F
FAROES REEFS
Roger McLean
School of Physical, Environmental and Mathematical
Sciences, Canberra, ACT, Australia
Synonyms
Basin reefs; Faros; Little ring-shaped reefs; Mini-atolls;
Miniature atolls
Faro is a Maldivian name given to small atolls that rise
in the lagoons of large composite atolls, or, are found on
their rims (Agassiz, 1902). Despite his vast experience
of coral reefs in the Pacific and Caribbean, Agassiz
(Agassiz, Alexander (1835–1910)) said he had “seen nothing so striking” as “those remarkable rings which are so
characteristic a feature in Maldivian coral reef scenery”.
Classical faros are indeed striking, being perfectly circular
reefs, usually less than 3 or 4 km in diameter surrounding
a shallow secondary lagoon of depths generally less than
20 m. To J. S. Gardiner (Gardiner, John Stanley (1872–
1946)) such reefs were technically “little atolls” but where
a more precise term was necessary, he borrowed faro and
velu from the Maldivian, the former signifying a small
ring-shaped reef and the latter its central pond or basin.
Because faros rise from the lagoon floor and edges of
atolls, their mode of formation must differ from oceanic
atolls whose foundations extend to great ocean depths.
And yet there has been no substantive study of faros in
the Maldives, which contrary to popular belief do not
occur throughout the archipelago but are restricted to the
double chain of atolls in its central part, where there are
several hundred faros. The occurrence of circular or oval
faros within the lagoons appears to be related to two
factors: the presence of frequent or wide gaps or passes
through the atoll rim; and, to the alternating northeast
and southwest monsoons with reversals in swell and sea
waves and locally generated wind waves. Faros developed
on the peripheral rims themselves are rarely circular or
even occluded. Rather they are often elongated parallel
to the atoll edge, or are crescent- or horseshoe-shaped with
the convex side facing the open sea.
A number of faro reefs are surmounted by islands,
whose shape frequently mimics that of the parent reef.
Some islands are restricted to parts of the reef rim, especially on faro with deep velu. In other cases, infill from
sediments produced on the reef surface and transported
into the velu results in centrally located, often circular
islands (Kench et al., 2005).
While reefs that resemble Maldivian faros have been
described from elsewhere including Indonesian waters,
the northern Great Barrier Reef, and New Caledonia, the
terms faro and velu should be limited to reefs in the Maldives. Moreover, faros sensu strictu are not to be confused
with either micro atolls (Microatoll) or “oceanic faros”.
Bibliography
Agassiz, A., 1902. An expedition to the Maldives. American Journal of Science, 13, 297.
Gardiner, J. S., 1903: The Fauna and Geography of the Maldive and
Laccadive archipelagoes. Cambridge: Cambridge University
Press, Volume 1.
Kench, P. S., McLean, R. F., and Nichol, S., 2005. New model of
reef island evolution: Maldives, Indian Ocean. Geology, 33, 145.
Cross-references
Atolls
Maldives
Patch Reefs: Lidar Morphometric Analysis
David Hopley (ed.), Encyclopedia of Modern Coral Reefs, DOI 10.1007/978-90-481-2639-2,
# Springer Science+Business Media B.V. 2011
FAROES REEFS
Roger McLean
School of Physical, Environmental and Mathematical
Sciences, Canberra, ACT, Australia
Synonyms
Basin reefs; Faros; Little ring-shaped reefs; Mini-atolls;
Miniature atolls
Faro is a Maldivian name given to small atolls that rise
in the lagoons of large composite atolls, or, are found on
their rims (Agassiz, 1902). Despite his vast experience
of coral reefs in the Pacific and Caribbean, Agassiz
(Agassiz, Alexander (1835–1910)) said he had “seen nothing so striking” as “those remarkable rings which are so
characteristic a feature in Maldivian coral reef scenery”.
Classical faros are indeed striking, being perfectly circular
reefs, usually less than 3 or 4 km in diameter surrounding
a shallow secondary lagoon of depths generally less than
20 m. To J. S. Gardiner (Gardiner, John Stanley (1872–
1946)) such reefs were technically “little atolls” but where
a more precise term was necessary, he borrowed faro and
velu from the Maldivian, the former signifying a small
ring-shaped reef and the latter its central pond or basin.
Because faros rise from the lagoon floor and edges of
atolls, their mode of formation must differ from oceanic
atolls whose foundations extend to great ocean depths.
And yet there has been no substantive study of faros in
the Maldives, which contrary to popular belief do not
occur throughout the archipelago but are restricted to the
double chain of atolls in its central part, where there are
several hundred faros. The occurrence of circular or oval
faros within the lagoons appears to be related to two
factors: the presence of frequent or wide gaps or passes
through the atoll rim; and, to the alternating northeast
and southwest monsoons with reversals in swell and sea
waves and locally generated wind waves. Faros developed
on the peripheral rims themselves are rarely circular or
even occluded. Rather they are often elongated parallel
to the atoll edge, or are crescent- or horseshoe-shaped with
the convex side facing the open sea.
A number of faro reefs are surmounted by islands,
whose shape frequently mimics that of the parent reef.
Some islands are restricted to parts of the reef rim, especially on faro with deep velu. In other cases, infill from
sediments produced on the reef surface and transported
into the velu results in centrally located, often circular
islands (Kench et al., 2005).
While reefs that resemble Maldivian faros have been
described from elsewhere including Indonesian waters,
the northern Great Barrier Reef, and New Caledonia, the
terms faro and velu should be limited to reefs in the Maldives. Moreover, faros sensu strictu are not to be confused
with either micro atolls (Microatoll) or “oceanic faros”.
Bibliography
Agassiz, A., 1902. An expedition to the Maldives. American Journal of Science, 13, 297.
Gardiner, J. S., 1903: The Fauna and Geography of the Maldive and
Laccadive archipelagoes. Cambridge: Cambridge University
Press, Volume 1.
Kench, P. S., McLean, R. F., and Nichol, S., 2005. New model of
reef island evolution: Maldives, Indian Ocean. Geology, 33, 145.
Cross-references
Atolls
Maldives
Patch Reefs: Lidar Morphometric Analysis
David Hopley (ed.), Encyclopedia of Modern Coral Reefs, DOI 10.1007/978-90-481-2639-2,
# Springer Science+Business Media B.V. 2011