The red marker on the map is the epicenter of the earthquake, the origin of which was in the Pacific Ocean near the Tonga Islands, at a depth of 33 km, 204 km E-SE off Neiafu and 370 km NE off Nuku'alofa, the capital of the Kingdom of Tonga.
|
Time in origin (GMT) |
Latitude, degree |
Longitude, degree |
Depth, km |
Stations number |
Ms/N |
mb/N |
I0 (calculated) |
GAP |
Center |
| 1
|
10:48:45.0
|
-19.31 |
-172.23 |
33.0 |
66
|
7.1/40 |
7.0/22 |
8-8.5 |
51
|
GS RAS(Verified) Federal research center, Geophysical survey of Russian Academy of Sciences
|
|
2
|
10:48:41.4
|
-19.33 |
-172.54 |
10.0 |
17
|
|
7.1/17 |
10-10.5 |
|
GS RAS(Preliminary) Federal research center, Geophysical survey of Russian Academy of Sciences
|
|
3
|
10:48:50.5
|
-19.17 |
-172.33 |
60.0 |
189
|
Mw 7.3 |
|
|
74
|
CSEM European - Mediterranean seismological center
|
|
4
|
10:48:45.1
|
-19.32 |
-172.1 |
24.8 |
109
|
7.1/12 |
7.0/99 |
|
21
|
NEIC National Earthquakes Information Center of US Geological Service
|
Fig. 1 presents fragments of records obtained from digital stations Monsavu (∆ 9.6º), Port Moresby (∆ 40.5º), Kipapa (∆ 42.8º), Stephens Creek (∆ 43.2º), Matsushiro (∆ 72.6º). Fig. 2 presents fragments of records obtained from digital stations Kurilsk (∆ 73.8º), Petropavlovsk (∆ 76.3º), Yuzhno-Sakhalinsk (∆ 77.4º), Vladivostok (∆ 80.6º), Magadan (∆ 84.2º).
Image 1
Image 2
GS RAS registered three aftershocks with mb>=4.9 within 1 day and 4 hours after te main shock.
| N |
Time in origin (GMT) |
Latitude, degree |
Longitude, degree |
Depth, km |
Stations number |
Ms/N |
mb/N |
I0 (calculated) |
Region |
| 20224583
|
11/11/2022 11:57:35.0.0 |
-17.94 |
-171.97 |
20.0 |
36 |
|
5.1/20 |
4.5-5 |
Tonga Islands region
|
| 20224586
|
11/11/2022 14:42:59.0.0 |
-18.59 |
-172.25 |
33.0 |
15 |
|
4.9/10 |
3-3.5 |
Tonga Islands region
|
| 20224603
|
12/11/2022 14:41:23.0.0 |
-18.63 |
-172.48 |
33.0 |
20 |
|
5.1/11 |
3.5-4 |
Tonga Islands region
|
Focal mechanism solution of the origin was calculated by GS RAS with signs of initial arrivals of P waves at 82 stations, including 61 stations which registered compression waves (plus signs), and 21 stations which registered tensile waves (minus signs). The stations are located in the interval of epicentral distances 1.8-99.2º and in azimuth sector Az=4-357º. Focal mechanism solution in stereographic projection on the lower hemisphere and elements of the mechanism are presented in the table. The table also contains focal mechanism solutions obtained at the USGS NEIC with W-phase Moment Tensor (Mww) technique and in Lamont-Dohert Earth Observatory of Columbia University, USA (LDEO GCMT) with СМТ (Centroid moment tensor) technique. Solutions from different centers are close. The earthquake occurred under prevailing action of compression stresses oriented E-SE (AZ=108-114º ) according to GS RAS and USGS NEIC and W-NW (AZ=296 º ) according to LDEO GCMT. One nodal plane NP1 strikes south (STK=188º) according to GS RAS and USGS NEIC and S-SW (STK=207º) according to LDEO GCMT, another plane NP2 strikes N-NE (STK=24º-29º) according to GS RAS and USGS NEIC and NE (STK=37º) according to LDEO GCMT. The planes are dipping at close angles NP2 (DP=40-54º). The type of motion along both planes– reverse fault. Seismic moment according to USGS NEIC makes Mo=1.18*10**20 N*m, Mww=7.3. According to LDEO GCMT it makes Mo=1.09*10**20 N*m, Mw=7.3.
| Axes of main strengths |
Nodal planes |
Center |
|
| T |
P |
N |
NP1 |
NP2 |
PI: 79
Azm: 18
|
PI: 0
Azm: 108
|
PI: 11
Azm: 198
|
Stk: 188
Dp: 46
Slip: 75
|
Stk: 29
Dp: 46
Slip: 105
|
GS RAS Federal research center, Geophysical survey of Russian Academy of Sciences
|
|
PI: 73
Azm: 358
|
PI: 7
Azm: 114
|
PI: 15
Azm: 206
|
Stk: 188
Dp: 40
Slip: 67
|
Stk: 37
Dp: 54
Slip: 108
|
NEIC National Earthquakes Information Center of US Geological Service
|
|
PI: 87
Azm: 145
|
PI: 3
Azm: 296
|
PI: 2
Azm: 26
|
Stk: 207
Dp: 48
Slip: 92
|
Stk: 24
Dp: 42
Slip: 87
|
GCMT Lamont-Doherty Earth Observatory Global CMT Columbia University, USA
|
|