Seismic risk The concepts of earthquake preparedness can help plan for emergencies arising from an earthquake. Building codes are intended to help to manage seismic risk and are updated as more is learned about the effects of seismic ground motion on buildings. This type of active improvement of mitigation of damage from earthquakes is known as seismic retrofit. However, the changes generally do not immediately improve seismic risk in a community since existing buildings are rarely required to be upgraded to meet the revisions. Seismic risk Seismic risk refers to the risk of damage from earthquake to a building, system, or other
Seismic source Seismic source A seismic source is a device that generates controlled seismic energy used to perform both reflection and refraction seismic surveys. A seismic source can be simple, such as dynamite, or it can use more sophisticated technology, such as a specialized air gun. Seismic sources can provide single pulses or continuous sweeps of energy, generating seismic waves, which travel through a medium such as water or layers of rocks. Some of the waves then reflect and refract and are recorded by receivers, such as geophones or hydrophones. Seismic sources may be used to investigate shallow subsoil structure, for engineering