Places of Interest nearby
Number of texts: 4
The Rupes Nigra (“Black Rock”), a phantom island, was believed to be a 33-mile-wide magnetic island of black rock located at the Magnetic North Pole or at the North Pole itself. It purportedly explained why all compasses point to this location. The idea came from a lost work titled Inventio Fortunata, and the island features on maps from the sixteenth and seventeenth centuries, including those of Gerardus Mercator and his successors. Mercator describes the island in a 1577 letter to John Dee.
One of the most famous representations of the cartographer Gerardus Mercator is the one with a compass pointing at a specific point on the globe. His compass is placed exactly at the Magnetum Insula, the island north of Scandinavia which Mercator thought it was constructed from magnetic stones. Mercator was fascinated by the magnetic deviation. He showed a lifelong interest in this phenomenon.
Did you know that the magnetic poles swap every 300,000 years. NewScientist mentions that Earth is overdue for reversal, and rapid shifts would cause widespread chaos - for navigation and migratory birds and many other aspect on Earth.
The Earth’s North Magnetic Pole is the point on the surface of the Northern Hemisphere at which the Earth’s magnetic field points vertically downwards (i.e., the “dip” is 90°). This point moves gradually over time.