Pseudo-atoll Pseudo-atoll A pseudo-atoll, like an atoll, is an island that encircles a lagoon, either partially or completely. A pseudo-atoll differs from an atoll as established by several authorities, such as how it is formed (not by subsidence, nor by coral). It is considered a preferable term to "near-atoll". There is a need for rigorous definition of "pseudo-atoll" before it can be accepted as a general term. Alexander Agassiz gave the term pseudo-atoll to "any ring-shaped reefs not formed as a result of subsidence". while Norman D. Newell and J. Keith Rigby called such reefs non-coral. and "We conclude that almost-atoll
Baa Atoll Biosphere Reserve the environment. Baa Atoll has a warm and humid tropical climate. The weather is dominated by two monsoon periods – a rainy monsoon period, which lasts from May to November, and a dry monsoon period, which lasts from January to March. The dominant natural environment of the reserve is marine, surrounded by deep ocean. The water depth varies considerably and includes lagoons with depths ranging from 30 m to 80 m, opening into the Indian Ocean, while channels running through the atoll may be up to 250-300 m in depth. The lagoons enclose a variety of reef structures including faros,