What is an Island? Land that is surrounded by water. Islands are always being created and sometimes destroyed. Earth has 657 more barrier islands than previously thought, according to a new global survey by researchers from Duke University and Meredith College. The researchers identified a total of 2,149 barrier islands worldwide using satellite images, topographical maps and navigational charts. The new total is significantly higher than the 1,492 islands identified in a 2001 survey conducted without the aid of publicly available satellite imagery. The 2,149 barrier islands measure 20,783 kilometers in length, are found along all continents except Antarctica and in all oceans, and make up roughly 10 percent of the Earth’s continental shorelines. Seventy-four percent of the islands are found in the northern hemisphere.