What surprised scientists when they first mapped the ocean floor?
The ocean’s islands are floating on the surface of the water.
The ocean is a smooth, flat plain from one continent to the other.
The ocean floor contains tall mountains and deep canyons.
The ocean floor is almost totally covered in vegetation.
The correct answer is: The ocean floor contains tall mountains and deep canyons.
When scientists first mapped the ocean floor, they were surprised to discover that the ocean floor was not a smooth, flat plain as they had previously thought. Instead, they found tall mountains, deep canyons, and other geological features that were previously unknown. This led to a better understanding of plate tectonics and the formation of the Earth's crust.