Why “bergshrund” is a great word
A large and often treacherous fissure in a glacier, marking the boundary where the flowing ice tears away from the stagnant ice anchored to the rock of a mountain. Borrowed from German Bergschrund, from Berg ('mountain') + Schrund ('crevice, crack'). Unlike a generic 'crevasse' (a fissure anywhere in a glacier's body) or the more technical 'rimaye' (which can specify a separation at the glacial headwall), a bergschrund is the specific, yawning rupture at the cradle of motion. It is the deep, shadowed lip of the frozen river, a blue and silent gash that swallows the sound of falling stones and divides the living flow from the dead, stationary chill—a stark, geologic incision between movement and stasis.
Definitions & examples from Wiktionary (CC BY-SA 3.0).