If the ice caps melt (or when, if you like) we're going to have a massive surpless of the wet stuff. Too much of a good thing. I propose massive air and water tight cyclinders be built in the oceans to contain the spare.
Dunk a glass into a sink of water to fill it, turn it over, then pull almost all the way out. You now have a glass of water, upside down; and the sink is one glass smaller.
Let's do the same in the oceans. Build a massive container (actually, perhaps a cylinder isn't the best shape), and open it where it's below the waves; Support it from sinking, like you might an oil rig; then pump the air out from the top. It'll fill the unwanten H2O.
Yeah, it's a massive project. Probbaly the biggest of all the projects so far. All of them. But I don't think it unfeasable, and could even be profitable. Here's a few financial reasons to get it started...
1) The lower the sea level, the more land there is. Countries with a shallow and/or long coast line are more likely to benefit, so perhaps they'd foot part of the bill.
2) Think about how much light is getting to that massive volume of water - it's coming at it from nearly every side! You could probably create quite a nutritional space for farming. "Take as many fish as you like, but only out of that giant bubble".
3) It's an interesting new environment with commercial potential. It's like a little 3d country from reclaimed ocean. I know if there were hotels there, and some lax drug laws (or gambling, or prostitution - whatever you're in to) I'd want to pay a visit. It would certainly a spectacular sight to see.-- seanbo, Jul 09 2009 Land below Sea Level http://geology.com/below-sea-level/A quick reference. [neutrinos_shadow, Jul 09 2009] Spun off Great_20Pykrete_20P...id_20of_20Ellesmere [BunsenHoneydew, Jul 10 2009] The Australian Sea The_20Australian_20seaThe "Lake Eyre" mentioned in this idea would presumably be the center of the Australian Sea. [bungston, Jul 13 2009] The oceans may be a self correcting system. There is a computer model that suggests Northern Europe will freeze over if too much fresh water gets into the oceans from glacial melt due to the Atlantic currents shutting down.-- Zimmy, Jul 09 2009 You can only lift water 10m at sea level by this method. Therefore you're better off with a large disc than a tall cylinder.
If you're trying to lower the sea level by any significant portion, do you realise that at only 10m lift, you'll have to have these discs covering a very large percentage of the world's oceans.
[marked-for-ridicule] - absurd science.-- Custardguts, Jul 09 2009 You could only lift the surface by ~10m (atmospheric pressure and all that), so it wouldn't gain you much. <Edit> - [Custardguts] bet me to it... Better to use existing empty spaces - fill up areas that are below sealevel (sorry, Israel, Jordan, Syria, Djibouti, China, Egypt, Kazakhstan, Ethiopia, Argentina , United States, Eritrea, Morocco, Western Sahara, Libya, Dominican Republic, Algeria, Azerbaijan, Iran, Russia, Tunisia, Australia, Uzbekistan, Mexico, Denmark, Netherlands, Mauritania, Japan, United Kingdom, Germany, Sweden, France, Poland, and Suriname). If you're lucky, the land gained at continental coastlines will compensate for the land lost with sea-filling.-- neutrinos_shadow, Jul 09 2009 So obviously, these cylinders must be turned upside down. With open tops they can hold as much water as the walls will support. One humongor cylinder might be made from the asteroid Eros or some similarly sized body, landed in mid ocean, then gradually filled using windmills mounted along the top.
If placed at the equator, the top of this cylinder (at 30,000 feet mimimum )might do double duty as the mooring for the space elvator.
There are other comparably sized engineering projects on the HB. Many, in fact.-- bungston, Jul 09 2009 Build it out of Pykrete in northern Canada or Siberia - that way you're using water (ice) as your structural mass. It'll need to be a cone shape, rather than a cylinder, for strength, whatever it's made of. Heck, make the outside a pyramid shape, just for fun.
Let's say you want to capture a meter's worth of the Earth's surface water.
Radius of Earth = 6 378 100 meters Surface Area of a Sphere = 4 pi r^2 Ocean = 3/4 Earth's surface => 3 pi r^2 = 383401471732908.7 sq m x 1 meter = 383401471732908.7 cu m 1 cu km = 10^9 cu m
~ 383402 cu km
Volume of a cone = (h pi r^2)/3
Solve for r-- BunsenHoneydew, Jul 09 2009 Oh hey, that's an approximation!-- daseva, Jul 09 2009 Only when I get to the final answer, Shirley?-- BunsenHoneydew, Jul 09 2009 Let's assume - generously - that Pykrete can support a 45° slope (1:1), thus making r = h, then
Volume of Pykrete cone = (pi r^3)/3
Solve for r
v = (pi r^3)/3 => r = (3v/pi)^-3
In fact, 3 "approximates" to pi, so let's just leave that out
r = v^-3
= 72.65 km
So you end up with a cone about 73 km (45 miles) high and 150 km (90 miles) across.
