Namonuito Atoll, also called Namonweito, Weito, or Magur Islands, is the largest atoll of the Federated States of Micronesia and of the Caroline Islands, with a total area of 2267 km², unless one considers the still larger Truk Lagoon as a type of atoll in an early stage of development. In Micronesia, only Kwajalein Atoll of the Marshall Islands is larger.
Namonuito Atoll lies in the northwestern region (Oksoritod) of Chuuk State, the largest federal State of the Federated States of Micronesia, about 170 km northeast of Truk Lagoon (measured from Pisaras Islet to the northern and western parts of the fringing reef of Truk Lagoon). It is roughly triangular in shape, with the base running 82 km along its southern side. The southwest corner of the triangle is marked by Ulul islet, the main island (largest and most populated), also called Onoun. The other islets lie mostly on the northeast side, from Pisaras islet in the southeast corner to Magur (Makur) islet in the north corner. The 12 islets have an aggregate land area of only 4.5 km². The total population is 1.341 (census of 2000).
The reef rim of the atoll is submerged for the greater part and is marked by the lighter color of the water over it. The depths on the reef range from 0.9 to 18.3 meters. The reef appears to be in the process of formation and can be crossed at many places. The lagoon is not of uniform depth. Except for a 5.5 meter patch, located 22 km west of Pisaras island, and a detached reef, with depths of 2.7 to 3.7 meters, located about 10 km of Pisaras, there appears to be no less than 9 meters on the scattered coral heads.
Pisaras Island has coconut palms and other trees growing on it. Reefs extend northwest and WNW from the island, enclosing a shallow and foul bay. Ulul Island is densely covered with coconut palms. A drying reef fringes the island. There is a radio station on the island.
The atoll is home to five of the 40 municipalities of Chuuk state, listed in counterclockwise sequence, with population (2000):
Landsat visible color image |
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| Municipality | alternate or former name |
Land area km² |
Population (census 2000) |
location | islands | coordinates | ||
|---|---|---|---|---|---|---|---|---|
| Onoun | Ulul | 2.54 | 598 | southwest corner | Ulul Island | |||
| Piherararh |
Pisaras |
0.80 |
227 |
southeast corner |
Wabonoru Islet Pisaras Island Pielimal Islet Weltot Islet |
|||
| Unanu |
Onari |
0.26 |
178 |
northeast rim |
Onari Island Bihof Islet Behiliper Islet Amurtride Islet |
|||
| Onou | Ono | 0.31 | 182 | northeast rim | Ono Island | |||
| Makur |
Magur Islands |
0.47 |
156 |
north corner |
Magur Island Magererik Islet |
|||
| Namonuito Atoll | Magur Islands | 4.38 | 1,341 | |||||