Earthquakes occur when tectonic plates clash together underground, causing the ground to shake. While most earthquakes are small, they occur frequently around the world. Alaska experiences the most earthquakes in the United States. It is important to prepare an emergency kit with supplies like food, water, a radio, and first aid supplies to last at least three days in the event of an earthquake. The largest earthquake recorded in the United Kingdom was a 4.8 magnitude quake, while the Caribbean's biggest was a 7.3 magnitude earthquake that impacted much of the region.