When the tectonic plates that make up Earth's crust move past each other, they often bump or rub against each other. The earth, or ground,above the plates moves as well . This movement is called an earthquake. Sometimes the plates get stuck. The pressure increases as the two plates try to move past each other but cannot. They finally move with a sudden and powerful jerk.This can also cause an earthquake.During a small earthquake,the ground simply shakes a little, and people may not even notice. However, a strong movement can cause the ground to shake and roll violently. It can mank buildings and bridges fall. It can also cause the ground to split open and form a large fault, or crack