Information message about the strong earthquake in Tajikistan, December 7, 2015 |
| The strong earthquake M=7.5 has occurred on December 7, 2015 at 07:50 GMT (10:50 Moscow time) in Tajikistan. |
| 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 10 min after
registration to the Ministry of Emergency of the Russian Federation (EMERCOM). |
| Preliminary processing has been done with data from 26 stations, accurate processing - with data 56 stations. |
| Fig. 1 presents fragments of records obtained from digital stations Ala-Archa (∆ 4.5º), Makanchi Array (∆ 10.9º), Kurchatov (∆ 13º), Borovoe (∆ 14.8º), Jazzator (∆ 15.4º). Fig. 2 presents fragments of records obtained from digital stations Zalesovo Array (∆ 17.6º), Arti (∆ 20.4º), Belogornoe (∆ 22.5º), Talaya (∆ 25.3º), Kirov (∆ 25.3º). |
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 |
07-50-06.1 |
38.34 |
72.84 |
33 |
56 |
7.5/42 | 6.8/32 | 8.5-9 | 212 | IPC GS RAS (Accurate) | | 2 |
07-50-03.8 |
38.44 |
72.81 |
10 |
26 |
| 6.4/18 | 8.5-9 | | IPC GS RAS (Preliminary) | | 3 |
07-50-07.2 |
38.19 |
72.92 |
30 |
464 |
Mw 7.2 | | | 22 | CSEM | | 4 |
07-50-06.6 |
38.26 |
72.77 |
26 |
269 |
Mw 7.2 | 6.6/234 | | 22 | NEIC | | 5 |
07-50-07.0 |
38.54 |
72.65 |
33 |
15 |
| 6.8/15 | | 271 | IS NAS KR | | 6 |
07-50-15.9 |
38.13 |
72.95 |
30 |
7 |
7.5 | | | 284 | 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 the epicenter of this earthquake, its origin was located in Tajikistan, at a depth of 33 km, 32 km E of Barchideva, Tajikistan, 100 km W-N-W of Murghab, Tajikistan, 241 km S of Osh, Kyrgyzstan, and 346 km E-S-E of Dushanbe, capital of Tajikistan. |
Figure 3 |
|
| Aftershock |
| GS RAS registered 6 aftershocks M>=4.7 within 4 hours after the main shock. The intensity of the strongest aftershock M=5.5 was 2-3 MSK in Dushanbe. |
| 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 |
| 20154268 | 2015-12-07 08:24:13.0 | 38.38 | 72.73 | 33 | 25 | - | 4.8/ 13 | 3-3.5 | Tajikistan | | 20154270 | 2015-12-07 08:55:51.0 | 38.8 | 73.53 | 33 | 35 | - | 4.8/ 15 | 3-3.5 | Tajikistan-Xinjiang border reg. | | 20154271 | 2015-12-07 09:24:56.0 | 38.81 | 73.16 | 33 | 37 | - | 4.8/ 17 | 3-3.5 | Tajikistan-Xinjiang border reg. | | 20154272 | 2015-12-07 10:04:58.0 | 38.65 | 73.25 | 33 | 51 | - | 5.5/ 23 | 4.5-5 | Tajikistan-Xinjiang border reg. | | 20154273 | 2015-12-07 10:34:24.0 | 38.21 | 72.72 | 33 | 39 | - | 4.7/ 21 | 2.5-3 | Tajikistan | | 20154274 | 2015-12-07 11:48:01.0 | 38.52 | 73.2 | 33 | 37 | - | 5.0/ 19 | 3.5-4 | Tajikistan-Xinjiang border reg. | |
| Macroseismic manifestations |
| According to RIA-Novosti one person was killed in a rockfall that occurred because of the earthquake in the Gorno-Badakhshan Autonomous Region of Tajikistan. Dozens of people were injured in one village of Bartang Region, more than 500 houses were destroyed. Murghab regional administration announced partial destruction of several residential buildings. Dushanbe residents jumped into the street. The cabinets rattled, swinging chandeliers. Tremors were felt after the earthquake in northern India, including the capital New Delhi. Also, tremors were felt in many parts of Xinjiang, which borders Tajikistan. The strongest tremors were felt in Kashgar region. It was reported about two minutes of rocked furniture, staggered chandeliers and splashed water in aquariumsthe in the houses.
According to Geophysical Survey of the Academy of Sciences of the Republic of Tajikistan this earthquake was felt in: Sarez - 5-6 MSK, Dushanbe - 3-4 MSK. According to Institute of Seismology of the National Academy of Sciences of the Kyrgyz Republic this earthquake was felt in: Daraut-Kurgan, Bordobo, Irkeshtam - 5 MSK, in Osh - 4 MSK, in Bishkek, Naryn - 3 MSK.
According to Kazakh National Data Center in Kazakhstan this earthquake was felt in Almaty with intensity 2-3 MSK.
Fig. 4 was obtained from USGS NEIC , it presents USGS Community Internet Intensity Map made by 45 responses in 30 cities. |
Figure 4 |
|
| Historical records |
| The epicenter of this earthquake was located near Lake Sarez, formed in February 1911 in a landslide caused by the earthquake M=7.3, which blocked the Murghab River. Over the last century 18 earthquakes M>=6.5 have occurred in a radius of 250 km from the epicenter. |
| Focal mechanism and seismic moment of the earthquake |
| Focal mechanism solution of the origin was calculated in IPC GS RAS with signs of initial arrivals of P waves at 75 stations, including 36 stations which registered compression waves (plus signs) and 39 stations which registered tensile waves (minus sign). These stations are located in the interval of epicentral distances 1.4-98º and azimuth alignment Az=0-357º. Focal mechanism in stereographic projection at lower hemisphere is shown in Fig. 5, elements of the mechanism are given in Table 2. Fig. 6, 7 present solutions obtained in the USGS NEIC with W-phase Moment Tensor (Mww) technique and in Quick CMT Catalog Center, USA with CMT technique, focal mechanism elements are presented in Table 2. These solutions obtained in different centers are close.
The earthquake has occurred under the action of similar magnitude compressive stresses directed to the south (IPC GS RAS, Quick CMT) and to the north (USGS); tensile stresses were directed to the east (IPC GS RAS, USGS) and the west (Quick CMT). Both planes lie vertically (DP = 74-90º), NP1 plane is SW oriented (STK = 213-218º), NP2- strikes W (STK = 303-309º) in the case of IPC GS RAS and CMT; S-W (STK = 123º) in the case of USGS. The type of motion along both planes - uplift with slip components - left latteral for NP1 and right latteral for NP2.
According to the USGS NEIC - Mo=7.061*10**19 N*m, Mw=7.2, according to the CMT - Mo=7.71*10**19 N*m, M =7.2. |
| 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 |
| 10 | 82 | 13 | 174 |
74 | 315 | 218 | 74 | -2 | 309 |
88 | -164 | IPC GS RAS | | 11 | 78 | 1 | 348 |
79 | 55 | 123 | 82 | 173 | 214 |
83 | 8 | NEIC | | 11 | 259 | 11 | 167 |
75 | 33 | 303 | 75 | 180 | 33 |
90 | 15 | 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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