Fault line意思

"Fault line" is a geological term that refers to a crack or fracture in the Earth's crust where movement has occurred along a plane of weakness. These lines mark the boundaries between tectonic plates or blocks of rock. When these plates move relative to each other, earthquakes can occur. Fault lines are a result of the Earth's plates moving, which can happen due to thermal or gravitational changes in the mantle, or even the motion of the Moon and Sun on the Earth's surface.