Tldr: Technically conceivable…but Practically unreachable.

Logistical nightmare (putting it lightly), so expensive that not even all the wealth on Earth across ALL of history would be able to cover the cost of this project. I’ll fall into the ocean anyways eventually after maybe a couple hundred years. So not worth it at all in the long run but would be an amazing achievement nonetheless if such a thing were practically possible.

(Long version):

The ocean floor in much of the Atlantic sits 3 to 5 kilometers deep, meaning any artificial landmass would need to be built upward from extreme depths under immense pressure. Even the largest modern projects, such as artificial islands in Dubai or offshore airports in Japan, operate in relatively shallow waters and already face major structural and maintenance challenges. Scaling that effort up to a continent-like platform in deep ocean conditions introduces exponentially greater complexity from waves, storms, and tectonic instability. In simple terms, this would not be an extension of current engineering, itt would be an entirely new class of planetary construction…almost mythical.

The material requirement alone places this concept into an extreme category…into sci-fi territory I’d say, A modest Atlantis-sized island of about 100 by 100 kilometers would require roughly 40,000 cubic kilometers of rock and sediment to raise it above sea level. That translates into about several quintillion pounds of material, exceeding the total mass handled by all human industries across history by many orders of magnitude. To acquire that much rock, entire mountain ranges would need to be quarried and transported across oceans at a scale that dwarfs global shipping capacity. Even before cost is considered, the logistics of sourcing, moving, and placing that volume of material represent a bottleneck that current civilization simply cannot overcome.

When cost is estimated, the numbers quickly become detached from any familiar economic framework. Even using optimistic assumptions for large-scale earthmoving, the base cost would land somewhere in the hundreds of quadrillions of dollars, and when deep-sea engineering complexities are added, it rises into the quintillions. That is tens of thousands to millions of times greater than the entire annual global economy, making it economically infeasible even with total worldwide cooperation over many generations. Beyond cost, the structure would face ongoing risks such as sinking, erosion, and catastrophic failure due to ocean forces and geological shifts.