Conducted with state-of-the-art technology, a new global survey uncovered 657 more barrier islands around the world than previously thought.
As OurAmazingPlanet.com is reporting, researchers from Duke University and Meredith College in Raleigh, N.C. identified a total of 2,149 barrier islands worldwide using satellite images, topographical maps and navigational charts. A similar survey, conducted without the aid satellite imagery, identified a mere 1,492 islands.
The study also helped to re-define what classifies as a barrier island, DigitalTrends.com reports. Previously, experts believed that barrier islands could not exist in waters with seasonal tides more than 13 feet. But the latest study reveals the world's longest stretch of barrier islands -- a 54-island chain that runs 355 miles -- resides off the coast of Brazil, where spring tides reach 23 feet in depth.
With a total of 405 barrier islands, the U.S. has the most of any nation in the world, and while the term may conjure up visions of tropic seas, many barrier islands exist along the Alaskan Arctic shoreline. "This provides proof that barrier islands exist in every climate and in every tide-wave combination," study team member Orrin H. Pilkey of Duke University told DigitalTrends. "We found that everywhere there is a flat piece of land next to the coast, a reasonable supply of sand, enough waves to move sand or sediment about, and a recent sea-level rise that caused a crooked shoreline, barrier islands exist."
Matthew L. Stutz, assistant professor of geosciences at Meredith, reportedly believes the islands -- which account for 12,914 miles of uncharted land, or 10 percent of the earth's continental shoreline -- have simply been misclassified or overlooked in the past.