Information message about the sensitive earthquake in the region of Crete Island, Greece, October 12, 2013 |
| The sensitive earthquake with M=6.5 has occurred on October 12, 2013 at 13:11 GMT (17:11 Moscow time) in the region of Crete Island, 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 16 min after
registration to the Ministry of Emergency of the Russian Federation (EMERCOM). |
| Preliminary processing has been done with data from 28 stations, accurate processing - with data 57 stations. |
| Fig. 1 presents fragments of records obtained from digital stations Apeiranthos of Naxos (∆ 2.3º), Isparta (∆ 6.2º), Kasperske Hory (∆ 15.3º), Kislovodsk (∆ 17.1º), Garni (∆ 17.5º). Fig. 2 presents fragments of records obtained from digital stations Kaliningrad (∆ 19.1º), Obninsk (∆ 21.6º), Vasula (∆ 23º), Arti (∆ 31.6º), Borovoe (∆ 37.1º). |
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 |
13-11-50.3 |
35.6 |
23.3 |
33 |
57 |
6.5/23 | 6.6/19 | 7-7.5 | 144 | IPC GS RAS (Accurate) | | 2 |
13-12-01.9 |
35.89 |
23.71 |
100 |
28 |
| 6.7/17 | 6-6.5 | 144 | IPC GS RAS (Preliminary) | | 3 |
13-11-54.0 |
35.56 |
23.31 |
46.8 |
567 |
Mw 6.4 | | | 39 | CSEM | | 4 |
13-11-52.4 |
35.487 |
23.261 |
36.19 |
138 |
| 6.4 | | 40 | 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 presents with red star epicenter of this earthquake which origin was located in Mediterranean Sea near the coast of Crete, Greece, at the depth of 33 km, 66 km W-N-W of Сhania, 170 km W-N-W of Iraklion and 262 km S-S-W of Athens, the Capital of Greece. |
Figure 3 |
|
| Aftershock |
| GS RAS registered 1 aftershock with M=4.5 within one hour 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 |
| 20133567 | 2013-10-12 14:05:47.0 | 35.35 | 23.51 | 33 | 10 | - | 4.5/ 7 | 2-2.5 | Crete, Greece | |
| Macroseismic manifestations |
| According to Russian RFI the earthquake caused material damage at Crete: broken panes in living houses and shops. Residents reported about significant piece of rock which has fallen to the road in the area of Сhania, it blocked traffic. Undeground wave reached Greek Capital, resident of other cities in Greece also felt it.
Fig. 4 presents USGS Community Internet Intensity Map USGS NEIC , based on 45 responses in 30 cities. |
Figure 4 |
|
| 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 114 station, including 90 stations which registered compression waves (plus signs), and 24 stations which registered expansion waves (minus signs). All these stations are located in the interval of epicentral distances of 5–100º and are evenly dispersed along the azimuths. Focal mechanism solution of the origin in stereographic projection at the lower hemisphere is shown at fig. 5, elements of mechanism are presented in table.2.
Fig. 6, 7 present focal mechanism solutions obtained in USGS NEIC with W-phase Moment Tensor technique and in Quick CMT Catalog, USA with CMT technique. Both solutions are close.
The earthquake has occurred under the action of close in value compression stresses oriented south-west and under stresses of extension oriented north-east. One nodal plane NP1 in all solutions are almost vertical (DP=83-88º), it is oriented south-east (STK=119-127º), another plane NP2 is flat (DP=3–19º) and is oriented north-west–north-east. The type of motion along vertical plane NP1 – overthrust, along NP2 – right side slip with overthrust components, overthrust with right side slip components.
Seismic moment of the earthquake was obtained in IPC GS RAS with Р wave spectra registered at «Talaya» station (∆57.43º), Мо=1.2*10**19 N*m, Mw=6.7.
According to USGS NEIC – Мо=8.38*10**18 N*m, Mw=6.5; according to Quick CMT – Мо=1,42*10**19 N*m, Mw=6.7. |
| 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 |
| 48 | 10 | 37 | 225 |
18 | 121 | 119 | 84 | 72 | 11 |
19 | 161 | IPC GS RAS | | 52 | 34 | 38 | 218 |
2 | 127 | 127 | 83 | 88 | 322 |
7 | 105 | NEIC | | 48 | 27 | 42 | 211 |
2 | 119 | 119 | 87 | 88 | 340 |
3 | 130 | 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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