Information message about the destructive earthquake in Japan, November 22, 2014 |
| The destructive earthquake M=6.6 has occurred on November 22, 2014 at 13:08 GMT (16:08 Moscow time) in Japan. |
| 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 9 min after
registration to the Ministry of Emergency of the Russian Federation (EMERCOM). |
| Overall processing has been done according to 51 stations. |
| Fig. 1 presents fragments of records obtained from digital stations Erimo (∆ 6.8º), Vladivostok (∆ 8º), Taejon (∆ 8.5º), Yuzhno-Skhalinsk (∆ 11º), Kurilsk (∆ 11.5º). Fig. 2 presents fragments of records obtained from digital stations Bilibino (∆ 35.3º), Tiksi (∆ 35.4º), Borovoe (∆ 48.8º), Arti (∆ 54.8º), Obninsk (∆ 66.7º). |
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 |
13-08-15.5 |
36.61 |
137.86 |
10 |
51 |
6.6/29 | 6.2/35 | 9-9.5 | 88 | IPC GS RAS | | 2 |
13-08-17.7 |
36.7 |
137.852 |
2.1 |
519 |
Mw 6.2 | | | 20 | CSEM | | 3 |
13-08-18.5 |
36.64 |
137.911 |
10 |
131 |
Mw 6.2 | | | 26 | NEIC | | 4 |
13-08-00.0 |
36.7 |
137.9 |
10 |
|
Mw 6.8 | | | | JMA | |
| 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 |
| JMA - Japan Meteorological Agency |
| Epicenter |
| Fig. 3 presents with red star epicenter of this earthquake which origin was located at Honshu Island, Japan, at the depth of 10 km, 11 km N of Omachi, 30 km W of Nagano, 165 km N-E of Gifu and 203 km N-W of Tokyo, the Capital of Japan. |
Figure 3 |
|
| Aftershock |
| GS RAS registered one aftershock М=4.4 within the day 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 |
| 20144275 | 2014-11-23 03:46:35.0 | 36.6 | 137.86 | 10 | 13 | - | 4.4/ 8 | 4 | Eastern Honshu, Japan | |
| Macroseismic manifestations |
| According to ITAR-TASS 37 houses were totally destroyed. All these destructions occurred in two settlements - Hokubu and Otari, they are located close to so called Japanese Alps - the famous mountain ski resort. Another 20 houses were partially destroyed. 39 persons were injured. According to Japan Meteorological Agency this earthquake was felt in Nagano, Otari and Ogawa with intensity 6, in Hokubu and Shinano with intensity 5-6, in Itoigawa, Myoko, Nakano, Omachi and Iizuna with intensity 4-5 of JMA scale.
Fig. 4 was obtained from USGS NEIC , it presents USGS Community Interenet Intensity Map based on 102 responses in 50 cities. |
Figure 4 |
|
| Historical records |
| This earthquake has occurred 123 km S-W of strong earthquake July 16, 2007 М=6.7, which killed 7 persons and injured 700 persons.
|
| 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 71 stations, including 58 stations which registered waves of compression (plus signs) and 13 stations which registered waves of expansion (minus signs). These stations are located in the interval of epicentral distances of 0–99º and in azimuth sector of Az=3-339º. Focal mechanism solution in stereographic projection at the lower hemisphere is presented at fig. 5, elements of mechanism are presented in table.2. Fig. 6, 7 present focal mechanism solutions obtained in USGS NEIC with W-phase Moment Tensor (Mww) technique and in Quick CMT Center obtained with CMT technique.
These solutions are almost identical. The motion has occurred under the action of compression stresses oriented S-E–N-W. Both nodal planes strike N-E–S-W (STK= 13-270º) and dip under the angles DP=43-66º. The type of motion – overthrusts with slip elements along both nodal planes. For NP1 in case of IPC GS RAS (DP=66º) – with elements of left lateral slip, in case of USGS NEIC and Quick CMT (DP=51 -55º) – right lateral slip. For NP2 in case of IPC GS RAS – right lateral slip with overthrust elements, in case of USGS NEIC and Quick CMT - overthrusts with components of left lateral slip.
Seismic moment of the earthquake obtained in IPC GS RAS with Р wave spectra registered at «Obninsk» (∆66.7º) station makes Мо=6.8*10**18 N*m, Mw=6.5.
According to USGS NEIC – Mo=2.32*10**18 N*m, Mw=6.2, according to Quick CMT Mo=2.97*10**18 N*m, Mw=6.2. |
| 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 |
| 49 | 245 | 10 | 143 |
39 | 44 | 23 | 66 | 46 | 270 |
49 | 147 | IPC GS RAS | | 74 | 207 | 4 | 312 |
15 | 43 | 236 | 51 | 110 | 26 |
43 | 67 | NEIC | | 58 | 218 | 2 | 311 |
32 | 43 | 249 | 55 | 130 | 13 |
51 | 47 | 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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