It is unlikely that Earth’s magnetic field is about to reverse. The current field is still stronger than the field has been in the last 50,000 years. Earth’s magnetic field is always increasing or decreasing based on changes in the way the molten outer core is circulating. If a random time in history is selected, there is a 50 % chance of seeing the strength of the field increasing or decreasing. Finally, the magnetic field constantly has small areas that reverse in polarity, but the magnetic field locked into the solid inner core means that it is unlikely a weak, localized reversal like the Southern Atlantic Anomaly will remain for long, unless the magnetic field in the inner core dissipates first. Which of the following would NOT support the argument made by Scientist 2?

Question

It is unlikely that Earth’s magnetic field is about to reverse. The current field is still stronger than the field has been in the last 50,000 years. Earth’s magnetic field is always increasing or decreasing based on changes in the way the molten outer core is circulating. If a random time in history is selected, there is a 50 % chance of seeing the strength of the field increasing or decreasing. Finally, the magnetic field constantly has small areas that reverse in polarity, but the magnetic field locked into the solid inner core means that it is unlikely a weak, localized reversal like the Southern Atlantic Anomaly will remain for long, unless the magnetic field in the inner core dissipates first. Which of the following would NOT support the argument made by Scientist 2?
A Measurements indicating that Earth’s magnetic field begins to strengthen.
B Measurements indicating that the Souther Atlantic Anomaly begins to weaken.
C Measurements indicating that the rate of decrease in the strength of Earth’s magnetic field is slowing down.
D Measurements indicating that the magnetic field of the inner core is weakening.

GPT-4o mini · Answer

To determine which option would NOT support the argument made by Scientist 2, we need to consider what supports the notion that the Earth's magnetic field is stable and unlikely to reverse soon.

Option A states that measurements indicate the Earth's magnetic field begins to strengthen. This supports the argument that the field is currently stable and not about to reverse.
Option B states that measurements indicate the Southern Atlantic Anomaly begins to weaken. This would also support the argument, as a weakening of a localized area could suggest stability in the overall magnetic field.
Option C states that measurements indicate the rate of decrease in the strength of Earth’s magnetic field is slowing down. This suggests that even though the field might be decreasing, it is doing so at a slower rate, indicating stability, thus supporting the argument.
Option D, however, states that the magnetic field of the inner core is weakening. This would NOT support the argument made by Scientist 2, as a weakening inner core field could lead to instability and potential reversals or changes in the overall magnetic field.

Thus, the correct answer is:

D Measurements indicating that the magnetic field of the inner core is weakening.