The Earth is covered in massive slabs of irregularly shaped rock. These slabs of rock are called tectonic plates. Tectonic plates are pieces of the Earth's crust and uppermost mantle. When together, they are referred to as the lithosphere. Tectonic plate boundaries are where the plates meet. Boundaries are the sections where valleys, volcanoes, earthquakes and mountains occur. There are three different types of tectonic plate boundaries; divergent, convergent and transform.
|
Divergent plate boundaries
Divergent plates separate from each other and create lithosphere. These movements are often found on the ocean floor, where magma comes out of the core and streams outwards to cool and harden, thus creating new crust. Mid-oceanic ridges such as the Mid-Atlantic ridge which reaches from Iceland all through to the tip of South America are found at divergent plates. The Mid-Atlantic ridge is dividing North America from Europe through the formation of lithosphere. This process is identified as sea floor spreading.
Divergent plates separate from each other and create lithosphere. These movements are often found on the ocean floor, where magma comes out of the core and streams outwards to cool and harden, thus creating new crust. Mid-oceanic ridges such as the Mid-Atlantic ridge which reaches from Iceland all through to the tip of South America are found at divergent plates. The Mid-Atlantic ridge is dividing North America from Europe through the formation of lithosphere. This process is identified as sea floor spreading.
Convergent plate boundaries
Convergent plates collide together and destroy lithosphere. When these plates collide, one plate goes over and the other plate goes over. This is known as a subduction zone. The collision of two plates usually result in island arcs, oceanic trenches, volcanoes and mountain ranges. A famous example of mountain ranges caused by plate collision is the Himalayas. The Himalayas were formed from the Indian plate moving into the Eurasian plate.
Transform plate boundaries
Transform plates slide next to each other, and can result in very powerful earthquakes. A famous example of a transform fault is the San Andreas Fault line that runs from California to Mexico. The San Andreas Fault is found at the boundary of the Pacific Plate and the North American Plate. The Pacific plate is sliding northways alongside the North American Plate.
What is sea floor spreading?
Sea floor spreading is a hypothesis developed in the early 1960's that proposed that new ocean floor is created when two plates move away from each other. Sea floor spreading is a procedure that develops at mid-ocean ridges where new oceanic crust is composed through volcanic activity and then eventually moves away from the ridge.
Sea floor spreading is a hypothesis developed in the early 1960's that proposed that new ocean floor is created when two plates move away from each other. Sea floor spreading is a procedure that develops at mid-ocean ridges where new oceanic crust is composed through volcanic activity and then eventually moves away from the ridge.