How do crevasses typically form in relation to glacial flow?

Crevasses commonly form perpendicular to the direction of flow due to the tension created as a glacier moves. When a glacier flows over uneven terrain, the variations in the underlying surface can cause sections of the ice to stretch and crack. This tension leads to the development of vertical fractures known as crevasses.

The flow of ice within a glacier is not uniform; it can change speed and direction depending on the topography and internal dynamics. When the glacier moves from a thick area to a thinner one, or when it encounters obstacles, the ice at the surface can be pulled apart more than the ice underneath, forming crevasses perpendicular to the movement.

This formation process illustrates the complexities of glacial dynamics and highlights how glacial movement and stress distribution can shape the glacier’s structure and geography. Understanding the mechanics of glacier flow is essential to interpreting glacial features and their evolution over time.