Information message about the strong earthquake in Mexico-Guatemala border region, July 7, 2014. |
| The strong earthquake M=6.7 has occurred on July 7, 2014 at 11:23 GMT (15:23 Moscow time) in Mexico-Guatemala border region. |
| 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 18 min after
registration to the Ministry of Emergency of the Russian Federation (EMERCOM). |
| Preliminary processing has been done with data from 34 stations, accurate processing - with data 57 stations. |
| Fig. 1 presents fragments of records obtained from digital stations Juntas de Abangares (∆ 8.3º), Hockley (∆ 15.5º), Albuquerque (∆ 23.9º), Pinyon Flat (∆ 28.9º), Nana (∆ 30.6º). Fig. 2 presents fragments of records obtained from digital stations Bilibino (∆ 80.7º), Lovozero (∆ 89.1º), Petropavlovsk (∆ 89.5º), Norilsk (∆ 96.2º), Obninsk (∆ 98.1º). |
Figure 1
| 
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 |
11-23-56.4 |
14.75 |
-92.17 |
90 |
57 |
6.7/25 | 6.5/19 | 6-6.5 | 72 | IPC GS RAS (Accurate) | | 2 |
11-23-58.8 |
14.93 |
-92.15 |
90 |
34 |
6.7/18 | 6.5/16 | 6-6.5 | 77 | IPC GS RAS (Preliminary) | | 3 |
11-23-58.9 |
14.91 |
-92.28 |
90 |
337 |
7.0 Mw | | | 40 | CSEM | | 4 |
11-23-55.4 |
14.74 |
-92.41 |
60 |
108 |
6.9 Mw | | | 30 | 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 yellow star epicenter of this earthquake which origin was located at the coast of Chiapas, Mexico, Mexico-Guatemala border region, at the depth of 90 km, 77 km W of Quetzaltenango, Guatemala, 177 km W of Guatemala City, and 242 km S-S-E of Tuxtla Gutiérrez, Mexico. |
Figure 3 |
|
| Macroseismic manifestations |
| At least four persons were killed after the powerfull shock which occurred at the border area between Mexico and Guatemala. Reuters Agency reports about dozens of damaged buildings.
Fig. 4 was obtained from USGS NEIC , it presents USGS Community Internet Intensity Map, based on 200 responses in 60 cities.
|
Figure 4 |
|
| Historical records |
| This earthquake has occurred 85 km N-W of Guatemala earthquake М=7.4 of November 7, 2012 , which killed 52 and injured 200 persons.
|
| Focal mechanism and seismic moment of the earthquake |
| Focal mechanism was obtained in IPC GSRAS with signs of initial arrivals of P waves at 119 stations inluding 82 stations which registered the waves of compression (plus signs) and 37 stations which registered transverse waves (minus signs). These stations are located in the interval of epicentral distances of 1.6–97.7º and are rather uniformly dispersed along the azimuths. Focal mechanism solution of the origin in stereographic projection at the lower hemisphere is presented in fig. 5, elements of 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 Cstalogue Center with CMT technique. All solutions obtained in different centers are close.
This earthquake has occurred under prevailing action of expansion stresses oriented to the east. Nodal plane NP1 in all solutions is nearly vertical (DP=64-71º), plane NP2 is more flat (DP=21-27º).
Plane NP1 strikes N-W (STK=315-342º), plane NP2 strikes S-E (STK=134-150º). The type of motion along both planes – normal fault with minor slip components.
Seismic moment was obtained in IPC GSRAS with P wave spectra at «Obninsk» station (∆97.9º) - Мо=5.7*10**19 N*m, Mw=7.1. According to USGS NEIC – Mo=3.25*10**19 N*m, Mw=6.9, according to Quick CMT Mo=2.9*10**19 N*m, Mw=6.9. |
| 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 |
| 25 | 64 | 63 | 268 |
9 | 159 | 342 | 71 | -80 | 134 |
21 | -117 | IPC GS RAS | | 19 | 50 | 70 | 211 |
6 | 318 | 315 | 64 | -97 | 150 |
27 | -76 | NEIC | | 22 | 52 | 68 | 221 |
4 | 321 | 319 | 67 | -94 | 150 |
24 | -80 | 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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