a subterranean interface at which seismic velocities change
A lack of continuity, regularity or sequence; a break or gap.
A point in the range of a function at which it is undefined or discontinuous.
A series of holes punched through something in order to assist in separating parts.
That portion of a surface that remains after an open disk is removed from it.
An abnormal opening in an organ, such as a rupture.
Any opening in a solid object.
The act of perforating or the state of being perforated.