Divergent plate boundaries arise when two plates move apart from each other. Magma rises from the mantle, filling the gap and forming new oceanic crust.

This often leads to elongated underwater mountain ranges and mild volcanism.

 

The Mid-Atlantic Ridge between the North American and Eurasian, or South American and African plates. Frequent light earthquakes and shield volcanoes occur here, such as on Iceland—which sits directly on this plate boundary.