Seismic code limit states design philosophy. In February 2004 a new set of seismic codes was issued. In Spain the seismic code is called the "Norma de Construcción Sismorresistente". (See the ) In the United States the Federal Emergency Management Agency (FEMA) publishes "Recommended Seismic Provisions for New Buildings and Other Structures". Seismic code Seismic codes or earthquake codes are building codes designed to protect property and life in buildings in case of earthquakes. The need for such codes is reflected in the saying, "Earthquakes don't kill people—buildings do." Or in expanded version, “Earthquakes do not injure or kill people. Poorly built
Passive seismic Passive seismic Passive seismic is the detection of natural low frequency earth movements, usually with the purpose of discerning geological structure and locate underground oil, gas, or other resources. Usually the data listening is done in multiple measurement points that are separated by several hundred meters, over periods of several hours to several days, using portable seismometers. The conclusions about the geological structure are based on the spectral analysis or on the mathematical reconstruction of the propagation and possible sources of the observed seismic waves. If the latter is planned, data are usually acquired in multiple (in the ideal case