Urban seismic risk seismic risk, which experienced rapid growth particularly in developing countries, by helping to raise public awareness. One of the disaster risk reduction themes set forth by the United Nations International Strategy for Disaster Reduction project PreventionWeb, is urban risk and planning. This theme refers to the measurement and management of urban hazards and vulnerability in order to improve awareness and local capacity to effectively reduce disaster risk. Urban seismic risk Urban seismic risk is a subset of the general term seismic risk which describes the problems specific to centers of population when they are subjected to earthquakes. Many risks can
Seismic refraction velocity of the first layer V - velocity of the second layer h - thickness of the first layer T0 - intercept Seismic refraction Seismic refraction is a geophysical principle (see refraction) governed by Snell's Law. Used in the fields of engineering geology, geotechnical engineering and exploration geophysics, seismic refraction traverses (seismic lines) are performed using a seismograph(s) and/or geophone(s), in an array and an energy source. The seismic refraction method utilizes the refraction of seismic waves on geologic layers and rock/soil units in order to characterize the subsurface geologic conditions and geologic structure. The methods depend on the fact