[ExI] Glacier Geoengineering

[Keith Henson]

On Mon, Feb 1, 2010 at 5:00 AM,  Alfio Puglisi <alfio.puglisi at gmail.com> wrote:

> On Sun, Jan 31, 2010 at 10:52 AM, Keith Henson <hkeithhenson at gmail.com>wrote:
>
>> The object is to freeze a glacier to bedrock.

snip
>
> Temperatures at the glacier-bedrock interface can be amazingly high. This
> article talks about bedrock *welding* with temperatures higher than 1,000
> Celsius:
>
> http://jgs.lyellcollection.org/cgi/content/abstract/163/3/417
>
> I guess the energy comes from the potential energy of the ice sliding down
> the terrain.

True.  The article makes the point that it happened in a very short
time in a small volume though.

> This is only enough to take  out the heat coming out of the earth.  Probably
>> need it somewhat
>> larger to pull the huge masses of ice in a few decades down to a
>> temperature where they would flow much slower.
>>
>
> If one also needs to remove the heat generated gravitationally, this could
> be potentially much larger than just the Earth's heat flux.

Good point.   Let's put numbers on it.  Take a square km of ice a km
deep.  Consider the case of it sliding at 10 m/year down a 10 m/km
(1%) slope.  So the energy release would be Mgh.  1000 kg/cubic meter
x 10E9cubic m/cubic km x 9.8 x 0.1m =9.8 10E12 J.

That is released over a year, so divide by seconds in a year, 3.15 x
10E7or ~3.1 10E5 watts, which is 310 kW.

So for this case of a fairly fast moving glacier, gravity released
heat would be about 3 times the geo heat.  Of course the heat from
this motion would stop if the glacier was frozen to the bedrock.

Keith