Space conditions during a month of a sequence of six M > 6.8 earthquakes ending with the tsunami of 26 December 2004

This paper examines space and seismological data for the time period about one month before the giant Sumatra-Andaman strong (9.3) earthquake (EQ). The com- bination of seismological and space data reveals some inter- esting features for this time period: (1) six successive high speed solar wind streams obviously triggering a sudden in- crease of geomagnetic activity were all followed by strong to giant (M > 6.8) EQs, (2) the 6 strong EQs present cer- tain spatial-temporal constraints, with the epicentre of the EQs occuring at the edges of the Pacific Plate (the Sumatra- Andaman EQ occurred at the end of this series of EQs, east- ward of the first one), in a clockwise direction, (3) the EQs occurred after a sudden increase of geomagnetic activity, as inferred from the 3 h-Kp index, following a quiet geomag- netic period and (4) the time delay of the M > 6.2 earth- quakes (in the broad area examined) from the last maximum sudden Kp increase was on average 1.5 days. These find- ings from the study of the Earth's space environment during the month preceding the Sumatra-Andaman giant (9.3) EQ provide new information for a possible better understanding of the Sun-magnetosphere-lithosphere coupling.