2. Paleomagnetism The study of changes in Earth’s magnetic field, as shown by patterns of magnetism in rocks that have formed overtime.
3. Normal Polarity A magnetic field that is the same as that which exists in the present.
4. Reverse Polarity A magnetic field opposite to that which exists at present.
5. Hot Spot A concentration of heat in the mantle capable of producing magma; which rises to Earth’s surface.
6. Key Concept What evidence supports the theory of plate tectonics? Continental drift, seafloor spreading, palemagnetism, earthquake patterns, ocean drilling, and ocean hot spots.
7. Key Concept How does paleomagnetism support the theory of plate tectonics? By showing how Earth’s magnetic field affects rocks overtime.
