Information message on felt earthquakes in Chechnya on December 12 and 13, 2020

The felt earthquake with М=4.7 has occurred on December 12, 2020 at 21:29 GMT (December 13, 00:29 Moscow time) in Chechnya (moderate in the epicenter on the ShSI-17 scale) . Another shock with М=4.8 (moderate in the epicenter on the ShSI-17 scale) has been registered in 13:55 minutes after it on December 13, 2020 at 11:34 GMT (14:34 Moscow time).

Parameters of the earthquake have been determined in the Alert Service (AS) of Information Processing Center (IPC) of Geophysical Survey of RAS in Obninsk with station data obtained from digital and analog seismic stations of Russia, countries of CIS and from abroad. Alert message on the first earthquake has been delivered in 23 min after registration to the Ministry of Emergency of the Russian Federation (EMERCOM). Alert message on the second earthquake has been delivered in 19 min.

Preliminary processing for the first earthquake has been done with data from 11 stations, accurate processing - with data from 46. Preliminary processing for the second earthquake has been done with data from 11 stations, accurate processing - with data from 46.

The red markers on the map present epicenters of the earthquakes which origins were located on the territory of Chechnya, at the depth of 10 km, the first origin was 5 km SWу of Urus-Martan, 18 km W of Chiri-Yurta and 28 km SW of Grozny. EPicenter of the second shock was 5 km NW of the first one.
Time in origin (GMT) Latitude, degree Longitude, degree Depth, km Stations number Ms/N mb/N I0 (calculated) GAP Center
1 21:29:50.0 43.08 45.52 10.0 46 4.7/27 5-6 62 GS RAS(Verified [1])
Federal research center, Geophysical survey of Russian Academy of Sciences
2 21:29:50.6 43.56 45.58 10.0 11 5.0/10 5-5.5 GS RAS(Preliminary [1])
Federal research center, Geophysical survey of Russian Academy of Sciences
3 21:29:48.6 43.04 45.54 19.7 50 4.9 87 RCNC GS RAS (Verified [1])
Regional center for the North Caucasus
4 21:29:51.0 43.23 45.67 20.0 343 4.7/58 23 CSEM(Verified [1])
European - Mediterranean seismological center
5 21:29:51.4 43.21 45.52 25.0 92 4.7/90 43 NEIC(Verified [1])
National Earthquakes Information Center of US Geological Service
6 11:34:19.0 43.12 45.49 10.0 42 4.8/6 5-6 61 GS RAS(Verified [2])
Federal research center, Geophysical survey of Russian Academy of Sciences
7 11:34:18.0 43.02 45.51 19.6 49 4.6 89 RCNC GS RAS (Verified [2])
Regional center for the North Caucasus
8 11:34:18.0 43.18 45.59 10.0 178 ML 4.6 17 CSEM(Verified [2])
European - Mediterranean seismological center
9 11:34:18.8 43.23 45.64 10.0 45 4.6/45 47 NEIC(Verified [2])
National Earthquakes Information Center of US Geological Service