The atolls are composed of live coral reefs and sand bars, situated atop a submarine ridge 960 kilometers long that rises abruptly from the depths of the Indian Ocean and runs from north to south.

环礁由活着的珊瑚礁和沙洲组成，生长在印度洋深处从南到北长贯960公里的陡峭海脊之上。

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The towering ridge of a sand dune in the Arabian Desert points to the afternoon sun.

阿拉伯沙漠上一座高耸的沙丘脊指向着午后的落日。

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This crescent-shaped ridge of sand dune in Oman was formed by strong trade winds that form a smooth hill facing the wind (left) and concave slipface on the back.

阿曼一座新月形的沙丘脊由强信风吹成，在迎风的方向（图左侧）形成一面平缓的凸破，在背风面形成凹坡。

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Berm crest: ridge of sand or gravel deposited by wave action on the shore just above the normal high water mark.

UNESCO: L O S S A R Y

The birds, which feed on Sand Eeels, make the 4, 000 mile trip from west Africa in order to nest on the shingle ridge, amongst the sand dunes in Gronant.

BBC: A Little Tern protects two of its chicks

Search for bargains at the Tanger Outlet Mall, or head for Jockey's Ridge State Park, home to the tallest natural sand dune on the East Coast.

BBC: Daily deal: Two nights in the Outer Banks