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Images for earthquake liquefaction; more images...

Images, UC QuakeStudies

Liquefaction and buckled tarmac on a residential street in North New Brighton. The photographer comments, "In the February 2011 earthquake in Christchurch the kerb at the end of my road was pushed from both ends. This caused it to move away from the grass verge and push itself under the tarmac. The tarmac would normally have been 3 inches below the top of the kerb. Between the kerb and the grass can be seen the colour of the liquefaction that spewed out from the ground. The tarmac in the area seemed to flow downhill".

Images, UC QuakeStudies

Dried liquefaction silt in North New Brighton. The photographer comments, "The liquefaction after the 23 December earthquake in Christchurch started to dry out and the thicker deposits started to curl up like broken drain pipe".

Images, UC QuakeStudies

Liquefaction and flooding in Waitaki Street, Bexley. The photographer comments, "Waitaki Street a week after the Christchurch Earthquake. Because of the damage to the drains and liquefaction in the area the streets are not drying out".

Research papers, University of Canterbury Library

Spatial variations in river facies exerted a strong influence on the distribution of liquefaction features observed in Christchurch during the 2010-11 Canterbury Earthquake Sequence (CES). Liquefaction and liquefaction-induced ground deformation was primarily concentrated near modern waterways and areas underlain by Holocene fluvial deposits with shallow water tables (< 1 to 2 m). In southern Christchurch, spatial variations of liquefaction and subsidence were documented in the suburbs within inner meander loops of the Heathcote River. Newly acquired geospatial data, geotechnical reports and eye-witness discussions are compiled to provide a detailed account of the surficial effects of CES liquefaction and ground deformation adjacent to the Heathcote River. LiDAR data and aerial photography are used to produce a new series of original figures which reveal the locations of recurrent liquefaction and subsidence. To investigate why variable liquefaction patterns occurred, the distribution of surface ejecta and associated ground damage is compared with near-surface sedimentologic, topographic, and geomorphic variability to seek relationships between the near-surface properties and observed ground damages. The most severe liquefaction was concentrated within a topographic low in the suburb of St Martins, an inner meander loop of the Heathcote River, with liquefaction only minor or absent in the surrounding areas. Subsurface investigations at two sites in St Martins enable documentation of fluvial stratigraphy, the expressions of liquefaction, and identification of pre-CES liquefaction features. Excavation to water table depths (~1.5 m below the surface) across sand boils reveals multiple generations of CES liquefaction dikes and sills that cross-cut Holocene fluvial and anthropogenic stratigraphy. Based on in situ geotechnical tests (CPT) indicating sediment with a factor of safety < 1, the majority of surface ejecta was sourced from well-sorted fine to medium sand at < 5 m depth, with the most damaging liquefaction corresponding with the location of a low-lying sandy paleochannel, a remnant river channel from the Holocene migration of the meander in St Martins. In the adjacent suburb of Beckenham, where migration of the Heathcote River has been laterally confined by topography associated with the volcanic lithologies of Banks Peninsula, severe liquefaction was absent with only minor sand boils occurring closest to the modern river channel. Auger sampling across the suburb revealed thick (>1 m) clay-rich overbank and back swamp sediments that produced a stratigraphy which likely confined the units susceptible to liquefaction and prevented widespread ejection of liquefied material. This analysis suggests river migration promotes the formation and preservation of fluvial deposits prone to liquefaction. Trenching revealed the strongest CES earthquakes with large vertical accelerations favoured sill formation and severe subsidence at highly susceptible locations corresponding with an abandoned channel. Less vulnerable sites containing deeper and thinner sand bodies only liquefied in the strongest and most proximal earthquakes forming minor localised liquefaction features. Liquefaction was less prominent and severe subsidence was absent where lateral confinement of a Heathcote meander has promoted the formation of fluvial stratum resistant to liquefaction. Correlating CES liquefaction with geomorphic interpretations of Christchurch’s Heathcote River highlights methods in which the performance of liquefaction susceptibility models can be improved. These include developing a reliable proxy for estimating soil conditions in meandering fluvial systems by interpreting the geology and geomorphology, derived from LiDAR data and modern river morphology, to improve the methods of accounting for the susceptibility of an area. Combining geomorphic interpretations with geotechnical data can be applied elsewhere to identify regional liquefaction susceptibilities, improve existing liquefaction susceptibility datasets, and predict future earthquake damage.

Images, UC QuakeStudies

Grass growing through liquefaction silt in Avondale. The photographer comments, "Although this grass seems to be growing on the liquefaction created by the earthquakes in Christchurch, New Zealand, they are actually only growing through it. Nothing seems to grow even though seeds will sprout almost anywhere else. The seeds are growing in the soil which got covered up by the liquefaction. If liquefaction gets mixed with even a little soil then nature can get a foothold".

Images, UC QuakeStudies

A digitally manipulated image of broken objects. The photographer comments, "Digital painting of breakages and liquefaction after the February 22 earthquake in Christchurch".

Images, Canterbury Museum

Plastic and wood model of three liquefaction volcanoes. The working model pumps water over the grey surface which is decorated with a basket of laundry, a bucket of pegs and a football. The model is surrounded by artificial green grass and rests atop a black wooden base.

Videos, UC QuakeStudies

Aerial footage of a site in Avondale where several liquefaction remediation options are being tested. Gelignite explosives have been buried throughout the site. These will be set off to simulate liquefaction caused by an earthquake. The result, if successful, will help EQC protect people's houses from future earthquakes, and settle land claims. The video was recorded using a drone aircraft.