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
Northern Thiladhunmathi Atoll Northern Thiladhunmathi Atoll Haa Alif Atoll - officially referred as Thiladhunmathi Uthuruburi (Northern Thiladhunmathi Atoll) is the northernmost administrative division of the Maldives. As the administrative division known as Haa Alif it includes Ihavandhippolhu, the northernmost natural atoll of the Maldive archipelago, as well as a section of the larger Thiladhunmathi or Tiladummati Atoll. Thiladhunmathi was divided into its northern and southern divisions on May 21, 1958. The north division was integrated with Ihavandhippolhu forming administratively a new atoll called Haa Alif atoll or Thiladhumathi North. In total Haa Alif atoll contains 42 islands, 14 of which are inhabited.At present