Shelf wear on bottom edge Foxing on book ledge Time Inc, 1973, 184 pages The long reach of the Hawaiian archipelago, a chain of volcanic islands ranging in age from 700,000 years to 16 million years and stretching 1,600 miles across the mid-Pacific Ocean. Washed on all sides by the sea the islands have a total land area of 6,500 square miles. The oldest geological formations, such as Pearl and Hermes Reef stand above sea level only because coral built up on eroded volcanoes.