Information message about the strong earthquake on the northern coast of West Papua, Indonesia, September 24, 2015 |
| The strong earthquake M=6.3 has occurred on September 24, 2015 at 15:53 GMT (18:53 Moscow time) on the north coast of West Papua, Indonesia. |
| 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 28 stations, accurate processing - with data 61 stations. |
| Fig. 1 presents fragments of records obtained from digital stations Tennant Creek (∆ 19.5º), Stephens Creek (∆ 32.6º), Taejon (∆ 37º), Matsushiro (∆ 37.5º), Ussuriysk (∆ 44.6º). Fig. 2 presents fragments of records obtained from digital stations Yuzhno-Sakhalinsk (∆ 48.5º), Kuldur (∆ 49.7º), Petropavlovsk-Kamchatsky Group (∆ 57.9º), Magadan (∆ 61.9º), Jazator (∆ 62.5º). |
Figure 1
| 
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 |
15-53-28.1 |
-0.61 |
131.17 |
33 |
61 |
6.3/26 | 6.7/35 | 7-7.5 | 131 | IPC GS RAS (Accurate) | | 2 |
15-53-25.3 |
-0.69 |
130.94 |
10 |
28 |
| 6.6/13 | 9-9.5 | | IPC GS RAS (Preliminary) | | 3 |
15-53-32.7 |
-0.6 |
131.21 |
46 |
199 |
Mw 6.9/26 | | | | CSEM | | 4 |
15-53-28.7 |
-0.63 |
131.25 |
24 |
173 |
Mw 6.6 | 6.5 | | 19 | 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 northern coast of West Papua, Indonesia, at the depth of 33 km, 29 km N of Sorong, 475 km N-E of Ambon and 740 km E-S-E of Manado. |
Figure 3 |
|
| Aftershock |
| GS RAS registered aftershock М=4.9 within 9 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 |
| 20153395 | 2015-09-25 00:41:08.0 | -0.7 | 131.18 | 33 | 23 | - | 4.9/ 16 | 3-3.5 | Irian Jaya region, Indonesia | |
| Macroseismic manifestations |
| According to ITAR-TASS as a result of the earthquake, 62 people were injured and about 200 homes destroyed. |
| Historical records |
| This earthquake has occurred 67 km W of strong earthquake on January 3, 2009 М=7.3. Than 4 persons were killed by the earthquake. |
| 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 61 stations, including 54 stations which registered compression waves (plus signs) and 17 stations which registered tensile waves (minus signs). The stations are located in the interval of epicentral distances 9,5-96º and azimuth alignment Az = 9-359º. Fig 4. presents focal mechanism solution in stereographic projection at the lower hemisphere obtained by IPC GS RAS, Fig.5 presents focal mechanism solution obtained in USGS NEIC with Moment Tensor (Mww) technique, Fig.6 presents focal mechanism solution obtained in Quick CMT Catalog (GCMT), USA with Mwc technique. Elements of mechanism are presented in table.2. All solutions obtained in different centers are close. This earthquake has occurred under prevailing action of N-E-S-W oriented compression stress. Nodal planes decline to horizon under the close angles.
The motion in origin along both planes presents reverse fault with slip components (for NP1 – left lateral in case of USGS, right lateral – in case of IPC GS RAS and Quick CMT), (for NP2 – right lateral in case of USGS, left lateral in case of IPC GS RAS and Quick CMT). According to USGS NEIC Mo=1.032*10**19 N*m, Mw=6.6, according to Quick CMT Mo=0.92*10**18 N*m, Mw=6.6. |
| 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 |
| 66 | 349 | 12 | 229 |
20 | 135 | 344 | 37 | 125 | 123 |
60 | 67 | IPC GS RAS | | 80 | 187 | 9 | 31 |
4 | 301 | 298 | 54 | 85 | 126 |
36 | 97 | NEIC | | 80 | 310 | 2 | 210 |
10 | 120 | 310 | 44 | 104 | 111 |
48 | 76 | 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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