A motion-blurred photograph of houses, with the Port Hills in the background. The photographer comments, "This I hope gives you a feel of what it feels like in an earthquake. When you spend your whole life thinking that you and your home are built on solid ground, it can be quite a shock when you find it is not. You can feel the house shaking like a dog with a toy, rising up violently underneath you or the most gentle form which is when the ground moves gently like a wave moving under a rowing boat. It is not just the movement, you often get a rumbling sound which can precede a violent shake or can result in no movement at all. This means that some vehicles can sound like the rumbling initially and in the early days would get your heart racing. Another form of stress is when big excavators as heavy as a tank move as you can feel the ground shake from streets away, but you do not always hear the engine. For most of us the problem when the shaking starts, is wondering if this is the start of an extremely violent earthquake or will it peter out".
A flow chart depicting potential hazards earthquakes pose to coastal geography.
An earthquake engineering expert wants to change the way we predict how the ground will shake during an earthquake. Professor Brendon Bradley from the University of Canterbury is the recipient of a Marsden Fund grant to accelerate his research into seismic hazard analysis and forecasting. He says the idea is to get to a point where they can provide the same sort of information as a weather forecast. Professor Bradley says just like a severe weather warning, engineers would be able to provide information about severe ground shaking, how it varies locally in each city or suburb, and the likely consequence to buildings. Kathryn speaks to Professor Brendon Bradley, the director of Te Hirangu Ru QuakeCoRE - The New Zealand Centre for Earthquake Resilience.
A digitally manipulated photograph of a shop security shutter. The photographer comments, "Sometimes before you feel the ground rolling any metal shutters around start their rattling noises as if someone is shaking them".
Liquefaction silt. The photographer comments, "After the earthquake in Christchurch New Zealand, liquefaction covered the streets, but after it had risen from below ground whilst the ground was shaking it the liquid in the liquefaction wanted to drain away".
This research employs a deterministic seismic risk assessment methodology to assess the potential damage and loss at meshblock level in the Christchurch CBD and Mount Pleasant primarily due to building damage caused by earthquake ground shaking. Expected losses in terms of dollar value and casualties are calculated for two earthquake scenarios. Findings are based on: (1) data describing the earthquake ground shaking and microzonation effects; (2) an inventory of buildings by value, floor area, replacement value, occupancy and age; (3) damage ratios defining the performance of buildings as a function of earthquake intensity; (4) daytime and night-time population distribution data and (5) casualty functions defining casualty risk as a function of building damage. A GIS serves as a platform for collecting, storing and analyzing the original and the derived data. It also allows for easy display of input and output data, providing a critical functionality for communication of outcomes. The results of this study suggest that economic losses due to building damage in the Christchurch CBD and Mount Pleasant will possibly be in the order of $5.6 and $35.3 million in a magnitude 8.0 Alpine fault earthquake and a magnitude 7.0 Ashley fault earthquake respectively. Damage to non-residential buildings constitutes the vast majority of the economic loss. Casualty numbers are expected to be between 0 and 10.
Suburbs
Suburbs
Masonry debris on the ground following the magnitude 7.1 earthquake in Christchurch on Saturday 4-9-2010.
Cupcake Parlour on Kilmore St :(
Barbadoes St
Barbadoes St
Fitzgerald Ave
Fitzgerald Panorama
Our Garage
Our front door.
Fitzgerald Ave
Cupcake Parlour on Kilmore St :(
Avon River
Fitzgerald Ave
Barbadoes St
Fitzgerald Ave
Fitzgerald Ave
Fitzgerald Ave
Ground heaving on the faultline from which the Saturday 4 September 2010 earthquake originated.
Kilmore St and Barbadoes St Intersection
Kilmore St and Barbadoes St Intersection
Kilmore St and Barbadoes St Intersection
Kilmore St and Barbadoes St Intersection
Kilmore St and Barbadoes St Intersection