Information message about the strong earthquake in the Iran-Pakistan border region on April 16, 2013 |
| The strong earthquake with M=7.8 has occurred on April 16, 2013 at 10:44 GMT (14:44 Moscow time) in the Iran-Pakistan border region, it caused victims and destructions. |
| 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 14 min after
registration to the Ministry of Emergency of the Russian Federation (EMERCOM). |
| Preliminary processing has been done with data from 59 stations, accurate processing - with data 70 stations. |
| Fig. 1 presents fragments of records obtained from digital stations Ala-Archa (∆ 17.6º), Garni (∆ 18.6º), Nalchik (∆ 21.4º), Kislovodsk (∆ 22.2º), Borovoe (∆ 25.6º). Fig. 2 presents fragments of records obtained from digital stations Obninsk (∆ 32.7º), Pulkovo (∆ 38.3º), Talaya (∆ 38.9º), Lovozero (∆ 43º), Tiksi (∆ 56.3º). |
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 |
10-44-17.7 |
28.14 |
62.06 |
70 |
70 |
7.6/33 | 7.1/38 | 7.5-8 | | IPC GS RAS (Accurate) | | 2 |
10-44-17.7 |
28.13 |
62.08 |
70 |
59 |
7.6/27 | 7.1/29 | 7.5-8 | 57 | IPC GS RAS (Preliminary) | | 3 |
10-44-20.9 |
28.144 |
62.079 |
86.6 |
569 |
Mw 7.8 | | | 29 | CSEM | | 4 |
10-44-20.7 |
28.107 |
62.053 |
82 |
175 |
Mw 7.8 | 7.1/322 | | 32 | NEIC | | 5 |
10-44-17.0 |
27.85 |
62.1 |
62 |
12 |
| 7.6 | | 239 | IIEES | | 6 |
10-44-17.4 |
28.04 |
62.03 |
95 |
16 |
ML 7.5 | | | | IGUT | |
| 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 |
| IGUT - Institute of Geophysics, University of Tehran |
| Epicenter |
| Fig. 3 presents with red star epicenter of this earthquake which origin was located in the border area between Iran and Pakistan, at the depth of 70 km, 190 km S-S-E of Zahedan, Iran, 327 km south of Zaranj, Afghanistan, and 535 km E-S-E of Quetta, Pakistan. |
Figure 3 |
|
| Aftershock |
| GS RAS registered 5 aftershocks with M≥4.1 within 19 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 |
| 20131376 | 2013-04-16 13:54:01.0 | 28.16 | 62.34 | 70 | 13 | - | 4.5/ 12 | - | Southwestern Pakistan | | 20131378 | 2013-04-16 16:26:44.0 | 28.13 | 62.08 | 70 | 18 | - | 4.1/ 8 | - | Southwestern Pakistan | | 20131385 | 2013-04-17 03:04:32.0 | 28.1 | 62 | 70 | 20 | - | 4.1/ 16 | - | Southern Iran | | 20131384 | 2013-04-17 03:15:52.0 | 28.22 | 62.33 | 70 | 61 | - | 5.9/ 37 | 4.5-5 | Southwestern Pakistan | | 20131386 | 2013-04-17 04:53:27.0 | 28.31 | 62.43 | 70 | 30 | - | 5.0/ 20 | 2-2.5 | Southwestern Pakistan | |
| Macroseismic manifestations |
| In accordance with RIA-Novosti 30 were killed on the territory of Pakistan, thousands of houses were destroyed in Pakistan and more than 1200 houses in Iran. This earthquake was felt on the whole territory of south-west Asia. Residents of India, UAE, Bahrain and Qatar were in panic, people ran away from houses and offices. «Interfax» Agency reported about evacuation from trade center in Dubai.
Fig. 4 obtained from USGS NEIC , presents USGS Community Internet Intensity Map made by 450 responses in 91 cities. |
Figure 4 |
|
| Focal mechanism and seismic moment of the earthquake |
| The focal mechanism of this earthquake was calculated at the IPC GS RAS by the signs of initial arrivals of the waves at 170 stations, including 103 of them which registered compression waves (plus signs) and 67 which registered expansion waves (minus signs). The stations are located evenly in the range of epicentral distances of 8-96 º along the azimuth.
Focal mechanism in stereographic projection on the lower hemisphere is shown in figure 5, elements of this mechanism are presented in table 2.
Table 2 and figures 6, 7 also present focal mechanism solutions obtained with Centroid Moment Solution in USGS NEIC and with method of centroid moment tensor obtained in Quick CMT Catalog, USA.
All solutions obtained in different centers are close. The earthquake occurred under the action of expansion stresses oriented to the north. Nodal planes lie at angles DP = 33-73º. One of them NP1 in accordance with USGS and CMT has a northeastern direction of propagation (Stk = 80-82º), another NP2 - southwest (Stk = 236-239º). In case of P-waves direction of propagation for the plane with DP = 33º - south-east (Stk = 131º), for the plane with DP = 73º - south-west (Stk = 249º). Type of motion for both planes – normal faults with slip components (left-hand on NP1 and right-hand on NP2).
The seismic moment of the earthquake obtained in IPC GS RAS from spectra of P-waves at two stations: "Arti" (Δ28.4º) and "Obninsk" (Δ32.7º) is Mo = 1.8*10**20 N*m The average value of moment magnitude calculated by Kanamori formula Mw=7.5. The seismic moment of the earthquake according to USGS NEIC - Mo=4.1*10**20 N*m, Mw=7.7, according to the Quick CMT - Mo=5.07*10**20 N*m, Mw=7.7. |
| 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 |
| 23 | 1 | 53 | 124 |
28 | 259 | 131 | 33 | -32 | 249 |
73 | -119 | IPC GS RAS | | 13 | 336 | 72 | 113 |
12 | 244 | 82 | 34 | -68 | 82 |
34 | -68 | NEIC | | 10 | 338 | 76 | 112 |
10 | 246 | 80 | 36 | -73 | 239 |
55 | -102 | 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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