Environmental Seismic Intensity scale Environmental Seismic Intensity scale The Environmental Seismic Intensity scale (ESI 2007) is a seismic scale used for measuring the intensity of an earthquake on the basis of the effects of the earthquake on the natural environment (Earthquake Environmental Effects). The international effort to develop a new scale of macroseismic intensity that would focus exclusively on environmental effects of earthquakes began in the early 1990s and was sponsored by the International Union for Quaternary Research (INQUA). After the final draft of the scale was approved by INQUA at its XVII Congress in Cairns, Australia, in 2007, the scale became officially known
Seismic source fewer safety concerns. Correlation-based processing techniques also enable seismologists to image the interior of the Earth at multiple scales using natural (e.g., the oceanic microseism) or artificial (e.g., urban) background noise as a seismic source. For example, under ideal conditions of uniform seismic illumination, the correlation of the noise signals between two seismographs provides an estimate of the bidirectional seismic impulse response. <br> 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