What phenomenon is described by the creation of layers in a water body due to density differences?

The phenomenon of creating layers in a water body due to density differences is known as density stratification. This occurs when water at varying temperatures and salinities forms distinct layers because denser water tends to sink below less dense water. For instance, when warm water sits on top of colder water, the temperature difference creates a stratified layer, with warmer, less dense water above the colder, denser water. These layered structures can significantly influence the distribution of nutrients, oxygen levels, and aquatic life within the water body, as each layer can have different characteristics.

In contrast, the diel cycle refers to the regular pattern of changes in biological or chemical processes that occur over the course of a day, often linked to the presence of sunlight. Dissolution involves the process of a solute dissolving in a solvent, which does not inherently lead to layering based on density. Diffusion, on the other hand, is the movement of particles from an area of higher concentration to an area of lower concentration, which does not specifically refer to the stratification of layers based on density but rather the mixing of substances.