Mw 6.8 South Sandwich Islands Region
updated 22 August 2021

On 22 August 2021 a strong earthquake occurred in the South Sandwich Islands Region at a depth of 10 km. The seismic event occurred at 00:45:08 UTC and had an estimated moment magnitude (Mw) 6.8. It is the second aftershock in this magnitude range of the major earthquakes that occurred in the region on 12 August.

While considered an aftershock, the earthquake did occur after notable critical planetary and lunar geometry, in particular the Earth-Mercury-Mars alignment, which can cause major seismic activity, like in 2015 and 2017. Two lunar peaks followed on this plantary geometry and the earthquake occurred at the second lunar peak. Increased seismic activity was anticipated at these lunar peaks because of the critical planetary geometry preceding them (see Telegram post below).

Earth-Mercury-Mars        2021-08-19,  3:23:37  162°30'42"
Sun-Earth-Jupiter         2021-08-20,  0:17:02  326°55'40"

Earth:   Moon-Saturn      2021-08-20, 23:30:58    0°00'00"
Earth:   Moon-Jupiter     2021-08-22,  6:54:06    0°00'00"
Moon:    Earth-Sun        2021-08-22, 11:36:15    0°00'00"
					
SSGI chart
SSGI depiction of planetary (PG) and lunar (LG) geometry

atmospheric electricity
atmospheric electricity before and during the earthquake