Estimating the energy of seismotectonic deformations in the lithosphere of the Baikal Rift Zone

摘要

Estimation and comparison of the energy of seismotectonic deformations in the lithosphere of the Baikal Rift Zone (BRZ) based on observations of large (M ≥ 6) earthquakes for the period of instrumental recording (1950-2002), for a historical period lasting 210 years (1740-1949), and inferred from palaeo-seismological materials for the past 2000 years, all indicate that the hypothesis of a stationary seismic process is appropriate for the region. The locations of maxima of the density of seismotectonic strain energy released during the time intervals under investigation show that most of the failures in the lithosphere occurred approximately in the same areas, which may be interpreted as stress concentrators. The isolines of increased density for the energy of seismotectonic deformations align themselves along the rift features from southwest to northeast in the Baikal region and this allows one to treat the BRZ lithosphere as an extended zone of enhanced, inhomogeneous, energy release of endogenous geotectonic processes. We assessed the power of the seismotectonic processes that reflect the release of endogenous energy through earthquakes. Identification of areas with deficits in the energy of seismotectonic deformations ("energy gaps") is an important step toward long-term solution of seismic-safety problems for the Baikal region.