A Glossary of Beach Terms

Have you ever heard a term while you’re at the beach and weren’t sure what it meant? Earth 911 has compiled the most extensive glossary on the Web of beach terms so you’ll be in the know the next time you “hang 10″ or “soak up the sun.” For even more beach information, including beach and water quality advisories, visit Earth 911’s sister site, Beaches 911.

A

Anadromous — Fish that spend most of their lives in the ocean, coming back to freshwater only to spawn, such as salmon, trout, and smelt.

B

Backwash — See Swash

Bank — Land sloping down to a river or body of water smaller than a lake

Base flood — Flood that has a one percent probability of being equaled or exceeded in any given year (aka the 100-year flood)

Beach replenishment — Replacement of beach sand removed by ocean waters by trucking in new sand, dredging and returning the off-shore sand, or substituting artificial sands made from recycled glass

Break — Colloquial or alternate name for a popular surfing location, often for reasons no longer obvious to visitors, and not indicated on maps

Bulkhead — Wall or other structure, often made of wood, steel, stone or concrete, designed to retain or prevent sliding or erosion of the land (occasionally they are used to protect against wave action)

C

Coast — That part of an island or continent that borders an ocean or its saltwater tributaries

Coastal barrier — Geologic feature such as a bay barrier, barrier spit or barrier island that protects beach aquatic habitats from direct wave attack

Coastal erosion — See Erosion

D

Debris — Solid objects or masses carried by or floating on the surface of moving water

Debris line — See Wrack Line

Dune — See Frontal dune and Primary frontal dune

Dune toe — Junction of the gentle slope seaward of the dune and the dune face, which is marked by a slope of 1 on 10 or steeper

E

Ebb tide — The time period after high tide until low tide; often referred to as the time that the “tide is going out”

Encroachment — Any physical object placed in a floodplain that hinders the passage of water or otherwise affects the water flows

Episodic erosion — Erosion induced by a single storm event, which involves two factors: general beach profile lowering and localized conical scour around foundation supports like pier pilings; episodic erosion is relevant to foundation embedment depth and potential undermining (See Erosion, Scour)

Erosion — The process of wearing away of land masses, generally involving the detachment and movement of sand and rock fragments through the action of wind, water or other geologic processe; usually this is a gradual process, but it can happen rapidly during a flood or storm (See Episodic erosion, Scour)

Erosion analysis — Analysis of the short- and long-term erosion potential of soil or strata, including the effects of flooding or storm surge, moving water, wave action and the interaction of water and structural components

Estuary — The complex ecosystem of brackish waters where fresh water mixes with near-shore ocean waters, including river mouths, bays, salt marshes, wetlands and lagoons

F

Fetch — Distance over which wind acts on the water surface to generate waves

Flood-related erosion area or Flood-related erosion-prone area — A land area adjoining the shore of a lake or other body of water, which due to the composition of the shoreline or bank and high water levels or wind-driven currents, is likely to suffer flood-related erosion damage

Flood tide — The time period after low tide until high tide. This is often referred to as the time that the “tide is coming in”

Flood — Either a general and temporary condition or partial or complete inundation of normally dry land areas from the overflow of inland or tidal waters caused by the unusual and rapid accumulation or runoff of surface waters from any source

Frontal dune — Ridge or mound of unconsolidated sandy soil, extending continuously alongshore landward of the sand beach and defined by relatively steep slopes abutting markedly flatter and lower regions on each side

J

Jetty — Wall built out into the water to restrain currents or protect a structure

L

Levee — Artificial earthen dam intended to retain the water of a river or pond

Littoral — Of or pertaining to the shore, especially of the sea; coastal

Littoral drift — Movement of sand by littoral (alongshore) currents in a direction parallel to the beach along the shore

M

Marsh — Wetland dominated by plants with soft rather than woody tissues, often developing in shallow ponds, tidal areas and estuaries

Microcystins — A group of liver toxins produced by a number of cyanobacterial genera, the most notable of which is the widespread Microcystis from which the toxins take their name

Mitigation — Action taken to reduce or eliminate risk to life and property from natural or man-made hazards

Mooring — Permanent watercraft fastener or anchor used in harbors to reduce damage to coral reefs and to manage harbor space

