Information message about the strong earthquake in New Zealand August 16, 2013 |
| The strong earthquake with M=6.8 has occurred in New Zealand on August 16, 2013 at 02:31 a.m. GMT (6:31 a.m. Moscow time).
|
| 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 25 min after
registration to the Ministry of Emergency of the Russian Federation (EMERCOM). |
| Fig. 1 presents fragments of records obtained from digital stations Tennant Creek (∆ 39.7º), Port Moresby (∆ 39.9º), Erimo (∆ 87.9º), Yuzhno-Sakhalinsk (∆ 92.6º), Petropavlovsk (∆ 95.4º). Fig. 2 presents fragments of records obtained from digital stations Tiksi (∆ 117.6º), Borovoe (∆ 129.4º), Arti (∆ 136.8º), Garni (∆ 141.9º), Obninsk (∆ 149.2º). |
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 |
02-31-07.3 |
-41.87 |
173.66 |
10 |
32 |
6.8/20 | 6.3/6 | 9.5-10 | 108 | IPC GS RAS | | 2 |
02-31-07.0 |
-41.72 |
174.13 |
2 |
96 |
6.5 Mw | | | 80 | CSEM | | 3 |
02-31-07.0 |
-41.767 |
174.061 |
10 |
24 |
6.5 Mw | | | 126 | 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 red star epicenter of this earthquake, it's origin was located on the territory of New Zealand at the depth of 10 km, 113 km W-S-W of the Capital city Wellington, 73 km S-S-E of Nelson and 200 km N-E of Christchurch. |
Figure 3 |
|
| Aftershock |
| GSRAS registered 5 aftershocks with M≥5.5 whithin 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 |
| 20132931 | 2013-08-16 02:45:26.0 | -42 | 174.12 | 10 | 11 | - | 5.5/ 4 | 6.5-7 | Off e. coast of S. Island, N.Z. | | 20132932 | 2013-08-16 03:09:09.0 | -41.98 | 173.71 | 10 | 16 | - | 5.6/ 3 | 6.5-7 | South Island, New Zealand | | 20132933 | 2013-08-16 03:51:33.0 | -41.62 | 174.15 | 10 | 14 | - | 5.5/ 4 | 6.5-7 | Cook Strait, New Zealand | | 20132934 | 2013-08-16 05:31:15.0 | -41.77 | 173.84 | 10 | 20 | - | 6.0/ 8 | 7.5-8 | South Island, New Zealand | | 20132937 | 2013-08-16 06:55:57.0 | -41.56 | 174.33 | 10 | 12 | - | 5.0/ 5 | 5-5.5 | Cook Strait, New Zealand | |
| Macroseismic manifestations |
| According to ITAR-TASS tsunami warning and message about victims and destructions was not announced. At the same time suburb trains and bus traffic was temporarily stopped in Wellington, mobile phone communications and electricity supply were terminated in some parts of the city. Capital airport remains open, but delays in departure of some flights were announced. In accordance with newspaper Dominion Post one building crashed in Seddon district of the capital.
Fig. 4 presents USGS Community Internet Intensity Map obtained from site of USGS NEIC based on 12 responses in 6 cities.
|
Figure 4 |
|
| Historical records |
| Epicenter of this earthquake was located 84 km W-S-W of another strong earthquake's epicenter July 21 with M=6.5 and 222 km N-E of destructive earthquake's epicenter February 21, 2011 with М=6.3 near Christchurch city, which killed 185 persons. |
| Focal mechanism and seismic moment of the earthquake |
| Focal mechanism solution of the origin of this earthquake was obtained in USGS NEIC with USGS Body-Wave Moment Tensor Solution techniques and in Quick CMT Catalog, USA, with CMT technique. These solutions are shown in stereographic projection at the lower hemisphere in figures 5,6, elements of mechanism are presented in table 2. All solutions are close.
The earthquake has occurred under the close in value stresses of compression oriented south-east and stresses of extension, oriented to the south. Both nodal planes are steeply dipping (DP=57-83º), NP1 plane is oriented south-west, NP2 – north-west. Type of motion along both planes – slips with uplift, right side for NP1 and left side for NP2.
In accordance with USGS NEIC Мо=6.2*10**18 N*m, Mw=6.5. In accordance with Quick CMT – Мо=7.92*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 |
| 24 | 197 | 6 | 104 |
65 | 0 | 238 | 69 | 167 | 333 |
78 | 72 | NEIC | | 28 | 200 | 17 | 101 |
56 | 342 | 238 | 57 | 172 | 332 |
83 | 33 | Quick CMT | |
| NEIC - National Earthquakes Information Center of US Geological Service |
| Quick CMT - Quick CMT catalog |
Figure 5 | 
Figure 6 |
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