Information message about sensible earthquake in the region of Baikal Lake , July 16, 2011. |
| Sensible earthquake with M = 5.2 has occurred on July 16, 2011 at 18:38 UTC (22:38 Moscow time) near Baikal Lake. |
| 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 13 min after
registration to the Ministry of Emergency of the Russian Federation (EMERCOM). |
| Preliminary processing has been done with data from 45 stations, accurate processing - with data 56 stations. |
| Fig. 1 presents fragments of records obtained from digital stations Hailar (∆ 7.9º), Yakutsk (∆ 14.6º), Kuldur (∆ 15º), Mys Shultsa (∆ 18.3º), Vladivostok (∆ 18.4º). Fig. 2 presents fragments of records obtained from digital stations Kurchatov (∆ 18.6º), Tiksi (∆ 20.9º), Borovoe (∆ 22.8º), Magadan (∆ 24.1º), Ala Archa (∆ 24.8º). |
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 |
18-38-50.1 |
52.89 |
108.51 |
15 |
56 |
5.2/26 | 5.5/31 | 6.5-7 | 92 | IPC GS RAS (Уточненный) | | 2 |
18-38-50.4 |
52.92 |
108.53 |
15 |
45 |
5.2/23 | 5.5/22 | 6.5-7 | 92 | IPC GS RAS (Предварительный) | | 3 |
18-38-52.6 |
52.89 |
108.53 |
18.5 |
516 |
| 5.4 | | 53 | CSEM | | 4 |
18-38-51.1 |
52.86 |
108.47 |
8.8 |
407 |
4.9/316 | 5.6/345 | | 36 | NEIC | | 5 |
18-38-52.0 |
52.87 |
108.52 |
10 |
|
К14.3 | | | | 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 blue star epicenter of this earthquake, which origin was located on the territory of Burat Republic at the depth of 15 km, 67 km S-S-W of Ust-Barguzin, 132 km N-N-E of Ulan-Ude, 293 km E-N-E of Irkutsk. |
Figure 3 |
|
| Macroseismic manifestations |
| The earthquake was felt in: Turka 6-7, Kotokel 6, Novi Enkhaluk, Goryachinsk 5-6, Maksimikha, Ongureni 5, Suvo, Elantsi, Elan, Selenga, Khorinsk 4-5, Uro, Kabansk, Ulan-Ude, Ust-Barguzin, Selenginsk 4, Irkutsk, Shelekhov 3-4, Angarsk, Usolie-Sibirskoe 3, Chita, Zakamensk, Ust-Kut with intensity 2 MSK. |
| Historical records |
| On May 20, 2008 another earthquake with M=5.4, felt with intensity of 5 MSK has occurred in 50 km to the north from epicenter of this earthquake. |
| Focal mechanism and seismic moment of the earthquake |
| Focal mechanism solution of this earthquake which occurred on July 16, 2011 at 18:38 UTC was calculated with moment of tensor (spatial waves) techniques in NEIC USA, USGS and with CMT techniques in Global CMT Catalog, USA.
Focal solutions of the origin in stereographic projection at the lower hemisphere are presented in figures 4-5, elements of these solutions are presented in table 2. Solutions obtained in different centers are close. The earthquake has occurred under the action of expansion forces oriented to the north in case of USGS and to the south-east in the case of Global CMT. Both nodal planes have N-E direction of propagation (in case of Global CMT), in case of USGS one nodal plane had N-E direction of propagation, another - almost along the latitude. Type of motion – the fault with shift components – left side for NP1 (DP=48º) and right side for NP2 (DP=45-55º).
Seismic moment obtained in IPC GS RAS with Р-wave spectra obtained at three stations: «Arti» (∆ 28.59º), «Obninsk» (∆ 40.62º), «Kislovodsk» (∆ 43.16º) makes Mo=3.1*10**17 n*m. Averaged value of moment magnitude calculated with Kanamori formula makes Mw=5.6.
According to USGS Mo=1.1*10**17 n*m, Mw=5.3; according to Global CMT – Мо=1.19*10**17 n*m, Mw=5.3. |
| 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 |
| 4 | 342 | 61 | 80 |
29 | 250 | 100 | 48 | -50 | 228 |
55 | -126 | NEIC | | 2 | 132 | 27 | 35 |
13 | 222 | 54 | 48 | -72 | 209 |
45 | -109 | Quick CMT | |
| NEIC - National Earthquakes Information Center of US Geological Service |
| Quick CMT - Quick CMT catalog |
Figure 4 | 
Figure 5 |
|
