Despite over a century of study, the relationship between lunar cycles and earthquakes remains controversial and difficult to quantitatively investigate. Perhaps as a consequence, major earthquakes around the globe are frequently followed by 'prediction' claims, using lunar cycles, that generate media furore and pressure scientists to provide resolute answers. The 2010-2011 Canterbury earthquakes in New Zealand were no exception; significant media attention was given to lunarderived earthquake predictions by non-scientists, even though the predictions were merely 'opinions' and were not based on any statistically robust temporal or causal relationships. This thesis provides a framework for studying lunisolar earthquake temporal relationships by developing replicable statistical methodology based on peer reviewed literature. Notable in the methodology is a high accuracy ephemeris, called ECLPSE, designed specifically by the author for use on earthquake catalogs, and a model for performing phase angle analysis. The statistical tests were carried out on two 'declustered' seismic catalogs, one containing the aftershocks from the Mw7.1 earthquake in Canterbury, and the other containing Australian seismicity from the past two decades. Australia is an intraplate setting far removed from active plate boundaries and Canterbury is proximal to a plate boundary, thus allowing for comparison based on tectonic regime and corresponding tectonic loading rate. No strong, conclusive, statistical correlations were found at any level of the earthquake catalogs, looking at large events, onshore events, offshore events, and the fault type of some events. This was concluded using Schuster's test of significance with α=5% and analysis of standard deviations. A few weak correlations, with p-5-10% of rejecting the null hypothesis, and anomalous standard deviations were found, but these are difficult to interpret. The results invalidate the statistical robustness of 'earthquake predictions' using lunisolar parameters in this instance. An ambitious researcher could improve on the quality of the results and on the range of parameters analyzed. The conclusions of the thesis raise more questions than answers, but the thesis provides an adaptable methodology that can be used to further investigation the problem.
Animals have also suffered upheaval because of the Christchurch earthquakes. Jan Collins is one of those caring for some the hundreds of pets who have been left homeless because of the earthquakes.
A story submitted by Mark Darbyshire to the QuakeStories website.
A story submitted by Liza Rossie to the QuakeStories website.
An entry from Ruth Gardner's blog for 11 June 2012 entitled, "Sobering Sunday Stroll".
An entry from Ruth Gardner's blog for 2 July 2012 entitled, "Walking on Worcester".
Transcript of participant number QB1200's earthquake story, captured by the UC QuakeBox project.
Summary of oral history interview with Irene Cleary about her experiences of the Canterbury earthquakes.
The "Lyttelton Review" newsletter for 23 July 2012, produced by the Lyttelton Harbour Information Centre.
The "Lyttelton Review" newsletter for 21 May 2012, produced by the Lyttelton Harbour Information Centre.
The "Lyttelton Review" newsletter for 1 October 2012, produced by the Lyttelton Harbour Information Centre.
A copy of the CanCERN online newsletter published on 21 September 2012
Shirley Community Centre, Shirley Road, Christchurch. File reference: CCL-2012-05-10-Around-Shirley-May-2012 DSC_02866.JPG From the collection of Christchurch City Libraries.
Shirley Community Centre, Shirley Road, Christchurch. File reference: CCL-2012-05-10-Around-Shirley-May-2012 DSC_02862.JPG From the collection of Christchurch City Libraries.
Shirley Community Centre, Shirley Road, Christchurch. File reference: CCL-2012-05-10-Around-Shirley-May-2012 DSC_02869.JPG From the collection of Christchurch City Libraries.
Shirley Community Centre, Shirley Road, Christchurch. File reference: CCL-2012-05-10-Around-Shirley-May-2012 DSC_02863.JPG From the collection of Christchurch City Libraries.
Shirley Community Centre, Shirley Road, Christchurch. File reference: CCL-2012-05-10-Around-Shirley-May-2012 DSC_02867.JPG From the collection of Christchurch City Libraries.
This paper examines the consistency of seismicity and ground motion models, used for seismic hazard analysis in New Zealand, with the observations in the Canterbury earthquakes. An overview is first given of seismicity and ground motion modelling as inputs of probabilistic seismic hazard analysis, whose results form the basis for elastic response spectra in NZS1170.5:2004. The magnitude of earthquakes in the Canterbury earthquake sequence are adequately allowed for in the current NZ seismicity model, however the consideration of ‘background’ earthquakes as point sources at a minimum depth of 10km results in up to a 60% underestimation of the ground motions that such events produce. The ground motion model used in conventional NZ seismic hazard analysis is shown to provide biased predictions of response spectra (over-prediction near T=0.2s , and under-predictions at moderate-to-large vibration periods). Improved ground motion prediction can be achieved using more recent NZ-specific models.
Detail of some earthquake damage inside the cordon.
House being re-built on the corner of Hercules Street and Quinns Road, Shirley, Christchurch. File reference: CCL-2012-05-10-Around-Shirley-May-2012 DSC_02847.JPG From the collection of Christchurch City Libraries.
House being re-built on the corner of Hercules Street and Quinns Road, Shirley, Christchurch. File reference: CCL-2012-05-10-Around-Shirley-May-2012 DSC_02848.JPG From the collection of Christchurch City Libraries.
Ngai Tahu says its people are turning to the tribe for help with legal and engineering advice about their earthquake-damaged homes in Christchurch; The Chairperson of the Maori Midwives Collective Nga Maia, says the earthquake a year ago forced the organisation to start its administrative operations from scratch; Efforts are underway to find out how many Maori left Christchurch after the earthquake; The Ngai Tahu hapu, Ngai Tuahuriri in Christchurch, will be welcoming the Governor-General to Rehua Marae this morning to commemorate the anniversary of last year's earthquake; Christchurch will hear today whether it'll be hosting the biggest Maori performance event on the calendar - Te Matatini National Festival.
The September 2010 Canterbury and February 2011 Christchurch earthquakes and associated aftershocks have shown that the isolator displacement in Christchurch Women's Hospital (Christchurch City's only base-isolated structure) was significantly less than expected. Occupant accounts of the events have also indicated that the accelerations within the hospital superstructure were larger than would usually be expected within a base-isolated structure and that residual low-level shaking lasts for a longer period of time following the strong-motion of an event than for non-isolated structures.
The Canterbury Earthquake Recovery Authority has spent more than three-and-a-half million dollars on communications in the past year. The Earthquake Recovery Authority chief executive is Roger Sutton.
A presentation by Dr Charlotte Brown (Department of Civil and Natural Resource Engineering) on "A Waste-Full Recovery: Managing waste after the 2010/2011 Christchurch earthquakes".
A story submitted by Kerry Grant Donnelly to the QuakeStories website.
Summary of oral history interview with Erica Wheeler about her experiences of the Canterbury earthquakes.
Summary of oral history interview with Jane Higgins about her experiences of the Canterbury earthquakes.
Summary of oral history interview with April about her experiences of the Canterbury earthquakes.
Summary of oral history interview with Rosemary Bloxham about her experiences of the Canterbury earthquakes.