Kaiser effect (material science) Kaiser effect (material science) The Kaiser effect is a phenomenon observed in geology and material science that describes a pattern of acoustic emission or seismicity in a body of rock or other material subjected to repeated cycles of mechanical stress. In material that exhibits an initial seismic response under a certain load, the Kaiser effect describes the absence of acoustic emission or seismic events until that load is exceeded. The Kaiser effect results from discontinuities (fractures) created in material during previous steps that do not move, expand, or propagate until the former stress is exceeded. Induced seismicity associated with fluid
Passive seismic have been also applied in another planets. For instance, during Apollo missions, the Passive Seismic Experiment sensors were deployed that detected lunar "moonquakes" and provided information about the internal structure of the Moon. Passive seismic is much less expensive than well drilling. It is also cheaper and more environmentally friendly than active seismic, which requires a strong source of the seismic waves (like an underground explosion) to predict the structure. In some cases it may be the only method for which land access is granted by the land owner. Despite the method having been successfully applied in many parts of