Some animals that migrate across the globe -- such as birds, salmon, lobsters and sea turtles -- are known to navigate using the magnetic field lines that stretch from Earth's north to south pole.

Check your compass again — Earth’s north magnetic ... on the globe. The magnetic north pole, where compass needles point, is about 1,200 miles south and is where geomagnetic field lines ...

the angle at which magnetic field lines intersect the Earth. The turtles use these two pieces of information, which vary at every point on the planet's surface, as navigational markers that help ...

Doomsayers would have a field day ... As the time line at right shows, hundreds of times in our planet's history the polarity of the magnetic shield ensheathing the globe has gone from "normal ...