Faults, especially those capable of generating major earthquakes, are rarely new; they are usually ruptures that are already present in the Earth’s crust and have generated earthquakes in the past. Thus, faults provide a preferred pathway for energy release and strain recovery for future earthquakes.

Their distribution is not uniform; they are denser in certain portions of the Earth’s crust.

Distribution of active faults from the GEM catalog, Global Earthquake Model (https://www.globalquakemodel.org/product/active-faults-database)

On a global scale, the distribution of faults helps to define the margins of tectonic plates, which we can imagine as a rigid blocks that move and interact with each other under the pull of forces from the mantle.

tectonic plate margins