A single large crevasse or series of sub-parallel crevasses that develop at the head of a glacier. The location where ice pulls away from the bedrock wall of the cirque against which it accumulated. In winter, the crevasse fills with snow. In spring or summer, it reopens. (Originally a German term).
A bergschrund is a split or crevasse in the ice of a glacier, where the glacier detaches itself from the mountain's rock. It is often a serious obstacle to a mountaineer wishing to gain access to the mountain.