Thursday, August 27, 2015

Earthquake Primers - The Big Bad Earth - Part 1

I'm writing this primer series for all my fans who are making their way in first-class containers to Canada, with Internet.  We welcome you all, as long as you are willing to open up good restaurants in our horrible monoglot places such as Flin Flon or Montreal.  :)  I used to do illustrations, but it was too much work.  You can see many of my illustrations on Wikipedia, from when I was in a more productive phase.

The Big Bad Earth has a problem.  In the deep infra-red it glows like a lightbulb in space, even if we turned off the Sun for a while.  That's the heat from our natural radioactivity, and it's a huge amount of energy.  If the Earth were an onion, our atmosphere and oceans would be a molecular layer of graphene on top.  Forget global warming, this is the big stuff!

So every day the Earth must radiate this heat out into space.  On the surface, standing in your garden, it doesn't seem like much, but once you dig more than a metre or two you start getting into the Earth's heat flow.  If you covered the planet with very thick insulating foam, the whole thing would probably melt in a few hundred million years.  :)

But the Earth's been happy for a few billion years, and in all that time we've had oceans and continents, in the exact same ratio as we see today.  Obviously things have settled down to equilibrium where enough heat has been shed to keep us in a shirtsleeve environment (suitable for life).

The continents are always growing, and you can see that in huge accretion bands, such as the megathrusts that enrich the earthquakes of Oklahoma.  That's because the deep hot rock is always producing silicate 'scum' that floats to the surface.  By now we should be just one big continent, but it hasn't happened.  That's because our continents are the big foam insulator, and the Earth just can't have that.

So even if the Gorists are right and we become a big waterless desert, we will still have ocean basins.  That's where we have the main heat flow radiating out into space.  Now I hope that all of you in the far reaches have had your Grade 8 physics, which our climate-teests somehow slept through.  There are three types of heat transfer:  conduction, convection, and radiation.  Convection is orders of magnitude above the others, so we make insulating foam with super-tiny air cells that eliminate convection.  The foam is also non-transparent to stop radiation.  The Gorries envision CO2 as acting like a big foam blanket on the Earth, they have forgotten about convection.

In our thought experiment, we turn off the Sun again, and mop up all  the water.  Then we look at the Earth with a thermal camera.  All the heat is radiating out ocean basins, with some tiny bright spots for volcanoes.  The ocean basins are our radiator fins!

-to be continued

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