PDF slides from a presentation given by Dr. Thomas Wilson from the UC Geology department on 29 November 2010. The presentation was delivered at two public lectures, one at Lincoln University and another in Darfield.
Ground heaving on the faultline from which the Saturday 4 September 2010 earthquake originated.
A team of earthquake geologists, seismologists and engineering seismologists from GNS Science, NIWA, University of Canterbury, and Victoria University of Wellington have collectively produced an update of the 2002 national probabilistic seismic hazard (PSH) model for New Zealand. The new model incorporates over 200 new onshore and offshore fault sources, and utilises newly developed New Zealand-based scaling relationships and methods for the parameterisation of the fault and subduction interface sources. The background seismicity model has also been updated to include new seismicity data, a new seismicity regionalisation, and improved methodology for calculation of the seismicity parameters. Background seismicity models allow for the occurrence of earthquakes away from the known fault sources, and are typically modelled as a grid of earthquake sources with rate parameters assigned from the historical seismicity catalogue. The Greendale Fault, which ruptured during the M7.1, 4 September 2010 Darfield earthquake, was unknown prior to the earthquake. However, the earthquake was to some extent accounted for in the PSH model. The maximum magnitude assumed in the background seismicity model for the area of the earthquake is 7.2 (larger than the Darfield event), but the location and geometry of the fault are not represented. Deaggregations of the PSH model for Christchurch at return periods of 500 years and above show that M7-7.5 fault and background source-derived earthquakes at distances less than 40 km are important contributors to the hazard. Therefore, earthquakes similar to the Darfield event feature prominently in the PSH model, even though the Greendale Fault was not an explicit model input.
The ground literally opened up! On the previously unknown faultline along which the Saturday 4 September 2010 earthquake originated.
The ground literally opened up! On the previously unknown faultline along which the Saturday 4 September 2010 earthquake originated.
The ground literally opened up! On the previously unknown faultline along which the Saturday 4 September 2010 earthquake originated.
The ground literally opened up! On the previously unknown faultline along which the Saturday 4 September 2010 earthquake originated.
Photograph captioned by Fairfax, "New Zealand's Governor-General Anand Satyanand and his wife Susan Satyanand visited sites around earthquake-stricken Canterbury today. Satyanand at the epicentre near Darfield where the new fault line can be clearly seen across a rural paddock".
Photograph captioned by Fairfax, "Damage to St. Mary's Anglican Church Timaru resulting from 7.1 Magnitude Earthquake centred near Darfield. (L to R): Builder Kevin Deam and St. Mary's parishioner Craig Perkins inspect a damaged spire on the church tower".
Photograph captioned by Fairfax, "New Zealand's Governor-General Anand Satyanand and his wife Susan Satyanand visited sites around earthquake stricken Canterbury today. Satyanand at the epicentre near Darfield where the new fault line can be clearly seen across a rural paddock".
Photograph captioned by Fairfax, "New Zealand's Governor-General Anand Satyanand and his wife Susan Satyanand visited sites around earthquake stricken Canterbury today. Satyanand at the epicentre near Darfield where the new fault line can be clearly seen across a rural paddock".
Photograph captioned by Fairfax, "New Zealand's Governor-General Anand Satyanand and his wife Susan Satyanand visited sites around earthquake stricken Canterbury today. Satyanand at the epicentre near Darfield where the new fault line can be clearly seen across a rural paddock".
The 2010 Darfield earthquake is the largest earthquake on record to have occurred within 40 km of a major city and not cause any fatalities. In this paper the authors have reflected on their experiences in Christchurch following the earthquake with a view to what worked, what didn’t, and what lessons can be learned from this for the benefit of Australian earthquake preparedness. Owing to the fact that most of the observed building damage occurred in Unreinforced Masonry (URM) construction, this paper focuses in particular on the authors’ experience conducting rapid building damage assessment during the first 72 hours following the earthquake and more detailed examination of the performance of unreinforced masonry buildings with and without seismic retrofit interventions
The September Canterbury earthquake. These pictures were taken of Colombo Street in Sydenham. A lot of masonry in this area has been damaged/fallen down. Note: these photos were taken on a cellphone; mind the quality.
The September Canterbury earthquake. These pictures were taken of Colombo Street in Sydenham. A lot of masonry in this area has been damaged/fallen down. Note: these photos were taken on a cellphone; mind the quality.
The September Canterbury earthquake. These pictures were taken of Colombo Street in Sydenham. A lot of masonry in this area has been damaged/fallen down. Churchill tavern. Note: these photos were taken on a cellphone; mind the quality.
The September Canterbury earthquake. These pictures were taken of Colombo Street in Sydenham. A lot of masonry in this area has been damaged/fallen down. Churchill Tavern. Note: these photos were taken on a cellphone; mind the quality.
At Greendale Faultline on Highfield Road in mid-Canterbury, where the magnitude 7.1 earthquake on 4 September 2010 originated.
The September Canterbury earthquake. These pictures were taken of Colombo Street in Sydenham. A lot of masonry in this area has been damaged/fallen down. Note: these photos were taken on a cellphone; mind the quality.
Heaving and subsidence on the faultline left scars where the magnitude 7.1 earthquake on Saturday 4 September 2010 originated.
The September Canterbury earthquake. These pictures were taken of Colombo Street in Sydenham. A lot of masonry in this area has been damaged/fallen down. Note: these photos were taken on a cellphone; mind the quality.
The latest (but temporary) tourist attraction in mid-Canterbury! This was the previously unknown faultline where the Saturday 4 September 2010 earthquake originated.
At Greendale Faultline on Highfield Road in mid-Canterbury, where the magnitude 7.1 earthquake on 4 September 2010 originated.
At Greendale Faultline on Highfield Road in mid-Canterbury, where the magnitude 7.1 earthquake on 4 September 2010 originated.
Tension cracks at least 300 mm deep, on the previously unknown faultline from which the Saturday 4 September 2010 earthquake originated.
Rolleston/Burnham, South Island, NZ This used to be a perfectly straight and flat road!
Photograph captioned by Fairfax, "Damage to St. Mary's Anglican Church Timaru resulting from 7.1 Magnitude Earthquake centred near Darfield. Damage can be seen to the spires on the church tower. The spire-tops were removed for safety and to be repaired".
Photograph captioned by Fairfax, "Damage to St. Mary's Anglican Church Timaru resulting from 7.1 Magnitude Earthquake centred near Darfield . (L to R): St. Mary's parishioner Craig Perkins and builder Kevin Deam secure the final damaged spire to be removed from the church tower".
A report by Thomas Wilson, Zach Whitman, Matt Cockcroft, Mike Finnemore, Peter Almond, Derrick Moot, et al on various remediation techniques for farms on the Greendale fault scarp. The purpose of the report was to brief the Rural Recovery Group on 20 September 2010.
The September Canterbury earthquake. These pictures were taken of Colombo Street in Sydenham. A lot of masonry in this area has been damaged/fallen down. Note: these photos were taken on a cellphone; mind the quality.