What did Frederick Vine and Drummond Matthews explain about marine magnetic anomalies?

English geologists Frederick J. Vine and Drummond H. Matthews, along with Canadian geophysicist Lawrence W. Morley, developed a theory explaining marine magnetic anomalies by synthesizing three key concepts: Earth’s magnetic field periodically reverses polarity, seafloor spreading occurs, and oceanic crust becomes permanently magnetized as it cools at spreading centres.1

The theory posits that as new crust forms, it records the polarity of Earth's magnetic field at that time. Crust formed during a "normal" polarity period creates a positive magnetic anomaly, while crust formed during a reversed period creates a negative anomaly. As seafloor spreading pushes these crustal blocks away from the ridge, they remain permanently magnetized, creating a symmetrical pattern of anomalies on either side of the ridge crest. This discovery allowed scientists to use magnetic anomaly patterns to date the ocean crust and calculate the rate of seafloor spreading.12