Information message about the strong earthquake in Southern Iran on April 9, 2013 |
| The strong earthquake with M=6.4 which caused victims and destructions has occurred in Southern Iran on April 9, 2013 at 11:52 GMT (15:52 Moscow time).
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| Preliminary processing has been done with data from 50 stations, accurate processing - with data 62 stations. |
| Fig. 1 presents fragments of records obtained from digital stations Garni (∆ 12.9º), Makhachkala (∆ 14.9º), Nalchik (∆ 16.4º), Kislovodsk (∆ 17.1º), Isparta (∆ 20º). Fig. 2 presents fragments of records obtained from digital stations Borovoe (∆ 28.2º), Arti (∆ 28.4º), Obninsk (∆ 28.8º), Vasula (∆ 34.6º), Tiksi (∆ 59.3º). |
Figure 1
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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 |
11-52-48.1 |
28.43 |
51.62 |
10 |
62 |
6.4/26 | 6.1/24 | 9-9.5 | 86 | IPC GS RAS (Accurate) | | 2 |
11-52-48.3 |
28.44 |
51.65 |
10 |
50 |
6.4/17 | 6.1/18 | 9-9.5 | 86 | IPC GS RAS (Preliminary) | | 3 |
11-52-50.7 |
28.48 |
51.58 |
10 |
518 |
Mw 6.3 | | | 43 | CSEM | | 4 |
11-52-50.1 |
28.5 |
51.59 |
10 |
156 |
Mw 6.3 | 5.9/268 | | 25 | NEIC | | 5 |
11-52-46.0 |
28.31 |
51.55 |
0 |
14 |
ML 6.0 | | | 222 | IIEES | |
| 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 |
| IIEES - International Institute of Earthquake Engineering and Seismology, Tehran, Iran |
| Epicenter |
| Fig. 3 presents with red star epicenter of this earthquake which origin was located in Southern Iran, at the depth of 10 km, 94 km S-E of Bushehr and 156 km S-W of Shiraz. |
Figure 3 |
|
| Aftershock |
| GS RAS registered 17 aftershocks with М≥4.2 within 18 hours after the main shock. |
| N |
Date & Time (GMT)
yy-mm-dd hh:mm:sec |
Lat
degr. |
Lon
degr. |
Depth
km |
N
station |
Ms/ N |
mb/ N |
Io
calc. |
Region |
| 20131271 | 2013-04-09 12:05:38.0 | 28.5 | 51.54 | 10 | 23 | - | 5.5/ 9 | 6.5-7 | Southern Iran | | 20131272 | 2013-04-09 12:41:02.0 | 28.36 | 51.54 | 10 | 16 | - | 4.8/ 12 | 4.5-5 | Southern Iran | | 20131273 | 2013-04-09 12:47:46.0 | 28.33 | 51.74 | 10 | 16 | - | 5.0/ 11 | 5-5.5 | Southern Iran | | 20131274 | 2013-04-09 13:03:25.0 | 28.48 | 51.69 | 10 | 10 | - | 4.5/ 5 | 4-4.5 | Southern Iran | | 20131275 | 2013-04-09 13:30:42.0 | 28.49 | 51.66 | 10 | 19 | - | 5.0/ 15 | 5-5.5 | Southern Iran | | 20131276 | 2013-04-09 14:44:50.0 | 28.42 | 51.59 | 10 | 24 | - | 5.1/ 13 | 5.5-6 | Southern Iran | | 20131277 | 2013-04-09 15:05:44.0 | 28.24 | 51.7 | 10 | 8 | - | 4.2/ 4 | 3.5 | Southern Iran | | 20131278 | 2013-04-09 16:32:29.0 | 28.24 | 51.61 | 10 | 23 | - | 4.9/ 11 | 5-5.5 | Southern Iran | | 20131279 | 2013-04-09 17:20:58.0 | 28.43 | 51.83 | 10 | 10 | - | 4.4/ 7 | 4 | Southern Iran | | 20131281 | 2013-04-09 18:59:05.0 | 28.36 | 51.65 | 10 | 13 | - | 4.4/ 9 | 4 | Southern Iran | | 20131282 | 2013-04-09 20:06:47.0 | 28.13 | 51.45 | 10 | 14 | - | 4.7/ 9 | 4.5-5 | Southern Iran | | 20131283 | 2013-04-09 20:54:14.0 | 28.27 | 51.68 | 10 | 25 | - | 5.0/ 12 | 5-5.5 | Southern Iran | | 20131284 | 2013-04-09 21:53:37.0 | 28.31 | 51.64 | 10 | 14 | - | 4.7/ 8 | 4.5-5 | Southern Iran | | 20131285 | 2013-04-10 01:00:20.0 | 28.32 | 51.62 | 10 | 22 | - | 5.0/ 9 | 5-5.5 | Southern Iran | | 20131286 | 2013-04-10 01:58:25.0 | 28.36 | 51.65 | 10 | 34 | - | 5.8/ 15 | 7-7.5 | Southern Iran | | 20131288 | 2013-04-10 02:48:01.0 | 28.39 | 51.8 | 10 | 12 | - | 4.7/ 9 | 4.5-5 | Southern Iran | | 20131290 | 2013-04-10 06:18:30.0 | 28.34 | 51.49 | 10 | 14 | - | 4.4/ 11 | 4 | Southern Iran | |
