Spur and groove formations are a
geomorphic feature of many
coral reef
A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups.
...
s. They are ridges of reef formed by
coral
Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and ...
"spurs" separated by channels "grooves" which often have sediment or rubble bed. Spur and groove formations vary in their size and distribution worldwide but are a common feature on many forereefs of
fringing reef
A fringing reef is one of the three main types of coral reef. It is distinguished from the other main types, barrier reefs and atolls, in that it has either an entirely shallow backreef zone (lagoon) or none at all. If a fringing reef grows direc ...
s,
barrier reefs, and
atolls
An atoll () is a ring-shaped island, including a coral rim that encircles a lagoon partially or completely. There may be coral islands or cays on the rim. Atolls are located in warm tropical or subtropical oceans and seas where corals can gro ...
which are exposed to moderate wave energy. Spur and groove formations are influenced by the incoming
surface wave
In physics, a surface wave is a mechanical wave that propagates along the interface between differing media. A common example is gravity waves along the surface of liquids, such as ocean waves. Gravity waves can also occur within liquids, at th ...
s, and the waves induce a circulation pattern of counter rotating circulation cells.
The alongshore shape of spur and groove formations varies from smoothly varying rounded spurs, to flat spurs with shallow rectangular grooves, or deeply cut rectangular or overhanging channels sometimes called buttresses. Spur and groove formations have typical scales of: spur height 0.5 to 10 m, alongshore wavelength 5 to 150 m, width of groove 1 to 100 m, and found in depths from 0 to 30 m. The mechanism for maintaining preferential coral growth on the spur is thought to be caused by higher wave stress on the spur which causes sediment to be shed towards the groove and downslope and preferential
coral
Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and ...
growth on the spur.
Thus, it is believed that spur and grooves are essentially constructional in formation, while a less important mechanism may occur from sediment scour in the grooves.
See also
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Coastal morphodynamics
Coastal morphodynamics (i.e. the dynamics of beach morphology) refers to the study of the interaction and adjustment of the seafloor topography and fluid hydrodynamic processes, seafloor morphologies and sequences of change dynamics involving t ...
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Coral reef
A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups.
...
*
Coastal geography
Coastal geography is the study of the constantly changing region between the ocean and the land, incorporating both the physical geography (i.e. coastal geomorphology, climatology and oceanography) and the human geography (sociology and history) ...
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Fringing reef
A fringing reef is one of the three main types of coral reef. It is distinguished from the other main types, barrier reefs and atolls, in that it has either an entirely shallow backreef zone (lagoon) or none at all. If a fringing reef grows direc ...
References
Coral reefs
Geomorphology
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