Information message about destructive earthquake in Myanmar on March 24, 2011 |
| The significant earthquake with M=7.2 which caused victims and destructions has occurred on March 24, 2011 at 13:55 GMT (17:55 Moscow time) in Myanmar. |
| 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 17 min after
registration to the Ministry of Emergency of the Russian Federation (EMERCOM). |
| Preliminary processing has been done with data from 55 stations, accurate processing - with data 59 stations. |
| Fig. 1 presents fragments of records obtained from digital stations Ulaanbaatar (∆ 27.7º), Ala Archa (∆ 30.5º), Talaya (∆ 31º), Kurchatov (∆34.3º), Borovoe (∆ 39.5º). Fig. 2 presents fragments of records obtained from digital stations Arti (∆ 46.9º), Garni (∆ 50.5º), Kislovodsk (∆ 52.5º), Tiksi (∆ 53.6º), Obninsk (∆ 58.1º).
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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 |
13-55-10.7 |
20.72 |
99.92 |
10 |
59 |
7.2/41 | 6.5/40 | 10-10.5 | 65 | IPC GS RAS (Accurate) | | 2 |
13-55-10.7 |
20.73 |
99.91 |
10 |
55 |
7.2/40 | 6.5/38 | 10-10.5 | 65 | IPC GS RAS (Preliminary) | | 3 |
13-55-12.8 |
20.7 |
99.84 |
10 |
314 |
Mw 6.7 | | | 22 | CSEM | | 4 |
13-55-12.5 |
20.71 |
99.95 |
10 |
109 |
Mw 7 | 6.3/102 | | 36 | 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 yellow star epicenter of this earthquake which origin was located in the eastern part of Myanmar, at the border with Thailand and Laos, at the depth of 10 km, 417 km N-W from Vientiane the capital of Laos and 422 km E-S-E from Mandalay town of Myanmar. |
Figure 3 |
|
| Aftershock |
| GS RAS registered 3 aftershocks with M>=5.1 within 11 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 |
| 20111414 | 2011-03-24 14:23:50.0 | 20.56 | 99.94 | 10 | 25 | - | 5.1/ 18 | 5.5-6 | Myanmar | | 20111415 | 2011-03-24 15:54:33.0 | 20.62 | 99.9 | 10 | 31 | - | 5.7/ 15 | 7-7.5 | Myanmar | | 20111430 | 2011-03-25 00:22:37.0 | 20.78 | 99.87 | 10 | 25 | - | 5.1/ 16 | 5.5-6 | Myanmar | |
| Macroseismic manifestations |
| In accordance with RIA-Novosti this earthquake killed not less than 60 people and at least 90 people were injured. Undeground shocks destroyed dozens of living buildings in Terlay town.
Fig. 4, shared from Geological Service NEIC, USA , presents the map with intensities obtained from phone calls from 421 respondents in 45 living places.
|
Figure 4 |
|
| Focal mechanism and seismic moment of the earthquake |
| Focal mechanism solution of the origin for this earthquake which occurred on March 24, 2011 at 13:55 GMT was calculated in IPC GS RAS with initial arrivals of P-waves at 76 stations, including 48 stations which registered the waves of compression (plus signs) and 28 stations which registered the waves of expansion (minus signs). These stations are located with interval of distances between epicenters of 2º-86º with rather uniform disribution of stations along the azimuths. Focal solution of the origin in stereographic projection at the lower hemisphere is presented in figure 5, elements of this solution are presented in table 2. Table 2 and figures 6, 7 also present focal mechanism solution which was calcualted with CMT technique in NEIC USA, USGS and Global CMT Catalog, USA. All solutions are almost identical.
This earthquake occurred under close in value expansion forces oriented N-W-S-E, and under compression forces oriented S-W. Both nodal either with N-E or with N-W direction of propagation were steeply falling, almost vertically (DP=79º–88º). The types of motion along both planes are nearly the «pure» slips (with minor uplift components).
Seismic moment of this earthquake which occurred on March 24,2011 obtained in IPC GS RAS Р-wave spectra at three stations: «Talaya» (∆ 31.03º), «Arti» (∆ 46.92º), «Kislovodsk» (∆ 52.46º), makes Mo=1.7*10**19 n*m. Averaged value of moment magnitude Mw was calculated with Kanamori formula and makes Mw=6.8.
Seismic moment of this earthquake which occurred on March 24,2011 in accordance with USGS makes Мо=2.1*10**19 n*m, the value of moment magnitude makes Mw=6.8. The value of seismic moment in accordance with Global CMT Catalog makes Мо=2.28*19**20 n*m, the value of moment magnitude makes Mw=6.8. |
| 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 | 296 | 5 | 205 |
78 | 90 | 71 | 86 | 11 | 340 |
79 | 176 | IPC GS RAS | | 2 | 115 | 4 | 205 |
85 | 1 | 250 | 86 | -2 | 340 |
88 | -176 | NEIC | | 10 | 295 | 4 | 205 |
79 | 93 | 70 | 86 | 10 | 340 |
80 | 176 | 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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