Here, the entire animation plays without pausing.
The strength of our world's magnetic field has been
diminishing for the past 300 years. If the
Glatzmaier-Roberts model accurately simulates the
processes that drive the magnetic field, the loss of
strength could be an indication that a reversal is
under way. This would be no surprise. On average,
reversals of the Earth's magnetic field happen every
250,000 years. It's now been about 720,000 years since
our last reversal. Judging from history, we know that
a reversal is long overdue. But there's no need to
throw away your old compasses. A reversal usually
takes hundreds or thousands of years to complete.
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