Formalized analysis of crustal seismicity in the Sikhote Alin orogen and adjacent areas

Abstract

The fractal dimension of the epicentral field of earthquakes (D = 1.6) is determined for the Sikote Alin orogen and adjacent areas. According to this parameter, the region occupies the position between the Kamchatka Peninsula, Kuril Islands (1.61 and 1.69), the East China area, and the Lake Baikal region (1.55 and 1.40). Differentiation of the studied area based on the fractal dimension of the number of earthquakes and on the released energy calculated per unit square shows that the most active crustal areas are associated with the Kharpi–Kur–Priamur’e zone of the northeastern orientation, which is the northern segment of the Tan-Lu transregional fault system. Analysis of the time series of seismic events (MLH ≥ 2.4) in the Sikhote Alin and adjacent areas in the period from 1960 to 2013 shows that the “harmonic” with a 10.5-year period is most clearly displayed. This period (11–13 years) was previously distinguished by B.V. Levin and coauthors from the study of the largest number of earthquakes with M ≥ 4.4 for the period of 1971–2003.