Hello. I'm M. Jackson, a geographer and a glaciologist. I study glaciers around the world. A glacier is a large body of ice moving slowly down a slope or valley or spreading out on land. The end point of a glacier is
its terminus. When a glacier flows into water, the ice can calve, or break off.

A serac is a ridge of ice on the surface of a glacier. These stick up like shark fins. They can be fun to climb. While climbing near one, I slipped and fell into a crevasse.

Thankfully, my team was nearby and fished me out of the deep, icy crack.