[ExI] Glacier Geoengineering
hkeithhenson at gmail.com
Mon Feb 1 17:28:56 UTC 2010
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.
> Temperatures at the glacier-bedrock interface can be amazingly high. This
> article talks about bedrock *welding* with temperatures higher than 1,000
> 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.
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