Elastic Discontinuity
Elastic Discontinuity : A boundary between rock strata of differing density, or having different elastic properties. Seismic waves passing through rocks that are not uniform in all directions, or from one kind of rock into another (e.g. limestone to shale), are refracted or reflected. Where a P or S wave meets an elastic discontinuity, it generates two new P waves and two new S waves. See also: seismic waves