Paul Morellato, age 10, of Niagara Falls, Ontario, Canada, for his question:

How did the Ice Age form the Niagara Escarpment?

The Niagara Escarpment is a high cliff in the bed of the Niagara River. Over this ledge the water plunges almost 200 feet to the lower level of the river bed. The formation of the stupendous sight goes back perhaps 20,000 years to the last Ice Age. The weight of the ace age glaciers was so immense that vast areas of the landscape were crushed and shoved out of shape. The earth's crust, of course, is a super sandwich of assorted rocks with harder and softer layers piled one upon another. Hard layers, such as the Niagara Escarpment, tended to resist reshaping by the glaciers while other layers around them were crushed down.

When the glaciers melted, streams of icy water were forced to find new courses. Hollows, chewed out by the heavy ice, filled with lake water and still more melting water. Lake Erie overflowed and its surplus water formed the Niagara River. At one point along its path, the river came to a high cliff, the Niagara Escarpment. Its streaming waters, pushed by the overflowing lake, plunged over the cliff to the lower level at its feet. There the river continued its downward path to Lake Ontario, to the St. Lawrence River and finally to the sea.