So, when you are asked to build a volcano observatory near Mount Rainier in Washington, you know your observatory must be built to withstand an earthquake. After all, you don't want to have to rebuild the observatory after every earthquake, nor do you want anyone to get hurt if the observatory is not built properly. You also have to consider the building and the type of land on which the observatory is built. The crust is broken into a number of pieces, each of which moves slowly in different directions, a process known as plate tectonics. Earthquakes occur when there is a slip or break between two tectonic plates.
Earthquake waves compress the soil, as well as move it side to side and up and down.
Earthquake waves damage buildings and structures because they twist and push them in ways that they cannot always withstand. The land on which the building stands is a factor too - sand or landfill can become like quicksand during an earthquake, pulling a building down into the ground. Though some parts of the world are more likely to experience earthquakes than other parts, an earthquake can occur anywhere on the Earth's surface.