Information message about the strong earthquake off the east coast of Kamchatka March 20, 2016 |
| The strong earthquake M=6.5 has occurred March 20, 2016 at 22:50 GMT (March 21, 01:50 Moscow time) off the east 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 12 min after
registration to the Ministry of Emergency of the Russian Federation (EMERCOM). |
| Preliminary processing has been done with data from 29 stations, accurate processing - with data 55 stations. |
| Fig. 1 presents fragments of records obtained from digital stations Petropavlovsk (∆ 2.8º), Petropavlovsk Array (∆ 3.3º), Severo-Kurilsk (∆ 5.4º), Seimchan (∆ 10.5º), Kurilsk (∆ 13.2º). Fig. 2 presents fragments of records obtained from digital stations Ulaanbaatar (∆ 35º), Norilsk (∆ 36.2º), Kurchatov (∆ 48.7º), Arti (∆ 53.8º), Obninsk (∆ 62.6º). |
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 |
22-50-19.5 |
54.05 |
162.98 |
60 |
55 |
6.5/30 | 6.5/36 | 6.5 | 122 | IPC GS RAS (Accurate) | | 2 |
22-50-27.5 |
54.13 |
162.18 |
100 |
29 |
| 6.5/25 | 5.5-6 | | IPC GS RAS (Preliminary) | | 3 |
22-50-20.1 |
54.28 |
162.9 |
30 |
746 |
Mw 6.4 | | | 20 | CSEM | | 4 |
22-50-20.7 |
54.33 |
162.8 |
31 |
363 |
6.4/99 | 6.3/99 | | 20 | NEIC | | 5 |
22-50-17.5 |
54.15 |
163.06 |
41 |
|
Ml 6.7 | K 14.9 | | | KRIPC | |
| 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 |
| KRIPC - Regional Informational Processing Center of Kamchatka |
| Epicenter |
| Fig. 3 presents with red star the epicenter of this earthquake, its origin was located in the Pacific Ocean off the east coast of Kamchatka, at the depth 60 km, 245 km S of Ust-Kamchatsk, 289 km S-S-E of Kluchi and 308 km E-N-E of Petropavlovsk-Kamchatsky. |
Figure 3 |
|
| Aftershock |
| GS RAS registered aftershock M=5 within two days 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 |
| 20161002 | 2016-03-22 04:55:53.0 | 54.16 | 163.13 | 60 | 26 | - | 5.0/ 13 | 2.5-3 | Off east coast of Kamchatka | |
| Macroseismic manifestations |
| According to GS RAS earthquake was felt in Petropavlovsk-Kamchatsky with intensity 2-3 MSK. |
| Historical records |
| January 30, 2016 the strong earthquake M=6.6 at the depth 170km, 277 km W of the reported 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 80 stations, including 52 stations which registered compression waves (plus signs) and 29 stations which registered tensile waves (minus signs). These stations are located in the interval of epicentral distances 6–94º and azymuth sector Az=2-383º. Focal mechanism in stereographic projection at lower hemisphere according to IPC GS RAS data is presented in fig. 4, its elements are in table.2. Fig. 5, 6 present focal mechanisms 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. All solutions of various centers are similar. The earthquake has occurred under prevailing action of compression stress oriented to the south and tensile stress oriented to the west. Nodal plane NP1 in all solutions is nearly vertical (DP=71º-73º), it strikes to the north ( STK=5º-8º); NP2 plane is flat (DP=18º-25º) it strikes S-S-E (STK=144º-168º). The type of motion for steeply dipping plane NP1 is reverse fault with right latteral slip component, for NP2 plane - thrust with left latteral slip component.
Seismic moment of the earthquake was obtained in IPC GS RAS with Р-wave spectra registered at «Obninsk» station (∆62.61º), Мо=7.0*10**18 N*m, Mw=6.5; according to USGS NEIC – Mo=4.9*10**18 N*m, Mw=6.4; according to СМТ – Mo=4.9*10**18 N*m, 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 |
| 61 | 299 | 24 | 83 |
15 | 180 | 5 | 71 | 106 | 144 |
25 | 51 | IPC GS RAS | | 62 | 288 | 27 | 93 |
6 | 186 | 8 | 73 | 96 | 168 |
18 | 71 | NEIC | | 62 | 288 | 27 | 93 |
6 | 186 | 8 | 73 | 96 | 168 |
18 | 71 | 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 |
|
