Information message about the strong earthquake in Kyushu, Japan, April 14, 2016 |
| The strong earthquake M=6.3 has occurred on April 14, 2016 at 12:26 GMT (15:26 Moscow time) in Kyushu, 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 15 min after
registration to the Ministry of Emergency of the Russian Federation (EMERCOM). |
| Preliminary processing has been done with data from 36 stations, accurate processing - with data 64 stations. |
| Fig. 1 presents fragments of records obtained from digital stations Taejon (∆ 4.4º), Matsushiro (∆ 7.3º), Mys Shultsa (∆ 9.8º), Vladivostok (∆ 10.4º), Ussuriisk Array (∆ 11.4º). Fig. 2 presents fragments of records obtained from digital stations Erimo (∆ 13.6º), Yuzhno-Sakhalinsk (∆ 16.9º), Petropavlovsk (∆ 28.5º), Zalesovo Array (∆ 38.5º), Tiksi (∆ 38.9º). |
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 |
12-26-33.5 |
32.8 |
130.54 |
10 |
64 |
6.3/22 | 6.2/22 | 8.5-9 | 113 | IPC GS RAS (Accurate) | | 2 |
12-26-33.8 |
32.68 |
130.58 |
10 |
36 |
| 6/24 | 7.5-8 | | IPC GS RAS (Preliminary) | | 3 |
12-26-36.2 |
32.82 |
130.63 |
15 |
419 |
Mw 6.1 | | | 16 | CSEM | | 4 |
12-26-36.4 |
32.85 |
130.64 |
10 |
119 |
Mw 6.2 | | | 17 | 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 the epicenter of this earthquake, its origin was located on the island of Kyushu, Japan, at a depth of 10 km, 62 km E of Nagasaki, 88 km S of Fukuoka, 237 km S-W of Matsuyama. |
Figure 3 |
|
| Aftershock |
| GS RAS registered 12 aftershocks М>=4.4 within 10.5 hours after the main shock, the strongest of them М=6.2 has occurred in 2.5 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 |
| 20161316 | 2016-04-14 12:42:22.0 | 32.6 | 130.67 | 10 | 16 | - | 5.2/ 9 | 5.5-6 | Kyushu, Japan | | 20161317 | 2016-04-14 13:07:32.0 | 32.78 | 130.71 | 10 | 46 | - | 5.7/ 27 | 7-7.5 | Kyushu, Japan | | 20161318 | 2016-04-14 13:38:44.0 | 32.68 | 130.4 | 10 | 27 | - | 4.8/ 10 | 4.5-5 | Kyushu, Japan | | 20161320 | 2016-04-14 14:43:40.0 | 32.74 | 130.6 | 10 | 37 | - | 5.2/ 15 | 5.5-6 | Kyushu, Japan | | 20161322 | 2016-04-14 15:03:45.0 | 32.7 | 130.79 | 10 | 60 | 6.2/ 19 | 5.8/ 25 | 8.5-9 | Kyushu, Japan | | 20161324 | 2016-04-14 15:06:20.0 | 32.77 | 130.88 | 10 | 31 | - | 5.4/ 20 | 6-6.5 | Kyushu, Japan | | 20161325 | 2016-04-14 15:34:16.0 | 32.76 | 130.96 | 10 | 24 | - | 4.8/ 13 | 4.5-5 | Kyushu, Japan | | 20161326 | 2016-04-14 15:50:30.0 | 32.69 | 130.65 | 10 | 14 | - | 4.5/ 10 | 4-4.5 | Kyushu, Japan | | 20161332 | 2016-04-14 16:52:59.0 | 32.59 | 130.9 | 10 | 32 | - | 5.1/ 12 | 5.5-6 | Kyushu, Japan | | 20161329 | 2016-04-14 17:14:35.0 | 32.72 | 130.71 | 10 | 16 | - | 4.4/ 4 | 4 | Kyushu, Japan | | 20161331 | 2016-04-14 20:10:34.0 | 32.53 | 130.62 | 10 | 24 | - | 4.8/ 14 | 4.5-5 | Kyushu, Japan | | 20161335 | 2016-04-14 22:46:53.0 | 32.86 | 130.79 | 10 | 16 | - | 4.5/ 11 | 4-4.5 | Kyushu, Japan | |
| Macroseismic manifestations |
| According to ИТАР-ТАСС 9 persons were killed and nearly 1000 transported to hospital after this earthquake. The greatest damage was recorded in the village of Mashiko, where there are dozens of collapsed buildings. The rescue operations are attended by about five thousand military defense forces, police, firefighters and rescue workers.
In the city of Kumamoto (the administrative center of the prefecture with the same name) it was seriously damaged 13-storey residential building - the line of split balconies is observed along the entire height of the building.
Authorities blocked gas supply at about 4.5 thousand houses to prevent explosions and fires. Operation of railway transport was disrupted after the earthquake.
Driving on motorways is limited. The collapse of the roadway has occurred in a number of areas. Fig. 4 was obtained from USGS NEIC , it presents USGS Community Internet Intensity Map based on 28 responses in 15 cities. |
Figure 4 |
|
| Historical records |
| The earthquake M=7 has occurred on March 20, 2015 in 90 km N-N-W, then nearly 1000 persons were injured and at least one death registered. |
| Focal mechanism and seismic moment of the earthquake |
| Focal mechanism solution of the origin was obtained in IPC GS RAS with signs of initial arrivals of P waves at 64 stations, including 24 of them which registered compression waves (plus), and 40 which registered tensile waves (minus). These stations are located in the interval of epicentral distances 0.4–95.1º and azimuth sector Az=19-357º. Focal mechanism solution in stereograthical projection at the lower hemisphere is shown at fig. 5, elements of mechanism are presented in table 2. Fig. 6, 7 present focal mechanism solutions of the origin obtained in USGS NEIC with W-phase Moment Tensor (Mwс) technique and in Quick CMT Catalog Center, USA obtained with CMT technique.
Both solutions obtained in USGS NEIC and Quick CMT are close.
The earthquake has occurred under prevailing action of tensile stresses oriented north and north-east (AZ=3-165º) and compression stresses oriented north-west (AZ=257-268º). Nodal planes NP1 and NP2 are nearly vertical (DP=65º-82º), NP1 strikes north-west in IPC GS RAS solution (STK=314º) and north-east (STK=32º) in USGS and Quick CMT solutions; NP2 strikes north-east in GS RAS solution (STK=48º) and north-west in USGS and Quick CMT (STK=300º) solutions. The type of motion is left lateral slip with reverse fault component for NP1 in case of GS RAS solution and right lateral slip for NP1 in case of Quick CMT. For NP2 the type of motion is right lateral slip with reverse fault component in case of GS RAS solution and left lateral slip with fault component in case of USGS and Quick CMT.
Seismic moment of the earthquake obtained in IPC GS RAS with spectra of P waves at station "Obninsk" (∆65.24º) Мо=2.7*10**18 N*m, Mw=6.2, according to USGS NEIC – Mo=2.26*10**18 N*m, Mw=6.2; according to СМТ – Mo=2.26*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 |
| 11 | 3 | 23 | 268 |
64 | 117 | 314 | 82 | -25 | 48 |
65 | -171 | IPC GS RAS | | 4 | 165 | 15 | 257 |
74 | 60 | 32 | 82 | -166 | 300 |
76 | -8 | NEIC | | 4 | 165 | 15 | 257 |
74 | 60 | 32 | 82 | -166 | 300 |
76 | -8 | 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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