* Earth's Crust is Always Moving: The Earth's tectonic plates are constantly moving, driven by forces within the planet. These movements cause stress to build up at the edges of the plates.
* Faults: Zones of Weakness: Faults are fractures in the Earth's crust where rocks have broken and moved. These breaks are weaker than the surrounding rock, making them the points where the stress from tectonic plate movement is most likely to be released.
* Stress Build-Up: As tectonic plates move, the rocks on either side of a fault are pushed, pulled, or ground against each other. This builds up stress within the rocks.
* Sudden Release of Stress: When the stress on the rocks exceeds their strength, they suddenly break and move along the fault. This sudden release of energy causes the ground to shake, creating an earthquake.
Types of Fault Movements:
* Strike-slip faults: Rocks slide horizontally past each other. (e.g., San Andreas Fault)
* Dip-slip faults: Rocks move up or down relative to each other.
* Normal faults: The hanging wall (rock above the fault) moves down relative to the footwall (rock below).
* Reverse faults: The hanging wall moves up relative to the footwall.
In short, faults act as pathways for the release of stress accumulated due to tectonic plate movements, resulting in the shaking of the Earth's surface we experience as earthquakes.
