A disappearing island..?



Last year, a group of Australian researchers "undiscovered" an island the size of Manhattan in the South Pacific.

A mysterious place called Sandy Island had popped up on maps, northwest of New Caledonia. It even showed up as a black polygon on Google Earth. But when scientists sailed there last November, they found open water instead of solid ground.

In an obituary for the island published this month, the researchers explained why the phantom landmass had been included on some maps for more than a century, pointing to some human errors and a possible pumice raft.

Sandy Island was first recorded by the whaling ship Velocity in 1876 and first mentioned on a British Admiralty chart in 1908. But future expeditions failed to find the island, and it was removed from some official hydrographic charts by the 1970s.

However, the errant island stuck on some maps and then crept into digital databases like the widely used World Vector Shoreline Database, which was developed by the U.S. military.

"During the conversion from hard-copy charts to digital formats the 'Sandy Island' error was entrenched," said Maria Seton, of the University of Sydney. (Seton was chief scientist on an expedition to study plate tectonics on the RV Southern Surveyor when the "undiscovery" was made.)

"We all had a good giggle at Google as we sailed through the island," Steven Micklethwaite, a scientist at the University of Western Australia who was on the voyage, told the Sydney Morning Herald at the time of the undiscovery. "Then we started compiling information about the seafloor, which we will send to the relevant authorities so that we can change the world map."
Floating pumice in the South Pacific.

 Taken in the afternoon on July 19, 2012, this NASA MODIS image reveals the Havre Seamount eruption, including the gray pumice, ash-stained water and the volcanic plume.