Information message about destructive earthquake in Philippines, October 15, 2013 |
| The strong earthquake with M=7 has occurred in Philippines on October 15, 2013 at 00:12 GMT (04:12 Moscow time), it caused victims and destructions. |
| 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 24 stations, accurate processing - with data 49 stations. |
| Fig. 1 presents fragments of records obtained from digital stations Taejon (∆ 26.7º), Matsushiro (∆ 29.6º), Mys Shultsa (∆ 33.3º), Vladivostok (∆ 33.9º), Erimo (∆ 36.3º). Fig. 2 presents fragments of records obtained from digital stations Borovoe (∆ 60.9º), Tiksi (∆ 61.9º), Arti (∆ 68.4º), Kislovodsk (∆ 77º), Obninsk (∆ 80.6º). |
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 |
00-12-30.1 |
9.68 |
123.77 |
10 |
24 |
| 6.1/20 | 8-8.5 | 160 | IPC GS RAS (Preliminary) | | 2 |
00-12-32.2 |
9.78 |
124 |
33 |
49 |
7/31 | 6.4/30 | 8-8.5 | 148 | IPC GS RAS (Accurate) | | 3 |
00-12-35.6 |
9.89 |
124.21 |
30 |
281 |
Mw 7.2 | | | 30 | CSEM | | 4 |
00-12-32.9 |
9.866 |
124.011 |
20 |
111 |
Mw 7.1 | | | 25 | 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 presnts epicenter of this earthquake with red star, it's origin was located on the territory of Bohol Island of Philippines at the depth of 33 km, 6 km W of Bayahayan, 21 km N-E of Tagbilaran and 59 km S-S-E of Cebu. |
Figure 3 |
|
| Aftershock |
| GS RAS registered 10 aftershocks with M>=4.9 within 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 |
| 20133596 | 2013-10-15 00:29:02.0 | 9.85 | 124.21 | 80 | 30 | - | 5.5/ 20 | 3-3.5 | Mindanao, Philippines | | 20133597 | 2013-10-15 00:33:43.0 | 9.8 | 124.35 | 33 | 22 | - | 5.6/ 15 | 5 | Mindanao, Philippines | | 20133598 | 2013-10-15 01:07:32.0 | 9.77 | 124.2 | 10 | 31 | - | 5.3/ 20 | 6-6.5 | Mindanao, Philippines | | 20133599 | 2013-10-15 01:24:52.0 | 9.31 | 124.27 | 33 | 16 | - | 4.9/ 14 | 3-3.5 | Mindanao, Philippines | | 20133600 | 2013-10-15 01:30:03.0 | 9.9 | 124.52 | 33 | 16 | - | 5.1/ 13 | 3.5-4 | Mindanao, Philippines | | 20133601 | 2013-10-15 01:37:56.0 | 9.78 | 123.72 | 33 | 28 | - | 5.4/ 22 | 4.5 | Negros, Philippines | | 20133602 | 2013-10-15 01:55:29.0 | 9.59 | 124.04 | 33 | 27 | - | 5.2/ 19 | 4-4.5 | Mindanao, Philippines | | 20133605 | 2013-10-15 02:42:01.0 | 9.9 | 124.17 | 33 | 32 | - | 5.2/ 21 | 4-4.5 | Mindanao, Philippines | | 20133606 | 2013-10-15 04:22:30.0 | 9.96 | 124.15 | 33 | 27 | - | 5.2/ 9 | 4-4.5 | Mindanao, Philippines | | 20133608 | 2013-10-15 05:12:14.0 | 9.57 | 124.05 | 33 | 20 | - | 4.9/ 11 | 3-3.5 | Mindanao, Philippines | |
| Macroseismic manifestations |
| According to RIA-Novosti 85 persons were killed. Some sources of information reported that many persons were injured after the crowd run away in panic from the premises. This earthquake interrupted power supply and communications with many regions of three islands. The authorities reported about "heavy damaged" sea port at Bohol Island, which stays closed (Fig.4). |
Figure 4 |
|
| Focal mechanism and seismic moment of the earthquake |
| Focal mechanism solutions of the origin were obtained in USGS NEIC with W-phase Moment Tensor technique and in Quick CMT Catalog, USA with CMT technique (fig. 5, 6). Both solutions are close.
This earthquake has occurred under the action of compression stresses oriented north-west (Az=318-319º). Both nodal planes in all solutions have nearly the same declination angle to the horizon (DP=44-48º). They strike from north-east to south-west (STK=38-40º and 237-238º). The type of motion – reversed faults along both planes with slip components (right lateral for NP1, left lateral for NP2).
Averaged value of seismic moment was obtained in IPC GS RAS with Р-wave spectra obtained at two stations «Talaya» (∆44.96º) and «Obninsk» (∆80.59º) Mo=2.2*10**19 N*m, Mw=6.9. According to USGS NEIC – Mo=5.57*10**19 N*m, Mw=7.1; according to Quick CMT – Mo=5,6*10**19 N*m, Mw=7.1. |
| 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 |
| 80 | 227 | 0 | 318 |
10 | 48 | 238 | 46 | 103 | 39 |
46 | 77 | NEIC | | 80 | 215 | 2 | 318 |
10 | 49 | 237 | 48 | 103 | 38 |
44 | 76 | Quick CMT | |
| NEIC - National Earthquakes Information Center of US Geological Service |
| Quick CMT - Quick CMT catalog |
Figure 5 | 
Figure 6 |
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