An iceberg breaks from the end of this tidewater glacier.

There are many other types of glaciers. Valley glaciers erode rocks. Tidewater glaciers flow into the ocean. What happens when a frozen glacier meets ocean water? Chunks of ice can break off of glaciers and become ocean icebergs.

Piedmont glaciers form wide, round shapes as they spill out onto flat areas.

Glacier 101

Today, there are hundreds of thousands of glaciers. Some are huge. We have ice sheets about the size of Delaware, Maryland, and New Jersey combined! Only two ice sheets existin Greenland and in Antarctica.

A lake forms at the end of this valley glacier.

Piedmont glaciers flow from steep mountain areas onto flat areas. There are tiny glaciers called glacierets. There are mysterious glaciers made of fused rock and ice called rock glaciers. There are so many other types of glaciers, and no two are alike.

Global Glaciers

Glaciers are found all over the world. They affect the climate. They build and shape landscapes. They provide water and other vital resources. They show us when environments are not in balance. They connect cultures to landscapes. To me, that’s what is so powerful about glaciers.

Muir Glacier, Alaska:
August 13, 1941 and August 31, 2004

This winter ice cave formed inside a glacier.

Now, due to climate change, glaciers are melting. This will have a serious effect on Earth. Sea levels will rise. Other water sources may dry up. And many people who live with glaciers may lose part of their way of life. Ice influences people just as much as we influence ice.

Life at the Extremes

By exploring our planet’s most extreme places, National Geographic is discovering new information about Earth’s climate.