Magnetic North



The North pole of a compass needle is a North seeking pole. The compass points to a South magnetic pole in Northern Canada.



Bangkok - the shadow is cast in late April when the Sun is on an East-West path, overhead at noon.

Figure: Dan Baker

Not only is the South magnetic pole in the North, but the pole it is not stationary. It wanders about. Occasionally, at apparently random million-year intervals, the magnetic field collapses and reverses. The mechanism that sustains electric currents in the core is not fully understood - neither is the process of reversal.

> Next