Decline in probability of lower magnitude aftershocks
Latest aftershock probabilities show there has been a slow steady decline since the start of the year in the probabilities for lower magnitude aftershocks, says GeoNet.
That decline has been about one per cent per month.
The latest calculations show for the 12 months to November 9, 2013 there is:
- A 69 per cent probability of a magnitude 5.0 to 5.4 aftershock - compared to 71 per cent in October and 82 per cent in January 2012
- A 29 per cent probability of a magnitude 5.5 to 5.9 aftershock - compared to 30 per cent in October and 39 per cent in January 2012
- A 9 per cent probability of a magnitude 6.0 to 6.4 aftershock - unchanged from October and 13 per cent in January 2012
- A two per cent probability of a magnitude 6.5 to 6.9 aftershock - compared to three per cent in October and four per cent in January 2012
- A one per cent probability, or one in a hundred chance, of a magnitude 7.0 or higher - unchanged from October.
The calculations are for the entire aftershock zone and not just Christchurch city.
This zone stretches from the Canterbury foothills in the west to Pegasus Bay in the east, and from Rangiora in the north to Tai Tapu in the south.
More information on the sequence of aftershocks is available on the GeoNet website:
http://info.geonet.org.nz/display/home/Aftershocks
