Geoscience Reference
In-Depth Information
through the inner core made the trip 0.3 seconds faster in 1995 than in 1967, showing that
the fast track axis of the inner core has been swinging into alignment at about 1.1 degrees
per year. Understanding why the inner core is spinning so fast may give insight into what is
going on in that strongly magnetic environment. It could be that currents in the outer core,
analogous to the jet streams in the atmosphere, are putting a magnetic tug on the inner core.
So far, only about 4% of the total core has frozen. But, in 3 or 4 billion years' time, the
entire core will have solidified and we may lose our magnetic protection.
