We present ground motion simulations of the Porters Pass (PP) fault in the Canterbury region of New Zealand; a major active source near Christchurch city. The active segment of the PP fault has an inferred length of 82 km and a mostly strike-slip sense of movement. The PP fault slip makes up approximately 10% of the total 37 mm/yr margin-parallel plate motion and also comprises a significant proportion of the total strain budget in regional tectonics. Given that the closest segment of the fault is less than 45 km from Christchurch city, the PP fault is crucial for accurate earthquake hazard assessment for this major population centre. We have employed the hybrid simulation methodology of Graves and Pitarka (2010, 2015), which combines low (f<1 Hz) and high (f>1 Hz) frequencies into a broadband spectrum. We have used validations from three moderate magnitude events (𝑀𝑤4.6 Sept 04, 2010; 𝑀𝑤4.6 Nov 06, 2010; 𝑀𝑤4.9 Apr 29, 2011) to build confidence for the 𝑀𝑤 > 7 PP simulations. Thus far, our simulations include multiple rupture scenarios which test the impacts of hypocentre location and the finite-fault stochastic rupture representation of the source itself. In particular, we have identified the need to use location-specific 1D 𝑉𝑠/𝑉𝑝 models for the high frequency part of the simulations to better match observations.
The 2010-2011 Canterbury earthquake sequence, and the resulting extensive data sets on damaged buildings that have been collected, provide a unique opportunity to exercise and evaluate previously published seismic performance assessment procedures. This poster provides an overview of the authors’ methodology to perform evaluations with two such assessment procedures, namely the P-58 guidelines and the REDi Rating System. P-58, produced by the Federal Emergency Management Agency (FEMA) in the United States, aims to facilitate risk assessment and decision-making by quantifying earthquake ground shaking, structural demands, component damage and resulting consequences in a logical framework. The REDi framework, developed by the engineering firm ARUP, aids stakeholders in implementing resilience-based earthquake design. Preliminary results from the evaluations are presented. These have the potential to provide insights on the ability of the assessment procedures to predict impacts using “real-world” data. However, further work remains to critically analyse these results and to broaden the scope of buildings studied and of impacts predicted.
Heathcote Valley school strong motion station (HVSC) consistently recorded ground motions with higher intensities than nearby stations during the 2010-2011 Canterbury earthquakes. For example, as shown in Figure 1, for the 22 February 2011 Christchurch earthquake, peak ground acceleration at HVSC reached 1.4 g (horizontal) and 2 g (vertical), the largest ever recorded in New Zealand. Strong amplification of ground motions is expected at Heathcote Valley due to: 1) the high impedance contrast at the soil-rock interface, and 2) the interference of incident and surface waves within the valley. However, both conventional empirical ground motion prediction equations (GMPE) and the physics-based large scale ground motions simulations (with empirical site response) are ineffective in predicting such amplification due to their respective inherent limitations.
Liquefaction-induced lateral spreading during earthquakes poses a significant hazard to the built environment, as observed in Christchurch during the 2010 to 2011 Canterbury Earthquake Sequence (CES). It is critical that geotechnical earthquake engineers are able to adequately predict both the spatial extent of lateral spreads and magnitudes of associated ground movements for design purposes. Published empirical and semi-empirical models for predicting lateral spread displacements have been shown to vary by a factor of <0.5 to >2 from those measured in parts of Christchurch during CES. Comprehensive post- CES lateral spreading studies have clearly indicated that the spatial distribution of the horizontal displacements and extent of lateral spreading along the Avon River in eastern Christchurch were strongly influenced by geologic, stratigraphic and topographic features.
