What is Magnetic ********* of Mid-ocean ridge system?
The short answer is that when a rift opens in the mid-ocean plate division and magma comes up through it, it aligns with the Earth’s magnetic field as it is at the time, because of the magnetite in the basaltic magma. The Earth’s magnetic poles are moving slowly, and over a period of thousands of years, they become reversed. The long explanation is below. Magnetic striping and polar reversals Beginning in the 1950s, scientists, using magnetic instruments (magnetometers) adapted from airborne devices developed during World War II to detect submarines, began recognizing odd magnetic variations across the ocean floor. This finding, though unexpected, was not entirely surprising because it was known that basalt — the iron-rich, volcanic rock making up the ocean floor– contains a strongly magnetic mineral (magnetite) and can locally distort compass readings. This distortion was recognized by Icelandic mariners as early as the late 18th century. More important, because the presence of magn
