Another event that causes sudden changes to Earth's surface is an earthquake. An earthquake is a sudden movement in the rocks that make up Earth's crust. Earthquakes are caused by forces deep within Earth. The forces cause rocks to break. The breaking rock makes the ground shake.
Strong earthquakes cause landslides, great destruction, and loss of lives.
People may be left homeless when houses are destroyed. Cities may lose electricity and water as power and water lines break. Food supplies may run low if transportation is interrupted. Fires may also break out. Sudden changes to Earth's surface are also caused by volcanoes.