Glaciers and Ice Ages for Kids: Rivers of Ice That Shape the Land (Grades 6 to 8 Science)

Hi, I'm Luna from DoodleBeez. A glacier is a huge, slow moving mass of ice on land. Glaciers are powerful enough to carve mountains and move giant boulders. Let's see how they shape Earth.

Glaciers form where more snow falls in winter than melts in summer. Year after year, the snow piles up. Its weight squeezes the lower layers into dense, solid ice.

Once thick enough, a glacier starts to flow downhill under its own weight. Most move very slowly, often less than a few feet per day. That is why some people call them rivers of ice.

As glaciers move, they scrape and pluck rock from the ground. This erosion carves deep valleys shaped like the letter U. Glaciers also leave scratches on rocks that show which way the ice moved.

When glaciers melt, they drop the rock they carried. Ridges of rock and soil are called moraines. Big boulders left far from home are called erratics. These deposits are clues to where ice once was.

During ice ages, giant ice sheets spread over continents. About twenty thousand years ago, ice covered most of Canada and parts of the northern United States. Melting ice helped form the Great Lakes.

Now it's your turn. You find a huge boulder in a field, made of rock that does not match the area. What is it, and how did it get there? Pause and try. It is an erratic, carried by a glacier.

Great job! Remember, glaciers form from packed snow, flow slowly, carve U shaped valleys and leave moraines and erratics behind. Practice glaciers and ice ages in the Science Lab at doodlebeez.com. See you next time!