discontinuity

noun

1. A lack of continuity, regularity or sequence; a break or gap.

   “structural discontinuity”

   “sharp discontinuity”

   “detect a discontinuity”

   “The data shows a clear discontinuity in temperature around 1990.”

   “Geologists noted a discontinuity between the two rock layers.”

2. A point in the range of a function at which it is undefined or discontinuous.
3. a subterranean interface at which seismic velocities change