Information message about the appreciable earthquake in Buryatia, September 2, 2015 |
| Appreciable earthquake with M = 4.8 has occurred on September 2, 2015 at 19:46 GMT (22:46 Moscow time) in Buryatia. |
| 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 this earthquake has been delivered in 10 min after
registration to the Ministry of Emergency of the Russian Federation (EMERCOM). |
| Preliminary processing has been done with data from 55 stations, accurate processing - with data 60 stations. |
| Fig. 1 presents fragments of records obtained from digital stations Yakutsk (∆ 8.9º), Ulaanbaatar (∆ 10.4º), Kuldur (∆ 12.3º), Ussuriisk (∆ 16.3º), Vladivostok (∆ 17.2º). Fig. 2 presents fragments of records obtained from digital stations Petropavlovsk (∆ 24.7º), Bilibino (∆ 25.2º), Borovoe (∆ 26º), Arti (∆ 30.7º), Obninsk (∆ 42º). |
Figure 1
| 
Figure 2
|
|
| IPC GS RAS also has obtained information with parameters of this event from some seismological centers, these data are given in table 1: |
| Table 1 |
| NN |
Time in origin h-min-s (GMT) |
Lat degr. |
Lon degr. |
Depth km |
N s/st |
Ms/ N |
mb/ N |
I0 calc |
GAP |
Center | | 1 |
19-46-49.8 |
56.79 |
115.67 |
10 |
60 |
4.8/14 | 5.1/33 | 6.5-7 | 68 | IPC GS RAS (Accurate) | | 2 |
19-46-49.5 |
56.82 |
115.69 |
10 |
55 |
4.8/9 | 5.1/30 | 6.5-7 | 68 | IPC GS RAS (Preliminary) | | 3 |
19-46-51.8 |
56.665 |
115.785 |
5 |
147 |
| 4.9/67 | | 39 | CSEM | | 4 |
19-46-52.9 |
56.817 |
115.746 |
16.1 |
78 |
| 4.9/94 | | 54 | NEIC | | 5 |
19-46-51.9 |
56.76 |
115.65 |
10 |
18 |
К 13.9 | | | | BRIPC | |
| IPC GS RAS - Informational Processing Center, Geophysical Survey, Russian Academy of Sciences |
| CSEM - European - Mediterranean seismological center |
| NEIC - National Earthquakes Information Center of US Geological Service |
| BRIPC - Regional Informational Processing Center of Baikal Experimental-Methodical Seismological Expedition Geophysical Survey Siberian Branch Russian Academy of Sciences |
| Epicenter |
| Fig. 3 presents with red star the epicenter of this earthquake, its origin was located on the territory of Buryatia, at a depth of 10 km, 30 km N of Nelyaty, 144 km E-N-E of Severomuisk, 148 km S-E of Bodaibo, 158 km W of Chara. |
Figure 3 |
|
| Macroseismic manifestations |
| According to GS RAS this earthquake was felt in Nelyaty with intensity 5 MSK, in Bodaibo, Mamakan with intensity 4 MSK in Chara with intensity 3 MSK, in Chita with intensity 2 MSK.
|
| Focal mechanism and seismic moment of the earthquake |
| Focal mechanism solution was obtained in IPC GS RAS with signs of initial arrivals of P waves at 31 stations, including 22 stations which registered compression waves (plus signs) and 9 stations which registered tensile waves (minus sign). These stations are located in the interval of epicentral distances 7-82º and azimuth alignment Az = 15-302º. Focal mechanism in stereographic projection at lower hemisphere is shown in figure 4, elements of the mechanism are given in table 2. The quake occurred under the influence of compressive stresses, oriented to the northeast, the axis of tension at an angle (Pl = 61º) is directed to the southeast (Az = 143º). Nodal plane NP1 strikes NW, NP2 strikes SE. Both planes are inclined to the horizon at the same angle (DP = 52º). The type of motion along both planes - reverse faults with slip components, left lateral for NP1 and right lateral for NP2. |
| Table 2 |
| Axes of main strengths |
Nodal planes |
Center |
| T |
P |
N |
NP1 |
NP2 |
| Pl |
Azm |
Pl |
Azm |
Pl |
Azm |
Stk |
Dp |
Slip |
Stk |
Dp |
Slip |
| 61 | 143 | 0 | 53 |
29 | 323 | 297 | 52 | 52 | 169 |
52 | 128 | IPC GS RAS | |
| IPC GS RAS - Informational Processing Center, Geophysical Survey, Russian Academy of Sciences |
Figure 4 |
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