Final answer:
Magnetic poles do switch in a process known as geomagnetic reversal, happening roughly every 200,000 years. The evidence for these reversals is found in the magnetic minerals of volcanic rocks and ocean floor sediments, which align according to the Earth's magnetic field direction at the time of their formation.
Step-by-step explanation:
Yes, magnetic poles do switch. This phenomenon is known as geomagnetic reversal, where the direction of the Earth's magnetic field flips, occurring approximately once every 200,000 years. Essentially, the north and south magnetic poles switch places. The evidence for this comes from the study of volcanic rocks and ocean floor sediments, where minerals that are sensitive to Earth's magnetism record these changes. When new volcanic rock cools, the magnetic minerals within align themselves with the current direction of Earth's magnetic field, essentially capturing a 'snapshot' of the magnetic field at that time.
We currently experience what is known as normal polarity, with the magnetic north pole near the geographic north pole. However, during periods of reversed polarity, the magnetic north pole would be located near the geographic south pole. The geomagnetic reversals are recorded on the Geomagnetic Polarity Time Scale (GPTS), which geologists use to understand the timing and duration of these reversals.