Sandy Island was an island off the northeast coast of Australia that is believed to have disappeared entirely after having been discovered in the late 18th century and documented up until the 20th century. James Cook was the first to document its existence in 1774, and French maps corroborated the island in maps during the 19th century. However, recent expeditions have discovered that Sandy Island simply does not exist, and it wasn’t until November 2012 that the National Geographic Society officially removed Sandy Island from all maps. Even Google Maps, which is supposed to get its data from satellite imagery, featured Sandy Island until that date.
So what happened? The island appears to be relatively large, so it’s hard to imagine that it just disappeared over the last few hundred years. However, the idea is not too farfetched – the island could have simply been a low island of sand and nothing else, as its name evoques. The island’s supposed location, seen below, indeed raises the possibility that the island was at one time simply a raised bed of sand which eroded away over the centuries.
Sandy Island’s supposed location was in the heart of the Coral Sea, where there is an underwater range of mountains and coral reefs, so it is entirely plausible that a larger mountain breached the water’s surface for a period of time and was later washed away. However, when researching this topic I came upon a long list of once-documented islands that were found to be nonexistent, and not all of them can be attributed to erosion.
A glaring example of a wrongly-documented island is the island of Frisland, supposedly south of Iceland and west of Ireland. It is not entirely ridiculous for explorers to have thought and island existed in the area, as there is a bit of raised seabed in the area that could have served as an island at one point. But, something catastrophic would have had to have happened in order to sink an island of that size, so I’m going to go ahead and say that this island never existed. Frisland was mostly only featured on maps for about 100 years – from about 1560 to 1660 – but a few maps kept it on as late as the 18th century. Early maps, like the one below, gave it place names, and it was even given currency by the Maggiolo family of Genoa.
It’s possible that Frisland was actually the southern part of Greenland and that explorers mistakenly presumed it to be its own island, but there is no definite consensus on the topic. However, it seems that there have been many instances of nonexistent islands – accidental or otherwise – and thanks to satellite imagery, this sort of problem probably won’t be happening again anytime soon.