http://hdl.handle.net/10379/5974 2017-10-29T23:51:51Z 2017-10-29T23:51:51Z McNamara, David D. http://hdl.handle.net/10379/6822 2017-09-22T01:01:10Z 2016-01-01T00:00:00Z

Methods and techniques employed to monitor and manage carbon capture and sequestration (CCS) induced seismicity McNamara, David D. This report discusses the topic of induced seismicity resulting from the operations of subsurface CO2 injection at Carbon Capture and Storage (CCS) sites. The potential for induced seismicity to occur in CCS projects is an important factor when considering the capability of a project site s storage reservoir to retain injected CO2 for long periods of time. It is also important when assessing and addressing public concern over earthquake activity. This report discusses the measures carried out at global CCS sites to identify and monitor induced seismicity. This information is then distilled into a list of issues to be considered as part of the review process prior to establishing a CCS site in New Zealand.

2016-01-01T00:00:00Z Field, B.D. Lawrence, M.J. Nicol, A. McNamara, David D. Arnot, M.J. Coyle, F. Higgs, K.E. Mountain, B. Gerstenberger, M. Daniel, R. Bunch, M.A. Barton, B. http://hdl.handle.net/10379/6745 2017-08-18T01:01:05Z 2015-09-13T00:00:00Z

Feasibility of storing carbon dioxide on a tectonically active margin: New Zealand Field, B.D.; Lawrence, M.J.; Nicol, A.; McNamara, David D.; Arnot, M.J.; Coyle, F.; Higgs, K.E.; Mountain, B.; Gerstenberger, M.; Daniel, R.; Bunch, M.A.; Barton, B. New Zealand's sedimentary basins was found to have available several gigatonnes of CO2 storage capacity. However, CO2 storage is currently untested in New Zealand. The country's position on an active Neogene plate boundary raises additional key factors that will influence final site selection. Some risk factors will also influence the relationship between social acceptance and the design of regulations. Despite the risks, hydrocarbon producing fields in Taranaki indicate that viable reservoir-seal pairs are likely to be present.

2015-09-13T00:00:00Z Langridge, R. M. Villamor, P. Litchfield, N. J. Page, M. Ries, W. Ansell, I. A. McNamara, David D. Martin Gonzalez, F. http://hdl.handle.net/10379/6733 2017-08-16T08:53:43Z 2013-01-01T00:00:00Z

A7 Makaroro River dam site Phase 1C: Field characterisation of possible secondary fault displacement Langridge, R. M.; Villamor, P.; Litchfield, N. J.; Page, M.; Ries, W.; Ansell, I. A.; McNamara, David D.; Martin Gonzalez, F. GNS Science has undertaken a field study to investigate the possibility of active secondary faulting in the vicinity of the proposed A7 dam site on the Makaroro River, central Hawke’s Bay. The A7 site is located c. 750 m east of the primary active Mohaka Fault which has a short earthquake recurrence interval (average c. 1125 yr) and poses a credible shaking hazard to the dam site. Prior studies for the A7 dam site commissioned to GNS Science addressed the tectonic setting and characteristics of nearby active faults, as well as a literature review of the potential for secondary faulting at the dam site as a consequence of primary faulting along the Mohaka Fault. This current study focusses on site specific fieldwork undertaken to further evaluate the possibility of recent (late Quaternary) secondary faulting at, or near the proposed A7 dam site, and to define secondary faulting parameters such as possible displacement size, sense of movement, and recurrence. Based on our brief and previous investigations, we selected likely candidate sites for excavation to bedrock on the true left side of the valley on Smedley Station. The three trench sites were located to: 1) investigate the bedrock within the A7 dam footprint; 2) to intercept a NNE-striking mapped fault/shear zone; and 3) test whether evident linear hillslope geomorphology was related to recent faulting near the dam site. To assess recent displacement on bedrock exposed in the trenches we have: 1) mapped the bedrock structure (bedding and defects) in detail to identify faults/shear zones that could have potentially moved with fault displacements; 2) assessed whether bedrock faults had displaced the late Quaternary cover deposits or the strath surface (bedrock/cover contact); and, 3) assessed if fault rocks have characteristics of recent movement (i.e., non-cohesive materials such as fault breccias and gouge or clays. The surface fault rupture history of an active fault, the Gwavas Fault, located 5 km to the north of the A7 dam site and its relevance to the potential for faulting at the dam site have also been investigated through paleoseismic trenching.

2013-01-01T00:00:00Z Williams, Jack N. Toy, Virginia G. Massiot, Cécile McNamara, David D. Wang, Ting http://hdl.handle.net/10379/6729 2017-08-16T01:01:44Z 2016-07-25T00:00:00Z

Damaged beyond repair? Characterising the damage zone of a fault late in its interseismic cycle, the Alpine Fault, New Zealand Williams, Jack N.; Toy, Virginia G.; Massiot, Cécile; McNamara, David D.; Wang, Ting X-ray computed tomography (CT) scans of drill-core, recovered from the first phase of the Deep Fault Drilling Project (DFDP-1) through New Zealand's Alpine Fault, provide an excellent opportunity to study the damage zone of a plate-bounding continental scale fault, late in its interseismic cycle. Documentation of the intermediate-macro scale damage zone structures observed in the CT images show that there is no increase in the density of these structures towards the fault's principal slip zones (PSZs), at least within the interval sampled, which is 30 m above and below the PSZs. This is in agreement with independent analysis using borehole televiewer data. Instead, we conclude the density of damage zone structures to correspond to lithology. We find that 72% of fractures are fully healed, by a combination of clays, calcite and quartz, with an additional 24% partially healed. This fracture healing is consistent with the Alpine Fault's late interseismic state, and the fact that the interval of damage zone sampled coincides with an alteration zone, an interval of extensive fluid-rock interaction. These fractures do not impose a reduction of P-wave velocity, as measured by wireline methods. Outside the alteration zone there is indirect evidence of less extensive fracture healing.

2016-07-25T00:00:00Z