Reflections on the Canterbury / Christchurch Earthquakes of 4 September 2010 and 22 February 2011

Dr Vaughan Wood

photo-Gillian Needham

Summary Outline

a) Geomorphological / historical context

b) Seismological context

c) 4 September 2010 event

d) Notable aftershocks

e) 22 February 2011 event

f) Short term responses

g) Ongoing recovery & remediation

Christchurch (pop ~ 400 000)

•Tourism•Agribusiness•Regional admin.•Light industry

*

Adapted from Bedford & Sturman (eds), Canterbury at the Crossroads (1983), p 31

‘The city built on a swamp’

The Avon River in foreground and theCanterbury ProvincialCouncil building under construction in the rear (Photograph by Dr AC Barker, 1858)

Reproduced from Cookson& Dunstall (eds.) Southern Capital - Christchurch (2000), p 19

Natural vegetationin Christchurch as recorded on the ‘black maps’ in themid-1850s (i.e. at the time of the arrival of CanterburyAssociation settlers)

Reproduced from Bedford & Sturman (eds)Canterbury at the crossroads(1983), p 23

O

Reproduced from M Douglass (compiler),Christchurch City Centre:40 years of change, traffic,planning 1959-1999(2000)

Complex boundaryof Pacific plate & Indo-Australianplate

Subduction of Pacificplate off North Island, but in South Island, it ispushing up over theIndo-Australian plate,with strike-slip motionalong Alpine Fault

Reproduced from Cowan, ‘Structure, Seismicity and Tectonics of the Porter’s Pass-Amberley Fault Zone’ (Phd thesis, U of Canterbury, 1992)

Reproduced from Cowan (1992)

Adapted from Cowan (1992)

Adapted from Wards (ed.) New Zealand Atlas (1976), p 78