There's a distinct difference between the words crevice and crevasse: the former refers to a small cut in rock, and the latter is about a deep cleft in a glacier or ice sheet. Both words, despite their differences, may be traced back to the Old French word crevace, which meant "gap" of any kind. This comes from the verb crever, meaning "to break" or "burst". This derives from Latin crepare, meaning "to crack". The connections to chasms are clear. Crepare may be reconstructed to to Proto-Indo-European korh, an onomatopoeic noise that is imitative of natural creaking sounds. In that vein, korh eventually also gave way to the Proto-Germanic khrabanaz (with the same meaning), which spawned Old English hræfn, which meant "bird" (because the creaking of birds is similar to that of crevices, apparently). A few centuries of development, and we are left with the word raven. An interesting etymological connection, to be sure, but a welcome one.
Adam Aleksic, a rising sophomore studying linguistics and government at Harvard University, has been described as the internet's sixth most famous etymologist. He also has disturbing interests in politics, vexillology, geography, board games, conlanging, and law.