The rupture stretched from Haupiri River on the West Coast of the South Island down at least as far as Milford Sound and the two researchers estimate it reached a magnitude of 8.1, higher than the previously thought mean magnitude of 7.9.

Christchurch City Council has gifted more than 100 pieces of the track, which was irreparably damaged in the February 2011 earthquake, for charity auction.

"It's about time," said Brian Kennedy of Dr Alan Reay's apology at the Royal Commission of Inquiry into the CTV collapse.

Young cancer fighter Jayden Halliwell this morning pushed the button which set off a series of explosions and turned the earthquake-damaged 14-storey building to dust and rubble.

Christchurch's earthquake-damaged Radio Network House was demolished in spectacular style.