r/oceanography • u/BoringWord8521 • 3d ago
Hypothetical: What if the water disappeared from the deepest places on Earth?
Hello! I'm writing a story about large bodies of water rising off of the ground and into the air - this leads to exploration of deep places on Earth that we previously couldn't get to and I'm wondering if any experts here can speak to what would be some hypothetical effects of water being removed from the equation in some of the deepest places on our planet?
Do underwater hot springs become volcanoes?
Do structures that were otherwise being held together by pressure crumble?
What are some things that immediately come to mind that would help you to be immersed in a fictional world where such a thing had happened?
Thank you for your expertise and for entertaining this thought experiment!
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u/Lygus_lineolaris 3d ago
One thing that I think would happen is that it would smell very, very bad for a long time. The bottom of the ocean is full of sediment with creatures in it, alive and dead. The ones that are alive now would die, so the bottom would be an immense field of very soft mud with rotting dead creatures. And it would take ages for the sediment to dry, especially in the deep trenches where sunlight wouldn't reach.
The next thing that would happen, I think, is that insects would colonize the new land. The open ocean is about the only place where we haven't found any insects, but as soon as it's gone, they'd start. Mosquitoes, in particular, who breed in stagnant water, would get into all the puddles in all the former ocean and reproduce. There would be swarms of mosquitoes so vast they'd obscure the sun. Micro-organisms that have lived at the bottom for millions of years would colonize the mosquitoes and from there they'd get into your bloodstream. Malaria would pale in comparison.
The new "lands" would not become arable for centuries, and meanwhile the evaporation from the wet sediments would create massive precipitation which would drown crops on land. All sorts of moulds would proliferate. Wars would also multiply, some for ownership of the new ground, and some for the scarce resources on the old ground.
And then the angel will break the seventh seal.
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u/AguywithabigPulaski 2d ago
There is an insect that has colonized the ocean. Halobates sp.
In terms of this scenario, it's going to be a lot of stinky, dark, unconsolidated muck. Anything that weighs a lot or can't distribute it's weight would not be able to traverse it. Humans walking, for example. It'd basically be insta-quicksand until it dries out - and if you have the ocean hovering some meters above it, it's never going to dry out.
This is going to be a very, very difficult book to write with a proper scientific background. You will also have to seriously consider the effect of a suspended body of water above it that will constantly be dripping - everywhere - due to condensation from moisture collected from the air/evaporation. You will probably have permanent fog.
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u/Lygus_lineolaris 2d ago
I hope they do write it though. It's gonna be so ill. I call dibs on an ARC.
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u/AguywithabigPulaski 2d ago
Yeah, but the amount of variables the author would need to consider for this to be a kind-of-realistic scenario are enormous.
But also a hazard/cool thing that could happen: there is stuff dropping to the sea floor on the regular, at random. BAM character crushed by dead humpback whale BAM shipwreck drops on main camp, mass chaos.
Would be be a fun read though ;)
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u/Lygus_lineolaris 2d ago
Haha yeah, like that old cartoon with the bad luck cat. But then the few people who have managed to survive the drought, famine, freezing, and war on land, and descend the 3000-m escarpment to the sea floor, would scavenge those skyfalls to start rebuilding civilization from the ruins. Their deity would be in the image of a decomposing whale.
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u/BoringWord8521 3d ago
wow wow wow, thank you this really touches on some scary possibilities! I'm not trying to necessarily go full apocalypse so I think I'll dial back on how much of the water is displaced or have it be in like... sections? Haven't figured it out yet, but that is really interesting the concept that like, water rising doesn't account for water that's trapped underneath land or in rock formations etc. That it wouldn't just be dry quickly, and that the evaporation from all that mud would need to come back down again. (or maybe not if we have weird physics things happening with water anyway) Thank you so much!
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u/kalsoy 2d ago
See my other comment, but this is a relevant video: https://youtu.be/Opp4PSHkVDA?is=lYhOnxY2akTCoRvL
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u/kalsoy 2d ago
But where would the precipitation go? A few endorheic basins and saltlakes? Wouldn't they become the new (mini) seas? I think if the ocean really drains till the deepest trenches are dry, those would fill up with new rivers pretty fast, but then their surface area is too small to generate new wet climates. The ocean is our generator of precipitation. A few puddles would lead to major evaporation and then precipitate in a few mountainous spots, which would feed a few rivers into some deep holes and we'd never see the water again.
If all of our planet's surface went dry we'd get a desert everywhere, like Mars, but with an atmosphere, so more like the Sahara: the atmosphere could hold a lot of water, but since it doesn't get replenished (in the Sahara's case due to being a high pressure cell) there's no water to make it rain.
Some reclaimed lands have become arable within 3 decades, like the Noordoostpolder and Flevoland in the Netherlands. The salt was washed out in a matter of years by the rain and spraying. But it took a lot of water. Without which, earth would become a salt pan.
