What are warm-based glaciers?

A warm-based glacier is like a giant ice cake that’s melting from the inside out, and it keeps moving because of it.

Imagine you have a big block of ice in your freezer, but instead of being frozen solid all the way through, there's some water sloshing around underneath. That’s what happens with warm-based glaciers, they're not completely frozen at their base, so they can slide along the ground like a sled on snow.

When you put ice in the freezer, it gets hard and stays still. But if there's water under the ice, maybe from melted snow or warm weather, the glacier can slide over the ground below. It’s kind of like when you put a wet sock on a smooth floor, it slides easily instead of sticking.

Most glaciers are cold-based, meaning they’re frozen all the way down to the ground, and they creep along very slowly. But warm-based glaciers are more active, they move faster because of that hidden water underneath. It’s like having a sleepy turtle versus a playful dog, one moves slow, the other zooms ahead!