Why are crevasses often deeper in polar glaciers than in temperate glaciers?

Crevasses are fissures in a glacier that form when the ice undergoes brittle failure due to tensile stress. The depth of these cracks is determined by the balance between the rate of surface stretching and the rate of plastic flow, which acts to close the crevasses at depth.123

The temperature of the ice is a critical factor in this process. Temperate glaciers exist at the pressure-melting point throughout their mass, making the ice relatively soft and capable of deforming more easily through plastic flow. This flow effectively closes crevasses at shallower depths, which is why cracks deeper than 50 meters (160 feet) are rare in temperate mountains.23

In contrast, polar glaciers are significantly colder and more rigid. Because this colder ice is less capable of adjusting its shape through plastic flow, it is more prone to brittle failure. Consequently, the rate of closure is slower, allowing crevasses to reach depths of 100 meters or more.23