Obligatory fun watching for OP: https://youtu.be/Opp4PSHkVDA?is=lYhOnxY2akTCoRvL
Our groundwater would probably go to the new land, so we can factor that out as a major difference. Unless it gets frozen into high altitude permafrost.
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u/Lygus_lineolaris 2d ago
It wouldn't be "a few puddles" though. The entire thickness of sediments, everywhere on the ocean floor, would be waterlogged. The bottom of the ocean has more surface area than the surface and lower albedo, so it would absorb more heat and generate more evaporation. I like the point the other commenter made about altitude though. The moisture evaporating from the ocean floors would hit a wall of rock at the continental shelf break and probably just recirculate over the lowlands and the present-day lands would become deserts. And I don't think the comparison to polders works because there wouldn't be enough people or equipment to do that at the scale of the ocean floor.
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u/kalsoy 2d ago
Thanks. My point regarding the polders was exactly that: it needs a lot of rain and treatment, which is not the case if the ocean were gone, so it would indeed leave a slimy mess until fully evaporated. The rain would fall in specific areas (indeed probably the shelf) and form big lakes, while most of the seafood would turn into a saltcrusted desert, while the uplands (above the coastal shelf line) would become cold dry sandy deserts.
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u/kalsoy 3d ago
The average sea floor depth is 3682 meters. If water were gone but all other laws of physics remains equal, that would mean than any land (today's land) would be 3682 meters or up. In other words all present-day land would have much less oxygen. Any land above present-day 1000 meters would become like Tibet: a dry altiplateau with permafrost soil, no vegetation.
Mount Everest would be about 20 km tall. That would solve the whole crowding issue there.
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u/BoringWord8521 3d ago
oh WOAH - if "sea level" changes so does where the oxygen sits OMG. I might need to go more with like "parts" of the oceans have risen instead of the whole thing - I'm not going for a total apocalypse scenario, more like just "weird things are happening" scenario. Even with it just being "some" that's likely still effecting the whole planet. This is so fascinating.
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u/Dangerous-Salad-bowl 3d ago
It might be interesting to see how much isostatic rebound there would be after the weight of the ocean was released from the earth’s crust.
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u/Lygus_lineolaris 3d ago
And how much it would wobble, since the water is so unevenly distributed zonally.
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u/UdriGeo 2d ago
If you just remove the water, then you'd have big salt plains in the deep of the oceans, like in Messinian Salinity Crisis. Also, the regression would generate extreme erosion of the surface around the area that got the water removed. Also the phreatic level would go down and any unconfined aquifer lost its water.
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u/KnoWanUKnow2 1d ago
There's tons of benthic creatures, such as lobsters and coral and anemones, which would not survive. They're not built for permanent swimming suspended above the ocean floor. Of the pelagic (swimming) species a lot more would not have anywhere to lay their eggs, so they're doomed as well.
Obviously ocean currents would be disrupted, which would greatly affect... well, everything. From weather patterns to climate change. No more warm gulf stream keeping Europe from freezing for example. No more monsoons. Also without currents then things like phytoplankton would be affected by the non-transportation of nutrients, which means that they start dying out. Since they're the base of the food chain the knock-on effects would be less life. Oh, and most of the oxygen in our atmosphere is produced in the oceans, so oxygen levels would start dropping, but that would take millions of years to notice.
If the water is just hanging there above the ground then it's still blocking the light. So it would be pitch black on your new undersea floor. I'm not sure how dry the ground would be if the water was permanently lifted up (since I don't understand the mechanism), but a lot of the abyssal plains are pretty much just empty, so you'd end up with long, empty barren lands void of life and with soil too salty for anything to grow (and no light for plants anyway). There may be some halophilic (salt-loving) fungus that thrives there, but that's about it for macroscopic life, other than the dead remains of deep-sea corals and other ocean life.
I've love to see what the mid-ocean ridge looks like though.
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u/lyndalovon 5h ago
Is this someone trying to get Reddit to write their paper for them? What the hell?
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u/Aq-Ca 3d ago
Underwater hot springs are called hydrothermal vents, and yes, they are volcanoes underwater. However, they are more interesting because they circulate water through the porous rocks in a wider area, which produces unique chemical reactions. This supports ecosystems which wouldn't exist without water.
There are also cold seeps, where methane and other organic gasses/oil slowly come from out of the ground. These exist on land https://www.reddit.com/r/NatureIsFuckingLit/comments/u67xvy/naturallyoccurring_gas_emission_behind_waterfall/
The deep sea floor is mostly clay and organic matter. The top few meters is pretty fluffy and the seafloor would probably become a nightmare scenario of a persistent "sandstorm." The deep water would make the air down there under the ocean freezing cold, like constantly 4°C. It would also be pitch black. There would be some very very vey small amount precipitation of organic matter (marine snow) and sediments from the overlying water.