Information message about the strong earthquake in Eastern Iran on December 5, 2012 |
| The strong earthquake with M=5.7 has occurred on December 5, 2012 at 17:08 GMT (21:08 Moscow time) in Eastern Iran. 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 1 10 min after
registration to the Ministry of Emergency of the Russian Federation (EMERCOM). |
| Preliminary processing has been done with data from 40 stations, accurate processing - with data 54 stations. |
| Fig. 1 presents fragments of records obtained from digital stations Garni (∆ 13.5º), Ala-Archa (∆ 14.9º), Kislovodsk (∆ 16.8º), Borovoe (∆ 21º), Obninsk (∆ 26.9º). Fig. 2 presents fragments of records obtained from digital stations Kiev (∆ 28º), Talaya (∆ 36.5º), Lovozero (∆ 37.3º), Ulaanbaatar (∆ 38.2º), Tiksi (∆ 52.1º). |
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 |
17-08-11.6 |
33.54 |
59.53 |
10 |
54 |
5.7/32 | 5.7/32 | 8 | 80 | IPC GS RAS (Accurate) | | 2 |
17-08-11.6 |
33.53 |
59.54 |
10 |
40 |
| 5.7/27 | 7-7.5 | 80 | IPC GS RAS (Preliminary) | | 3 |
17-08-13.4 |
33.507 |
59.599 |
10 |
445 |
Mw 5.6 | | | 39 | CSEM | | 4 |
17-08-12.2 |
33.49 |
59.554 |
5.6 |
251 |
Mw 5.6 | 5.6/172 | | 14 | NEIC | |
| 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 |
| Epicenter |
| Fig. 3 presents with red star epicenter of this earthquake which origin was located in Eastern Iran at the depth of 10 km, 260 km W-S-W of Herat, Afghanistan, 310 km S of Mashhad, Iran, and 430 km N-E of Kerman, Iran. |
Figure 3 |
|
| Macroseismic manifestations |
| In accordance with RIA-Novosti 5 persons were killed after this earthquake. The earthquake has destroyed a few country houses and broke electricity supply and telephone lines. Undeground shocks in Birdzhend town caused panic among the population, people extremely leaved their houses. |
| Historical records |
| Iran is located in the zone of enhanced seismic activity. In the last century more than 170 thousands of Iranians became the victims of 20 most significant earthquakes. Epicenter of this earthquake is located in 505 km N-N-E of ancient city Bam, which on December 26, 2003 was fully destroyed by the undeground shock with magnitude 6,6. More than 30 thousands of people were killed at that moment. |
| Focal mechanism and seismic moment of the earthquake |
| Focal mechanism solution of this earthquake, which occurred on December 5, 2012 at 17:08 was calculated in IPC GS RAS with signs of initial arrivals of P-waves at 81 stations, including 61 stations which registered the waves of compression (plus signs) and 20 stations which registered the waves of expansion (minus signs). These stations are located in the interval of epicenter distances 8–89º, mainly in 1-st and 4-th quadrants along the azimuths. Focal mechanisms in stereographic projection at the lower hemisphere are presented at figure 4, elements of mechanism are presented in table 2. Table 2 and figures 5-6 also present focal mechanism solutions obtained in USGS NEIC based on spatial waves with method of moment centroid and with CMT technique obtained in Quick CMT Catalog, USA.
All solutions obtained in various center are almost identical.
This earthquake has occurred under the action of compression forces oriented N-E. Both nodal planes are rather steeply dipping (DP=47-72º). Propagation of one nodal plane – nearly along meridian, of the other nodal plane – latitudinal. The type of motion along both planes is presented by left and right side slips with components of uplift.
Seismic moment of this earthquake was calculated in IPC GS RAS with Р wave spectra obtained at "Талая" (∆ 36.54º) station, it makes Мо=8.7*10**17N*m, Mw=5.9;
In accordance with USGS NEIC – Мо=3.3*10**17N*m, Mw=5.6, in accordance with Quick CMT – Мо=5.26*10**17 N*m, Mw=5.7.
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| 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 |
| 52 | 312 | 10 | 56 |
36 | 153 | 354 | 65 | 131 | 110 |
47 | 36 | IPC GS RAS | | 40 | 306 | 4 | 40 |
50 | 135 | 346 | 66 | 146 | 91 |
60 | 28 | NEIC | | 36 | 305 | 9 | 42 |
52 | 144 | 348 | 72 | 146 | 90 |
58 | 21 | 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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