Mudslide or Mudflow — 1) a river or sheet flow of liquid mud on the surfaces of normally dry land areas, as when earth is carried by a current of water and deposited along the path of the current, or 2) the collapse or subsidence of land along the shore of a lake or other body of water as a result of an unusual level of erosion or undermining caused by waves or currents of water exceeding anticipated levels; can be caused by an unusually high water level in a natural body of water, a severe storm, flash flood or abnormal tidal surge

P

Pelagic coast — A coast which adjoins the open ocean, as opposed to a more sheltered gulf coast or bay coast

R

Recreational — Use of time for entertainment and refreshment of body and mind by means of some pastime, agreeable exercise or other means affording relaxation and enjoyment

Recycle — To use discarded material for another purpose

Riparian — Pertaining to a river or river bank environment

Rip currents — A strong current of water returning seaward from near the shore, caused by sandbars diverting the return flow of water to breaks as they develop in the sandbar

Rip tide — See Rip currents

Riprap — Broken stone, cut stone blocks or rubble that is placed on slopes to protect them from erosion or scour caused by flood waters or wave action

Runoff — Water that does not get soaked into the ground from rain, snow melt, or spills that washes the surface of the ground to surface water.

S

Salp — A free-floating, saclike filter feeder with incurrent and outcurrent siphons that are used to move it through the water, which is important in the sequestering of carbon to mitigate climate change but can result in slimy mats of dead salp bodies on the beach

Sandbar — An offshore ridge or mound which is caused by wave action and submerged (at least at high tide) near the shoreline; they are very mobile and rarely charted

Sand dunes — Natural or artificial ridges or mounds of sand landward of the beach

Scour — Removal of soil or fill material by the flow of floodwaters; frequently used to describe storm-induced, localized conical erosion around pilings and other foundation supports where the obstruction of flow increases turbulence (See Episodic Erosion)

Seawall — Solid barricade built at the water’s edge to protect the shore and to prevent inland flooding

Sets — Colloquial term used by surfers to describe a series of better-than-average waves that break one after one another

Shore — Land which adjoins ocean and lakes

Shoreline retreat — Progressive movement of the shoreline in a landward direction caused by the composite effect of all storms considered over decades and centuries (expressed as an annual average erosion rate); considers the horizontal component of erosion and is relevant to long-term land use decisions and building

Spit — A type of beach, or bar, that has formed by the movement and accumulation of sediment; typically forms at points along littoral currents when the coast turns inwards, and the current can no longer handle the amount of sediment it was transporting

Stillwater elevation — Projected elevation that flood waters would assume, referenced to the National Geodetic Vertical Datum, North American Vertical Datum or other datum, in the absence of waves resulting from wind or seismic effects

Storm surge — Rise in the water surface above normal water level on the open coast due to the action of wind stress and atmospheric pressure on the water surface

Storm tide — The combined effect of storm surge, existing astronomical tide conditions, and breaking wave setup

Surf — 1) The wave activity occurring on a beach inshore of the point at which incoming waves break; consists of waves that have broken and therefore have air to some degree mixed in with the water, resulting in a lighter color of water, 2) Riding the surf with a surfboard for sport or pleasure

Surge — See Storm surge

Swale — A shallow natural depression or wide shallow ditch used to convey, store or filter runoff

Swash — the intermittent flow of water washing on shore, driven by the action of breaking waves

T

Tide — The regular rise and fall of the ocean surface caused by changes in gravitational forces outside of the Earth; primary influence is the Moon, but the Sun’s gravity also exerts some influence

Tide tables — Tables predicting the local high tide and low tide times and the water level height of each as compared to the Mean Lower Low Water (MLLW) height

U

Undertow — See Rip currents

W

Wave — Ridge, deformation or undulation of the water surface

Wave height — Vertical distance between the wave crest and wave trough

Wave runup — Rush of wave water up a slope or structure

Wave setup — Increase in the stillwater surface near the shoreline, due to the presence of breaking waves

Wrack — Algae, plant/animal matter and drift material (including solid wastes and other pollutants) that accumulate on beaches, usually at the high tide mark

Wrack line — A row of debris running parallel to the shore, cast ashore and stranded by the last high tide