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Term Description
SAC Special Area of Conservation
Salinity The inorganic ionic solutes (salts) present seawater
Salinity (S) The total amount of solid material in grams contained in 1 kilogram of sea water when all the carbonate has been converted to oxide, the bromine and iodine replaced by chlorine, and all organic matter completely oxidized. S(‰) = 1.806,55 x Cl (‰) Where Cl(‰) is chlorinity in parts per thousand.
Saltmarshes Flat areas of finely deposited silts that are occasionally inundated by seawater  and dominated by salt tolerant (halophytic) communities of plants. Located in the intertidal zone.
SAM Scheduled Ancient Monument
Sea Level Rise The long-term trend in mean sea level
Sea Waves Waves in coastal waters resulting from the interaction of different wave trains and locally generated waves. Typically, sea waves are of short wave length and of disordered appearance
Sediment transport The transportation of sedimentary particles by water or air
Seiche A stationary wave usually caused by strong winds and/or changes in barometric pressure. Found in lakes, semi enclosed bodies of water, and in areas of the open ocean.
Semidiurnal Having a period or cycle of approximately one-half of a day
Shallow water Water of such a depth that surface waves are noticeably affected by bottom topography. Typically a water depth equivalent to less than half the wavelength.
Shingle A loose term for coarse beach material, a mixture of gravel, pebbles and larger material, often well-rounded and of hard rock (e.g. chert, flint, etc) with a modal grain size exceeding 5 mm.
Shoaling The influence of the seabed on wave behaviour resulting in a reduction in wave speed, a shortening in wave length and an increase in wave height.
Shoreline The interface between land and sea.
Shoreline management The development of strategic, long-term and sustainable coastal defence policy. Can also relate to managing the natural environment in terms of it's habitat and biodiversity.
Side-scan sonar A geophysical technique for recording the texture and morphology of the seabed.
Significant wave height The average height of the highest one-third of the waves in a given Sea State.
Silt Sediment particles with a grain size between 0.004 mm and 0.062 mm, i.e. coarser than clay particles but finer than sand.
SINC Sites of Importance for Nature Conservation
Slack water (slack) The period of low or zero current speed near the time of turning of the current between flood and ebb tides.
SLR Sea Level Rise
SMP Shoreline Management Plan
Soft defences Usually refers to beaches (natural or man-made) but may also relate to energy-absorbing beach-control structures, including those constructed of rock, where these are used to control or redirect coastal processes rather than opposing or preventing them. In contrast to hard defences such as concrete sea walls.
Solar tide The part of the tide that is due to the tide-producing force of the Sun.
SPA Special Protection Area
Spatial Variability within space.
Spilling Waves The wave crest breaks gradually as the wave travels to the shore. Characterised by the appearance of white water at the crest.
Spit A narrow accumulation of sand or shingle, lying generally in line with the coast, with one end attached to the land, the other projecting into the sea or across the mouth of an estuary .
Spring tide Tides over a 14 day period with highest tidal range between high and low water
Spring tides or tidal currents Tides of increased range or tidal currents of increased speed occurring semi-monthly as the result of the Moon being new or full.
SSSI Site of Special Scientific Interest
Stand of tide An interval at high or low water when there is no change in the height of the tide (see slack water).
Steady state Condition that is maintained over some time interval even though there are fluctuations taking place over shorter time intervals
Still-water level (SWL) The water level that would exist in the absence of waves.
Storm Event Period of high wave activity.
Storm surge The local change in the elevation of the ocean along a shore due to a storm.  Normally associated with a decrease in atmospheric pressure. It typically has a duration of a few hours.
Stratification Vertical layering or structure of a substance within the water column.
Stratigraphy The study of stratified rocks especially their sequence in time, character of the rocks and the correlation of beds in different localities.
Sublittoral see subtidal.
Sublittoral Along the shore, below the reach of lowest tide and out to the limit of wave activity
Substrate The base on which an organism lives and grows.
Subtidal Depths below the lowest reach of the tide.
Surf Beat Periodic rise and fall in coastal water levels caused by two or more wave trains arriving at the shoreline.
Surf Zone Coastal waters between the breaker zone and the swash zone characterised by broken swell waves moving shorewards in the form of bores. Typically in water depths of 5-10 m.
Surficial Of, or pertaining to, a surface, e.g. of a beach or the seabed.
Surging Waves The wave does not "break" but maintains its basic shape as it moves towards the shore, where it surges up the beach. Very little white water is evident before surging waves reach the shore.
Suspended load A mode of sediment transport in which the particles are supported and carried along by the fluid.
Swash Zone That area of the shoreline characterised by regularly spaced wave crests.
Swell (waves) Remotely wind-generated waves.  Swell characteristically exhibits a more regular and longer period and has longer crests than locally generated waves.

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Last Modified on: 14 December 2023
Printed from the Estuary Guide on 18/06/2024 12:09:20