Here's why:
* Friction: Glaciers experience friction at their base and sides as they move over bedrock or against the valley walls. This friction slows the glacier down.
* Internal Flow: The center of the glacier is furthest from these points of friction, experiencing less resistance.
* Pressure: The weight of the ice above creates pressure that causes the ice to deform and flow. This pressure is greatest at the center of the glacier, further contributing to faster movement.
Think of it like a river. The water in the middle of the river flows the fastest, while the water at the edges is slowed down by friction with the riverbanks.
