What‘s the process for the parallel magnetic strips form
Molten (semi-liquid) material is seeping from the ridges to form new seafloor, on either side of the ridge. Magnetic elements like iron in the molten material form things called dipoles, which are little magnets, with a northpole/southpole arrangement. In a liquid state, the dipoles line up with Earth's magnetic field, like a compass pointing toward magnetic north. When the rock hardens, the orientation of all the little dipoles is frozen. The farther you go in either direction from the ridge, the longer ago in time the rock was formed. By this means, we are able to establish how the Earth's magnetic field has changed over time in orientation.
Along the middle of most oceans is a Mid-Oceanic ridge. Here, the ocean floor is spreading apart, and new magma cools to form new oceanic crust. When the magma cools, it records the magnetic field at the time. About every 100,000 years, the Earth's magnetic field reverses, so that the north pole becomes the south pole, and visa-versa. These two phenomena combine to produce strips of alternating magnetism on the sea floor.
