Sand volcanos cover Rydal Street

Images, eqnz.chch.2010

This has made a huge mess for the residents to clean up. I heard on the news that homes have been damaged by subsidence in areas of earthquake-caused liquefaction like this.

neighbours survey the sand volcanos

Images, eqnz.chch.2010

Lots of people were out and about in the streets checking on everyone after the earthquake. When it was clear that everyone was OK, the sand volcanos became the feature of interest.

Rydal Street sand volcanos

Images, eqnz.chch.2010

It would have been a glorious Spring day in Christchurch had it not been for the magnitude 7.1 earthquake at 4:30 am. All the water and silt you can see covering the street in this photo erupted from the ground following the earthquake.

sand volcano tours

Images, eqnz.chch.2010

Yes, it was a joke. The tours, that is, not the yard filled with earthquake-caused sand volcanos. They were very real. You can see one covering the driveway in this photo. The signs read as follows. "Tours run 1/2 hourly. $5.25 admission. Eftpos unavailable." "If you think this is bad... you should see the back!"

Rockfall in the Port Hills of Christchurch: Seismic and non-seismic fatali…

Research papers, Lincoln University

Numerous rockfalls released during the 2010–2011 Canterbury earthquake sequence affected vital road sections for local commuters. We quantified rockfall fatality risk on two main routes by adapting a risk approach for roads originally developed for snow avalanche risk. We present results of the collective and individual fatality risks for traffic flow and waiting traffic. Waiting traffic scenarios particularly address the critical spatial-temporal dynamics of risk, which should be acknowledged in operational risk management. Comparing our results with other risks commonly experienced in New Zealand indicates that local rockfall risk is close to tolerability thresholds and likely exceeds acceptable risk.

RECOVERING FROM A WORST-CASE SCENARIO: SHOULD NEW ZEALAND IMPLEMENT A DISA…

Research papers, University of Canterbury Library

In response to the February 2011 earthquake, Parliament enacted the Canterbury Earthquake Recovery Act. This emergency legislation provided the executive with extreme powers that extended well beyond the initial emergency response and into the recovery phase. Although New Zealand has the Civil Defence Emergency Management Act 2002, it was unable to cope with the scale and intensity of the Canterbury earthquake sequence. Considering the well-known geological risk facing the Wellington region, this paper will consider whether a standalone “Disaster Recovery Act” should be established to separate an emergency and its response from the recovery phase. Currently, Government policy is to respond reactively to a disaster rather than proactively. In a major event, this typically involves the executive being given the ability to make rules, regulations and policy without the delay or oversight of normal legislative process. In the first part of this paper, I will canvas what a “Disaster Recovery Act” could prescribe and why there is a need to separate recovery from emergency. Secondly, I will consider the shortfalls in the current civil defence recovery framework which necessitates this kind of heavy governmental response after a disaster. In the final section, I will examine how

Assessment of Empirical Lateral Spreading Displacement Models using Data f…

Research papers, University of Canterbury Library

Liquefaction-induced lateral spreading during the 2011 Christchurch earthquake in New Zealand was severe and extensive, and data regarding the displacements associated with the lateral spreading provides an excellent opportunity to better understand the factors that influence these movements. Horizontal displacements measured from optical satellite imagery and subsurface data from the New Zealand Geotechnical Database (NZGD) were used to investigate four distinct lateral spread areas along the Avon River in Christchurch. These areas experienced displacements between 0.5 and 2 m, with the inland extent of displacement ranging from 100 m to over 600 m. Existing empirical and semi-empirical displacement models tend to under estimate displacements at some sites and over estimate at others. The integrated datasets indicate that the areas with more severe and spatially extensive displacements are associated with thicker and more laterally continuous deposits of liquefiable soil. In some areas, the inland extent of displacements is constrained by geologic boundaries and geomorphic features, as expressed by distinct topographic breaks. In other areas the extent of displacement is influenced by the continuity of liquefiable strata or by the presence of layers that may act as vertical seepage barriers. These observations demonstrate the need to integrate geologic/geomorphic analyses with geotechnical analyses when assessing the potential for lateral spreading movements.