Destructive Plate Boundaries PDF

**Describe and Explain Destructive Plate Boundaries** 1.Convection currents moving through the magma in the mantle cause plates to collide with each other at convergent plate boundaries. **[Oceanic/oceanic]** 2.When an oceanic plate collides with another plate (oceanic or continental) the heavier...

**Describe and Explain Destructive Plate Boundaries** 1.Convection currents moving through the magma in the mantle cause plates to collide with each other at convergent plate boundaries. **[Oceanic/oceanic]** 2.When an oceanic plate collides with another plate (oceanic or continental) the heavier and denser of the two plates subducts under the lighter, less dense plate. 3.As convection currents drag the plate downwards, an arc-shaped ocean trench is formed at the subduction zone. 4.Fluids (water) and gases (carbon dioxide and Sulphur dioxide) are released from the crust, causing temperatures in the area to rapidly increase and the sinking crust to melt. 5\. A silica and gas rich magma formed from the destroyed crust burns a path through the overlying, lighter oceanic crust. **[Oceanic/Continental]** 6.At the boundary where the Pacific and the Eurasian oceanic plates collide, explosive volcanic eruptions occur on the sea floor where the magma reaches the surface of the earth. 7.Over time a chain of volcanic islands known as an island arc form parallel to the oceanic trench (e.g. the Japanese islands) 8.Oceanic crust is also destroyed at the boundary where the Nazca Oceanic plate and South American Continental plate collide. 9.Overtime, a chain of volcanic mountains form on the South American (continental plate) parallel to the subduction zone (Andes Volcanic Arc) 10.Rocks at the edges of the South American (continental plate) also buckle upwards, forming a range of fold mountains such as the Andes in South America. 11.Powerful earthquakes are also common at destructive plate boundaries as the rough edges of rocks at either side of the boundary can lock in position. **[Continental/continental]** 12.The last type of destructive plate boundary is where a continental plate collides with another continental plate (e.g. Eurasian and African plates) 13.No crust in destroyed, instead both plates buckle upwards forming fold mountain ranges (e.g the Alps). 14\. Earthquakes are generated when convection currents eventually force the plates to move past one another very suddenly. 15.Diagram of destructive plate boundary.