Discoveries along the ocean floor have provided evidence of large scale geologic changes, like continental drift, and supported theories, like plate tectonics. Scientists believe that the ocean floor can tell us much more about the geologic processes on Earth. However, humans generally cannot see below 50 m (164 ft) from the surface because most of the entire ocean area is covered in eternal darkness. The water that covers the ocean floor has proven to be such an obstacle that even today, we know more about the surface features of the moon, Venus, and Mars than many parts of our own oceans!

As a result, Dr. Walter Smith must rely on state-of-the-art technology to map the ocean floor. He analyzes streams of data from orbiting satellites that detect slight changes in elevation on the ocean’s surface.

Why does the elevation change matter? Gravity is the force of attraction between two objects, and is directly proportional to an object’s mass. Therefore, the larger the object’s mass, the larger its gravitational field. The gravitational field of a massive underwater volcano, called a seamount, will attract more water molecules to it than a smaller seamount. This results in the appearance of a slight bulge on the ocean’s surface just above the seamount that can be detected by satellites. By scouring the ocean surface for these bulges, Walter is able to generate maps of the ocean floor.

The maps that Dr. Smith produces are helping us solve many mysteries of our planet. His maps provide areas of safe passage for boats and submarines, a better understanding of the geologic processes that continue to shape our planet, and information to improve weather forecasts that are affected by ocean currents.