Earth's Layers

Standing on the surface of Earth, it’s hard to imagine just how complex the ground underneath our feet really is. But our planet isn’t just a dead ball of rock—it’s made up of many layers of material, and those layers are always shifting and changing.

Have you ever seen a geyser in person? Have you ever experienced an earthquake or seen a live volcano? These natural occurrences are evidence of Earth’s changes, and they are the result of activity underneath Earth’s surface.

Earth’s interior structure causes changes on its surface—changes that affect our lives. The effects we see on our landscape can be extreme, but they only reflect a small part of what’s really going on underneath.

Under the Ocean

There is one part of Earth’s surface that humans have explored very little of: the ocean floor. The deepest areas of the ocean are still difficult to access, but our limited exploration has already yielded impressive insights into what makes up our planet.

Marine geologist Carol Reiss researches earthquakes by diving to the ocean floor in a submersible. She takes samples of newly formed sediment to determine how earthquakes change Earth’s crust over time. Reiss’s work contributes to a growing body of knowledge about Earth’s oceanic and continental crusts.

Geologists studying the development of Earth’s crust believe that we can learn a great deal from the ocean floor. Sediment samples like Reiss’s reveal a record of Earth’s past natural disasters. Geologists analyze them to gather new evidence about how earthquakes and tsunamis change Earth’s surface. As a society, we can use this information to better prepare for future natural disasters.