SEISMICITY of TAJIKISTAN and ADJACENT TERRITORIES in 2016–2017

Abstract

In 2016–2017, seismic monitoring of the territory of Tajikistan and adjacent areas was carried out by a network of 7 seismic stations of the Geophysical Survey of the National Academy of Sciences of Tajikistan. In total for 2 years, 17855 earthquakes were registered in the range of KR=8.6–15.9, of which 4882 were small–focus shocks with h<70 km scattered throughout the territory of Southwestern Tien Shan (zone I), Southern Tien Shan (II), Pamir-Hindukush zone of crustal earthquakes (III), and 12973 – with intermediate depths h=70–400 km, located in the Pamir-Hindukush zone IV. 140 earthquakes were felt, for two of them (Gazorchashma earthquake of July 1, 2016 with KR=12.5, I0=6–7 and Karamyk earthquake of May 3, 2017 with KR=14.2, I0=7) the isoseismal maps were constructed and described in separate articles. The strongest earthquakes with a foci in the Earth's crust were grouped in 2016 in the northeast of zone III, on the border with China (June 26, KR=15.3, Mw=6.4 and November 25, KR=15.9, Mw=6.6) and in 2017 – in zone II, on the border with Kyrgyzstan (May 3 and 5 with KR=14.2, Mw=6.0 and 14.1, Mw=5.8 respectively). The strongest earthquake with an intermediate depth of h=230 km occurred on April 10, 2016 with KR=15.1, Mw=6.6 near the southern border of Tajikistan, on the territory of Pakistan. It was felt on the territory of Tajikistan, Kazakhstan, Afghanistan, Pakistan and India. A rare instrumental fact of the seismic field of the Pamir-Hindu Kush earthquakes in 2017 was the registration of the May 6, 2017 earthquake with KR=12.6 (Mw=5.3) with maximum depth of 400 km according to the regional network and 411 km according to the exchange pP-waves in ISC decision. Earlier, only in 1971 a close depth of 405 km was recorded for the November 14 earthquake with KR=9.0. For the region as a whole, in 2016 the maximum seismic energy (E=1.021016 J) was released in zone III, in 2017 – in zone II (E=3.291014 J).