Constructive (divergent) plate boundaries

When two oceanic plates pull apart, a gap forms, and magma rises due to convection currents. This magma cools and solidifies into new basaltic crust, a process called sea floor spreading or ridge push, which can trigger small earthquakes. Over time, the crust forms mid-ocean ridges and submarine volcanoes, which may emerge as volcanic islands. These are called shield volcanoes, known for non-explosive eruptions due to low pressure. . An example is the Mid-Atlantic Ridge between the Eurasian and North American plates. If continental plates pull apart, a rift valley can form as land drops between faults.