The red marker on the map is the epicenter of the earthquake, which originated in the Drake Passage at a depth of 10 km, 253 km NE of the Chilean settlement in Antarctica, Villa las Estrellas, and 700 km SE of Puerto Williams, Chile.
|
Time in origin (GMT) |
Latitude, degree |
Longitude, degree |
Depth, km |
Stations number |
Ms/N |
mb/N |
I0 (calculated) |
GAP |
Center |
| 1
|
20:29:21.0
|
-60.24 |
-61.44 |
10.0 |
42
|
7.3/36 |
6.9/6 |
10-10.5 |
83
|
GS RAS(Verified) Federal research center, Geophysical survey of Russian Academy of Sciences
|
|
2
|
20:29:22.9
|
-60.17 |
-61.84 |
15.0 |
546
|
Mw 7.7 |
7.1/156 |
|
11
|
CSEM European - Mediterranean seismological center
|
|
3
|
20:29:20.6
|
-60.2 |
-61.8 |
8.8 |
401
|
7.5/517 |
6.7/297 |
|
12
|
NEIC National Earthquakes Information Center of US Geological Service
|
FIg. 1 presents fragments of records obtained from digital stations East Falkland Island (∆ 8.8), Sanae (∆ 25.3º), Novolazarevskaya (∆ 30.2º), Nana (∆ 30.1º), Santo Domingo (∆ 69.3º). Fig. 2 presents fragments of records obtained from digital stations Kislovodsk (∆ 133.4º), Obninsk (∆ 138.5º), Kirov (∆ 146.2º), Arti (∆ 149.1º), Kurchatov (∆ 155.8º).
Image 1
Image 2
GS RAS registered 2 aftershocks with М>=5.6 within 2 hours after the main shock.
| N |
Time in origin (GMT) |
Latitude, degree |
Longitude, degree |
Depth, km |
Stations number |
Ms/N |
mb/N |
I0 (calculated) |
Region |
| 20255919
|
10/10/2025 21:28:41.0.0 |
-60.05 |
-62.5 |
10.0 |
43 |
|
5.9/5 |
7.5-8 |
Drake Passage
|
| 20255921
|
10/10/2025 21:34:21.0.0 |
-60.14 |
-62.49 |
10.0 |
25 |
|
5.6/5 |
6.5-7 |
Drake Passage
|
Focal mechanism solution of the origin was calculated by GS RAS with signs of initial arrivals of P waves at 67 stations, including 53 stations which registered compression waves (plus signs), and 14 stations which registered tensile waves (minus signs). The stations are located in the interval of epicentral distances 2.5-99º and in azimuth sector Az=5-359º. 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 WW-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 was caused by similar compressive stresses oriented west-southwest (AZ=245º) according to GS RAS and E-NE (AZ=59-60º) according to USGS NEIC and LDEO GCMT and tensile stresses oriented S-SE (AZ=148-154º) according to GS RAS and USGS NEIC and N-NW (AZ=327º) according to LDEO GCMT. One nodal plane NP1 strikes W-NW (STK=284-290º) according to GS RAS and USGS NEIC and E-SE (STK=106º) according to LDEO GCMT, another plane NP2 strikes S-SW (STK=194-199º) according to GS RAS abd USGS NEIC and north (STK=11º) according to LDEO GCMT, both planes are dipping to to the horizon quite steeply at close angles (DIP=67-88º). The type of motion along NP1 – left lateral slip, along NP2 – right lateral slip. The seismic moment of the earthquake was obtained by GS RAS from the spectra of longitudinal waves registered at the station "Novolazarevskaya" (∆ 30.1º), it makes Mo=2.847*10**20 N*m, Mw=7.6. The seismic moment according to USGS NEIC makes Mo=3.417 *10**20 N*m, Mww=7.62. According to LDEO GCMT it makes Mo=4.05*10**20 N*m, Mw=7.7.
| Axes of main strengths |
Nodal planes |
Center |
|
| T |
P |
N |
NP1 |
NP2 |
PI: 11
Azm: 154
|
PI: 5
Azm: 245
|
PI: 78
Azm: 359
|
Stk: 290
Dp: 79
Slip: 4
|
Stk: 199
Dp: 86
Slip: 169
|
GS RAS Federal research center, Geophysical survey of Russian Academy of Sciences
|
|
PI: 5
Azm: 149
|
PI: 2
Azm: 59
|
PI: 85
Azm: 308
|
Stk: 284
Dp: 88
Slip: 5
|
Stk: 194
Dp: 85
Slip: 178
|
NEIC National Earthquakes Information Center of US Geological Service
|
|
PI: 25
Azm: 327
|
PI: 7
Azm: 60
|
PI: 64
Azm: 165
|
Stk: 106
Dp: 67
Slip: 13
|
Stk: 11
Dp: 78
Slip: 156
|
GCMT Lamont-Doherty Earth Observatory Global CMT Columbia University, USA
|
|