Mid-Atlantic Ridge
Topic: Continental Drift, Sea-floor Spreading and Plate Tectonics · NCERT: Class 11, Ch 4 "Distribution of Oceans and Continents"; Class 11, Ch 12 "Water (Oceans)"
Meaning
The Mid-Atlantic Ridge is a long chain of underwater mountains that runs down the middle of the Atlantic Ocean. It is the best-known divergent boundary, a place where plates pull apart. Here the North and South American plates move away from the Eurasian and African plates. Magma rises into the gap, cools and forms new ocean crust. This keeps widening the Atlantic. Rocks nearest the crest are the youngest. Rocks get older the farther they are from it.
Example
Iceland is a part of the Mid-Atlantic Ridge that rises above sea level, with a hotspot underneath. Its eruptions, such as those on the Reykjanes peninsula, show new crust forming as the plates pull apart.
Don't confuse with
- East African Rift: also a divergent boundary, but it is on land. There the African plate is splitting into the Nubian and Somali plates and forming rift valleys, not an open ocean ridge.