The operation of telecommunication networks is critical during business as usual times, and becomes most vital in post-disaster scenarios, when the services are most needed for restoring other critical lifelines, due to inherent interdependencies, and for supporting emergency and relief management tasks. In spite of the recognized critical importance, the assessment of the seismic performance for the telecommunication infrastructure appears to be underrepresented in the literature. The FP6 QuakeCoRE project “Performance of the Telecommunication Network during the Canterbury Earthquake Sequence” will provide a critical contribution to bridge this gap. Thanks to an unprecedented collaboration between national and international researchers and highly experienced asset managers from Chorus, data and evidences on the physical and functional performance of the telecommunication network after the Canterbury Earthquakes 2010-2011 have been collected and collated. The data will be processed and interpreted aiming to reveal fragilities and resilience of the telecommunication networks to seismic events
As a result of the Canterbury earthquakes, over 60% of the concrete buildings in the Christchurch Central Business District have been demolished. This experience has highlighted the need to provide guidance on the residual capacity and repairability of earthquake-damaged concrete buildings. Experience from 2010 Chile indicates that it is possible to repair severely damaged concrete elements (see photo at right), although limited testing has been performed on such repaired components. The first phase of this project is focused on the performance of two lightly-reinforced concrete walls that are being repaired and re-tested after damage sustained during previous testing.
This poster presents preliminary results of ongoing experimental campaigns at the Universities of Auckland and Canterbury, aiming at investigating the seismic residual capacity of damaged reinforced concrete plastic hinges, as well as the effectiveness of epoxy injection techniques for restoring their stiffness, energy dissipation, and deformation capacity characteristics. This work is part of wider research project which started in 2012 at the University of Canterbury entitled “Residual Capacity and Repairing Options for Reinforced Concrete Buildings”, funded by the Natural Hazards Research Platform (NHRP). This research project aims at gaining a better understanding and providing the main end-users and stakeholders (practitioner engineers, owners, local and government authorities, insurers, and regulatory agencies) with comprehensive evidence-based information and practical guidelines to assess the residual capacity of damaged reinforced concrete buildings, as well as to evaluate the feasibility of repairing and thus support their delicate decision-making process of repair vs. demolition or replacement.
A video of a presentation by Professor David Johnston during the fourth plenary of the 2016 People in Disasters Conference. Johnston is a Senior Scientist at GNS Science and Director of the Joint Centre for Disaster Research in the School of Psychology at Massey University. The presentation is titled, "Understanding Immediate Human Behaviour to the 2010-2011 Canterbury Earthquake Sequence, Implications for injury prevention and risk communication".The abstract for the presentation reads as follows: The 2010 and 2011 Canterbury earthquake sequences have given us a unique opportunity to better understand human behaviour during and immediately after an earthquake. On 4 September 2010, a magnitude 7.1 earthquake occurred near Darfield in the Canterbury region of New Zealand. There were no deaths, but several thousand people sustained injuries and sought medical assistance. Less than 6 months later, a magnitude 6.2 earthquake occurred under Christchurch City at 12:51 p.m. on 22 February 2011. A total of 182 people were killed in the first 24 hours and over 7,000 people injured overall. To reduce earthquake casualties in future events, it is important to understand how people behaved during and immediately after the shaking, and how their behaviour exposed them to risk of death or injury. Most previous studies have relied on an analysis of medical records and/or reflective interviews and questionnaire studies. In Canterbury we were able to combine a range of methods to explore earthquake shaking behaviours and the causes of injuries. In New Zealand, the Accident Compensation Corporation (a national health payment scheme run by the government) allowed researchers to access injury data from over 9,500 people from the Darfield (4 September 2010) and Christchurch (22 February 2011 ) earthquakes. The total injury burden was analysed for demography, context of injury, causes of injury, and injury type. From the injury data inferences into human behaviour were derived. We were able to classify the injury context as direct (immediate shaking of the primary earthquake or aftershocks causing unavoidable injuries), and secondary (cause of injury after shaking ceased). A second study examined people's immediate responses to earthquakes in Christchurch New Zealand and compared responses to the 2011 earthquake in Hitachi, Japan. A further study has developed a systematic process and coding scheme to analyse earthquake video footage of human behaviour during strong earthquake shaking. From these studies a number of recommendations for injury prevention and risk communication can be made. In general, improved building codes, strengthening buildings, and securing fittings will reduce future earthquake deaths and injuries. However, the high rate of injuries incurred from undertaking an inappropriate action (e.g. moving around) during or immediately after an earthquake suggests that further education is needed to promote appropriate actions during and after earthquakes. In New Zealand - as in US and worldwide - public education efforts such as the 'Shakeout' exercise are trying to address the behavioural aspects of injury prevention.
