Upper shoreface refers to the portion of the seafloor that is shallow enough to be agitated by everyday wave action, the wave base.

Process

The continuous agitation of the sea floor in the upper shoreface environment results in sediments that are winnowed of the smallest grains, leaving only those grains heavy enough that the water cannot keep them suspended.

Depth of influence

Seawater Seawater, or sea water, is water from a sea or ocean. On average, seawater in the world's oceans has a salinity of about 3.5% (35 g/L, 35 ppt, 600 mM). This means that every kilogram (roughly one liter by volume) of seawater has approximat ...

is moved in a vertical circular motion when a wave passes. The

radius In classical geometry, a radius (: radii or radiuses) of a circle or sphere is any of the line segments from its Centre (geometry), center to its perimeter, and in more modern usage, it is also their length. The radius of a regular polygon is th ...

of the circle of motion for any given water molecule decreases with depth. The maximum depth of influence of a water wave is half the

wavelength In physics and mathematics, wavelength or spatial period of a wave or periodic function is the distance over which the wave's shape repeats. In other words, it is the distance between consecutive corresponding points of the same ''phase (waves ...

. Below that depth the water remains stationary as the wave passes. For instance, in a pool of water deep, a wave with a wavelength of would not be able to cause water movement on the bottom. However, a wave with a wavelength would be moving the water (barely) at the bottom.

References

Physical oceanography Wave mechanics {{Ocean-stub

Process

Depth of influence

See also

References