Information message about the strong earthquake in Greece November 17, 2015 |
| The strong earthquake M=6.5 has occurred on November 17, 2015 at 07:10 GMT (10:10 Moscow time) in Greece. |
| 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 10 min after
registration to the Ministry of Emergency of the Russian Federation (EMERCOM). |
| Preliminary processing has been done with data from 27 stations, accurate processing - with data 67 stations. |
| Fig. 1 presents fragments of records obtained from digital stations Malin Array Point (∆ 13.3º), Kislovodsk (∆ 17.4º), Khabaz (∆ 17.5º), Garni (∆ 18.8º), Obninsk (∆ 19.5º). Fig.2 presents fragments of records obtained from digital stations Kirov (∆ 27.1º), Lovozero (∆ 30.1º), Arti (∆ 30.6º), Borovoe (∆ 36.7º), Ala-Archa (∆ 40.5º).
|
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 |
07-10-06.7 |
38.89 |
20.45 |
10 |
67 |
6.5/36 | 6.1/37 | 9-9.5 | 145 | IPC GS RAS (Accurate) | | 2 |
07-10-06.7 |
38.86 |
20.35 |
10 |
27 |
| 6.0/20 | 7.5-8 | | IPC GS RAS (Preliminary) | | 3 |
07-10-09.1 |
38.8 |
20.4 |
10 |
629 |
Mw 6.5 | | | 39 | CSEM | | 4 |
07-10-08.7 |
38.75 |
20.25 |
11 |
254 |
Mw 6.5 | | | 39 | NEIC | | 5 |
07-10-07.7 |
38.67 |
20.53 |
1 |
27 |
ML 6.0/7 | | | 134 | THE | |
| 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 |
| THE - Aristotle University of Thessaloniki, Department of Geophysics |
| Epicenter |
| Fig. 3 presents with red star the epicenter of this earthquake, its origin was located in the Mediterranean Sea near the coast of Lefkada island, Greece, at a depth of 10 km, 93 km S-E of Kerkya, 93 km S-W of Ioannina and 298 km W-N-W of Athens, the capital of Greece. |
Figure 3 |
|
| Aftershock |
| GS RAS registered 4 aftershocks М>=4.4 within 5.5 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 |
| 20154008 | 2015-11-17 08:10:06.0 | 38.82 | 20.4 | 10 | 15 | - | 4.4/ 7 | 4 | Greece | | 20154007 | 2015-11-17 08:33:39.0 | 38.85 | 20.4 | 10 | 52 | - | 5.4/ 28 | 6-6.5 | Greece | | 20154010 | 2015-11-17 11:57:24.0 | 38.86 | 20.34 | 10 | 32 | - | 4.9/ 22 | 5-5.5 | Greece | | 20154011 | 2015-11-17 12:37:54.0 | 38.87 | 20.34 | 10 | 40 | - | 5.0/ 16 | 5-5.5 | Greece | |
| Macroseismic manifestations |
| According to RIA-Novosti this earthquake killed one woman in Ponti Vasiliki, later it became known about the death of another woman in the village Atani. Four people have been injured and are in hospital.
Severe destruction registered on the small island of Ithaca, the island is in an emergency situation. Serious damage was caused to houses, churches and shops, on some roads stopped traffic due to landslides.
Fig. 4 was obtained from USGS NEIC , it presents USGS Community Internet Intensity Map based on 19 responses in 17 cities. |
Figure 4 |
|
| Historical records |
| The epicenter of this earthquake was located 60 km N of the epicenter of strong earthquake registered on January 26, 2014 M=6.1. |
| Focal mechanism and seismic moment of the earthquake |
| Focal mechanism solution of the origin was calculated in IPC GS RAS with signs of initial arrivals of P waves at 69 stations, including 52 of them which registered the waves of compression (plus signs), and 17 stations which registered tensile waves (minus signs). These stations are located in the interval of epicentral distances 2.5-94º and azimuth alignment Az = 4-356º. Focal mechanism in stereographic projection at lower hemisphere is shown in Figure 5, the elements of the mechanism are presented in Table 2. Fig. 6, 7 present focal mechanism solutions of the origin obtained in USGS NEIC with W-phase Moment Tensor (Mww) technique and in Quick CMT Catalog Center, USA with CMT technique. Solutions obtained in different centers are close.
The quake occurred under the influence of similar magnitude compressive stresses S-W directed in cases of P and CMT and N-E directed in case of USGS, and tensile stresses directed to the NW according to all three centers. Nodal plane NP1 in all solutions is almost vertical (DP=85–87º), NP2 plane is flatter (DP=64-69º). NP1 plane strikes N-E in case of USGS (STK=21º), S-E in case of Р (STK=110º) and S-W in case of CMT (STK=292º). The type of motion along both planes – slips. For NP1 in case of Р and СМТ – left latteral slip with vertical components, in case of USGS – right latteral slip with uplift components. For NP2 – in case of Р and СМТ – right latteral slip, in case of USGS – left latteral slip with uplift components.
Sesimic moment was calculated in IPC GS RAS with Р-wave spectra obtained at «Talaya» (∆56.87º) station, Мо=4.5*10**18 N*m, Mw=6.4.
According to USGS NEIC – Mo=6.2*10**18 N*m, Mw=6.5; according to СМТ – Mo=6.9*10**18 N*m, Mw=6.5. |
| 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 |
| 20 | 338 | 16 | 242 |
116 | 64 | 111 | 87 | 26 | 19 |
64 | 177 | IPC GS RAS | | 13 | 340 | 17 | 246 |
68 | 104 | 292 | 87 | -21 | 24 |
69 | -176 | NEIC | | 13 | 340 | 17 | 246 |
68 | 104 | 292 | 87 | -21 | 24 |
69 | -176 | 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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