Аннотация:Strong induced seismicity can result from various strong man-made impact on the Earth's crust. In the absence of anti-seismic measures in construction and on soft soils, even moderate earthquakes can produce significant damage. The widely used “semaphore” technique aimed at reducing the risk of induced seismicity fails to incorporate possible generation of induced earthquakes at unusually great distances from places of human impact. Thus, the danger of induced seismicity may be underestimated. On the other hand, there are examples that induced seismicity may decrease under prolonged strong technogenic action. Based on the analysis of the seismic regime in two areas of strong induced seismicity (the Groningen gas field and the shale oil production area in Oklahoma), it was shown that the hazard of induced seismicity decreased under strong long-term technogenic action. A similar conclusion was obtained for Oklahoma from the analysis of the noise in GPS observations. Note that this monitoring method is free of the delay effect, which is almost inevitable in monitoring based on seismicity data. The decrease in induced seismicity can be due to relaxation of the initial tectonic stresses under a strong and long-term anthropogenic impact.
