Did you know that the North Pole has not always been in the same place? Tracing where is has moved to can help scientists find the date for a volcano erupting or when a pot was fired.

The Earth is like a giant bar magnet with its ends at the North and South poles. We know this because our compass points north. These poles, however, are not fixed in one place, they have been known to wander around and even flip-flop so that north becomes south and south becomes north.

Some minerals in rocks and clays are like tiny bar magnets. When the rocks and clays are heated to a very high temperature these tiny magnets line up with the direction of north at that moment and when they cool they are locked in that position.

Scientists have found ways of measuring the direction of the locked magnetism in pots and rocks and this can be used to help us date when the pot was fired or when the volcano erupted. They can then compare the results from the pot or the lava to their maps to work out how old their samples are.

Geologists call this technique Palaeomagnetic dating and archaeologists call it Archaeomagnetic dating.