Which actually seems kind of doable, unless I've dropped a decimal place somewhere. Does anyone want to check my working?-- BunsenHoneydew, Jul 09 2009 //Dunk a glass into a sink of water to fill it, turn it over, then pull almost all the way out. You now have a glass of water, upside down; and the sink is one glass smaller.//
I'm more of a believer in small times many.... So, just get everyone on the planet to go down to the sea with a cup, and a small floating device that will hold its raised water in place as it drifts off.... the only problem is that unless it's actually anchored to the bottom, the sea level remains the same....-- xenzag, Jul 09 2009 Unless it's supported by a helium or hot air balloon-- BunsenHoneydew, Jul 09 2009 To correct a ten meter rise:
Ocean = 383401471732908.7 sq m x 10 meter = 3834014717329087 cu m 1 cu km = 10^9 cu m
~ 3834015 cu km
= 156.5 km
Which is a cone only about twice the height and breadth of the previous one. Blimey.
[seanbo]: I'll be spinning off a new idea about here.-- BunsenHoneydew, Jul 09 2009 The sub-title made me laugh.-- blissmiss, Jul 09 2009 Will somebody explain this ten meter limit? I can understand that it will become expanentially difficult to go increasingly high, but I don't understand why there would be an absolute ceiling.
I'm loving the anchor for a space elevator idea. If you had a space elevator sprouting from the top of it, you could pump a steady stream of water up, out of the top, then fire it at the Moon! Moon Pump. There's not enough water on the Moon.-- seanbo, Jul 10 2009 [seanbo] Think of the cylinder of water. The water is being pulled down by gravity, but is being held up in the cylinder by the weight of the atmosphere pressing down on the ocean. For a given cross sectional area, the weight of the atmosphere is about the same as 10m of water, so it doesn't matter how much higher you pull the cylinder - the water level will stay at 10m. If you pull the cylinder higher, it'll just form a vacuum above the water level, and the water will 'boil' to fill the void with water vapour.-- hippo, Jul 10 2009 Now I get it. Thanks hippo. To be taller it would have to be an entirely sealed container - as big as you like, containing as much water as you want, with some control over what pressure you store it at.-- seanbo, Jul 10 2009 // a cone about 73 km high [..] actually seems kind of doable // [marked-for-tagline]-- loonquawl, Jul 10 2009 //it'll just form a vacuum above the water level// known as the Torricelli vacuum I believe?-- xenzag, Jul 10 2009 Couldn't we just simply dig the ocean floor deeper to a much lower depths and then use the soil to build and/or extend the land masses?-- Jscotty, Jul 11 2009 or maybe run a pipeline from undersea volcanos.... yeah okay same thing but I just wanted to sign in.-- FlyingToaster, Jul 11 2009 I might be missing something, here: is not an 3-fold conic section the most gravitationally economical way? i.e: an egg: pointy side up? I could be wrong, or mis-paraphrasing Archimedes...
Thanks, [hippo]: I actually missed that, too (9.8 M/s² is an mantra of mine, yet...)
[jscotty] scares me. Yet his ridiculous idea seems the most rational here. If one eon in the future, his idea becomes manifest, than you heard it here first, on HalfBakery...-- Wily Peyote, Jul 12 2009 idea of dredging the oceans is sorta baked in Niven's "Ringworld" where the massive oceans are dredged and the "flup" deposited in the mountains (where it eventually erodes away and flow downhill; rinse and repeat)-- FlyingToaster, Jul 12 2009 You scare me [Ian]
Flooding the lowlands is much less likely to fail catastrophically than a huge coffer dam holding half the ocean. But with evaporation, we risk turning all those areas into salt pans.
I refer to my previous comments on the "Flood Lake Eyre" idea. In short, underground tunnels connecting the new lakes to the ocean to allow salt flushing.
Someone still needs to do some sums to work out if there's enough lowland available.-- BunsenHoneydew, Jul 12 2009 //Someone still needs to do some sums to work out if there's enough lowland available.// Define "lowland". I think that is where the problem becomes a problem...-- 4whom, Jul 12 2009 I'm loving the idea of dedging the ocean floor. There's not too much water, but the container isn't big enough. If you deposit all the 'flup' in the Sahara, might you be able to build a mountain large enough to bring rainfall to that part of the planet? I'm not a meteorologistm in fact I'm not even sure I've spelt it correctly, but I think rain on the Sahara would mean there wouldn't be anough rain to cause the Monoons over India.-- seanbo, Jul 13 2009 // Define "lowland". //
Land that's currently below sea level, or below an acceptably risen sea level of the future.-- BunsenHoneydew, Jul 13 2009 hmmm... mid-ocean would be too far (unless you wanted to build islands... just off the continental shelves and you'd have real flup, ie: stuff that's been washed out from land. I don't think the word "easy" comes into this at all. (Generously) assuming an energy cost equal to simply hoisting that mass (and attendant transport medium, water) up 400 feet, how much could we transport.
[edit: the shelves are teeming with life, so I guess you'd have to go to the "abyssal plain"(bottom of the ocean)]-- FlyingToaster, Jul 13 2009 <Imagines [seanbo]'s dredgers being used by Holland to get above [Bunsen...]'s "lowland" definition, <smiles></s></i...>-- 4whom, Jul 13 2009 For some reason I keep picturing WALL-E humming to himself a thousand years in the future while maintaining a dilapidated gigantic dam of trash and recycled sea floor.-- RayfordSteele, Jul 14 2009 random, halfbakery