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
|
Fig. 1 presents fragments of records obtained from digital stations Groznyy (∆ 0.2º), Vedeno (∆ 0.5º), Nalchik (∆ 1.5º), Neytrino (∆ 2.1º), Кисловодск (∆ 2.2º) for the first earthquake.
Fig. 2 presents fragments of records obtained from digital stations Groznyy (∆ 0.2º), Vedeno (∆ 0.5º), Nalchik (∆ 1.4º), Neytrino (∆ 2º), Kislovodsk (∆ 2.2º) for the second earthquake.
Image 1
Image 2
GS RAS registered another 9 earthquakes with minor magnitudes of М>=3.2 within December 12,13 and 14.
The earthquake of December 12 occurred at 23:50 and was felt in Urus-Martan and Grozny with intensity 2-3 MSK.
The earthquake of December 13 occurred at 13:05 and was felt in Urus-Martan, Chechen-Aul, Grozny, Shali, Achkhoy-Martan with intensity 3 MSK.
N |
Time in origin (GMT) |
Latitude, degree |
Longitude, degree |
Depth, km |
Stations number |
Ms/N |
mb/N |
I0 (calculated) |
Region |
20204709
|
12/12/2020 23:50:22.0.0 |
43.09 |
45.55 |
10.0 |
20 |
|
4.1/12 |
3-3.5 |
Eastern Caucasus
|
20204715
|
13/12/2020 09:15:46.0.0 |
42.94 |
45.48 |
10.0 |
19 |
|
3.7/1 |
2-2.5 |
Eastern Caucasus
|
20204717
|
13/12/2020 12:08:27.1.0 |
43.04 |
45.5 |
10.0 |
22 |
|
3.8/5 |
2.5-3 |
Eastern Caucasus
|
20204718
|
13/12/2020 13:05:02.0.0 |
43.05 |
45.49 |
10.0 |
37 |
|
4.5/5 |
4-4.5 |
Eastern Caucasus
|
20204719
|
13/12/2020 13:36:43.0.0 |
43.11 |
45.52 |
10.0 |
22 |
|
3.9/4 |
2.5-3 |
Eastern Caucasus
|
20204723
|
14/12/2020 00:13:00.1.0 |
43.08 |
45.49 |
10.0 |
25 |
|
3.9/1 |
2.5-3 |
Eastern Caucasus
|
20204724
|
14/12/2020 00:37:17.0.0 |
43.13 |
45.55 |
10.0 |
20 |
|
3.5/1 |
|
Eastern Caucasus
|
20204725
|
14/12/2020 00:56:15.1.0 |
43.05 |
45.49 |
10.0 |
16 |
|
3.3/1 |
|
Eastern Caucasus
|
20204730
|
14/12/2020 08:52:45.0.0 |
43.0 |
45.51 |
5.0 |
13 |
|
3.2/4 |
2-2.5 |
Eastern Caucasus
|
According to GS RAS the earthquake on December 12 was felt in Urus-Martan, Chechen-Aul, Grozny, Achkhoy-Martan, Goy-Chu, Martan-Chu, Tangi-Chu, Roshni-Chu, Gekhi, Valerik, Gikalo, Starye Atagakh, Qatar-Yurt, Goyty with intensity 5 MSK, in Shali, Argun, Tsotsi-Yurt, Sernovodsky, Samashki, Assinovskaya, Avtury with intensity 4 MSK, in Makhachkala with intensity 2-3 MSK, the earthquake on December 13 was felt in Urus-Martan, Chechen-Aul, Grozny, Achkhoy-Martan, Staryh Atagah with intemsity 4 MSK, in Shali, Argun, Tsotsi-Yurt with intensity 3 MSK.
The focal mechanism solution of the origin of the earthquake was obtained by GS RAS with signs of initial arrivals of P waves at 42 stations including 19 stations which registered compression waves (plus signs) and 23 stations which registered tensile waves (minus signs). These stations are located in the epicentral distances of 0.3-4.6º and in azymuth sector Az=34-319º. The focal mechanism solution in stereographic projection on the lower hemisphere and the elements of the mechanism are presented in the table. The earthquake occurred under the action of prevailing compressive stresses oriented E-NE (AZ=162º). One nodal plane NP1 strikes E-NE (STK=66º), another plane NP2 strikes W-SW (STK=257º), both planes are inclined to the horizon at an angle DIP=45º. The type of motion along both planes – reverse faults.
The focal mechanism solution of the origin of the second earthquake was obtained by GS RAS with signs of initial arrivals of P waves at 40 stations including 23 stations which registered compression waves (plus signs) and 17 stations which registered tensile waves (minus signs). These stations are located in the epicentral distances of 0.3-4.0º and in azymuth sector Az=43-306º. The focal mechanism solution in stereographic projection on the lower hemisphere and the elements of the mechanism are presented in the table. The earthquake occurred under the action of the prevailing compression stresses oriented to the south (AZ=41º). One nodal plane NP1 strikes W-NW (STK=298º), another plane NP2 strikes S-SE (STK=153º). The plane NP2 lies flatter (DP=31º) if compared with NP1 (DP=64º). The type of motion along both planes – reverse faults.
Axes of main strengths |
Nodal planes |
Center |
|
T |
P |
N |
NP1 |
NP2 |
PI: 84
Azm: 252
|
PI: 0
Azm: 162
|
PI: 6
Azm: 72
|
Stk: 66
Dp: 45
Slip: 82
|
Stk: 257
Dp: 45
Slip: 98
|
GS RAS Federal research center, Geophysical survey of Russian Academy of Sciences
|
|
PI: 67
Azm: 177
|
PI: 17
Azm: 41
|
PI: 15
Azm: 306
|
Stk: 298
Dp: 64
Slip: 73
|
Stk: 153
Dp: 31
Slip: 121
|
GS RAS Federal research center, Geophysical survey of Russian Academy of Sciences
|
|