Common problem in man-made lakes. When you create a lake by damming a river it creates perfect conditions for lamination, deep narrow and filled with agricultural runoff. When they pull the plug on these dams all the de-oxygenated water flows out the bottom, basically just dumping unbreathable water into the river killing off the more sensitive fish, eg trout die catfish live, and smelling like a million firecrackers.
- Explosives. Drop large explosives deep into the lake periodically. It may kill a lot of life, but if you need to stir up organic matter at the bottom, it’s more efficient than attempting to stir it.
- Migrate life from similar depths at other lakes. If it’s going to die if you don’t, maybe it’s worth the effort.
- Drill. Just drill a deep hole until you get to a water source or heat.
It's an interesting question, here's some napkin math.
There's almost 19 gigaliters of water in Crater Lake. To pump that amount of water in a year would require pumping 52 megaliters of water per day. A small city produces about 200 megaliters of sewage in a day. (LA produces about 2 gigaliters per day.)
So it should be possible but would be very expensive. Maybe on the order of running the drinking water infrastructure for a town. I suspect I'm overestimating though, I think you might only have to pump half of the water to achieve good mixing. (ETA: After a tiny bit of research I think you might be able to do it with much less than half due to entrainment.)
You would also kill a lot of animals and microorganisms in the process. Pumps driven by impellers create cavitation that cracks open microorganisms, and things like peristaltic pumps which avoid this can't handle these volumes. As this material is decomposed by bacteria, they will reproduce and increase the biological oxygen demand in the water, which might end up making the lake anoxic anyway.
I wonder if there are any elegant passive solutions... like a floating sun-exposed surface that conducts heat down to a lower anchored point. Or lake-bottom structures that re-channel water movements from subtle tides or seiches.
I think that's the wrong way round: climate change causes longer summers and shorter winters, so the problem is one of cooling, not heating.
Shade balls[0] could work, but then they'd have to cover part of the lake with that.
EDIT: And of course, that also comes with a reduction in total light reaching the lake, which may have different side effects beyond temperature alone.
Modern society is falling apart over the cost of getting to net zero. I don't think we have the funds to put lakes on artificial life support in the foreseeable future.
Is it the cost of net zero? Or is it the cost of everything else pretending to be relevant to net zero?
Of the interests pushing for net zero, the bulk of them are only doing it insofar as it can be done in a way that basically guarantees them incomes and all of these earmarks are what's driving the non-starter cost while simultaneously souring people on the whole premise. You'd think that people who allege to think on environmental time scales wouldn't need to be told that a movement that looks like branded rent seeking and legalized corruption when viewed through the perspective of anyone who isn't rolling in money isn't gonna last long enough to do its job.
Algal blooms with limited mixing sounds like a pretty good carbon capture mechanism!
I wonder if there is oil and gas at the bottom of any of these deep lakes? /s
It would be interesting to know the gas balances for these lakes, in particular how reduced mixing affects methanotrophy and methanogenesis. If its talking about climate change, this article really should discuss methane, I think that's a bigger deal.
Common problem in man-made lakes. When you create a lake by damming a river it creates perfect conditions for lamination, deep narrow and filled with agricultural runoff. When they pull the plug on these dams all the de-oxygenated water flows out the bottom, basically just dumping unbreathable water into the river killing off the more sensitive fish, eg trout die catfish live, and smelling like a million firecrackers.
Some more ideas that might work:
- Explosives. Drop large explosives deep into the lake periodically. It may kill a lot of life, but if you need to stir up organic matter at the bottom, it’s more efficient than attempting to stir it.
- Migrate life from similar depths at other lakes. If it’s going to die if you don’t, maybe it’s worth the effort.
- Drill. Just drill a deep hole until you get to a water source or heat.
Why not use pumps to increase mixing?
It's an interesting question, here's some napkin math.
There's almost 19 gigaliters of water in Crater Lake. To pump that amount of water in a year would require pumping 52 megaliters of water per day. A small city produces about 200 megaliters of sewage in a day. (LA produces about 2 gigaliters per day.)
So it should be possible but would be very expensive. Maybe on the order of running the drinking water infrastructure for a town. I suspect I'm overestimating though, I think you might only have to pump half of the water to achieve good mixing. (ETA: After a tiny bit of research I think you might be able to do it with much less than half due to entrainment.)
You would also kill a lot of animals and microorganisms in the process. Pumps driven by impellers create cavitation that cracks open microorganisms, and things like peristaltic pumps which avoid this can't handle these volumes. As this material is decomposed by bacteria, they will reproduce and increase the biological oxygen demand in the water, which might end up making the lake anoxic anyway.
I wonder if there are any elegant passive solutions... like a floating sun-exposed surface that conducts heat down to a lower anchored point. Or lake-bottom structures that re-channel water movements from subtle tides or seiches.
I think that's the wrong way round: climate change causes longer summers and shorter winters, so the problem is one of cooling, not heating.
Shade balls[0] could work, but then they'd have to cover part of the lake with that.
EDIT: And of course, that also comes with a reduction in total light reaching the lake, which may have different side effects beyond temperature alone.
[0] https://www.youtube.com/watch?v=uxPdPpi5W4o
I think what they’re saying is that if you have sufficient heat at the bottom, hotter water rises, so you get cycling.
In addition to that, how many lakes would need to be pumped or would it be a feel-good project for famous lakes?
Perhaps a large horizontal whisk.
Do fluids appreciate sheer force when it is parallel to gravity?
Modern society is falling apart over the cost of getting to net zero. I don't think we have the funds to put lakes on artificial life support in the foreseeable future.
Actually it’s already done in some places. https://www.easthamptonct.gov/sites/g/files/vyhlif7556/f/upl...
Is it the cost of net zero? Or is it the cost of everything else pretending to be relevant to net zero?
Of the interests pushing for net zero, the bulk of them are only doing it insofar as it can be done in a way that basically guarantees them incomes and all of these earmarks are what's driving the non-starter cost while simultaneously souring people on the whole premise. You'd think that people who allege to think on environmental time scales wouldn't need to be told that a movement that looks like branded rent seeking and legalized corruption when viewed through the perspective of anyone who isn't rolling in money isn't gonna last long enough to do its job.
Based on nothing, I suspect a giant spoon would be better
Algal blooms with limited mixing sounds like a pretty good carbon capture mechanism!
I wonder if there is oil and gas at the bottom of any of these deep lakes? /s
It would be interesting to know the gas balances for these lakes, in particular how reduced mixing affects methanotrophy and methanogenesis. If its talking about climate change, this article really should discuss methane, I think that's a bigger deal.