Information message about sensitive earthquake in Uzbekistan, May 26, 2013 |
| The sensitive earthquake with M=6 has occurred in Uzbekistan on May 26, 2013 at 06:08 GMT (10:08 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 this earthquake has been delivered in 12 min after
registration to the Ministry of Emergency of the Russian Federation (EMERCOM). |
| Preliminary processing has been done with data from 62 stations, accurate processing - with data 69 stations. |
| Fig. 1 presents fragments of records obtained from digital stations Ala-Archa (∆ 5.9º), Borovoe (∆ 13.1º), Kurchatov (∆ 13.2º), Arti (∆ 17.4º), Kislovodsk (∆ 18.7º). Fig. 2 presents fragments of records obtained from digital stations Obninsk (∆ 25.4º), Kiev (∆ 28.5º), Vasula (∆ 31.6º), Apeiranthos of Naxos (∆ 32.6º), Lovozero (∆ 33.1º). |
Figure 1
| 
Figure 2
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|
| 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 |
06-08-13.1 |
40.09 |
67.39 |
10 |
62 |
| 6.3/19 | 8.5 | 56 | IPC GS RAS (Preliminary) | | 2 |
06-08-13.3 |
40.09 |
67.35 |
10 |
69 |
6/22 | 6.3/21 | 8.5 | 56 | IPC GS RAS (Accurate) | | 3 |
06-08-16.9 |
40.033 |
67.435 |
20.8 |
921 |
Mw 5.8 | | | 13 | CSEM | | 4 |
06-08-16.0 |
39.919 |
67.385 |
19.4 |
573 |
Mw 5.8 | | | 15 | NEIC | | 5 |
06-08-12.7 |
39.975 |
67.186 |
10 |
17 |
K 14.6 | 6.2 | | 322 | IS NAS KR | | 6 |
06-08-18.3 |
40.28 |
67.31 |
19 |
19 |
K 13 | 6.2 | | 264 | KNDC | |
| 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 |
| IS NAS KR - Institute of Seismology National Academy of sciences of the Kyrgyz Republic |
| KNDC - Kazakhstan National Data Center |
| Epicenter |
| Fig. 3 presents with red star epicenter of this earthquake which origin was located in Uzbekistan at the depth of 10 km, 38 km W of Dzhizak, 61 km N-E of Samarkand, 210 км S-W of Tashkent - the Capital of Uzbekistan. |
Figure 3 |
|
| Macroseismic manifestations |
| According to «Tashkent» station this earthquake was felt in Tashkent and Almalyk with intensity 4, in Dzhizak and Samarkand with intensity 5, in Gazli with intensity 3, in Andizhan with intensity 2.
According to « Almaty » station this earthquake was felt in Taraz and Shymkent with intensity 3-4. |
| Historical records |
| This earthquake has occurred 182 km S-W of another sensitive earthquake of May 24, 2013 with mb=5.5 |
| Focal mechanism and seismic moment of the earthquake |
| Focal mechanism solution for this earthquake was calculated in IPC GS RAS with signs of initial arrivals of P waves at 196 stations, including 193 stations which registered the waves of compression (plus signs), and 3 stations which registered the waves of extension (minus signs). All these stations are located in the interval of epicentral distances of 3–100º and distributed rather uniformly by azimuth. The focal mechanism solution in stereographic projection at the lower hemisphere is presented in figure 4, its elements are presented in table 2. Fig. 5, 6 present focal mechanism solutions for this earthquake obtained in USGS NEIC with USGS Centroid Moment Solution technique and in Quick CMT Catalog, USA, with CMT technique.
All solutions are rather similar. The earthquake has occurred under prevailing action of compression stress oriented: according to USGS NEIC - to the west, according to IPC GS RAS and Quick CMT – to the south-east. According to IPC GS RAS both nodal planes have the same dip (DP=45º) and strike in the same direction – north-east–south-west. The type of motion along both planes – «pure» upthrust. According to USGS NEIC the nodal plane NP2 is nearly vertical (DP=76º) and strikes to the south (STK=177º), another nodal plane NP1 is more flat (DP=39º) and strikes to the north-east. According to Quick CMT both nodal planes have close dip (DP=36-58º), their strikes are north-east–south-west. Тhe type of motion along steeply dipping planes is upthrust with strike-slip components, for more flat plane the type is overthrust according to Quick CMT and strike slip according to USGS NEIC.
Seismic moment of this earthquake obtained in IPC GS RAS with spectra of Р waves registered at «Obninsk» station (∆25.37º) is Мо=2.1*10**18 N*m, Mw=5.8. According to USGS NEIC Мо=1.1*10**17 N*m, Mw=5.3, according to Quick CMT Мо=6.5*10**17 N*m, Mw=5.8.
|
| 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 |
| 89 | 225 | 0 | 135 |
1 | 45 | 44 | 45 | 88 | 226 |
45 | 92 | IPC GS RAS | | 46 | 49 | 22 | 294 |
36 | 188 | 69 | 39 | 157 | 177 |
76 | 53 | NEIC | | 71 | 4 | 11 | 130 |
15 | 223 | 52 | 58 | 108 | 202 |
36 | 64 | Quick CMT | |
| IPC GS RAS - Informational Processing Center, Geophysical Survey, Russian Academy of Sciences |
| NEIC - National Earthquakes Information Center of US Geological Service |
| Quick CMT - Quick CMT catalog |
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