Christchurch Earthquakes
4 Sep 2010
26 Dec 2010
22 Feb 2011
13 June 2011
Favourite Places
The week 11-19 Feb 2011 during the Festival of Flowers I was playing piano
in
the Cathedral 1-2 hours most days
Afternoon of Tue 22 Feb 2011:
My Software Firm (Beyond) used to be in this building - 2nd floor, the
middle window and the two the right of it
I used to live in this flat when I was at university..
Friends house 200 metres down the road
Favourite Cafe - before and after
Note almost all buildings in the second photos have issues -
including the 2 large buildings. Westpac future unkown,
Centra Hotel (right white building) across the road from the Grand
Chancellor now has a similar lean since 13 June
One of the demolitions that no-one will mourn:
Festival of Flowers was organised from the upstairs offices without
walls - they were there
My Kitchen 22 Feb
Office:
Others:
A favourite shop
Piko
Wholefoods
Civil Defence Film of
Chch CBD Red Zone
Quake
captured on Liverpool St CCTV
(note Liverpool St is the street on the left of the Kenton Chambers building
pictured above)
Figures
on Peak Ground Acceleration
The Peak Ground Acceleration (PGA) recorded at Christchurch Botanical
Gardens - Comparisons:
4:35am, September 4 2010 Magnitude 7.1: Between 0.15 and 0.20 times the
power of gravity
10:30am, December 26 2010 Magnitude 4.9 : 0.48
12:51pm, February 22 2011 Magnitude 6.3: 1.80
Statistically in terms of PGA, the February 22nd quake was a 1 in 1000
year event. Part of the reason for the destruction in Christchurch is
that New Zealand buildings with a ~50year life span are only required
to withstand a 1 in 500 year event, which is probably adequate enough.
Usually. Christchurch was just unlucky that such a fast and shallow
(not to be confused with strong) earthquake struck so close to the
city.
In fact this was the fastest earthquake to hit a significant population
base ever. The below table (while not the recording at the Botanical
Gardens site) shows the comparison between significant earthquakes
around the world. The 2.20g figure was recorded in the Christchurch
suburb of Heathcote, near the epicentre of the quake.
PGA Mag Depth
Fatalities Earthquake
2.2g 6.3 5km
166*
2011 Christchurch earthquake
1.7g 6.7 19km 57
1994 California earthquake
1.26g 7.1 10km 0
2010 Canterbury earthquake
(reading taken in Darfield, close to epicentre)
0.8g 6.8 16km
6,434
1995 Kobe earthquake
0.51g 6.4
612
2005
Zarand earthquake
0.5g 7.0 13km
92,000
2010 Haiti earthquake
Other observations