Abyssal Plain

As you explored the ocean floor, the last zone that you crossed on the continental margin was the continental rise. The rise had less than a one percent slope — hardly much of a hill. In fact, you might not be able to tell that it has a slope at all; however, there is a zone with an even smaller slope than the continental rise.

In many oceans, the next zone is the abyssal plain, and it marks the beginning of the deep ocean floor. Stretching on for miles in all directions, this is one of the flattest places on Earth. There are some small hills, which are remnants from past volcanic activity. If you have ever been to the Great Plains between the Rocky Mountains and the Mississippi River in the United States, the abyssal plain might look familiar.

View of the horizon in the Great Plains. This area once formed the bottom of a great, inland sea.

The abyssal plain will provide you with the opportunity to use real data to see how the age of the seafloor compares to ocean depth.

Essential Questions

• What is the difference between an abyssal plain and abyssal hill?
• What is the relationship between the depth and age of the ocean floor?