Atoll development

A series of 4 cartoon to illustrate how we go from an active volcanic island, to fringing and barrier reef, to atoll.

Detailed Description

Coral atolls develop from reefs fringing volcanic islands. As first hypothesized by Charles Darwin, and confirmed by ocean drilling done by British scientists a century ago, reefs fringing volcanic islands build vertically to sea level, forming steep-walled barrier reefs. As a volcanic island subsides, or sinks, with time, the growing reef keeps pace with the rising water level. When the island eventually submerges, the ring-shaped reef forms an atoll with a central lagoon. Graphic Design By Susan Mayfield and Sara Boore, USGS Fact Sheet 025-02


Image Dimensions: 1403 x 2162

Date Taken:

Location Taken: US