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Lord Jubjub
2011-Jan-07, 01:27 AM
I know the answer will include several zeroes but. . .

How much heat does the Moon induce in the Earth's crust as a result of tidal friction?

antoniseb
2011-Jan-08, 02:09 PM
I know the answer will include several zeroes but. . .

How much heat does the Moon induce in the Earth's crust as a result of tidal friction?

Interesting question. My approach to an answer is to calculate how much orbital energy the Moon is losing each second, and then convert to your favorite unit of heat.

chornedsnorkack
2011-Jan-09, 02:32 PM
Interesting question. My approach to an answer is to calculate how much orbital energy the Moon is losing each second, and then convert to your favorite unit of heat.

But this need not be relevant to crust!

Some of the heat is deposited by friction in Earth oceans, some in Earth atmosphere, some in Earth crust, some in Earth mantle, some in Earth core, some in Moon crust, some in Moon mantle and some in Moon core. Can somebody provide a breakdown of where the energy goes?

swampyankee
2011-Jan-09, 03:14 PM
But this need not be relevant to crust!

Some of the heat is deposited by friction in Earth oceans, some in Earth atmosphere, some in Earth crust, some in Earth mantle, some in Earth core, some in Moon crust, some in Moon mantle and some in Moon core. Can somebody provide a breakdown of where the energy goes?

I'm going to say "yes, but not me." To do so would require knowledge of, among other things, the damping coefficients of the various layers and of the distribution of tidal forces within those layers. This could be a place to start: http://onlinelibrary.wiley.com/doi/10.1046/j.1365-246x.2001.00356.x/abstract;jsessionid=5ACDF984ECEB5883AC5CD99E249CDC 37.d03t01

IsaacKuo
2011-Jan-12, 05:07 PM
Interesting question. My approach to an answer is to calculate how much orbital energy the Moon is losing each second, and then convert to your favorite unit of heat.
The Moon is gaining orbital energy. Since its orbital period is slower than Earth's rotational period, it is being flung outward. This adds to its orbital energy.

korjik
2011-Jan-12, 05:25 PM
The Moon is gaining orbital energy. Since its orbital period is slower than Earth's rotational period, it is being flung outward. This adds to its orbital energy.

Well.... If you want to get technical.... :)

I cant believe I missed that one. Bet ya Antoniseb cant either.

Now that I think about it, how would you find the energy? It is a frictional force, so there should be some heat generated. would it be like the Virial theorem and basically half the energy lost by the Earth is heat?

hmmmmm...

antoniseb
2011-Jan-12, 05:28 PM
... Bet ya Antoniseb cant either. ...

What's that monosyllable that Homer Simpson is often saying?

swampyankee
2011-Jan-12, 05:33 PM
I believe there are some measurements of the rate at which Earth's rotation is slowing and some estimates of the rate of rotation in the more distant past. E = (I ω²)/2.

chornedsnorkack
2011-Jan-12, 07:45 PM
Both the rotational energy of Earth and rotational energy of Moon decrease. The binding energy of Earth and Moon increases, but by less than the decrease of rotational energy. So a part of the rotational energy turns into heat - in sundry places.

neilzero
2011-Jan-21, 08:20 AM
Since no one guessed a number: I will: Earth's average surface temperature is 0.005 k = 0.009 f warmer because of the tidal effects of the moon. This is much less than the tidal warming of Io. Neil

grapes
2011-Jan-26, 09:50 AM
A guess? lol :)

One could imagine that tidal slowing could occur without any heat at all: allow the deformation to take place frictionlessly, then lock the deformation. Allow the gravitational forces to slow the rotation, then release the deformation (also without friction).