On 6 March 2011 a strong earthquake occurred in the South Sandwich Islands region at a depth of 80 km. The seismic event occurred at 14:32:35 UTC and had an estimated moment magnitude (Mw) 6.6.
Planetary geometry became critical a day earlier when Mercury aligned with the Sun and Saturn and Jupiter respectively, while the Moon aligned with both gas giants a good 24 hours later, which resulted in a high lunar peak (index 18). Obviously, Mercury was closely aligned with Jupiter and Saturn in opposite positions (grand opposition) and the three planets aligned on the 6th.
Major seismic activity followed on the 9th and 11th, following the Venus-Mars-Uranus alignment on the 7th.
Sun-Mercury-Uranus 2011-03-02, 19:27:00 0°11'07" Mercury-Sun-Saturn 2011-03-05, 8:14:21 192°44'22" Sun-Mercury-Jupiter 2011-03-05, 11:05:33 13°21'09" Jupiter-Mercury-Saturn 2011-03-06, 15:58:41 193°00'51" Venus-Mars-Uranus 2011-03-07, 1:28:56 2°02'53" Earth-Moon-Neptune 2011-03-03, 14:19:11 328°45'48" Earth-Moon-Mars 2011-03-04, 7:09:25 337°09'23" Earth-Moon-Sun 2011-03-04, 20:26:30 343°45'23" Earth-Moon-Mercury 2011-03-05, 12:36:11 351°45'55" Earth-Moon-Uranus 2011-03-06, 4:16:32 359°30'58" Earth-Moon-Jupiter 2011-03-06, 23:26:00 8°58'46" Moon-Earth-Saturn 2011-03-07, 13:03:21 195°42'31"