New Zealand earthquake officially upgraded to magnitude 7.8

Geonet, which had originally (with caveats) recorded the mainshock at 7.5 magnitude, has posted a statement on the new 7.8 rating. It explains:

Early indications are that this is one of the most complex earthquakes ever recorded on land. This complexity means we have had to take extraordinary efforts to determine the magnitude, depth, and locations …
Due to the size of the quakes, we’ve gathered data from our entire network of seismic stations. All of these stations would not normally need to be included in magnitude estimates.
Further, our techs at GeoNet went out to several sites which we lost communication with and we have now been able to upload this information, so we have a more complete understanding of the ground deformation and strong-motion data.
Finally, our science teams have been working tirelessly, going up and down the affected areas and measuring the length of faults and how much they moved. Their efforts have provided us with a clearer picture as to the size and length of the ruptures.
Based on all these ongoing efforts, we can say with some confidence that the earthquake was an M7.8.
This is consistent with estimates from several other international agencies, specifically the USGS. Their early model provided us important information and we used all our additional data sets to confirm the magnitude.

https://www.theguardian.com/world/live/2016/nov/16/new-zealand-earthquake-help-stranded-kaikoura-live