What is a geodynamo? A. The Earth's rotation and convection forces cause the liquid outer iron core to move creating a magnetic field.

B. The gravity of the Moon and Sun pulling against the Earth create a strong tidal magnetic field.
C. The circulation of the liquid core back through the mantle produces a powerful magnetic field.
D. The force created by the Earth's north and south magnetic poles.

1. crust 1 the metallic layer at the earth's center 2. inner core 3 the firm layer between the crust and the asthenosphere 3. lower mantle 2 the layer surrounding the inner core 4. asthenosphere 4 the semi-solid layer between the top layer and the upper mantle 5. upper mantle 5 the layer between the asthenosphere and lower mantle 6. top layer 6 the earth's outermost layer 7. outer core 7 the hottest part of the mantle