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 anisotropy Seismic anisotropy Seismic anisotropy is a term used in seismology to describe the directional dependence of the velocity of seismic waves in a medium (rock) within the Earth. A material is said to be anisotropic if the value of one or more of its properties varies with direction. Anisotropy differs from the property called heterogeneity in that anisotropy is the variation in values with direction at a point while heterogeneity is the variation in values between two or more points. Seismic Anisotropy can be defined as the dependence of seismic velocity on direction or upon angle. General anisotropy is described