Roy Terrace Birthplace Of The Falls
Roy Terrace and Eldridge Terrace, the niche visible on the U.S. side of the same height, mark the level of glacial Lake Iroquois (Lake Ontario). When the Wisconsin glacier receded about 12,000 years ago, the Falls of Niagara were born here, water falling 11 metres (35 feet) over the escarpment from a small Lake Erie into Lake Iroquois.
Birth of Niagara Falls
As the Glacier retreated, the upper Lakes began draining into the lower lakes at five to six locations across the Niagara Escarpment. Twelve thousand years ago, the Niagara River ultimately became the main water outlet over the Niagara Escarpment. The waters of a much larger Lake Erie began to flow over the escarpment into a larger Lake Iroquois (Lake Ontario).
The Niagara River began to flow from the Lake Erie basin through Lake Tonawanda and down the present path of the river to the escarpment.
At this time, the lake plain from Queenston to Niagara on the Lake was covered with the waters of Lake Iroquois (Lake Ontario). The height of the lake was within 11 meters (35 feet) of the average level of the Niagara Escarpment at Queenston, Ontario.
The height of the initial Niagara Falls was only 11 meters (35 feet) as it flowed over the Niagara Escarpment at Queenston to the waters of Lake Iroquois below. As the water flowed over the escarpment to the water below, the water began eating through the glacial material and the limestone rock of the Niagara Escarpment to begin the formation of the Niagara Gorge.
The site of the birth of Niagara Falls was discovered by a geologist named Doctor Roy Spencer and today this site is known as "Roy Terrace".
The flow rate of water back then was only twenty-five percent of the present flow rate. Scientists have calculated that the volume of water flowing over the Falls initially was 37,500 cubic feet per second.
As the Glacier continued receding further north, it opened silt barriers allowing waters to drain to the ocean resulting in the lowering of the water levels of Lake Iroquois (Lake Ontario).
The rising of the northern crust of the earth, a reflex action to the weight of a Glacier a half a mile or more thick, caused a faster outpouring of Lake Iroquois (Lake Ontario). The lower 11.2 kilometer (7 mile) stretch of the Niagara River to Lake Ontario was once 19 kilometers (12 miles) long.
Scientists have suggested that the eastern part of the North American continent is still in the process of tilting as part of the glacial reflex action. As the crust of the earth rises along the eastern seaboard the water flowing from the Great Lakes system will become slower.
The beginning of the last glacial retreat began 12,000 years ago. The third and last Wisconsin Glacier retreated east of Hudson Bay in Labrador. As the glacier retreated, the land began to rise. The crust of earth rocks are elastic when bent over large sections.