Geomorphology and Topography
Roosts for seabirds
North Keeling Island is 2.0 km long and 1.3 km wide. Its shape is approximately rectangular with the long axis bearing slightly north-east. Like the southern atoll it is a true coral island. In form, the island is low and flat. The shore rises fairly steeply to a height of 3-5 m, and from this peripheral ridge the ground slopes gently down to a large, shallow, sandy-bottomed lagoon which occupies the greater part of the interior. The island varies from sand to rubble. On the northern shore there is a broad sandy beach. This continues along the western shore but with varying amounts of shingle. In profile the sandy beach rises up to about 4 m above mean sea level.
The southern shore of the island is composed of a spectacular steep shingle beach, with a series of berms, or ridges, being identifiable. Much of the eastern shore is composed of a series of shingle berms, these are particularly well-developed just south of the channel into the lagoon, but continue to the north as well. There are also outcrops of coral conglomerate. A broad platform of conglomerate extends out over the reef flat at the eastern part of the island, almost closing the channel into the lagoon completely.
The lagoon shore of the island slopes gradually and deepens slowly. At low tide its maximum depth is less than 2 m.
See also
Key
Links to another web site
Opens a pop-up window