Seep

Seep is a term used to describe the slow escape of liquid, typically water, through small openings or porous materials. As a verb, seep means to leak gradually; as a noun, a seep is a place where liquid leaks to the surface. Seepage refers to the process of such leakage and to the liquid that emerges.

In hydrology and geology, seepage occurs when groundwater moves through soils or rock via pores, fractures, or other pathways. The rate of seepage depends on the hydraulic gradient, the permeability of the material, and the available surface area through which water can escape. Seeps can occur along hillsides, riverbanks, coastal cliffs, or near man-made structures such as tunnels and dam foundations. In engineering, seepage can pose issues by eroding soils or promoting internal piping, which may threaten stability if not managed.

Seeps also have ecological significance. They can create localized moisture sources that support distinct plant communities and microbial life. In marine environments, cold seeps emit methane and hydrogen sulfide from the seabed, supporting specialized communities of organisms and influencing geochemical cycles and sediment chemistry.

Distinctions are often made between seeps and springs. A seep typically implies slow, diffuse emergence of water, while a spring is a more continuous and more defined surface outflow where the water table intersects the ground surface. Seeps are commonly described by their flow rate, mineral content, and seasonal variation.