5.83. Using Earth’s Magnetic Field http://www.ck12.org
FIGURE 5.180
Finding the Way
Another benefit of Earth’s magnetic field is its use for navigation. People use compasses to detect Earth’s magnetic
north pole and tell direction. Many animals have natural “compasses” that work just as well. For example, the
loggerhead turtle in theFigure5.181 senses the direction and strength of Earth’s magnetic field and uses it to
navigate along migration routes. Many migratory bird species can also sense the magnetic field and use it for
navigation. Recent research suggests that they may have structures in their eyes that let them see Earth’s magnetic
field as a visual pattern. You can learn more at this URL: http://www.smithsonianmag.com/science-nature/How-Do-
Birds-Find-Their-Way-Home.html
FIGURE 5.181
Q:In the past, Earth’s magnetic poles have switched places and reversed Earth’s magnetic field. How might a
magnetic reversal affect loggerhead turtle navigation?
A:You can find out at this URL: http://www.pbs.org/wgbh/nova/nature/magnetic-impact-on-animals.html