A large crack in the ground at Sullivan Park in Avonside. A large deposit of liquefaction has dried around it, and plants are growing up through the crack.
A large crack in the ground at Sullivan Park in Avonside. A large deposit of liquefaction has dried around it, and plants are growing up through the crack.
A sign on Robson Avenue warning the public of "Low Power Lines". The power poles sank during the earthquake due to liquefaction destabilising the ground underneath.
Damage to a building on Ferry Road. The side walls have partially collapsed, and bricks are scattered on the ground below. The building is cordoned off with security fencing.
Damage to a building on Ferry Road. The side walls have partially collapsed, and bricks are scattered on the ground below. The building is cordoned off with security fencing.
Damage to a building on Ferry Road. The side walls have partially collapsed, and bricks are scattered on the ground below. The building is cordoned off with security fencing.
A photograph of the dome of the Regent Theatre building. The dome has been removed from the building and is sitting on the ground in Cathedral Square.
St John's Presbyterian Church on Winchester Street in Lyttelton. The ground around the church is strewn with masonry that has fallen from the church's walls and collapsed tower.
A private pool on a property on Avonside Drive. The pool has lifted out of its casing and now looks like an above ground pool.
Damage to a building on Ferry Road. The side walls have partially collapsed, and bricks are scattered on the ground below. The building is cordoned off with security fencing.
Damage to a building on Ferry Road. The side walls have partially collapsed, and bricks are scattered on the ground below. The building is cordoned off with security fencing.
Photograph captioned by BeckerFraserPhotos, "At the end of the day, these workers on the Hotel Grand Chancellor take a ride back to ground".
Photograph captioned by BeckerFraserPhotos, "The Arts Centre, Hereford Street. Careful palleting of the pieces of the Arts Centre which fell to the ground".
Photograph captioned by BeckerFraserPhotos, "The Arts Centre, Hereford Street. Careful palleting of the pieces of the Arts Centre which fell to the ground".
Cracking along the pavement at Halswell Primary School. The ground has risen and fallen in places leaving an uneven surface where the children usually play.
This study explicitly investigates uncertainties in physics-based ground motion simulation validation for earthquakes in the Canterbury region. The simulations utilise the Graves and Pitarka (2015) hybrid methodology, with separately quantified parametric uncertainties in the comprehensive physics and simplified physics components of the model. The study is limited to the simulation of 148 small magnitude (Mw 3.5 – 5) earthquakes, with a point source approximation for the source rupture representations, which also enables a focus on a small number of relevant uncertainties. The parametric uncertainties under consideration were selected through sensitivity analysis, and specifically include: magnitude, Brune stress parameter and high frequency rupture velocity. Twenty Monte Carlo realisations were used to sample parameter uncertainties for each of the 148 events. Residuals associated with the following intensity measures: spectral acceleration, peak ground velocity, arias intensity and significant duration, were ascertained. Using these residuals, validation was performed through assessment of systematic biases in site and source terms from mixed-effects regression. Based on the results to date, initial standard deviation recommendations for parameter uncertainties, based on the Canterbury simulations have been obtained. This work ultimately provides an initial step toward explicit incorporation of modelling uncertainty in simulated ground motion predictions for future events, which will improve the use of simulation models in seismic hazard analysis. We plan to subsequently assess uncertainties for larger magnitude events with more complex ruptures, and events across a larger geographic region, as well as uncertainties due to path attenuation, site effects, and more general model epistemic uncertainties.
Photograph captioned by BeckerFraserPhotos, "The cleared site of Ground, corner on London and Canterbury Streets, Lyttelton. A rest area and garden sales have developed here".
A hydraulic excavator on Kilmore Street, lifting a steel beam over a hole in the ground. The area is fenced off by wire fencing and there are road cones across the street.
A photograph of steel bracing keeping up a section of the ceiling on the ground floor of the Crowne Plaza. The column to the left is damaged.
St John's Anglican Church in Hororata. The top of the bell tower has collapsed into the roof of the church, some falling onto the ground below where it still lies.
St John's Anglican Church in Hororata. The top of the bell tower has collapsed into the roof of the church, some falling onto the ground below where it still lies.
Photograph captioned by BeckerFraserPhotos, "The cleared site of Ground, corner on London and Canterbury Streets, Lyttelton. A rest area and garden sales have developed here".
A photograph of the east side of the Odeon Theatre, showing the severe damage at the back of the theatre. Part of the roof sits on the ground in the section next door.
The ground floor of the BNZ Building, seen from High Street. The glass has been removed and the insides gutted. The Cathedral can be viewed through the other side.
The top of one of the towers from the Arts Centre has been placed on the ground to prevent further damage. The photographer comments, "A bike ride around the CBD. Arts Centre".
A photograph captioned by BeckerFraserPhotos, "Workers deconstructing the Hotel Grand Chancellor. Panels are being detached and the crane is lowering them to the ground".
Photograph captioned by BeckerFraserPhotos, "At the end of the day, these workers on the Hotel Grand Chancellor take a ride back to the ground".
Sandbags placed along the river bank to prevent flooding onto the road. The earthquake caused the ground in this area to subside, making it susceptible to flooding.
Sandbags placed along the river bank to prevent flooding onto the road. The earthquake caused the ground in this area to subside , making it susceptible to flooding.
We present initial results from a set of three-dimensional (3D) deterministic earthquake ground motion simulations for the northern Canterbury plains, Christchurch and the Banks Peninsula region, which explicitly incorporate the effects of the surface topography. The simu-lations are done using Hercules, an octree-based finite-element parallel software for solving 3D seismic wave propagation problems in heterogeneous media under kinematic faulting. We describe the efforts undertaken to couple Hercules with the South Island Velocity Model (SIVM), which included changes to the SIVM code in order to allow for single repetitive que-ries and thus achieve a seamless finite-element meshing process within the end-to-end ap-proach adopted in Hercules. We present our selection of the region of interest, which corre-sponds to an area of about 120 km × 120 km, with the 3D model reaching a depth of 60 km. Initial simulation parameters are set for relatively high minimum shear wave velocity and a low maximum frequency, which we are progressively scaling up as computing resources permit. While the effects of topography are typically more important at higher frequencies and low seismic velocities, even at this initial stage of our efforts (with a maximum of 2 Hz and a mini-mum of 500 m/s), it is possible to observe the importance of the topography in the response of some key locations within our model. To highlight these effects we compare the results of the 3D topographic model with respect to those of a flat (squashed) 3D model. We draw rele-vant conclusions from the study of topographic effects during earthquakes for this region and describe our plans for future work.