Because the Curie temperature gives us a record of the orientation of the Earth’s magnetic poles, studies of rocks of different ages reveal a great deal of information about the strength and orientation of the Earth’s magnetic properties in the past. This study is known as paleomagnetism.

Paleomagnetism eventually helped to explain an unusual observation that had first been made in the 1950s. Magnetic studies of the ocean had determined that the ocean floor was covered by bands of magnetic stripes that varied between normal polarity and reversed polarity. Another odd fact was that these magnetic stripes were symmetric on the ocean floor about the mid-oceanic ridge.

This puzzling phenomenon of magnetic striping was finally explained in 1963 by two British scientists, Fred Vine and D. H. Matthews, who proposed that the magnetic striping was caused by paleomagnetism. Their proposal stated that magma flowing from the mid-oceanic ridges was preserving the then-current orientation of the Earth’s magnetic poles as it cooled below the Curie temperature. This new oceanic crust was then slowly carried away by seafloor spreading. A magnetic reversal of the poles would show up as a band of reversed polarity in the slowly spreading seafloor. The symmetric banding was the result of seafloor spreading on both sides of a mid-oceanic ridge. It was this explanation of magnetic striping by paleomagnetism that, in fact, finally convinced scientists that new oceanic crust was being continually formed at mid-oceanic ridges, and that seafloor spreading was a reality.