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Accretion - Accumulation of sand or other beach material at a point due to natural action of waves, currents and wind. A build-up of the beach.
Alongshore - Parallel to and near the shoreline; same as LONGSHORE.
Backhoe - Excavator similar to a power shovel except that the bucket faces the operator and is pulled toward him.
Bar - Fully or partly submerged mound of sand, gravel, or other unconsolidated material built on the bottom in shallow water by waves and currents.
Beach - Zone of sand or gravel extending from the low water line to a point landward where either the topography abruptly changes or permanent vegetation first appears.
Beach Fill - Sand or gravel placed on a beach by mechanical methods.
Beach, Perched - See PERCHED BEACH.
Bluff - High, steep bank at the water's edge. In common usage, a bank composed primarily of soil. See CLIFF.
Boulders - Large stones with diameters over 10 inches. Larger than COBBLES.
Breaker - A wave as it spills, plunges or collapses on a shore, natural obstruction, or man-made structure.
Breaker Zone - Area offshore where waves break.
Breaking Depth - Stillwater depth where waves break.
Breakwater - Structure aligned parallel to shore, sometimes shore connected, that provides protection from waves.
Bulkhead - A structure that retains or prevents sliding of land or protects the land from wave damage.
Clay - Extremely fine-grained soil with individual particles less than 0.00015 inches in diameter.
Cliff - High steep bank at the water's edge. In common usage, a bank composed primarily of rock. See BLUFF.
Cobbles - Rounded stones with diameters ranging from 3 to 10 inches. Cobbles are intermediate between GRAVEL and BOULDERS.
Crest - Upper edge or limit of a shore protection structure.
Cross Section - View of a structure or beach as if it were sliced by a vertical plane. The cross section should display structure, ground surface, and underlying material.
Culm - Single stem of grass.
Current - Flow of water in a given direction.
Current, Longshore - Current in the breaker zone moving essentially parallel to shore and usually caused by waves breaking at an angle to shore. Also called alongshore current.
Deep Water - Area where surf ace waves are not influenced by the bottom. Generally, a point where the depth is greater than one-half the surface wavelength.
Diffraction- Progressive reduction in wave height when a wave spreads into the shadow zone behind a barrier after the wave has passed its end.
Diurnal - Period or cycle lasting approximately one day. A diurnal tide has one high and one low in each cycle.
Downdrift - Direction of alongshore movement of littoral materials.
Dune - Hill, bank, bluff, ridge, or mound of loose, wind-blown material, usually sand.
Duration - Length of time the wind blows in nearly the same direction across a FETCH (generating area).
Ebb Tide - Part of the tidal cycle between high water and the next low. The falling tide.
Equilibrium - State of balance or equality of opposing forces.
Erosion - Wearing away of land by action of natural forces.
Fetch - Area where waves are generated by wind, which has steady direction and speed. Sometimes called FETCH LENGTH.
Fetch Length - Horizontal direction (in the wind direction) over which a wind generates waves. In sheltered waters, often the maximum distance that wind can blow across water.
Filter Cloth - Synthetic textile with openings for water to escape, but which prevents passage of soil particles.
Flood Tide - Part of the tidal cycle between low water and the next high. The rising tide.
Glacial Till - Unstratified glacial drift consisting of unsorted clay, sand, gravel, and boulders, intermingled.
Longshore - Parallel to and near the shoreline: same as ALONGSHORE.
Longshore Transport Rate - Rate of transport of littoral material parallel to shore. Usually expressed in cubic yards per year.
Low Tide - Minimum elevation reached by each falling tide.
Low Water Datum (LWD) - The elevation of each of the Great Lakes to which are referenced the depths shown on navigation charts and the authorized depths of navigation projects.
Marsh - Area of soft, wet, or periodically inundated land, generally treeless, and usually characterized by grasses and other low growth.
Mean Higher High Water (MHHW) - Average height of the daily higher high waters over a 19-year period. Only the higher high water of each pair of high waters of a tidal day is included in the mean.
Mean High Water (MHW) - Average height of the daily high waters over a 19-year period. For semidiurnal or mixed tides, the two high waters of each tidal day are included in the mean. For diurnal tides, the single daily high water is used to compute the mean.
Mean Lower Low Water (MLLW) - Average height of the daily lower-low waters of a 19-year period. Only the lower low water of each pair of low waters of a tidal day is included in the mean. Long used as the datum for Pacific coast navigation charts, it is now gradually being adopted for use across the United States.
Mean Low Water (MLW) - Average height of the low waters over a 19-year period. For semidiurnal and mixed tides, the two low waters of each tidal day are included in the mean. For a diurnal tide, the one low water of each tidal day is used in the mean. Mean Low Water has been used as datum for many navigation charts published by the National Ocean Survey, but it is being phased out in favor of Mean Lower Low Water for all areas of the United States.
