From MarineBiotech Infopages
A beach berm is a nearly horizontal shore parallel ridge formed on the beach due to the landward transport of the coarsest fraction of the beach material by the wave uprush (swash).
- Beach berms are most pronounced on so-called reflective beaches (characteristics: steep slope, coarse sediment, subject to low-energy swell waves, intertidal zone almost absent).
- There may be several beach berms and in some cases no berms.
- Under normal conditions a beach berm is formed on the upper part of the beach face, and over the backshore during storm events.
- Berms can also form on the higher intertidal zone of a tidal flat; these berms are generally called "swash bars".
- Beach berms are sometimes artificially reinforced as coastal protection measure.