Beach

A beach, or strand, is a
geological
landform
consisting of loose

rock particles - such as
sand,
gravel,

shingle,
pebbles,
cobble - or even
shell
fragments, along the
shoreline of a
body of water. Beaches occur along coastal areas, where

wave or

current action

deposits and reworks sediments, or at the margin of land along a
lake or
river subject
to erosion caused by rainfall. Beaches are not necessarily found in
conjunction with salt water, such as the ocean, in all instances. A
seashore
beach is merely one type of beach but it is the most commonly associated with
the perception of the word "beach".

Components

Some geologists consider a beach to be merely a shoreline feature of
deposited material, but William Bascom (1980) has argued that a beach is the
entire system of sand set in motion by waves to a depth of ten meters (30+
feet) or more off ocean coasts. Submerged, longshore bars are therefore also
part of the beach, and thus beaches can be viewed as either:

• small systems in which the rock material moves onshore, offshore, or
  alongshore by the forces of waves and currents; or


• geological units of considerable size.

The former are described in detail below; the larger geological units are
discussed elsewhere under

bars.

There are several conspicuous parts to a beach, all of which relate to the
processes that form and shape it. The part mostly above water (depending upon
tide), and more or less actively influenced by the waves at some point in the
tide, is termed the beach berm. The berm is the deposit of material
comprising the active shoreline. The berm has a crest (top) and a
face — the latter being the slope leading down towards the water from the
crest. At the very bottom of the face, there may be a trough, and
further seaward one or more longshore bars: slightly raised, underwater
embankments formed where the waves first start to break.

The sand deposit may extend well inland from the berm crest, where
there may be evidence of one or more older crests (the storm beach)
resulting from very large storm waves and beyond the influence of the normal
waves. At some point the influence of the waves (even storm waves) on the
material comprising the beach stops, and if the particles are small enough
(sand size or smaller), winds shape the feature. Where wind is the force
distributing the grains inland, the deposit behind the beach becomes a
dune.

The line between beach and dune is difficult to define in the field. Over
any significant period of time, sand is always being exchanged between them.
The drift line (the high point of material deposited by waves) is one
potential demarcation. This would be the point at which significant wind
movement of sand could occur, since the normal waves do not wet the sand
beyond this area. However, the drift line is likely to move inland under
assault by storm waves.

Beach formation

Beaches are

deposition
landforms,
and are the result of wave action by which
waves or

currents move sand or other loose
sediments
of which the beach is made as these particles are held in

suspension. Alternatively, sand may be moved by

saltation (a bouncing movement of large particles). Beach materials
come from erosion of rocks offshore, as well as from headland
erosion and
slumping
producing deposits of
scree. Some of
the whitest sand in the world, along Florida's

Emerald Coast, comes from the erosion of quartz in the Appalachian
Mountains. A coral
reef offshore is a significant source of sand particles.

The shape of a beach depends on whether or not the waves are constructive
or destructive, and whether the material is sand or shingle. Constructive
waves move material up the beach while destructive waves move the material
down the beach. On sandy beaches, the backwash of the waves removes material
forming a gently sloping beach. On shingle beaches the swash is dissipated
because the large particle size allows percolation, so the backwash is not
very powerful, and the beach remains steep. Cusps and horns form where
incoming waves divide, depositing sand as horns and scouring out sand to form
cusps. This forms the uneven face on some sand shorelines.

There are several beaches which are claimed to be the "World's longest",
including
Cox's
Bazar, Bangladesh (120kms),

Fraser Island beach,

90 Mile Beach in Australia and

90 Mile Beach in New Zealand and

Long Beach, Washington (which is about 30km).

Wasaga Beach, Ontario on

Georgian Bay claims to have the world's longest freshwater beach. But the
longest beach in the world is in fact

Praia do Cassino, a 240km long beach located in southern Brazil, near the
border with Uruguay.

