What is a Mid Ocean Ridge? (Plate Tectonics)

To understand the Mid-Ocean Ridge, you must understand the massive physics of Plate Tectonics. The Earth's crust is cracked into massive puzzle pieces called Tectonic Plates. At the bottom of the ocean, two plates are aggressively pulling away from each other (a Divergent Boundary). As they rip apart, a massive crack opens up. Extremely hot, violent liquid magma from deep inside the Earth's mantle forcefully erupts out of the crack. When this burning magma hits the freezing ocean water, it instantly cools down and solidifies into fresh black rock, creating massive underwater mountains.

The absolute most famous and heavily studied section is the Mid-Atlantic Ridge. It runs directly down the absolute center of the Atlantic Ocean, perfectly separating North America from Europe. It is actively growing right now. Because the magma keeps erupting, the Atlantic Ocean is physically becoming a few centimeters wider every single year!

Normally, these massive ridges are buried thousands of meters underwater. But in one rare, magical place on Earth, the volcanic eruptions were so massive that the mountain grew taller than the ocean surface. That place is the country of Iceland. If you visit Iceland, you can physically walk right between the two splitting tectonic plates.