I have some vague recollection that M8 (or maybe a little smaller) quakes come in pairs in this part of the world (Solomon Islands etc.). There was a M7 aftershock to the NE of the immediate cloud of aftershocks, off closer to the second cluster of quakes that have been occuring over the last 10 days. Roger, if you are easily intertained, do you want to look for pairs of M7.5 plus in this part of the SW Pacific...say, Fiji, Samoa, Solomon and Santa Cruz Islands...

I forget the time spacing in between in the past, and may be mis-remembering.

Chris