Knickpoint

A knickpoint is the break between the steep and gentle slopes of a river profile caused by erosion induced by a rejuvenated river, tectonic uplift of the riverbed or a change in lithology. On stable ground, a riverbed will tend to be a smooth surface with a gentle gradient. The Earth’s movement can cause uplift of the riverbed or drastic lowering of the erosional datum (i.e., ocean or lake surface); as a result, the river resumes downward erosion at the river mouth and headward erosion upstream. The break point between the new and old river courses is the knickpoint, which often appears in the form of a rapid, turbulent shore or waterfall. River terraces often correspond to the formation of knickpoints.