Additional Comments re NZ Earthquakes

Guest Posting from Ian McLean in NZ. He is the former Chair of the Earthquake Commission (EQC) in NZ.  

Two things are happening in New Zealand now that may be of interest to you:

The first is that retrofitting of apartments  is painfully slow. It will take some 20 years or so for all  earthquake prone apartments in Wellington to be brought up to the required standard. This standard is indeed minimal – only 33% of the New Building Standard in the Code. (A radio broadcast describing the challenge people face in retrofitting is at https://www.rnz.co.nz/audio/player?audio_id=2018726229 )

Parapets which present a danger to the public in the streets below are being dealt with much more quickly. So too are buildings which are found to be of higher risk. Thee  are being evacuated: like the Wellington Public Library , which was built as recently as 1991. The 7.8 Kaikoura Earthquake of 2016 in which at least four faults ruptured sequentially has demonstrated critical design weaknesses in a number of  multi-storey buildings of that vintage.

The second change is  strong interest in making buildings more resilient. The New Zealand Building Code is designed to keep occupants of buildings safe. Buildings constructed to the code have protected their inhabitants, even in the Christchurch earthquakes. But the buildings themselves paid the price. Now more emphasis is being placed on designs which will enable buildings to survive major earthquakes.

Important buildings such as Parliament Buildings and Te Papa (the National Museum) are already base-isolated. Radio NZ reports that the first base isolated apartment building in Wellington is currently underway.

I am not sure how much of this information is readily available to the emergency management community, although it is of course widely known in the earthquake engineering profession.

Recovery From Earthquake in NZ Contrasted with Possible Quake in CA

What Would a Devastating Earthquake in California Look Like? An example is the magnitude 6.2 earthquake that hit New Zealand on Feb. 22, 2011, that left physical, economic and psychological aftershocks that continue. The quake redrew the geography of Christchurch, which is flatter and smaller now.  Some excerpts:

The Christchurch rebuild is expected to cost $26 billion, according to an estimate by the Reserve Bank, making it New Zealand’s single biggest economic challenge.

“After the earthquake, we all sort of thought — oh, five years and the central city will be back to normal. And it was oh, probably 10. And then 15. And then 20. And so it goes on,”

The economic blow for many was lessened by New Zealand’s high rate of earthquake insurance.