Why are crevasses only 40m deep?

Crevasses are typically around 40 meters deep due to the balance between the glacier's movement and the structural integrity of the ice. As glaciers flow, stress builds up, causing cracks to form. However, beyond a certain depth, the ice's weight creates enough pressure to prevent further cracking, leading to a natural limit in depth. Additionally, deeper crevasses would require more significant ice deformation, which is less common in stable glacier environments.