Great Earthquakes In Diverse Places
New Zealand: Fresh Wave of earthquake Aftershocks shake Christchurch
By Debbie Roome
Last Updated Nov 14, 2010, Published Nov 13, 2010
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.
Read more at Suite101: Fresh Wave of Aftershocks after Christchurch
Earthquake
http://www.suite101.com/content/fresh-wave-of-aftershocks-after-christchurch-earthquake-a308592#ixzz15FeLBi2d