What would you study in order to determine the timescale on which the Earth's magnetic field reverses direction?
A) a spreading center on the sea floor
B) a volcano in the middle of a continental plate
C) a fault at the border between two plates
D) a subduction zone on the sea floor
E) the rate of motion of tectonic plates

Question

Quizplus · Accepted Answer

The spreading center on the sea floor is the best choice as it records the magnetic reversals of the Earth's magnetic field over geological time scales. As the magma rises from the mantle and solidifies on the crust, it preserves the magnetic signature of the Earth's magnetic field at that time. By studying the magnetic polarity of the rocks formed at different times, scientists can determine the timescale of the Earth's magnetic field reversals.

What Would You Study in Order to Determine the Timescale