GEOLOGY

Detailed explanation-1: -As Earth’s magnetic field varies over time, the positions of the North and South Magnetic Poles gradually change.

Detailed explanation-2: -Since the forces that generate our magnetic field are constantly changing, the field itself is also in continual flux, its strength waxing and waning over time. This causes the location of Earth’s magnetic north and south poles to gradually shift, and to even completely flip locations every 300, 000 years or so.

Detailed explanation-3: -It has always been a feature of our planet, but it has flipped in polarity repeatedly throughout Earth’s history. Each time it flips – up to 100 times in the past 20 million years, while the reversal can take about 1, 000 years to complete – it leaves fossilised magnetisation in rocks on Earth.

Detailed explanation-4: -Over the last century, the position of the magnetic north pole has shifted from the Canadian Arctic to Siberia. But, according to a new study by researchers in Italy and Spain, this shift was part of a longer trend, with the magnetic pole alternately ‘dribbling’ between the two regions for the past 22, 000 years1.

Detailed explanation-5: -A team of researchers used volcanic records to study Earth’s last magnetic-field reversal, which occurred about 780, 000 years ago. They found that this flip may have taken much longer than researchers previously thought, the scientists reported in a new study.