Information message about sensitive earthquake which happened on May 30, 2007 at the south of Kamchatka Peninsula. |
| The sensitive earthquake with magnitude М=5.9 has happened on May 30, 2007 at 20:22 GMT (May 31 at 00:22 Moscow time) at the south of Kamchatka Peninsula. |
| 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 45 min after
registration to the Ministry of Emergency of the Russian Federation (EMERCOM). |
| Preliminary processing has been done with data from 38 stations, accurate processing - with data 47 stations. |
| Figure 1 presents fragments of records obtained from digital stations Magadan (∆ 8.3º), Erimo (∆ 14º), Bilibino (∆ 16.6º), Yakutsk (∆ 17.8º), Tiksi (∆ 23.3º), Hailar (23.8º). Figure 2 presents fragments of records obtained from digital stations Talaya (∆ 32.5º), Kurchatov (∆ 46.8º), Borovoe (∆ 49.7º), Arti (∆ 53º), Kislovodsk (∆ 69.8º), Albuquerque (∆ 66.8º). |
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 |
20-22-11.3 |
52.12 |
157.31 |
120 |
47 |
5.9/15 | 6/12 | 4.5 | 88 | IPC GS RAS (Accurate) | | 2 |
20-22-11.7 |
52.16 |
157.25 |
120 |
38 |
5.9/15 | 5.9/10 | 4.5 | 88 | IPC GS RAS (Preliminary) | | 3 |
20-22-11.0 |
52.18 |
157.31 |
116 |
384 |
| 6.4 | | 62 | CSEM | | 4 |
20-22-12.7 |
52.14 |
157.31 |
116 |
269 |
| 6.4/138 | | 29 | NEIC (Accurate) | | 5 |
20-22-13.4 |
52.21 |
157.26 |
121 |
156 |
| 6.3/114 | | | NEIC (Preliminary) | |
| 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 |
| Epicenter of this earthquake was located at the south of Kamchatka Peninsula, in 135 km to the south-west from Petropavlovsk-Kamchatsky city and in 180 km to the north-north-east from Severo-Kutilsk settlement at the depth of 120 km. |
| Macroseismic manifestations |
| This earthquake was felt in Petropavlovsk-Kamchatsky city with intensity of 4-5 MSK, in Severo-Kurilsk - with 4 MSK. |
| Historical records |
| The earthquakes with the same or more intensities were registered before close to the epicentral zone of the reported here earthquake which happened on May 30, 2007.. The map on figure 3 presents epicenters of the earthquakes with М>=5.6 in accordance with Seismological Bulletin for the period since 1955 till November 2006. Most of the strong earthquakes in this zone with М=6.6-7.3 have happened in 60-70-s: October 26, 1959, October 28, 1960, December 26, 1964, September 21, 1974. The last significant earthquake has happened here on October 16, 2002 – it was felt in Severo-Kurilsk with intensity 4-5 MSK, in Petropavlovsk-Kamchatsky – with 2-3 MSK. |
Figure 3 |
|
| Focal mechanism and seismic moment of the earthquake |
| Focal mechanism solution of the earthquake 30.05.2007 has been calculated with method of moment tensor in NEIC USA and with Centroid Moment Tensor (CMT) method in Harvard Center, USA (HARVARD). These solutions are presented in table 2 and on figures 4-5. Both solutions are close. The earthquake has happened under the action of equal value compression strengths oriented to the west-north-west and expansion strengths oriented to the east-south-east. One nodal plane falls steep (DP=85 and 90°) is oriented to the north-east. The other nodal plane lays flat (DP=12 и 11°) and propagates to the south-east-north-west. In accordance with information from different centers the type of motion in the epicenter is almost the same: along the steep falling plane – normal fault with insignificant left side drift components, along the other plane – shift (in accordance with NEIC normal fault component was available).
The value of seismic moment Моof the earthquake 30.05.2007 in accordance with NEIC makes 5.3* 10** 18 n*m, the value of moment magnitude - Mw = 6.4. The value of seismic moment Мо in accordance with HARVARD makes 5.27* 10** 18 n*m, the value of moment magnitude - Mw = 6.4.
|
| 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 |
| 39 | 92 | 49 | 293 |
10 | 191 | 127 | 12 | -154 | 12 |
85 | -80 | NEIC | | 44 | 99 | 44 | 301 |
11 | 200 | 110 | 11 | 180 | 200 |
90 | 79 | HARVARD | |
| NEIC - National Earthquakes Information Center of US Geological Service |
| HARVARD - Harvard Geophysical Center (USA) |
Figure 4 | 
Figure 5 |
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