Quote:A robotic treasure hunter has laid claim to the find of the century, on the very archipelago that inspired the novel Robinson Crusoe. The robot, called "Arturito" or "Little Arthur", is said to have discovered the 18th-century buried treasure on the island of Robinson Crusoe - named after the book. The island lies 660 kilometres from the coast of Chile in South America.

A Scottish sailor called Alexander Selkirk was marooned on the island in 1704. His story inspired Daniel Defoe to write Robinson Crusoe, which was published in 1719.

The Chilean company responsible for developing Arturito, Wagner Technologies, announced at the weekend that the robot had found the booty by probing 15 metres below ground. The company plans to start excavating in a matter of days, as soon as permits can be obtained.


Gold ingots

According to legend, a fabulous treasure haul was buried on the island in 1715 by Spanish sailor Juan Esteban Ubilla-Echeverria. The bounty is said to have been discovered a few years later by British sailor Cornelius Webb, who reburied it on another part of the island.

By some estimates the haul would include 800 barrels of gold ingots, silver pieces, gems and other riches worth up to $10 billion. Naturally, the promise of such fabulous wealth has attracted scores or treasure hunters to the island in the past.

"The biggest treasure in history has been located," Fernando Uribe-Etxeverria, a lawyer working for Wagner Technologies told AFP News. And the announcement has already sparked a dispute over who could claim the treasure, with the Chilean government suggesting it would have full rights.

Wagner Technologies could not be reached for comment, but the robot Arturito has previously helped Chilean police locate buried weapons using ground-penetrating radar. GPR, or georadar, locates subsurface objects or structures by emitting microwave-frequency electromagnetic radiation and measuring the reflected signal, which is then represented as a two or three dimensional image.

Subsurface objects

Adam Booth an expert in GPR archaeology at the University of Leeds, UK, says it would be necessary to use a low-frequency signal to search at 15 metres' depth. But this would decrease the resolution of the signal, he says. It would be "very, very difficult", to distinguish between different metals so far down, Booth told New Scientist.

But Booth says further details could be gleaned by using other techniques in combination with GPR, such as magnetometry, which measures disturbances to the Earth's magnetic field.

Robert Richardson, a robotics expert at the University of Manchester, UK, says a robot could feasibly hunt for treasure, but believes a human controller would be crucial. "It is difficult to interpret GPR images, requiring a trained operator," he says. "It sounds more of a mobile sensing platform than a robot."

Marvin Pitney of US company Subsurface Radar Solutions agrees that it can be tricky to identify sub-surface objects accurately. "It takes years of practice," he says. "But once you get really good at interpreting images you can tell the difference between metals and plastic."