Information message about sensitive earthquake in the region of Kuril Islands, June 18, 2010 |
| Sensitive earthquake with М=6.2 has occurred on June 18, 2010 at 02:23 GMT (06:23 Moscow Time) in the region of Kuril Islands. |
| 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 37 stations, accurate processing - with data 59 stations. |
| Fig. 1 presents fragments of records obtained from digital stations Erimo (∆ 4.8º), Petropavlovsk (∆ 10.8º), Vladivostok (∆ 12.3º), Seimchan (∆ 18.7º), Yakutsk (∆ 20.9º). Fig. 2 presents fragments of records obtained from digital stations Arti (∆ 54.7º), Obninsk (∆ 65.5º), Kislovodsk (∆ 70.2º), Kiev (∆ 71.8º), Garni (∆ 71.8º). |
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 |
02-23-05.0 |
44.4 |
148.77 |
45 |
59 |
6.2/23 | 6.1/34 | 6.5 | 82 | IPC GS RAS (Accurate) | | 2 |
02-23-05.0 |
44.4 |
148.79 |
45 |
37 |
6.1/17 | 6.3/22 | 6-6.5 | 82 | IPC GS RAS (Preliminary) | | 3 |
02-23-08.6 |
44.568 |
148.666 |
48 |
244 |
Mw 5.9 | | | 86 | CSEM | | 4 |
02-23-08.5 |
44.533 |
148.634 |
48 |
140 |
Mw 5.9 | 5.8/63 | | 86 | 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 depicts with red star epicenter of this earthquake, it's origin was located in Pacific Ocean near the eastern coast of Kuril Islands, at the depth of 45 km, 120 km S-E of Kurilsk, 167 km E-N-E of Malokurilsk and 235 km E-N-E of Yuzhno-Kurilsk. |
Figure 3 |
|
| Aftershock |
| GS RAS registered 1 aftershock with М=4 in 8 minutes afdter 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 |
| 20102121 | 2010-06-18 02:31:40.0 | 44.38 | 148.71 | 50 | 9 | - | 4.0/ 5 | - | Kuril Islands | |
| Macroseismic manifestations |
| This earthquake was felt in Kurilsk, Malokurilsk with intensity 3 MSK, in Yuzhno-Kurilsk - with intensity 2 MSK.
|
| Historical records |
| This earthquake which occurred on June 18, 2010 has happenned in the region of catastrophic Shikotan earthquake of October 4,1994 with magnitude М=8.4. In accordance with GS RAS data May 25, 2001 this is the sensitive earthquake with magnitude М=7. |
| Focal mechanism and seismic moment of the earthquake |
| Focal mechanism solution of this earthquake which occurred on June 18, 2010 at 02:23 (GMT) was calculated in GS RAS from initial signs of P-waves arrival at 161 stations, 140 of these stations registered the waves of compression (plus signs), 21 stations registered the waves of expansion (minus signs). These stations are located in the interval of epicenter distances of 1º-88º with rather uniform distribution along the azimuths. Focal mechanism solution of the origin in stereographic projection of the lower hemisphere is shown on figure 4, elements of this solution are presented in table 2. Table 2 and figures 5, 6 also present focal mechanism solutions of the origin, which were obtained in NEIC, USGS and Global CMT Catalog with CMT technique. These solutions are almost identical. The earthquake has occurred under the action of compression forces oriented S-E. Both nodal planes propagate N-E (in parallel with Kuril Ridge). One nodal plane NP1 lays rather flat (DP=27º-34º), another – steeply falling (declination angle DP=58º-67º). The type of motion along flat plane – thrust with right side drift components, and for steeply falling plane – uplift with left side drift components.
The value of seismic moment Мо of this earthquake which occurred on June 18, 2010 and obtained in GS RAS with Р-wave spectra at two stations: «Arti» (∆ 54.67º), "Obninsk" (∆ 64.36º), makes Мо=3.65* 10** 18 n*m. Averaged moment magnitude Mw was calculated with Kanomori formula and makes Mw=6.3.
The value of seismic moment Мо in accordance with USGS makes 2.1* 10** 18 n*m, the value of moment magnitude Mw=6.1.
The value of seismic moment Мо in accordance with Global CMT Catalog – Мо=2.28* 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 |
| 74 | 250 | 12 | 111 |
19 | 10 | 215 | 34 | 109 | 12 |
58 | 78 | IPC GS RAS | | 73 | 281 | 15 | 120 |
5 | 28 | 218 | 30 | 100 | 26 |
61 | 84 | NEIC | | 65 | 268 | 21 | 123 |
13 | 28 | 234 | 27 | 119 | 22 |
67 | 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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