Earthquake prediction

An earthquake is when the ground shakes. It happens when two big underground rocks quickly move against each other. Scientists study earthquakes, and sometimes they can guess when an earthquake might happen. This process of trying to guess when an earthquake might happen is called prediction. Scientists use special tools like equipment to measure the ground and weather reports to help them do prediction. They can also look back at history to see when past earthquakes happened and try to figure out when future earthquakes might happen. Unfortunately, it's very hard to make sure predictions, so usually scientists can only give very broad time frames or areas in which they think an earthquake might happen.