Seismicity of Northern Eurasia in 2018–2019
摘要
An overview of seismicity in 16 regions of Russia and neighboring countries in 2018–2019 is presented. Seismic monitoring of this territory was carried out by seismic networks of Russia, Azerbaijan, Armenia, Belarus, Kazakhstan, Kyrgyzstan, Moldova, Turkmenistan, Tajikistan, Uzbekistan, and Ukraine. In most regions, the seismic process occurred in the background. In Northern Eurasia as a whole, the total seismic energy in 2018 (ΣЕan = 3.2 × 1016 J) remained unchanged compared to that for the previous year, and in 2019 it fell to ΣЕan = 0.62 × 1016 J, with annual values of released energy for 2018 and 2019 significantly lower than its average annual level for the period 2006–2017 (ΣEan = 5.3 × 1016 J). The “Angular Uplift earthquake” on December 20, 2018 at 17:01 with MS = 7.4 (MwGCMT = 7.2), localized in the surface layer of the seismofocal zone of the Commander segment of the Aleutian arc with the epicenter in the Pacific Ocean was the strongest for the period 2018–2019. Maximum shaking intensity in the territory of Northern Eurasia (I = 6–7) was caused by earthquake on July 6, 2018, at 01:40 with MwGCMT = 6.2, h = 75 km in the seismofocal zone of the Kuril Islands–Southern Kamchatka and Katav-Ivanovsk earthquake on September 4, 2018, at 22:58 in Chelyabinsk oblast (Ural and Western Siberia region). The Katav-Ivanovsk earthquake is also unique in that it was accompanied by a significant number of aftershocks, which is the first known case for tectonic events within the Urals. In addition, it demonstrated that the natural seismic potential of the Urals exceeds the man-made component by orders of energy.