Eleanor Pupko, age 10,, of Remsen, NY for her question:
What happens when a glacier meets a stone wall?
When the hot days of summer roll around, our minds turn to glaciers and ice ages and other cooling ideas. This, says andy, happens every year, and it is quite natural. He claims that he can tell when it is summertime, just be reading all the cool questions in his mail bag.
A glacier is a monstrous thing,, and we must use our imaginations to grasp it. Forget the ice in the refrigerator, forget the ice on the winter window pane and the ice, perhaps several feet thick,, that freezes over the lakes. All these icy items are nothing compared with even a small sized glacier.
The monster may be just a few miles wide or it may spread over thousands of square miles. In greenland'. There is a glacier which covers 660,000 square miles; the glacial ice fields of Antarctica cover some 5 million square miles. In some places the ice there is two miles thick.
The hard ice of a glacier is made from densely packed snow, and it is mixed with all kinds of rock and rubble, dirt and debris. Water is a mineral.. And ice which is frozen water is also a mineral. It is more brittle than most of the rocky minerals of the earth's crust, and it behaves somewhat like liquid water., but at a much lazier pace,
A glacier 200 to 300 feet thick begins to move under its own weight. If it is on a slope., it slides slowly down like a lazy river. If it is a flat ice field.. It spreads slowly out from the center. Some move less than an inch a day, while some move 20 feet or more a day but glaciers are always moving. The outer edges are pushed along from behind by the pressure from countless tons of moving ice.
No manmade building is strong enough to resist a glacier or stop it in its path. Stone walls and huge cities would be crushed by the advancing ice. The ice age glaciers pushed down from the arctic over mountains and plains. Tall peaks did not stop them. The glaciers sheared off their ragged spires and left the mountains with rounded tops. In some places, a glacier flowed around a massive range, but the biggest glaciers cannot be stopped, even by a mountain.
Any stone wall would be crumbled by an advancing glacier. Its stones would be scattered and some of them might become frozen inside the ice. As the glacier moved, these stones would be carried along. Giant boulders were carried hundreds of miles by the glaciers of the ice ages. Later, when the ice melted, they were dumped on the ground far from their original homes.