Final answer:
Magnetic reversals are reversals of the Earth's magnetic field. They support sea floor spreading by providing evidence of new crust formation. Other evidence for sea floor spreading includes magnetic anomalies and the age progression of the sea floor.
Step-by-step explanation:
Magnetic reversals refer to the phenomenon where the Earth's magnetic field periodically changes direction. This means that the north and south magnetic poles swap places. These reversals can be observed by studying the magnetization of rocks on the sea floor.
Sea floor spreading is the process where new oceanic crust is formed at mid-ocean ridges as tectonic plates move apart. The coordinated magnetic reversals observed on the sea floor support the theory of sea floor spreading. As the new crust forms, it records the Earth's magnetic field at the time of its formation.
By studying the pattern of magnetic reversals on the sea floor, scientists can determine the spreading rate and use it to reconstruct the historical record of the Earth's magnetic field.
Other supporting evidence for sea floor spreading includes the symmetrical pattern of magnetic anomalies observed on either side of mid-ocean ridges and the age progression of the sea floor away from the ridges. Additionally, paleomagnetic studies have shown that continents have moved over time, supporting the concept of continental drift.