Figure 12.14

GEO-GRAPHIC: Rifting. (A) Rifting of a continent can eventually lead to the development of a new ocean basin. (B) The East African Rift system has been opening at a rate of about 3 mm (0.12 in) per year over the last 40 million years. The rifting started in the north, near the Red Sea, and has been working its way southward, like a big zipper unzipping the margin of the African continent.

(B. NOAA/NGDC)