Information message about destructive earthquake in the Western part of Iran on March 31, 2006. |
| The destructive earthquake with М=5.9, which caused victims has happened on March 31 at 01:17 GMT (at 05:17 Moscow time) in the Western part of Iran. |
| 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 55 min after
registration to the Ministry of Emergency of the Russian Federation (EMERCOM). |
| Preliminary processing has been done with data from 31 stations, accurate processing - with data 40 stations. |
| Fig. 1 presents fragments of records obtained from digital stations: Garni (7.4 degrees), Mahachkala (9.5 degrees), Kislovodsk (11.5 degrees), Isparta (15.5 degrees), Obninsk (23.3 degrees), Arti (23.9 degrees). Fig. 2 presents fragments of records obtained from digital stations: Kingsbai (48 degrees), Hailar (54 degrees), Tiksi (55 degrees), Yakutsk (57 degrees), Magadan (67 degrees), Bilibino (69 degrees). |
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 |
01-17-00.2 |
33.48 |
48.86 |
15 |
40 |
5.9/15 | 6/15 | 7.5-8 | 87 | IPC GS RAS (Accurate) | | 2 |
01-17-02.2 |
33.41 |
48.84 |
33 |
31 |
5.9/12 | 6.1/12 | 6.5 | 143 | IPC GS RAS (Preliminary) | | 3 |
01-17-02.5 |
33.63 |
48.73 |
25 |
372 |
| 5.7 | | 52 | CSEM | | 4 |
01-17-02.3 |
33.58 |
48.8 |
10 |
93 |
| 5.7 | | 54 | NEIC | | 5 |
01-17-04.0 |
33.48 |
48.86 |
18 |
|
5.9Mn | | | | 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 |
| IGUT - Institute of Geophysics, University of Tehran |
| Epicenter |
| Epicenter of this earthquake was located in the western Province Lorestan - 40 km to the east-north-east from Khorramabad, 100 km to the west-south-west from Arak, 135 km to the south from Hamadan and 335 km to the south-west from Tehran (fig.3 – the map from the site of Institute of Geophysics of Tehran University IGUT ) |
Figure 3 |
|
| Aftershock |
| On March 31 by 16 hours Moscow time it was known that this earthquake was accompanied with two foreshocks and one aftershock. They were registered by Geophysical Survey of RAS and
by the Institute of Geophysics of Tehran University .
|
| 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 |
| 20060859 | 2006-03-30 16:17:07.0 | 33.39 | 48.9 | 33 | 21 | - | 4.9/ 7 | 3-3.5 | Western Iran | | 20060861 | 2006-03-30 19:36:16.0 | 33.3 | 48.87 | 33 | 21 | 4.5/ 8 | 5.4/ 6 | 4-4.5 | Western Iran | | 20060869 | 2006-03-31 01:31:24.0 | 33.42 | 48.57 | 33 | 20 | - | 5.2/ 6 | 4-4.5 | Western Iran | |
| Macroseismic manifestations |
| In accordance with Russian TV channel ORT on March 31 by 12 hours 50 people have been killed and nearly 800 injured. 200 destructions reported in living places of Lorestan Province, rescue works are under way. |
| Focal mechanism and seismic moment of the earthquake |
| Focal mechanism solutions for this earthquake obtained from data of National Earthquakes Information Center USA (NEIC) are shown in fig. 4 in stereographical projection (lower hemisphere, darken areas are waves of compression) and in table 2. The earthquake on March 31, 2006 has occurred under prevailing action of expansion strengths, oriented to the north-west direction. One nodal plane lays flat, the type of motion along it – normal fault, the other plane has rather steep falling angle – the type of motion along it – left sided drift. The value of seismic moment Мо from NEIC makes 3.4* 10** 17 n*m, the value of moment magnitude - Mw = 5.6. |
| 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 |
| 40 | 325 | 48 | 123 |
11 | 226 | 113 | 12 | -22 | 225 |
86 | -101 | NEIC | |
| NEIC - National Earthquakes Information Center of US Geological Service |
Figure 4 |
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