Earth's magnetic field reverses roughly every 200,000 to 300,000 years, not the intervals suggested in the options. Thus, the more accurate range falls under one million years. The phenomenon of magnetic reversal occurs irregularly rather than on a strict schedule. ;
Earth's magnetic field reverses on average every 200,000 to 300,000 years, a process known as magnetic reversal. Although options provided in the question suggest longer intervals, the closest choice is A) About every one million years. These reversals happen irregularly and are influenced by changes in the Earth's outer core.
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