The atolls are composed of live coral reefs and sand bars, situated atop a submarineridge 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。
2
The levelness may be due to the subduction of a submarine mountain range known as the Juan Fernández Ridge.
板块的水平程度可能取决于一个被称为胡安 · 费尔南德斯脊的海底山脉的俯冲作用。
3
Acoustic instruments on the submarine told us that there was a ridge at the bottom of the ocean, sitting transverse to the flow of ice.