B
BEACH
Charles W. Finkl
Department of Geosciences, Florida Atlantic University,
Boca Raton, FL, USA
The Coastal Education and Research Foundation,
Coconut Creek, FL, USA
Synonyms
Bank; Beachfront; Coast; Lakeshore; Lakeside; Littoral;
Margin; Oceanfront; Seaboard; Seafront; Seashore;
Seaside; Shingle; Shore; Strand; Waterfront
Definition
In the most rudimentary sense, a beach may be considered
a shore (see Coasts) covered by sand (e.g., Shepard,
1973), gravel (e.g., Carter and Orford, 1984; Jennings
and Shulmeister, 2002), or larger rock fragments (but
lacking bare rock surfaces). More specifically, Jackson
(1997) defines a beach as a relatively thick and transitory
accumulation of loose waterborne materials that are
mostly well-sorted sand and pebbles, but contains admixtures of mud, cobbles, boulders, smoothed rock, and shell
fragments. The term was originally used in a scientific
sense to designate loose waterworn shingle or pebbles on
English shores (Johnson, 1919). Today, beaches are
defined in a wider geomorphological sense as having subaerial and submarine components that are systematically
interrelated. The beach system includes the dry
(subaerial) beach, the wet beach (swash or intertidal zone),
the surf zone, and the nearshore zone lying beyond the
breakers (Short, 2006). Mostly the nearshore zone is
defined as the area beginning from the low-water line
extending seaward. The surf zone is part of the nearshore
zone. The subaerial beach has a gentle seaward slope,
typically with a concave profile, and extends from the
low-water mark landward to a place where there is a
change in material or physiography (such as a dune, bluff,
or cliff, or even a seawall) or to the line of permanent vegetation marked by the limit of highest storm waves or
surge. If the area beginning from the low-water line is
regarded, the profile is not concave when looking to a
beach with a certain tidal range. The dry beach is concave,
but at low water when including the wet beach, the morphology switches from a concave beach (dry part) to a
convex beach (wet part). Nearshore bars and troughs
(in the subtidal domain) are often present in the surf zone,
but are obscured by waves and surf, as is the always submerged nearshore zone (Short, 2006). Beach morphology
refers to the shape of the beach, surf, and nearshore zone.
The beach per se contains numerous morphological–
processual subunits such as berms, storm ridges (e.g.,
Zenkovich, 1967; Pethick, 1984; Komar, 1998; Davis
and FitzGerald, 2004), cusps, beach face, shoreface (e.g.,
Swift et al., 1985), plunge step (Davis and Fox, 1971),
scarp, etc.
Related features include beach plains, beach ridges, and
beachrock. Beach plains are level or gently undulating
areas formed by closely spaced successive embankments
of wave-deposited materials added to a prograding shoreline (Jackson, 1997). Beach ridges are low mounds of
beach or beach-and-dune materials (sand, gravel, shingle)
accumulated by waves on the backshore beyond the present limit of storm waves or ordinary tides. Beach ridges
are roughly parallel to the shoreline and mark prior positions of an advancing shoreline (Jackson, 1997).
Beachrock is a friable to well-cemented sedimentary rock
formed in the intertidal zone in a tropical or subtropical
region. Beachrock formations, which slope gently seaward on the beach face, consist of sand or gravel (detrital
and skeletal) cemented with calcium carbonate.
J. Harff et al. (eds.), Encyclopedia of Marine Geosciences, DOI 10.1007/978-94-007-6238-1,
© Springer Science+Business Media Dordrecht 2016
BEACH
Charles W. Finkl
Department of Geosciences, Florida Atlantic University,
Boca Raton, FL, USA
The Coastal Education and Research Foundation,
Coconut Creek, FL, USA
Synonyms
Bank; Beachfront; Coast; Lakeshore; Lakeside; Littoral;
Margin; Oceanfront; Seaboard; Seafront; Seashore;
Seaside; Shingle; Shore; Strand; Waterfront
Definition
In the most rudimentary sense, a beach may be considered
a shore (see Coasts) covered by sand (e.g., Shepard,
1973), gravel (e.g., Carter and Orford, 1984; Jennings
and Shulmeister, 2002), or larger rock fragments (but
lacking bare rock surfaces). More specifically, Jackson
(1997) defines a beach as a relatively thick and transitory
accumulation of loose waterborne materials that are
mostly well-sorted sand and pebbles, but contains admixtures of mud, cobbles, boulders, smoothed rock, and shell
fragments. The term was originally used in a scientific
sense to designate loose waterworn shingle or pebbles on
English shores (Johnson, 1919). Today, beaches are
defined in a wider geomorphological sense as having subaerial and submarine components that are systematically
interrelated. The beach system includes the dry
(subaerial) beach, the wet beach (swash or intertidal zone),
the surf zone, and the nearshore zone lying beyond the
breakers (Short, 2006). Mostly the nearshore zone is
defined as the area beginning from the low-water line
extending seaward. The surf zone is part of the nearshore
zone. The subaerial beach has a gentle seaward slope,
typically with a concave profile, and extends from the
low-water mark landward to a place where there is a
change in material or physiography (such as a dune, bluff,
or cliff, or even a seawall) or to the line of permanent vegetation marked by the limit of highest storm waves or
surge. If the area beginning from the low-water line is
regarded, the profile is not concave when looking to a
beach with a certain tidal range. The dry beach is concave,
but at low water when including the wet beach, the morphology switches from a concave beach (dry part) to a
convex beach (wet part). Nearshore bars and troughs
(in the subtidal domain) are often present in the surf zone,
but are obscured by waves and surf, as is the always submerged nearshore zone (Short, 2006). Beach morphology
refers to the shape of the beach, surf, and nearshore zone.
The beach per se contains numerous morphological–
processual subunits such as berms, storm ridges (e.g.,
Zenkovich, 1967; Pethick, 1984; Komar, 1998; Davis
and FitzGerald, 2004), cusps, beach face, shoreface (e.g.,
Swift et al., 1985), plunge step (Davis and Fox, 1971),
scarp, etc.
Related features include beach plains, beach ridges, and
beachrock. Beach plains are level or gently undulating
areas formed by closely spaced successive embankments
of wave-deposited materials added to a prograding shoreline (Jackson, 1997). Beach ridges are low mounds of
beach or beach-and-dune materials (sand, gravel, shingle)
accumulated by waves on the backshore beyond the present limit of storm waves or ordinary tides. Beach ridges
are roughly parallel to the shoreline and mark prior positions of an advancing shoreline (Jackson, 1997).
Beachrock is a friable to well-cemented sedimentary rock
formed in the intertidal zone in a tropical or subtropical
region. Beachrock formations, which slope gently seaward on the beach face, consist of sand or gravel (detrital
and skeletal) cemented with calcium carbonate.
J. Harff et al. (eds.), Encyclopedia of Marine Geosciences, DOI 10.1007/978-94-007-6238-1,
© Springer Science+Business Media Dordrecht 2016