Sjávarbotnsskiptingin

Sjávarbotnsskiptingin, meaning "seafloor spreading" in Icelandic, is a fundamental geological process that occurs at mid-ocean ridges. It describes the phenomenon where new oceanic crust is formed as tectonic plates move apart. Magma from the Earth's mantle rises to the surface, erupts as lava, and cools to form new rock. This newly formed crust then pushes the older crust away from the ridge.

This process is a key component of the theory of plate tectonics. Mid-ocean ridges are underwater mountain ranges where this spreading is most active. As the seafloor spreads, it creates a gap that is continuously filled by rising magma. This magma solidifies, creating new basaltic rock that becomes part of the oceanic lithosphere. The rate of seafloor spreading varies, with some ridges spreading faster than others.

The discovery and understanding of seafloor spreading revolutionized our understanding of Earth's geology. It explains the formation of ocean basins, the distribution of earthquakes and volcanoes, and the movement of continents over geological time. The magnetic stripes found on the seafloor, which alternate in polarity, provide strong evidence for this process, as they record the Earth's magnetic field reversals as new crust forms and moves away from the ridge.