Aftershock activity moving back to the west of Christchurch is a sign stress still needs to be released from near the Greendale Fault, scientists say.
"But the area west of the February rupture – typically a bit east of Rolleston – does seem to rejuvenate a bit each time another segment goes.
"How these will play out is unclear to me, but ... it is reasonable to say that it is an area of the crust that still has not released its stress to the same degree that the main Greendale Fault has, so it still is unstable.
"You guys can't buy a break."
Says it all.