Seafloor Spreading

Seafloor spreading is the process by which new oceanic crust is formed through volcanic activity and then gradually moves away from the mid-ocean ridges. This process is a key component of plate tectonics, the theory that explains the movement of Earth's lithospheric plates.

Key Concepts

Mid-Ocean Ridges: These are underwater mountain ranges where seafloor spreading occurs. Magma rises from the mantle and solidifies to form new crust, pushing the existing crust away from the ridge.
Subduction Zones: As the new crust moves away from the mid-ocean ridges, it eventually encounters areas where it is forced beneath another tectonic plate in a process known as subduction.
Magnetic Striping: The seafloor is marked with alternating stripes of high and low magnetic intensity, which provide evidence for the process of seafloor spreading.
Age of the Seafloor: The further the crust is from the mid-ocean ridge, the older it is. This supports the idea of seafloor spreading, as new crust is constantly being created at the ridges.

Study Guide

When studying seafloor spreading, it's important to understand the following key points:

Describe the process of seafloor spreading and the role of mid-ocean ridges.
Explain the evidence for seafloor spreading, including magnetic striping and the age of the seafloor.
Understand the connection between seafloor spreading and plate tectonics, including the formation of new crust and the movement of tectonic plates.
Compare and contrast seafloor spreading with subduction, and explain how they are related in the process of plate tectonics.
Discuss the significance of seafloor spreading in shaping Earth's geology and its impact on the distribution of continents and ocean basins.

By mastering these concepts, you will have a solid understanding of seafloor spreading and its role in the dynamic processes that shape the Earth's surface.