Nick Mellsop

ME 2017 Nick studied at The University of Canterbury between 2010 and 2015, completing his undergraduate degree in geology before undertaking a post graduate diploma in Engineering Geology. After graduating, Nick worked for Tonkin & Taylor in Christchurch; at the time Christchurch was still in the early stages of recovery from the Canterbury Earthquakes. Tonkin & Taylor was heavily involved with the associated research spawning from the earthquakes, and Nick found himself working largely on the resulting research associated with liquefaction. This work and Tonkin & Taylor's connections with the University of Auckland (UoA) eventually lead Nick to Undertake a Masters in Engineering, funded by QuakeCore and with Liam Wotherperson as his supervisor. After completing his Masters, Nick continued to work for Tonkin & Taylor in Auckland, then left for his OE in late 2017. While overseas Nick worked for Wood Environment and Infrastructure in Seattle, WA, USA; a seismically active region which allowed him to continue developing his liquefaction knowledge. Nick returned to NZ in late 2019 and now works for ENGEO Ltd in Auckland.

​Liquefaction and associated lateral spreading in Whakatane during the 1987 Mw 6.5 Edgecumbe earthquake. 

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Research Title:
Liquefaction and associated lateral spreading in Whakatane during the 1987 Mw 6.5 Edgecumbe earthquake. Initial content of Publications Page.
Project Summary: Nicks research concerned liquefaction and associated lateral spreading in Whakatane during the 1987 Mw 6.5 Edgecumbe earthquake. The project was inspired by recent research in the city which appeared to indicate the central business district should have experienced liquefaction land damage during the earthquake, which did not appear to be the case. Using observations from literature, a regional geospatial database of liquefaction-induced land damage was developed to provide a one source of truth for this event. This database was combined with a large dataset of CPT investigations across the township and geospatial ground motion and groundwater models at the time of the Edgecumbe earthquake to assess the efficacy of liquefaction assessment methods. Liquefaction assessments using median PGA and median groundwater models were found to closely correspond with the observed severity of liquefaction manifestation at sites known to have surface manifestation, while significant over-prediction of manifestation severity evident in areas with no manifestations. Sensitivity analyses were not able to account for these issues, with lower estimates of PGA and groundwater models improving prediction inareas without manifestation, but under predicting in areas with manifestation. Overall, the findings suggest that standard CPT based methods of liquefaction assessment may be over-predicting liquefaction manifestation severity in some areas of Whakatane, likely a result of the combined effects of partial saturation, pumiceous soil content, and thin interlayering effects. These inconsistencies between prediction and observation align with trends evident in other recent earthquakes in New Zealand in similar deposition environments.