| Macroseismic manifestations |
| In accordance with RIA-Novosti (fig. 4) this earthquake caused significant destructions in Kaki, Kangan and Khormoj towns. Two villages were totally destroyed near Khormoj. 37 persons were killed and 850 injured. The Governor of Bushehr province confirmed that NPP located in this area was not influenced.
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Figure 4 |
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| Historical records |
| Epicenter of this earthquake was located 448 km E-N-E of another destructive earthquake epicenter September 10, 2008 (yellow star on fig. 5). |
Figure 5 |
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| Focal mechanism and seismic moment of the earthquake |
| Focal mechanism of the origin was calculated at the IPC GS RAS by the signs of the initial arrivals of the waves at 157 stations, including 148 stations which registered compression waves (the plus sign) and 9 stations which registered expansion waves (minus signs). The stations are located in the range of epicentral distances of 11-98 º azimuth and evenly. Focal mechanism in stereographic projection on the lower hemisphere is shown in figure 6, the elements of the mechanism are presented in table 2. Figures 7-8 and table 2 also present the focal mechanism solutions obtained in USGS NEIC with USGS Body-Wave Moment Tensor Solution technique and in Quick CMT Catalog with CMT technique.
These solutions obtained in different centers are similar. The earthquake has occurred under the action of compressive stresses oriented to the north-east. Both nodal planes are steeply falling (DP = 52-68 º). One nodal plane NP1 has latitudinal direction of propagation, another plane NP2 propagates north-west. Type of motion on both planes - faults with uplift components (right hand for NP1, left hand for NP2).
The seismic moment of this earthquake obtained in IPC GS RAS from the spectra of P-waves at two stations: "Arti» (Δ28.4) and "Obninsk» (Δ28.8), is Mo = 3.0 * 10 ** 18 N * m, the average value of moment magnitude calculated by Kanamori formula is Mw = 6.3. According to the USGS NEIC Mo = 2.7 * 10 ** 18 N * m, Mw = 6.2 and for Quick CMT - Mo = 3.63 * 10 ** 18 N * m, Mw = 6.3. |
| 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 |
| 61 | 143 | 0 | 233 |
29 | 323 | 169 | 52 | 128 | 297 |
52 | 52 | IPC GS RAS | | 39 | 147 | 6 | 53 |
50 | 316 | 182 | 59 | 154 | 286 |
68 | 34 | NEIC | | 56 | 140 | 1 | 48 |
34 | 318 | 168 | 53 | 134 | 290 |
55 | 47 | 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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