Examining the ocean floor had many benefits to science. For geologists, it was the final piece of a puzzle that would explain how the Earth might be constructed. Surrounding this mantle is a thin crust of colder, solid minerals. This crust is like a thin skin that floats on the fluid magma. We all live on this thin crust, on one of these plates.
Scientists often make the analogy to a loose skin surrounding an orange.
Areas that are free of this prodigious weight of water rise and form continents. Flaws in this delicate layer can result in volcanoes, and we now know that these can occur in the deepest oceans as well as on land.