Information about sensitive earthquake near the eastern coast of Kamchatka on July 30, 2010 |
| The sensitive earthquake with М=6.7 has occurred on July 30, 2010 at 03:56 GMT (07:56 Moscow time) near the eastern coast of Kamchatka. |
| 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 16 min after
registration to the Ministry of Emergency of the Russian Federation (EMERCOM). |
| Preliminary processing has been done with data from 48 stations, accurate processing - with data 66 stations. |
| Fig. 1 presents fragments of records obtained from digital stations Petropavlovsk (∆ 1º), Severo-Kurilsk (∆ 2.9º), Kurilsk (∆ 10.6º), Seimchan (∆ 11.3º), Erimo (∆ 15.3º), Yakutsk (∆ 18.8º). Fig. 2 presents fragments of records obtained from digital stations Mys Shultsa (∆ 21.6º), Matsushiro (∆ 22º), Taejon (∆ 27.9º), College, Alaska (∆ 29º), Ulaanbaatar (∆ 33.5º), Talaya (∆ 33.8º). |
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 |
03-56-14.4 |
52.36 |
159.88 |
50 |
66 |
6.7/25 | 6.3/41 | 7-7.5 | 77 | IPC GS RAS (Accurate) | | 2 |
03-56-14.5 |
52.35 |
159.85 |
50 |
48 |
6.7/24 | 6.5/28 | 7-7.5 | 77 | IPC GS RAS (Preliminary) | | 3 |
03-56-16.3 |
52.48 |
159.96 |
40 |
682 |
Mw 6.4 | | | 70 | CSEM | | 4 |
03-56-14.1 |
52.54 |
159.92 |
21 |
132 |
Mw 6.2 | 5.9/89 | | 76 | 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, which origin was located near the eastern coast of Kamchatka at the depth of 50 km, in 115 km E-S-E from Petropavlovsk-Kamchatsky, in 315 km E-N-E from Severo-Kurilsk. |
Figure 3 |
|
| Aftershock |
| GS RAS registered 2 foreshocks: with М=4.6 in 2 hours before the main shock and with М=4.2 in 26 hours before the main shock and 1 aftershock with М=5.9 in 32 minutes 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 |
| 20102546 | 2010-07-29 01:39:39.0 | 52.59 | 159.95 | 40 | 16 | - | 4.2/ 7 | - | Off east coast of Kamchatka | | 20102553 | 2010-07-30 01:48:44.0 | 52.41 | 159.91 | 50 | 15 | - | 4.6/ 7 | 3 | Off east coast of Kamchatka | | 20102556 | 2010-07-30 04:28:05.0 | 52.4 | 159.92 | 50 | 39 | - | 5.9/ 17 | 5-5.5 | Off east coast of Kamchatka | |
| Macroseismic manifestations |
| This earthquake was felt in Petropavlovsk-Kamchatsky with intensity of 4-5 MSK. It’s aftershock was felt in Petropavlovsk-Kamchatsky with intensity of 3 MSK. |
| Focal mechanism and seismic moment of the earthquake |
| This earthquake was felt in Petropavlovsk-Kamchatsky with intensity of 4-5 MSK. It’s aftershock was felt in Petropavlovsk-Kamchatsky with intensity of 3 MSK.
Focal mechanism solution of this earthquake which occurred on July 30, 2010 at 03:56 GMT was obtained in IPC GS RAS with first signs of P-wave arrivals at 164 stations, 150 of them registered the waves of compression (plus signs), 14 – the waves of expansion (minus signs). These stations are located in the interval of epicenter distances of 1º- 95º with rather uniform distribution along the azimuths. Mechanism of the origin in stereographic projection at the lower hemisphere is presented on figure 4, elements of this mechanism are presented in table. 2. Table 2 and figures 5, 6 also present solution of the origin calculated with TMC technique by NEIC USA, USGS and with CMT technique by Global CMT Catalog, USA. All solutions are almost identical.
The earthquake has occurred under the action of compression forces oriented south-east. Both nodal planes propagate N-E (in parallel direction with Kurils Ridge). Nodal plane NP1 was laying flat (DP=23-32º), another plane was steeply falling (declination angle of DP=58-67º). Type of motion along flat plane – over thrust, along the falling plane – uplift.
Seismic moment of the earthquake which has occurred on July 30, 2010 was calculated in IPC GS RAS from Р-wave spectra obtained at three stations: «Talaya» (∆ 33.83º), «Arti» (∆ 53.85º), "Obninsk" (∆ 63.06º) makes Мо=7.6* 10** 18 n*m. Averaged value of moment magnitude Mw was calculated with Kanamori formula and makes Mw=6.6.
The value of seismic moment Мо in accordance with USGS makes 4.1* 10** 18 n*m, the value of moment magnitude makes Mw=6.3. The value of seismic moment Мо in accordance with Global CMT Catalog – Мо=3.57* 10** 18 n*m and Mw=6.3.
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| 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 |
| 76 | 277 | 13 | 117 |
5 | 26 | 214 | 32 | 99 | 23 |
58 | 84 | IPC GS RAS | | 68 | 306 | 21 | 125 |
0 | 215 | 214 | 23 | 89 | 36 |
67 | 91 | NEIC | | 72 | 312 | 18 | 125 |
2 | 216 | 212 | 27 | 86 | 37 |
63 | 92 | 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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