This poster discusses several possible approaches by which the nonlinear response of surficial soils can be explicitly modelled in physics-based ground motion simulations, focusing on the relative advantages and limitations of the various methodologies. These methods include fully-coupled 3D simulation models that directly allow soil nonlinearity in surficial soils, the domain reduction method for decomposing the physical domain into multiple subdomains for separate simulation, conventional site response analysis uncoupled from the simulations, and finally, the use of simple empirically based site amplification factors We provide the methodology for an ongoing study to explicitly incorporate soil nonlinearity into hybrid broadband simulations of the 2010-2011 Canterbury, New Zealand earthquakes.
In 2010 and 2011 a series of earthquakes hit the central region of Canterbury, New Zealand, triggering widespread and damaging liquefaction in the area of Christchurch. Liquefaction occurred in natural clean sand deposits, but also in silty (fines-containing) sand deposits of fluvial origin. Comprehensive research efforts have been subsequently undertaken to identify key factors that influenced liquefaction triggering and severity of its manifestation. This research aims at evaluating the effects of fines content, fabric and layered structure on the cyclic undrained response of silty soils from Christchurch using Direct Simple Shear (DSS) tests. This poster outlines preliminary calibration and verification DSS tests performed on a clean sand to ensure reliability of testing procedures before these are applied to Christchurch soils.
A report created by the University of Canterbury Quake Centre and the University of Auckland, funded by the Building Research Levy. It shows how an innovation process was initiated and managed throughout the rebuilding of the horizontal infrastructure after the Canterbury earthquakes.
This poster presents work to date on ground motion simulation validation and inversion for the Canterbury, New Zealand region. Recent developments have focused on the collection of different earthquake sources and the verification of the SPECFEM3D software package in forward and inverse simulations. SPECFEM3D is an open source software package which simulates seismic wave propagation and performs adjoint tomography based upon the spectral-element method. Figure 2: Fence diagrams of shear wave velocities highlighting the salient features of the (a) 1D Canterbury velocity model, and (b) 3D Canterbury velocity model. Figure 5: Seismic sources and strong motion stations in the South Island of New Zealand, and corresponding ray paths of observed ground motions. Figure 3: Domain used for the 19th October 2010 Mw 4.8 case study event including the location of the seismic source and strong motion stations. By understanding the predictive and inversion capabilities of SPECFEM3D, the current 3D Canterbury Velocity Model can be iteratively improved to better predict the observed ground motions. This is achieved by minimizing the misfit between observed and simulated ground motions using the built-in optimization algorithm. Figure 1 shows the Canterbury Velocity Model domain considered including the locations of small-to-moderate Mw events [3-4.5], strong motion stations, and ray paths of observed ground motions. The area covered by the ray paths essentially indicates the area of the model which will be most affected by the waveform inversion. The seismic sources used in the ground motion simulations are centroid moment tensor solutions obtained from GeoNet. All earthquake ruptures are modelled as point sources with a Gaussian source time function. The minimum Mw limit is enforced to ensure good signal-to-noise ratio and well constrained source parameters. The maximum Mw limit is enforced to ensure the point source approximation is valid and to minimize off-fault nonlinear effects.
essential systems upon which the well-being and functioning of societies depend. They deliver a service or a good to the population using a network, a combination of spatially-distributed links and nodes. As they are interconnected, network elements’ functionality is also interdependent. In case of a failure of one component, many others could be momentarily brought out-of-service. Further problems arise for buried infrastructure when it comes to buried infrastructure in earthquake and liquefaction-prone areas for the following reasons: • Technically more demanding inspections than those required for surface horizontal infrastructure • Infrastructure subject to both permanent ground displacement and transient ground deformation • Increase in network maintenance costs (i.e. deterioration due to ageing material and seismic hazard) These challenges suggest careful studies on network resilience will yield significant benefits. For these reasons, the potable water network of Christchurch city (Figure 1) has been selected for its well-characterized topology and its extensive repair dataset.
