dc.contributor.author |
Pender, Michael |
en |
dc.contributor.author |
Lynne, Bridget |
en |
dc.contributor.editor |
Rotonda, T |
en |
dc.contributor.editor |
Cecconi, M |
en |
dc.contributor.editor |
Silvestri, F |
en |
dc.contributor.editor |
Tommasi, P |
en |
dc.coverage.spatial |
Lacco Ameno, Italy |
en |
dc.date.accessioned |
2017-11-08T01:50:24Z |
en |
dc.date.issued |
2016 |
en |
dc.identifier.citation |
International Workshop on Volcanic Rocks and Soils, Lacco Ameno, Italy, 24 Sep 2016 - 25 Sep 2016. Editors: Rotonda T, Cecconi M, Silvestri F, Tommasi P. Volcanic Rocks and Soils; Proceedings of the International Workshop on Volcanic Rocks and Soils, 2015. CRC Press, London, UK. 109-110. 2016 |
en |
dc.identifier.isbn |
978-1-138-02886-9 |
en |
dc.identifier.uri |
http://hdl.handle.net/2292/36356 |
en |
dc.description.abstract |
Geothermal fluid has been extracted for electricity generation from the Taupo Volcanic Zone in the central North Island of New Zealand since the mid-1950s. This has induced regional subsidence of more than 1m; but there are a few localized bowls with much greater subsidence. A comprehensive geotechnical investigation with recovery of undisturbed samples from depths of up to 774m was undertaken with testing of core samples from within and outside subsidence bowls to determine material properties. More than 130 Ko triaxial compression tests were done. Given the volcanic origins of most of the material, the observed wide variation in the measured constrained modulus values is not surprising. Scanning electron microscope images (SEM) reveal differences between the texture of the soft materials and the very stiff materials, these correlate with the constrained modulus values. It was SEM imaging that provided a window into the complex nature of these subsurface environments and identified processes driving the physio-chemical conditions acting and either hardening or softening rocks at specific depths. As geothermal environments are constantly changing and each environment leaves a footprint which is preserved within the rock, SEM can be used to track these changes placing them into a spatial and temporal context. While compressibility measurements identified soft zones within the formations, SEM observations documented subsurface processes responsible for weakening the various lithologic units; these changes in the subsurface conditions are ultimately responsible for the subsidence visible at the surface. |
en |
dc.publisher |
CRC Press |
en |
dc.relation.ispartof |
International Workshop on Volcanic Rocks and Soils |
en |
dc.relation.ispartofseries |
Volcanic Rocks and Soils; Proceedings of the International Workshop on Volcanic Rocks and Soils, 2015 |
en |
dc.rights |
Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher. |
en |
dc.rights.uri |
https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm |
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dc.subject |
Science & Technology |
en |
dc.subject |
Technology |
en |
dc.subject |
Physical Sciences |
en |
dc.subject |
Engineering, Geological |
en |
dc.subject |
Geology |
en |
dc.subject |
Geosciences, Multidisciplinary |
en |
dc.subject |
Engineering |
en |
dc.subject |
NEW-ZEALAND |
en |
dc.subject |
SUBSIDENCE |
en |
dc.title |
Compressibility of geothermal reservoir rocks from the Wairakei-Tauhara fields with insights gained from geotechnical laboratory testing and scanning electron microscope imaging |
en |
dc.type |
Conference Item |
en |
pubs.begin-page |
109 |
en |
dc.rights.holder |
Copyright: CRC Press |
en |
pubs.author-url |
https://www.crcpress.com/Volcanic-Rocks-and-Soils/Rotonda-Cecconi-Silvestri-Tommasi/p/book/9781138028869 |
en |
pubs.end-page |
110 |
en |
pubs.finish-date |
2016-09-25 |
en |
pubs.place-of-publication |
London, UK |
en |
pubs.publication-status |
Published |
en |
pubs.start-date |
2016-09-24 |
en |
dc.rights.accessrights |
http://purl.org/eprint/accessRights/RestrictedAccess |
en |
pubs.subtype |
Proceedings |
en |
pubs.elements-id |
515558 |
en |
pubs.org-id |
Engineering |
en |
pubs.org-id |
Civil and Environmental Eng |
en |
pubs.org-id |
Engineering Science |
en |
pubs.record-created-at-source-date |
2017-11-08 |
en |