How does the ocean floor keep track of magnetic fields?

Question

Responses

There are magnets in the ocean floor.
There are magnets in the ocean floor.

All rocks act like magnets.
All rocks act like magnets.

Basalt is iron-rich and responds to magnetic fields.
Basalt is iron-rich and responds to magnetic fields.

Being underwater makes the rocks respond to magnetic fields.

Answer 1

Being underwater does not directly make the rocks respond to magnetic fields. Rather, the minerals in the rocks, such as basalt, are iron-rich and can respond to magnetic fields. The magnetic minerals align themselves with the Earth's magnetic field at the time the rock is formed, effectively recording the direction and intensity of the magnetic field. As the Earth's magnetic field changes over time, the minerals preserve a record of these changes in the ocean floor rocks. By studying the magnetic properties of the rocks, scientists can extract information about the past movements of tectonic plates and changes in the Earth's magnetic field.