superior and Erie. 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. The land between the
lakes does not slope at an even grade, but forms a spectacular drop
approximately the same height as a 20 story building and this is known as the
"Niagara Escarpment" Two billion years ago it was buried under a
blanket of ice.
As the years passed, the process of erosion took place, (and
still does) five distinct 'gorges' were formed-Lewiston Brange Gorge, Old
Narrow Gorge, Upper & Lower Great Gorges and the Whirlpool Narrow Gorge.
Approximately 500 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 1780). 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, 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 Horseshoe Falls has no obstruction to divert it. It should be noted
that a third much narrower falls exists. Over the years these falls have been
called at different times; Luna Falls, Iris Falls and is currently named Bridal
Veil Falls.
Man has not been able to completely control the flow of the
water over the falls, even modern engineers have tried. Much of the water today
is fed through underground channels and pipes to nearby hydro electric power
stations.
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