I believe the answer is earthquakes.
Basically it means when something is moving in a line and is rotating in a larger system at the same time it appears to move. If you look it up online you can easily find a picture or two that should explain it pretty well.
Vast flat areas does NOT describe the land of the Czech Republic.
It is the isthmus of Suez which is very narrow.
Answer:
The crust is the coldest layer of Earth. It floats on the fluid-like matter called the Mantle.
Explanation: