When sea level is stationary, reefs will grow laterally in a seaward direction as reef sediments accumulate. Over long periods of time reef sediments will accumulate, and the growing pile will buid up in a seaward direction. Over time, this reef material will build broad shoals and platforms just below and near the ocean’s surface. However, if sea level rises and reefs are submerged by deep water, they will die. The deep water isolates them form the necessary solar light and warm water conditions they require. Similarly, a drop in sea level could leve them exposed on land.

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