The world is built of tectonic plates, or movable slabs of the Earth’s crust, floating on a liquid mantle. These plates fit together like a jigsaw puzzle at joins known as fault lines.
All tectonic plates move approximately one centimetre per year colliding with, sliding past, or moving away from the plates around them. The Australian plate is one of the fastest moving plates, moving at a rate of 7cm per year in a northeast direction.
As tectonic plates collide or slide past one another they can ‘catch’. Pressure to continue to move, however, remains as nearby plates collide with or slide past these plates. When the pressure becomes too much, the plates are forced to move. The two plates might slip past each other (slip-strike); one plate might slip under the other (megathrust), or over the other (reverse thrust).
[Geoscience Australia]
The worlds tectonic plates (ABC Science, 2017)
Tectonic plates moving under pressure - a) strike-slip b) megathrust c) reverse thrust
(The University of Melbourne Scientific Scribbles, 2021)
