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Natural disasters of the Asia Pacific Region: Tectonic Plates

Resources to support the study of natural disasters in the Asia Pacific Region.

The world's tectonic plates

   The movement of the plates, and the activity inside the Earth, is called plate tectonics.

   Plate tectonics cause earthquakes and volcanoes. The point where two plates meet is called a plate boundary. Earthquakes and volcanoes are most likely to occur either on or near plate boundaries.

   Today the earth is generally considered to have 15 major plates, 7 or 8 of which are primary plates and the others are smaller, secondary plates.

   Play with the interactive map to see the world's tectonic plates and the distribution of earthquakes and volcanoes.

Simulation of plate boundaries

   Explore how plates move on the surface of the earth. You can change temperature, composition, thickness, types and movements of the plates. Discover how to create new mountains, volcanoes, or oceans!

Plate Tectonics
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Plate boundaries

   The earth's continents are constantly moving due to the motions of the tectonic plates. The border between two tectonic plates is called a boundary. All the tectonic plates are constantly moving — very slowly — around the planet, but in many different directions. Based on their moving directions, tectonic plate boundaries are grouped into three types and sub types:



  • Divergent boundaries (also known as constructive boundaries): plates moving apart from each other, form of trenches, rifts, lakes, continents, oceans


  • Transform boundaries (also known as conservative boundaries): plates are sliding past each other, form of earthquakes

   The following animation explains the motions of three types of plate boundaries.

Plate movements

Subduction Zones and Volcanoes

   When an oceanic plate collides with a continental plate, the denser oceanic crust gets bent and subducted beneath the lighter and thicker continental crust. This forms what is called a subduction zone. As the oceanic crust sinks, a deep oceanic trench, or valley, is formed.


Faults and Earthquakes

   Transform boundaries and the resulting faults produce many earthquakes because edges of tectonic plates are jagged rather than smooth. As the plates grind past each other, the jagged edges strike each other, catch, and stick, "locking" the plates in place for a time. Because the plates are locked together without moving, a lot of stress builds up at the fault line. This stress is released in quick bursts when the plates suddenly slip into new positions. The sudden movement is what we feel as the shaking and trembling of an earthquake.