What is seafloor spreading?
Seafloor spreading is simply the idea that volcanic activity forms new oceanic crust.
In order to understand what seafloor spreading is in depth, it's important that we understand a few concepts and terms.
- What are divergent boundaries? - In plate tectonics, divergent boundaries are tectonic plates that move away from each other
- How are volcanoes formed in divergent boundaries? - As plates move away from each other, magma rises
- What is the mid ocean ridge? - The mid ocean ridge is a continuous range of underwater volcanoes that wrap around earth.
- What happens when magma touches water? - When magma touches water, it cools and eventually hardens.
If we can understand these terms, we can easily comprehend what seafloor spreading is.
If we take a look at the attached image, the image represents what occurs during sea floor spreading. First we must note that sea floor spreading occurs in mid ocean ridges. Because we know that mid ocean ridges is a continuous range of underwater volcanoes , we know that the mid ocean ridges are formed on divergent boundaries (as volcanoes under water are formed by divergent boundaries) . As we know, at divergent boundaries, the tectonic plates move away from each other. As the tectonic plates move away from each other, magma pushes itself up and as the magma touches the water it cools and hardens forming the crust as shown in the image. (Note that this takes several years to happen)