You might think that we already know about more or less all of the land masses on Earth, but you’d be wrong. A new study by researchers from Duke University and Meredith College of the globe’s geography has revealed the existence of 657 new islands, reports Our Amazing Planet.
An earlier study from 2001 recorded the existence of 1,492 barrier islands. In this most recent study, however researchers had greater access to satellite images, topographical maps and navigational charts, which allowed them to discover 2,149 islands. In other words, the islands did not all just miraculously appear, but were either unknown to scientists or misclassified due to a lack of research tools.
Unlike most pieces of land on the planet, barrier islands appear, disappear, change shape, and move over time, as the waves and tides build-up and erode the bits of earth. Together Earth’s barrier islands measure about 13,000 miles in length, and constitute roughly 10 percent of the planet’s continental shore lines. About 74 percent of barrier islands exist in the northern hemisphere. The Untied States has more barrier islands (about 400 miles worth) than any other nation. Most of those islands run along Alaska’s Arctic shoreline.
In addition to the discovery of new islands, the study has helped scientists learn more about what classifies as a barrier island. Before this study, for instance, experts believed that barrier islands could not exist in waters with seasonal tides more than 13 feet. The new study has revealed that 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.
The new study “provides proof that barrier islands exist in every climate and in every tide-wave combination,” said researcher Orrin H. Pilkey of Duke University, who participated in the study. “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.”
Because of their effects on the ocean, barrier islands help protect ecosystems and wildlife habitats that would drown without the islands. Researchers hope the new data can help them discover how to prevent the destruction of these vital land masses.