It was called pangea
The term for the separation of the continents is "continental drift." This theory, proposed by Alfred Wegener in the early 20th century, suggests that the Earth's continents were once joined as a single landmass called Pangaea before drifting apart over millions of years.
Continental drift is the theory that Earth's continents were once all connected as a single supercontinent called Pangaea and have since drifted apart to their current positions over millions of years. This movement is driven by the slow shifting of tectonic plates that make up Earth's crust.
The term "big continents" is not a specific geographical term. However, the biggest continents on Earth are Asia, Africa, and the Americas. These continents are large landmasses that are significant in terms of size and population.
Mockingbirds are a group of New World passerine birds from the Mimidae family. The "New World" is the term given to the two American continents.
One possible sentence for the term "continental drift" could be: "The theory of continental drift suggests that the Earth's continents were once joined together as a single supercontinent called Pangaea and have since moved apart over millions of years."
The term that best describes the movement is gradual.
Moving
Anti-continents refer to large areas of land that existed in the geological past but are now submerged under the ocean. These landmasses were part of the supercontinents that have been breaking apart and drifting over millions of years due to plate tectonics. Examples include Zealandia and the Kerguelen Plateau.
The term that best describes the movement is gradual.
The term for big bodies of land is continents.
That term could be "landform".
"Sustainable" means that it can be sustained in the long term. Obviously, if we expect to survive on this planets thousands or perhaps millions of years, short-term solutions are just that: for the short term. A long-term solution must be found eventually.