The Atlantic Ocean grows wider by roughly an inch each year, driven by molten rock that rises through the Mid-Atlantic Ridge and hardens into fresh seafloor. That rate, approximately 2.5 centimeters ...

The spread of the ocean floor, as tectonic plates spread apart, is known but hard to observe. Scientists have now documented the process in action. By K. R. Callaway Far down on the ocean floor, Earth ...

One of the central features of plate tectonics is the formation of new crust at mid-ocean ridges. Part of the spreading process that drives continents apart, it was arguably the discovery of these ...