Riss

Riss is a term with several distinct uses in geology, linguistics, and onomastics. The most widely cited meaning in scientific contexts is the Riss glaciation, a late Middle Pleistocene glacial stage in Central Europe. The Riss glaciation is traditionally dated to roughly 300,000 to 130,000 years ago and involved advances of alpine ice sheets across the Alps and adjacent regions. In the classic German sequence Günz–Mindel–Riss–Würm, the Riss stage lies between the Mindel and Würm stages, helping to divide the Pleistocene record of Central Europe.

In German, the word "Riss" means a crack, fissure, or rupture. As a general term, it is used in everyday language as well as in technical contexts to describe fractures or seams in rocks, wood, and other materials. The term appears in geological descriptions and in related disciplines as a concise way to refer to a fracture feature.

Riss also functions as a surname of Germanic origin. As a family name, it appears in German-speaking regions and among communities with German heritage. Like many surnames, it may be found in various forms and combinations and can be associated with individuals, families, or local histories.

In summary, Riss most commonly designates a well-known Pleistocene glaciation in Central Europe, but it also exists as a common noun meaning crack and as a surname.