Crevasse

Noun

 * 1)  A crack or fissure in a glacier or snow field; a chasm.
 * 2)  A discontinuity or “gap” between the accounted variables and an observed outcome.

Thesaurus
abysm, abyss, arroyo, box canyon, breach, break, chap, chasm, check, chimney, chink, cleft, cleuch, clough, col, coulee, couloir, crack, cranny, crater, crevice, cut, cwm, deep, defile, dell, depth, dike, ditch, donga, draw, excavation, fault, fissure, flaw, flume, fracture, furrow, gap, gape, gash, gorge, groove, gulch, gulf, gully, hole, hollow, incision, joint, kloof, leak, moat, notch, nullah, opening, pass, passage, pit, ravine, rent, rift, rime, rupture, scissure, seam, shaft, slit, slot, split, trench, valley, void, wadi, well, yawning abyss