There are 3 main types of plate boundaries, all of which can cause earthquakes. These are destructive, constructive and conservative margins.
Destructive Boundary
- Subduction zones are one type of destructive boundary. This is where an oceanic and continental plate move together. The oceanic crust is more dense and therefore is submerged below the continental crust. Earthquakes occur where the plates rub together, bend and fracture. The oceanic crust melts, forming magma, which rises and forms a volcano. This occurs in the Andes.
- Collision zones are the other type of destructive boundary. This involves two continental plates moving towards each other. Earthquakes occur as rock folds and fractures. An example of this is in the Himalayas.
Constructive Boundary
This is where two oceanic plates are moving away from each other. The mantle near the gap that is made melts due to decreasing pressure. The mantle comes out as pillow lava when underwater, with volcanoes all the way down the ridge. There are minor earthquakes due to lava solidifying and collapsing. An example is the Mid Atlantic Ridge.
Conservative Boundary
Two plates rub against each others side as they move in opposite directions. The earthquakes caused by this can be extremely dangerous as often, the tension between the two plates builds up, before suddenly being released, causing dramatic shocks through the ground. The San Andreas Fault is an example of this.
Destructive Boundary
- Subduction zones are one type of destructive boundary. This is where an oceanic and continental plate move together. The oceanic crust is more dense and therefore is submerged below the continental crust. Earthquakes occur where the plates rub together, bend and fracture. The oceanic crust melts, forming magma, which rises and forms a volcano. This occurs in the Andes.
- Collision zones are the other type of destructive boundary. This involves two continental plates moving towards each other. Earthquakes occur as rock folds and fractures. An example of this is in the Himalayas.
Constructive Boundary
This is where two oceanic plates are moving away from each other. The mantle near the gap that is made melts due to decreasing pressure. The mantle comes out as pillow lava when underwater, with volcanoes all the way down the ridge. There are minor earthquakes due to lava solidifying and collapsing. An example is the Mid Atlantic Ridge.
Conservative Boundary
Two plates rub against each others side as they move in opposite directions. The earthquakes caused by this can be extremely dangerous as often, the tension between the two plates builds up, before suddenly being released, causing dramatic shocks through the ground. The San Andreas Fault is an example of this.
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