NYT on some recent reserach:
Now it turns out that existing models of the core, for all their drama, may not be dramatic enough. Reporting recently in the journal Nature, Dario Alfè of University College London and his colleagues presented evidence that iron in the outer layers of the core is frittering away heat through the wasteful process called conduction at two to three times the rate of previous estimates.
The theoretical consequences of this discrepancy are far-reaching. The scientists say something else must be going on in Earth’s depths to account for the missing thermal energy in their calculations. They and others offer these possibilities:
- The core holds a much bigger stash of radioactive material than anyone had suspected, and its decay is giving off heat.
- The iron of the innermost core is solidifying at a startlingly fast clip and releasing the latent heat of crystallization in the process.
- The chemical interactions among the iron alloys of the core and the rocky silicates of the overlying mantle are much fiercer and more energetic than previously believed.
- Or something novel and bizarre is going on, as yet undetermined.
Obviously not much I can add, except some general geekery. Here’s the photo we all saw in high school.
We can thank the iron catastrophe for the core’s existence, which, by the way, produces the magnetosphere and protects us from cosmic rays.
Here’s a cool image of that with all kinds of sci-fi sounding terminology.
But don’t get all cocky, now, Ethan Siegel reports on how a super villain might overcome the magnetosphere and destroy the world!
Not Unreasonable 