By Stacy Palen
In January, geologists updated the model of Earth’s magnetic field, a year ahead of schedule.
1. Study the map titled “Magnetic Motion.” How much time separates each pair of red dots between 1900 and 2010?
Answer: The dots indicate 10-year time intervals until 2010. There is an extra dot placed for 2015.
2. In general, how does the movement of the magnetic pole since 1990 compare to the movement of the pole prior to that time?
Answer: Because the red dots are much farther apart after 1990, we can conclude that the pole is moving a lot faster in the last few decades than it did prior to that.
3. Why do we care about what happens to the magnetic pole of Earth?
Answer: The position of the magnetic pole underlies all navigation. If we don’t know where the pole is, we don’t know where we are.
4. Why did geologists decide to update the model a year earlier than expected?
Answer: Because the position of the pole was changing so fast that navigation was becoming inaccurate.
5. What is the working hypothesis for why the position of the magnetic pole is changing so rapidly right now?
Answer: A jet of liquid iron is weakening the magnetic field in Canada. This means that a second patch of magnetic field in Siberia is relatively stronger, so the pole is moving in that direction.
6. How does this news article relate to what you have learned about Earth’s magnetic field?
Answer: We have learned that Earth’s magnetic field changes over time, and that the history of those changes are recorded in rocks. We have also learned that the magnetic field affects the aurorae in Earth’s atmosphere. As the magnetic field changes, this should affect the aurorae as well.