Information message about destructive earthquake in Spain on May 11, 2011. |
| The destructive earthquake with M=4.9 has occurred on May 11, 2011 at 16:47 GMT (20:47 Moscow time) at the south-eastern coast of Spain, it caused victims and destructions. |
| Preliminary processing has been done with data from 30 stations, accurate processing - with data 45 stations. |
| Fig. 1 presents fragments of records obtained from digital stations Kongsberg (∆ 23.1º), Kiev (∆ 25.3º), Obninsk (∆ 31º), Kislovodsk (∆ 33.6º). Fig. 2 presents fragments of records obtained from digital stations Garni (∆ 35.7º), Arti (∆ 43.4º), Tiksi (∆ 65.5º), Talaya (∆ 69.7º). |
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 |
16-47-24.8 |
37.64 |
-1.43 |
5 |
45 |
4.9/22 | 5.3/25 | 7.5-8 | 214 | IPC GS RAS (Accurate) | | 2 |
16-47-25.6 |
37.65 |
-1.4 |
10 |
30 |
| 5.3/17 | 6-6.5 | 214 | IPC GS RAS (Preliminary) | | 3 |
16-47-25.4 |
37.68 |
-1.68 |
2 |
563 |
Mw 5.1 | | | 17 | CSEM | | 4 |
16-47-25.7 |
37.7 |
-1.67 |
1 |
299 |
Mw5.1 | 5.3/207 | | 43 | 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 at the south-eastern coast of Spain, at the depth of 5 km, 44 km S-W from Murcia, 370 km S-S-E from Spanish capital Madrid. |
Figure 3 |
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| Aftershock |
| GS RAS registered 1 foreshock with M=4.6 |
| 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 |
| 20112337 | 2011-05-11 15:05:14.0 | 37.71 | -1.36 | 10 | 14 | - | 4.6/ 13 | 4.5 | Spain | |
| Macroseismic manifestations |
| In accordance with RIA-Novosti 10 persons became the victims of this earthquake. Most of destructions were noticed in Lorka town of Murcia province. As a result of this earthquake the huge bell has fallen down from bell tower of local temple, after that the bell tower has fallen itself. Numerous ancient buildings in Lorka were destroyed.
Fig. 4, shared from USGS NEIC USA , presents the map with intensities obtained from phone calls to 246 respondents living in 90 places.
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Figure 4 |
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| Historical records |
| The South of Spain belongs to seismic active zone located in the border area between Eurasian and African plates. Nearly 2500 earthquakes occur here each year, but only insignificant part of them influence people. The reported here earthquake became most significant one in Spain since 1956, when the underground shocks in Andalusia it was killed 12 persons an 70 injured. Deep focus earthquake has occurred in this region on March 29, 1954 with М=7.9 and depth of 640 km., it seriously influenced Malaga, Madrid, Granada and Kadiz. The map at fig.5 presents with yellow stars epicenters of these historical earthquakes. |
Figure 5 |
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| Focal mechanism and seismic moment of the earthquake |
| Focal mechanism solution of the origin for the earthquake which occurred on May 11, 2011 at 16:47 was calculated with tensor method in NEIC USA, and with CMT method in USGS USA and Global CMT Catalog, USA.
Focal solution of the origin is presented in figures 6, 7 in stereo projection at lower hemisphere, elements of this mechanism are presented in table 2. All solutions are almost identical. In accordance with solutions of both centers this earthquake has occurred under prevailing action of compression forces oriented almost along meridian. Axes of propagation have along latitudinal direction. One nodal plane propagates in N-E direction, another – in N-W direction, both planes are steeply falling (DP=52º–76º). Type of motion along both planes – shift (left side and right side with uplift components). The difference in these two solutions is in direction of propagation of nodal planes.
Averaged value of seismic moment of this earthquake which occurred on May 11, 2011, was obtained in IPC GS RAS with P-wave spectra obtained at two stations: «Arti» (∆ 43.40º), «Kislovodsk» (∆ 33.64º), it makes Mo=1.5*10**17 n*m. Averaged value of moment magnitude Mw, was calculated with Kanamori formula and it makes Mw=5.4.
In accordance with USGS the value of seismic moment of the earthquake which occurred on May 11, 2011 makes Mo=5.1*10**16 n*m, the value of moment magnitude makes Mw=5.1. In accordance with Global CMT Catalog the value of seismic moment makes Мо=5.3*10**16 n*m, the value of moment magnitude makes Mw=5.1.
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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 |
| 24 | 266 | 4 | 358 |
65 | 97 | 310 | 76 | 159 | 45 |
70 | 15 | NEIC | | 47 | 78 | 8 | 177 |
41 | 274 | 118 | 65 | 137 | 230 |
52 | 32 | Quick CMT | |
| NEIC - National Earthquakes Information Center of US Geological Service |
| Quick CMT - Quick CMT catalog |
Figure 6 | 
Figure 7 |
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