Mean Sea Level - Average height of the sea surface over a 19-year period. Not necessarily equal to MEAN TIDE LEVEL.
Mean Tide Level - Plane midway between MEAN HIGH WATER and MEAN LOW WATER. Not necessarily equal to MEAN SEA LEVEL. Also called half-tide level.
Mixed Tide - A tide in which there is a distinct difference in height between successive high and successive low waters. For mixed tides there are generally two high and two low waters each tidal day. Mixed tides may be described as intermediate between semidiurnal and diurnal tides.
Module - A structural component, a number of which are joined to make a whole.
Neap Tides - Tides with decreased ranges that occur when the moon is at first or last-quarter- ;4nl in opposition to each other. The neap range is smaller than the mean range for semidiurnal and mixed tides.
Nearshore - In beach terminology, an indefinite zone extending seaward from the shoreline well beyond the breaker zone
Nourishment - Process of replenishing a beach either naturally by longshore transport or artificially by delivery of materials dredged or excavated elsewhere.
Offshore - (1) (Noun) In beach terminology, comparatively flat zone of variable width extending from the breaker zone to the seaward edge of the Continental Shelf. (2) (Adjective) Direction seaward from the shore.
Overtopping - Passing of water over a structure from wave runup or surge action.
Peat - Residual product produced by partial decomposition of organic matter in marshes and bogs.
Peat Pot (vegetation) - Pot formed from compressed peat and filled either with soil or peat moss in which a plant or plants, grown from seed, are transplanted without being removed from the pot.
Perched Beach - Beach or fillet of sand retained above the otherwise normal profile level by a submerged dike or sill.
Permeable - Having openings large enough to permit free passage of appreciable quantities of (1) sand or (2) water.
Pile - Long, heavy section of timber, concrete or metal driven or jetted into the earth or seabed as support or protection.
Pile, Sheet - Pile with a generally slender, flat cross section driven into the ground or seabed and meshed or interlocked with like members to form a diaphragm, wall, or bulkhead.
Piling - Group of piles.
Plug - Core containing both plants and underlying soil, usually cut with a cylindrical coring device and transplanted to a hole cut by the same device.
Polyvinyl Chloride (PVC) - Plastic material (usually black) that forms a resilient coating suitable for protecting metal from corrosion.
Profile, Beach - Intersection of the ground surface with a vertical plane that may extend from the top of the dune line to the seaward limit of sand movement.
PVC - See POLYVINYL CHLORIDE.
Ravelling - Progressive deterioration of a revetment under wave action.
Refraction (of water waves) - (1) Process by which direction of a wave moving in shallow water at an angle to the contours is changed. Part of the wave advancing in shallower water moves more slowly than the part still advancing in deeper water, causing the wave crest to bend toward alignment with the underwater contours. (2) Bending of wave crests by currents.
Revetment - Facing of stone, concrete, etc., built to protect a scarp, embankment, or shore structure against erosion by waves or currents.
Rhizome - Underground stem or root stock. New shoots are usually produced from the tip of the rhizome.
Riprap - Layer, facing, or protective mound of stones randomly placed to prevent erosion, scour, or sloughing of a structure or embankment; also, the stone so used.
Rubble - (1) Loose, angular, waterworn stones along a beach. (2) Rough, irregular fragments of broken rock or concrete.
Runup - The rush of water up a structure or beach on breaking of a wave. Amount of runup is the
vertical height above stillwater level that the rush of water reaches.
Sand - Generally, coarse-grained soils having particle diameters between 0.18 and approximately 0.003 inches. Sands are intermediate between SILT and GRAVEL.
Sandbag - Cloth bag filled with sand or grout and used as a module in a shore protection device.
Sand Fillet - Accretion trapped by a groin or other protrusion in the littoral zone.
Scour - Removal of underwater material by waves or currents, especially at the base or toe of a shore structure.
Screw Anchor - Type of metal anchor screwed into the bottom for holding power.
Seawall - Structure separating land and water areas primarily to prevent erosion and other damage by wave action. See also BULKHEAD.
Semidiurnal Tide - Tide with two high and two low waters in a tidal day, each high and each low approximately equal in stage.
Setup, Wind - Vertical rise in the Stillwater level on a body of water caused by piling up of water on the shore due to wind action. Synonymous with wind tide and STORM SURGE. STORM SURGE usually pertains to the ocean and large bodies of water. Wind setup usually pertains to reservoirs and smaller bodies of water.
Shallow Water - Commonly, water of such a depth that surface waves are noticeably affected by bottom topography. It is customary to consider water of depths less than one-twentieth the surface wavelength as shallow water.
