Roger and Pat de la Harpe Photography and Africa Imagery Photo Library

We recently took the trip of a lifetime and visited Alaska, mainly to photograph bears but also to shoot some images of glaciers. We went on a small boat cruise on Prince William Sound and saw a number of them - what an incredible experience! Here are ten facts about glaciers that we find interesting:

1. Glaciers are the largest reservoir of fresh water in the world and store some 75% of the world’s fresh water.

2. There are more than 100,000 glaciers in Alaska, most of them unnamed.

3. The longest glacier on earth is Lambert-Fisher Glacier in the Antarctic, which is 100km wide and about 435km long.

4. If all glaciers and ice sheets on earth melted, sea levels would rise by some 80m.

5. Glaciers do not travel at speed, but the Kutiah Glacier in Pakistan holds the record. In 1953 it moved more than 12km in 3 months, an average of about 112m per day or 4.6m/h.

6. As opposed to red and yellow light, blue light can penetrate snow and ice, in this way creating the wonderful blue colour of glaciers.

7. Glaciers can be found on every continent, with the exception of Australia.

8. The formation of a glacier is an incredibly slow process, which takes place over hundreds of years.

9. When glaciers move over bedrock, it grinds the rock to a fine powder that is suspended in water, thereby creating the turquoise blue colour of some glacial lakes.

10. "Glacier" is a French word and is derived from the Latin glacies meaning ice.

See more glacier images here.