You may think compasses always point to the north pole, but they do not always do that. The magnetic north and the geographic north are not the same. The Earth’s magnetic field can change. It can flip over many years. For example, during the Brunhes–Matuyama reversal, the magnetic north was near the equator.
Most people do not worry about the Earth’s magnetic field. It usually protects the Earth from particles from the Sun and creates beautiful lights in the sky called auroras. But the magnetic field is not always stable.
In the last 200 years, the Earth’s magnetic field has weakened by about 9 percent. However, it is still stronger than it was for the last 100,000 years. The magnetic north pole has moved more than 600 miles (1,100 kilometers) since it was found in 1831. It now moves faster, about 34 miles (55 kilometers) each year.
The magnetic poles can flip randomly over thousands of years. The last full flip was about 780,000 years ago. During such flips, the magnetic field can become much weaker. Despite these changes, scientists are still studying how the magnetic field behaves today.
Vocabulary List:
- Compass /ˈkʌm.pəs/ (noun): An instrument for determining direction relative to the Earth’s magnetic poles.
- Magnetic /mæɡˈnɛt.ɪk/ (adjective): Relating to the force of magnetism or the magnetic field of the Earth.
- Reversal /rɪˈvɜː.səl/ (noun): The action of reversing something or the state of being reversed.
- Auroras /əˈrɔː.rə/ (noun): Natural light displays in the sky typically seen in high-latitude regions.
- Weakened /ˈwiː.kənd/ (verb): Made or became less strong or powerful.
- Stable /ˈsteɪ.bəl/ (adjective): Not likely to change or fail; firmly established.
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