All Right? Audiences: Culturally and Linguistically Diverse (CALD) Photogr…

Images, UC QuakeStudies

A photograph of kaumatua listening to a speech. The photograph was taken at the Health Day at the Pa event held at Tuahiwi Marae in August 2015.

All Right? Audiences: Culturally and Linguistically Diverse (CALD) Photogr…

Images, UC QuakeStudies

A photograph of Aroha Reriti-Crofts (Aunty Aroha) taken at the Health Day at the Pa event held at Tuahiwi Marae in August 2015. The event was part of the All Right? mental health campaign of the CDHB.

All Right? Audiences: Culturally and Linguistically Diverse (CALD) Photogr…

Images, UC QuakeStudies

A photograph of staff member Vaea Hutchen from the All Right? mental health campaign of the CDHB standing behind a table of posters and brochures from the campaign. The photograph was taken at the Health Day at the Pa event held at Tuahiwi Marae in August 2015.

All Right? Audiences: Culturally and Linguistically Diverse (CALD) Photogr…

Images, UC QuakeStudies

A photograph of women participating in the Health Day at the Pa event held at Tuahiwi Marae in August 2015. Staff member Vaea Hutchen from the All Right? Mental health campaign of the CDHB is leading a group of women doing a Maori action song.

Photo by Jennifer Middendorf 175

Images, UC QuakeStudies

A "drummer boy" dummy dressed in a hi-vis jacket sits on top of one of a building on High Street. Written on the back of the building is "Merry Christmas Christchurch Pa Rum Pum Pum Pum".

Photo by Jennifer Middendorf 174

Images, UC QuakeStudies

A "drummer boy" dummy dressed in a hi-vis jacket sits on top of a building on High Street. Written on the back of the building is "Merry Christmas Christchurch Pa Rum Pum Pum Pum". Te Waiponamu House is visible in the background.

Photo by Jennifer Middendorf 158

Images, UC QuakeStudies

An empty section on the corner of Cashel and Colombo Streets where buildings have been demolished. In the background, a "drummer boy" dummy dressed in a hi-vis jacket sits on top of one of the still-standing High Street buildings. Written on the back of the building is "Merry Christmas Christchurch Pa Rum Pum Pum Pum".

Tidal Behavior and Water-Level Changes in Gravel Aquifers in Response to M…

Research papers, Victoria University of Wellington

©2019. American Geophysical Union. All Rights Reserved. Earthquakes have been inferred to induce hydrological changes in aquifers on the basis of either changes to well water-levels or tidal behavior, but the relationship between these changes remains unclear. Here, changes in tidal behavior and water-levels are quantified using a hydrological network monitoring gravel aquifers in Canterbury, New Zealand, in response to nine earthquakes (of magnitudes M w 5.4 to 7.8) that occurred between 2008 and 2015. Of the 161 wells analyzed, only 35 contain water-level fluctuations associated with “Earth + Ocean” (7) or “Ocean” (28) tides. Permeability reduction manifest as changes in tidal behavior and increased water-levels in the near field of the Canterbury earthquake sequence of 2010–2011 support the hypothesis of shear-induced consolidation. However, tidal behavior and water-level changes rarely occurred simultaneously (~2%). Water-level changes that occurred with no change in tidal behavior reequilibrated at a new postseismic level more quickly (on timescales of ~50 min) than when a change in tidal behavior occurred (~240 min to 10 days). Water-level changes were more than likely to occur above a peak dynamic stress of ~50 kPa and were more than likely to not occur below ~10 kPa. The minimum peak dynamic stress required for a tidal behavior change to occur was ~0.2 to 100 kPa.