A video of a presentation by Jai Chung during the Staff and Patients Stream of the 2016 People in Disasters Conference. The presentation is titled, "A Systematic Review of Compassion Fatigue of Nurses During and After the Canterbury Earthquakes".The abstract for the presentation reads as follows: Limited research is currently available about compassion fatigue of health professionals during and after disasters in New Zealand. The purpose of this systematic literature review was to provide a comprehensive outline of existing research. National and international literature was compared and contrasted to determine the importance of recognising compassion fatigue during and after disasters. Health professionals responding to disasters have played an important role in saving lives. Especially, during and after the Canterbury earthquakes, many health professionals cared for the traumatized public of the region. When responding to and caring for many distressed people, health professionals - particularly nurses - may strongly empathise with people's pain, fear, and distress. Consequently, they can be affected both emotionally and physically. Nurses may experience intensive and extreme distress and trauma directly and indirectly. Physical exhaustion can arise quickly. Emotional exhaustion such as hopelessness and helplessness may lead to nurses losing the ability to nurture and care for people during disasters. This can lead to compassion fatigue. It is important to understand how health professionals, especially nurses, experience compassion fatigue in order to help them respond to disasters appropriately. International literature explains the importance of recognising compassion fatigue in nursing, and explores different coping mechanisms that assist nurses overcome or prevent this health problem. In contrast, New Zealand literature is limited to experiences of nurses' attitudes in responding to natural disasters. In light of this, this literature review will help to raise awareness about the importance of recognising and addressing symptoms of compassion fatigue in a profession such as nursing. Gaps within the research will also be identified along with recommendations for future research in this area, especially from a New Zealand perspective. Please note that due to a recording error the sound cuts out at 9 minutes.
A video of a presentation by Associate Professor John Vargo during the fifth plenary of the 2016 People in Disasters Conference. Vargo is a senior researcher and co-leader of the Resilient Organisations Research Programme at the University of Canterbury. The presentation is titled, "Organisational Resilience is more than just Business Continuity".The abstract for this presentation reads as follows: Business Continuity Management is well-established process in many larger organisations and a key element in their emergency planning. Research carried out by resilient organisations follow the 2010 and 2011 Canterbury Earthquakes show that most small organisations did not have a business continuity plan (BCP), yet many of these organisations did survive the massive disruptions following the earthquakes. They were resilient to these catastrophic events, but in the absence of a BCP. This research also found that many of the organisations with BCP's, struggled to use them effectively when facing real events that did not align with the BCP. Although the BCPs did a good job of preparing organisations to deal with technology and operational disruptions, there was virtually no coverage for the continuity of people. Issues surrounding staff welfare and engagement were amongst the most crucial issues faced by Canterbury organisations, yet impacts of societal and personal disruption did not feature in BCPs. Resilience is a systematic way of looking at how an organization can survive a crisis and thrive in an uncertain world. Business continuity is an important aspect for surviving the crisis, but it is only part of the bigger picture addressed by organisational resilience. This presentation will show how organizational experiences in the Canterbury earthquakes support the need to move to a 'Business Continuity' for the '21st Century', one that incorporates more aspects of resilience, especially the 'people' areas of leadership, culture, staff welfare, and engagement.
