I’m not proposing this as an actual solution, it’s just a dumb idea. But if we dug a huge, wide hole at the bottom of the ocean, or maybe widened the Mariana Trench or something, could that extra space make the sea levels drop enough to keep the land from flooding?
The energy required to lift that amount of rock from the seabed to above the surface would be impractical. But good news! It doesn’t need to be from the bottom of the sea, just a part below the desired waterline. So we can dig these big holes you want right off the coastline and then, as a bonus, use the materials as landfill to raise or extend the current coastline. Still wildly impractical, but much less so than digging at the bottom.
Coopr8@kbin.earth 4 hours ago
Possible yes, practical no. Effectively you would need to build a new sub-continant to have an appreciable impact on sea level. That said, you don't need to dredge from the low point in the ocean, all that matters is displacing solid material from below sea level to above sea level, so the best option would be to find a shallow sea with an existing archipelago of islands and build up from there making it a deep sea with the islands connected as a continent. Alternately you could go after reefs, despite the collateral damage, with the great barrier reef being the obvious choice, essentially pump up dredged sand from the surrounding ocean bed onto the reef to make new land, the reef has the advantage of being very shallow and stabilized with lots of surface area, so good for making lots of land if you don't mind being the architect of an ecological apocalypse of unprecedented proportions.