A divergent boundary occurs when two tectonic plates move away from each other. Along these boundaries, earthquakes are common and magma (molten rock) rises from the Earth's mantle to the surface, solidifying to create new oceanic crust. ... Two plates sliding past each other forms a transform plate boundary.

Why is divergent boundary important?

Divergent boundaries within continents initially produce rifts, which eventually become rift valleys. ... This supplies the area with vast amounts of heat and a reduction in pressure that melts rock from the asthenosphere (or upper mantle) beneath the rift area, forming large flood basalt or lava flows.

Where do divergent boundaries usually occur?

Most divergent boundaries are located along mid-ocean oceanic ridges (although some are on land). The mid-ocean ridge system is a giant undersea mountain range, and is the largest geological feature on Earth; at 65,000 km long and about 1000 km wide, it covers 23% of Earth's surface (Figure 4.5.