A video of a presentation by Dr Scott Miles during the Community Resilience Stream of the 2016 People in Disasters Conference. The presentation is titled, "A Community Wellbeing Centric Approach to Disaster Resilience".The abstract for this presentation reads as follows: A higher bar for advancing community disaster resilience can be set by conducting research and developing capacity-building initiatives that are based on understanding and monitoring community wellbeing. This presentation jumps off from this view, arguing that wellbeing is the most important concept for improving the disaster resilience of communities. The presentation uses examples from the 2010 and 2011 Canterbury earthquakes to illustrate the need and effectiveness of a wellbeing-centric approach. While wellbeing has been integrated in the Canterbury recovery process, community wellbeing and resilience need to guide research and planning. The presentation unpacks wellbeing in order to synthesize it with other concepts that are relevant to community disaster resilience. Conceptualizing wellbeing as either the opportunity for or achievement of affiliation, autonomy, health, material needs, satisfaction, and security is common and relatively accepted across non-disaster fields. These six variables can be systematically linked to fundamental elements of resilience. The wellbeing variables are subject to potential loss, recovery, and adaptation based on the empirically established ties to community identity, such as sense of place. Variables of community identity are what translate the disruption, damage, restoration, reconstruction, and reconfiguration of a community's different critical services and capital resources to different states of wellbeing across a community that has been impacted by a hazard event. With reference to empirical research and the Canterbury case study, the presentation integrates these insights into a robust framework to facilitate meeting the challenge of raising the standard of community disaster resilience research and capacity building through development of wellbeing-centric approaches.
A video of a presentation by Elizabeth McNaughton during the fourth plenary of the 2016 People in Disasters Conference. McNaughton is the Director of the Canterbury Earthquake Recovery Learning and Legacy programme at the Department of the Prime Minister and Cabinet. The presentation is titled, "Leading in Disaster Recovery: A companion through the chaos".The abstract for this presentation reads as follows: Leading in disaster recovery is a deeply human event - it requires us to reach deep inside of ourselves and bring to others the best of who we can be. It's painful, tiring, rewarding and meaningful. The responsibility can be heavy and at times leaders feel alone. The experienced realities of recovery leadership promoted research involving over 100 people around the globe who have worked in disaster recovery. The result is distilled wisdom from those who have walked in similar shoes to serve as a companion and guide for recovery leaders. The leadership themes in Leading in Disaster Recovery: A companion through the chaos include hard-won, honest, personal, brave insights and practical strategies to serve and support other recovery leaders. This guidance is one attempt amongst many others to change the historic tendency to lurch from disaster to disaster without embedding learning and knowledge - something we cannot afford to do if we are to honour those whose lives have been lost or irreversibly changed by disaster. If we are to honour the courageous efforts of those who have previously served disaster-impacted communities we would be better abled to serve those impacted by future disasters.
A video of the keynote presentation by Alexander C. McFarlane during the third plenary of the 2016 People in Disasters Conference. McFarlane is a Professor of Psychiatry at the University of Adelaide and the Heady of the Centre for Traumatic Stress Studies. The presentation is titled, "Holding onto the Lessons Disasters Teach".The abstract for this presentation reads as follows: Disasters are sentinel points in the life of the communities affected. They bring an unusual focus to community mental health. In so doing, they provide unique opportunities for better understanding and caring for communities. However, one of the difficulties in the disaster field is that many of the lessons from previous disasters are frequently lost. If anything, Norris (in 2006) identified that the quality of disaster research had declined over the previous 25 years. What is critical is that a longitudinal perspective is taken of representative cohorts. Equally, the impact of a disaster should always be judged against the background mental health of the communities affected, including emergency service personnel. Understandably, many of those who are particularly distressed in the aftermath of a disaster are people who have previously experienced a psychiatric disorder. It is important that disaster services are framed against knowledge of this background morbidity and have a broad range of expertise to deal with the emerging symptoms. Equally, it is critical that a long-term perspective is considered rather than short-term support that attempts to ameliorate distress. Future improvement of disaster management depends upon sustaining a body of expertise dealing with the consequences of other forms of traumatic stress such as accidents. This expertise can be redirected to co-ordinate and manage the impact of larger scale events when disasters strike communities. This presentation will highlight the relevance of these issues to the disaster planning in a country such as New Zealand that is prone to earthquakes.