Sheet Pile - see PILE, SHEET.
Shoot - Collective term applied to the STEM and leaves, or any growing branch or twig.
Shore - Narrow strip of land in immediate contact with the sea, inc uding the zone between high and low water lines. A shore of unconsolidated material is usually called a beach.
Shoreline - intersection of a specified plane of water with the shore or beach (e.g., the high water shoreline would be the intersection of the plane of mean high water with the shore or beach). Line delineating the shoreline on National Ocean Survey nautical charts and surveys approximates the mean high water line.
Sill - Low offshore barrier structure whose crest is usually submerged, designed to retain sand on its landward side.
Silt - Generally refers to fine-grained soils having particle diameters between 0.003 and 0.00015 inches. Intermediate between CLAY and SAND.
Slope - Degree of inclination to the horizontal. Usually expressed as a ratio, such as 1:25 or 1 on 25, indicating 1-unit vertical rise in 25 units of horizontal distance; or in degrees from horizontal.
Specifications - Detailed description of particulars, such as size of stone , quality of materials, contractor performance, terms, and quality control.
Sprig - Single plant with its roots relatively bare, as pulled apart from a clump and used for transplanting.
Stem - Main axis of a plant, leaf-bearing and flower-bearing, as distinguished from the root-bearing axis.
Stillwater Level - Elevation that the surface of the water would assume if all wave action were absent.
Storm Surge - Rise above normal water level on the open coast due to action of wind on the water surface. Storm surge resulting from a hurricane also includes the rise in level due to atmospheric pressure reduction as well as that due to wind stress. See SETUP, WIND.
Swell - Wind-generated waves travelling out of their generating area. Swell characteristically exhibits a more regular and longer period, and has flatter crests than waves within their fetch.
Tidal Ranqe - Difference in height between consecutive high and low or higher high and lower low) waters. The mean range is the difference in height between mean high water and mean low water. The diurnal range is the difference in height between mean higher high water and mean lower low water. For diurnal tides, the mean and diurnal range are identical. For semidiurnal and mixed tides, the spring range is the difference in height between the high and low waters during the time of spring tides.
Tide - Periodic rising and falling of water resulting from gravitational attraction of the moon, sun and other astronomical bodies acting upon the rotating earth. Although the accompanying horizontal movement of the water resulting from the same cause is also sometimes called tide, it is preferable to designate the latter as tidal current, reserving the name TIDE for vertical movement.
Tide Station - Place at which tide observations are being taken. A primary tide station is a location where continuous observations are taken over a number of years to obtain basic tidal data for the locality. A secondary tide station is operated over a short period of time to obtain data for a specific purpose.
Tie Rod - Steel rod used to tie back the top of a bulkhead or seawall. Also, a U-shaped rod used to tie Sandgrabber blocks together, or a straight rod used to tie Nami Rings together.
Tiller - A plant SHOOT which springs from the root or bottom of the original plant stalk.
Topography - Configuration of a surface, including relief, position of streams, roads, buildings, etc.
Transplant - SHOOT or CULM removed from one location and replanted in another.
Trough of Wave - Lowest part of a waveform between successive crests. Also, that part of a wave below stillwater level.
Updrift - Direction opposite the predominant movement of littoral materials in longshore transport.
Wake (boat) - Waves generated by the motion of a vessel through water.
Wale - Horizontal beam on a bulkhead used to laterally transfer loads against the structure and hold it in a straight alignment.
Waterline - Juncture of land and sea. This line migrates, changing with the tide or other fluctuation in water level. Where waves are present on the beach, this line is also known as the limit of backrush. (Approximately, the intersection of land with Stillwater level.)
Wave - Ridge, deformation, or undulation of the surface of a liquid.
Wave Climate - Normal seasonal wave regimen along a shoreline.
Wave Crest - Highest part of a wave or that part above stillwater level.
Wave Diffraction - See DIFFRACTION.
Wave Direction - Direction from which a wave approaches.
Wave Height - Vertical distance between a crest and the preceding trough.
Wavelength - Horizontal distance between similar points on two successive waves measured perpendicular to the crest.
Wave Period - Time in which a wave crest traverses a distance equal to one wavelength. Time for two successive wave crests to pass a fixed point.
Wave Refraction - See REFRACTION (of water waves).
Wave Steepness - Ratio of wave height to wavelength.
Wave Trough - Lowest part of a wave form between successive crests. Also, that part of a wave below that part of a wave below Stillwater level.
Weep Hole - Hole through a solid revetment, bulkhead, or seawall for relieving pore pressure.
Wind Setup - See SETUP, WIND.
Windward - Direction from which wind is blowing.
Wind Waves - (1) Waves being formed and built up by wind. (2) Loosely, any waves generated by wind.