Modern satellite imagery has shown that features from a sixteenth-century CE marine chart accurately reflect hazardous currents found off the Icelandic coast. The Carta Marina, published in 1539 by Olaus Magnus, features swirls and whorls drawn off the south-east of Iceland, complete with ships, a giant fish and red sea serpent. Modern cartographers, using satellite imagery, have found that these swirls correspond with the the dangerous eddies of the Iceland-Faroes Front.

The swirls in the Carta Marina "are the earliest known description of large scale eddies in the ocean -- these are huge bodies of water, 100 kilometres in diameter, that turn slowly. It seems the lines were deliberately drawn to aid navigation," said Professor Tom Rossby, part of a team from Plymouth Marine Laboratory and the University of Rhode Island which has been studying the map. "We know mariners were aware of these fronts but they would not have the tools to quantify them nor the means to express them."