Crevasse

A crevasse was a large, crack-like opening in ice (COMIC: Blood and Ice) or ground. Cassandra O'Brien.Δ17 claimed that her mother and father built a house on the edge of the Los Angeles Crevasse. (TV: The End of the World)

In Barusa's universe, disagreements among the Time Lords would cause crevasses to appear across the surface of Gallifrey, which would close once harmony was restored. (PROSE: The Chronicles of Doctor Who?)