After a couple of relatively quiet days, Christchurch has experienced another wave of aftershocks with two of them measuring over 4 on the Richter scale.
The Christchurch earthquake on the 4th September has been followed by a couple of thousand aftershocks. These appear to be random and don’t follow any set pattern.
Christchurch residents had felt more settled over the last week but a strong 4.7 aftershock awoke many people at 1:35am on the 14th November.
What were the Strength of the Recent Aftershocks in Christchurch
According to Geonet, the Christchurch area only experienced one aftershock on Thursday 11th November and that was of 2.4 magnitude.
Friday showed more activity with 6 aftershocks ranging from 3.0 to 3.8 on the Richter scale. Only one aftershock was recorded on Saturday the 13th and that was a 3.1. Starting early on Sunday morning, Christchurch was shaken by a 3.2 just after midnight followed a few minutes later by a 3.8. At 1:35am a 4.7 magnitude tremor shook the area, setting alarms off and causing houses to bang, rattle and shake. The next aftershock was a 3.6 after 5pm followed by 4.9 at 7:21pm.
How are Christchurch Residents Handling the Aftershocks
People are generally coping better than they were a few weeks ago but most report that being awoken from a deep sleep by aftershocks sets their hearts racing. The stronger day-time ones also get the adrenaline flowing and many say that their biggest concern is that the city may still get an aftershock of over 6 in magnitude. This was a worry soon after the 7.1 earthquake but seismologists say the risk of such a large aftershock has diminished over the weeks although it has not completely disappeared.
What is the Prediction for Aftershocks in Christchurch
GNS seismologist, Bill Fry, has stated that Christchurch could still be experiencing aftershocks a year from now. The quakes are shallow which means they are generally felt more strongly. A special edition of Geonet News explains why seismologists study the aftershocks. “The pattern of aftershocks provides valuable information to scientists about where the stresses are moving to, the type of faulting they are causing and the rate at which they are occurring. How the whole sequence behaves can give us a clue as to what we might expect in future earthquakes.”
Aftershocks are a natural follow on to a major earthquake and it looks like Christchurch could still be experiencing them a year from now.
People find the random nature of the aftershocks hard to deal with along with the fear that another large earthquake may strike the city. While seismologists say this possibility decreases daily, strong aftershocks still cause an adrenaline rush in many people – especially when they occur in the middle of the night.