Beaches and recreation

Recreation on a California beach in the first decade of the 20th
century

A surfer
carries a

surfboard along the beach

In the

Victorian era, many popular beach resorts were equipped with

bathing machines because even the all-covering
beachwear
of the period was considered immodest. This social standard still prevails in
many Muslim
countries. At the other end of the spectrum are

clothing-optional beaches, where swimwear and other forms of clothing are
optional.

A walk along the beach is also popular, including a long walk in the case
of a long beach, for example from one seaside resort to the next. It is
customary for people to walk
barefoot
to the beach, because of the pleasant feeling of sand on their soles and
between their toes. The best beach walking areas typically are near the
shoreline, where the sand is wet and more comfortable to walk in. A person
will also enjoy walking with their bare feet in the water.

In more than thirty countries in Europe,
South
Africa,
New
Zealand,
Canada,
Costa
Rica,

South America and the
Caribbean,
the best recreational beaches are awarded

Blue Flag status, based on such criteria as water quality and safety
provision. Subsequent loss of this status can have a severe effect on tourism
revenues.

Due to intense use by the

expanding human population, beaches are often dumping grounds for
waste and
litter, necessitating the use of

beach cleaners and other cleanup projects. More significantly, many
beaches are a discharge zone for untreated sewage in most

underdeveloped countries; even in

developed countries beach closure is an occasional circumstance due to

sanitary sewer overflow. In these cases of marine discharge, waterborne
disease
from fecal
pathogens
and contamination of certain marine species is a frequent outcome.

Artificial beaches

Some beaches are artificial; they are either permanent or temporary (For
examples see
Monaco, Paris,
Rotterdam,Toronto,

Hong Kong and

Singapore).

The soothing qualities of a beach and the pleasant environment offered to
the beach goer are replicated in artificial beaches, such as "beach style"
pools with zero-depth entry and wave pools that recreate the natural waves
pounding upon a beach. In a zero-depth entry pool, the bottom surface slopes
gradually from above water down to depth. Another approach involves so-called
urban
beaches, a form of public
park becoming
common in large cities. Urban beaches attempt to mimic natural beaches with
fountains that imitate surf and mask city noises, and in some cases can be
used as a play park.

Beach nourishment involves pumping sand onto beaches to improve their
health. Beach nourishment is common for major beach cities around the world;
however the beaches that have been nourished can still appear quite natural
and often many visitors are unaware of the works undertaken to support the
health of the beach. Such beaches are often not recognized as artificial.
Crabs are also often used to keep beaches free from trees.

A concept of IENCE has been devised to describe investment into the
capacity of natural environments. IENCE is Investment to Enhance the Natural
Capacity of the Environment and includes things like beach nourishment of
natural beaches to enhance recreational enjoyment and snow machines that
extend ski seasons for areas with an existing snow economy developed upon a
natural snowy mountain. As the name implies IENCE is not quite mainstream
natural science as its goal is to artificially invest into an environment's
capacity to support

anthropogenic economic activity. An

artificial reef designed to enhance wave quality for surfing is another
example of IENCE.

The Surfrider Foundation has debated the merits of

artificial reefs with members torn between their desire to support natural
coastal environments and opportunities to enhance the quality of surfing
waves. Similar debates surround

Beach nourishment and
Snow
cannon in sensitive environments.

Beaches as habitat

A beach is an unstable environment which exposes plants and animals to
changeable and potentially harsh conditions. Some small animals burrow into
the sand and feed on material deposited by the waves.
Crabs,
insects and
shorebirds
feed on these beach dwellers. The endangered

Piping Plover and some
tern species rely
on beaches for nesting.
Sea
turtles also lay their eggs on ocean beaches.
Seagrasses
and other beach plants grow on undisturbed areas of the beach and dunes.

Ocean beaches are habitats with organisms adapted to salt spray, tidal
overwash, and shifting sands. Some of these organisms are found only on
beaches. Examples of these beach organisms in the southeast US include plants
like sea oats, sea rocket, beach elder, beach morning glory, and beach peanut,
and animals such as mole crabs, coquina clams, ghost crabs, and white beach
tiger beetles.^[1]