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Christopher Columbus, prepare to be blown away. Thanks to satellite imagery, scientists have discovered swaths of new islands scattered across the world.

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Thanks to high-resolution images, Duke University and Meredith College geoscientists were able to add 657 new barrier islands to the total count, adding 30 percent more to the known list. There are now 2,149 discovered islands in total.

The biggest string of islands happens to fall right off of Brazil’s coast, 54 islands strong over a stretch of 354 miles. They had previously blended into a mangrove, so scientists weren’t exactly sure what they were. Most of the newly discovered islands lie in the northern hemisphere.

(More on TIME.com: See video of sinking islands and Copenhagen.)

Barrier islands are often deposits of sand and sediment that erode away or build up over time depending on the ocean’s currents. They usually form off coasts, protecting them from erosion and storm damage.

Scientists cite Google Earth as a key tool in discovering the islands. Still the researchers point out that “Some of the islands we did not ‘discover’ until we visited them. That is, we weren’t really sure they were barrier islands.”