The flowchart illustrates a common natural phenomenon: the formation and growth of a volcano through successive stages.
Overall, there are nine key steps in this cyclical process, repeated infinitely from the beginning of “Preshield” to the “Guyot” stage.
In the first two steps, which are called “Preshield” and “Protoshield,” a small mountain begins to form beneath the surface of the sea. In the explosive phase, hydro-explosions occur which deposit a cone of ash. A large number of cinder cones then pile up to create a shield on top of the volcano.
This shield gradually erodes and subsides to form reefs below the surface of the sea. However, during this phase, the volcano remains potentially active (with a plume of smoke rising from the crater). By the time of the “Coral Atoll” stage, the volcano’s original shape has disappeared. Immediately afterwards, the entire structure sinks completely into the sea during the final stage, that is the stage of “Guyot”.