biology

• 1. Divergent plate boundary

  Movements: Two tectonic plates moving apart

  1. Convergent plate boundary

  Movement: Two tectonic plates moving towards each other

  1. Transform plate boundary

  Movement: Two tectonic plates sliding past each other.
• The type of plate movement that results in the formation of a rift valley is a divergent plate movement where two continental plates move apart.

  Rift valleys are formed when two continental plates move apart, rocks eventually fracture to form parallel faults. Lastly, the rock between these faults collapses to form a deep rift valley with steep sides.
•  The formation of a rift valley at divergent plate margins is when two continental plates move apart. The rocks eventually fracture to form parallel faults, as such these rocks collapse to form deep rift valleys with steep sides. As the plates move apart, the decrease in overlying pressure causes parts of the underlying mantle to melt, forming magma. The magma then rises through the weak areas in the crust to the earth’s surface, forming volcanoes.
• The theory of plate tectonics is that the Earth has a three-layered structure. The Earth’s lithosphere is broken up into huge pieces called tectonic plates, these tectonic plates are always moving. Plate movements result in the formation of landforms such as mountain ranges and phenomena such as tsunamis.
• The Earth’s internal structure consists of  uppermost part of the mantle and the crust are the solid parts of the Earth. Together, they are known as the lithosphere. The lithosphere is divided into huge pieces called tectonic plates. Two types of crusts that make up tectonic plates are continental and oceanic crusts. The asthenosphere lies below the lithosphere, heat from the core causes the rocks in the asthenosphere to melt. The plate movements result in three types of plate boundaries which are divergent, convergent and transform plate boundaries.
• Convection currents in the mantle result in plate movements as the heat from the Earth’s core causes the mantle material to become less dense which causes the mantle material to rise towards the surface. The rising mantle material then spread beneath the plates and drag them apart, causing divergent plate movement. The mantle material then loses heat and sinks towards the core. Convergent plate movement occurs where the convection currents collide. The material then gets heated again and the process repeats. This rising and sinking of the mantle material forms convection currents.