Plate tectonics is one of those topics that you generally skim through in junior high. But what exactly are plates and how are they related to earthquakes? Plate tectonics is a theory that has become a well-accepted reason to explain geological facts about Earth.
The basic idea of plate tectonics is that the Earth is made up of several large, moving pieces of solid rock, on the ocean and on continents. They are plates floating on softer like rock. The plates are in constant motion and sometimes run into one another, this is called a collision, or they slide along, over or under one another. Their motion, and collisions can explain several geological events including earthquakes. It also explains the presence of faults on many continents, where two plates collide, including the San Andreas fault in California.
Under the ocean, the plates explain why there is major seismic energy in the Pacific Ocean and how deep ocean trenches and large fracture zones and rifts in the ocean floor occur. Plates also give reason to associate volcanoes and large mountain belts like the Andes. Plates are the reason mountain belts form, from the pushing of plates and vast spreading and colliding of plate tectonics..
Why are plates so important to understand? How do they contribute to our overall understanding of Earth and seismic motion?
Here is a great article about Plate Tectonics with great illustrations and explanations about faults, environments and locations of plates on Earth. Check it out!
The Pangaea Theory asserts that all of the plates were connected at one point and slowly shifted away from one another. This large continent is called Pangaea. Take the online quiz to test and learn more about this excited theory related to plate tectonics!
There are four types of plate boundaries.
1. Convergent Plate Boundary also known as Destructive Boundary– This is when the continental plate and oceanic plate collide, this causes the oceanic plate to sink into the mantle and destroyed. This can cause explosive volcanoes and violent earthquakes. Example: The Himalayas.
2. Divergent Plate Boundary also known as Constructive Boundary– This boundary happens when two oceanic plates move away from each other. Lava erupts and a new crust is formed on the sea bed. There are underwater volcanoes and gentle earthquakes. Example: The Mid- Atlantic Ridge.
3. Transform Plate Boundary also known as Conservative Boundary – This is when two tectonic plates move in different directions or at different speeds. Plates are locked together by friction while pressure builds up. Finally, the plate breaks along the fault line. There shouldn’t be volcanoes but there will be violent earthquakes. Example: San Andreas Fault.
4. Collision Boundary- This is when two continental plates move together. The two plates are too light to sink into the mantle. Therefore, the plate buckles up and form mountains.