title: Precursory eruptions, magma priming and eruption dynamics associated with the climactic 19th February 1975 eruption of Ngauruhoe

authors: Geraghty, Krystal Joan

subjects: Ngauruhoe

abstract: Ngauruhoe is an active central North Island composite volcano, located at the south end of the Taupo Volcanic Zone. This basaltic andesite to andesite cone is one of the most active vents of the larger Tongariro Volcanic Complex; the active summit scoria cone (c. 150 m in diameter) was constructed within the older crater (c. 400 m in diameter) during the eruptions of 1954 to 1975. Approximately 9 m of volcanic material was added to the inner crater rim during the 1975 eruption. Past eruptions from Ngauruhoe have been well-documented in various studies; however, these generally lack detailed observation and analyses of the 1975 eruption deposit meaning that pre-eruptive conditions and explosion dynamics associated with this eruption were left poorly constrained.

This research investigates the physical parameters and eruption controls that led up to the 1975 eruption, including the activity observed from 1968. Specifically, this study examines the pre-eruptive conditions, triggers and eruption mechanisms that led to eruption and emplacement of the 1975 inner crater rim deposit. A key part of this study involved identifying the relationship between, and source of, different clast types comprising the deposit, in addition to determining whether a solid plug and/or magma-water interaction contributed to the high explosivity of the 1975 eruption. By improving our understanding of magmatic and volcanic processes associated with this eruption, this study may assist with more reliable interpretation of monitoring data prior to and during such eruptions (not only at Ngauruhoe, but also basaltic-andesitic volcanoes worldwide). Fieldwork involved stratigraphic logging, high-resolution photography, and sample collection, in addition to sub-sample collection of the 1954-75 volcanic ash deposits stored on archive at GNS Science. Outcrop photos were subsequently point-counted to discriminate between the components, and collected samples described and characterised. Further laboratory analyses included optical microscopic petrography, component point counting, vesicularity studies, scanning electron microscopy, electron microprobe analysis, laser sizing, and quantitative software shape analysis.

This study has demonstrated the importance of crystal fractionation and magma mixing in the evolution of the magma that erupted during 1975. In particular, the transporting magma may have interacted with, and entrained, exotic crystals from a cooler, more evolved crystal mush zone formed by an antecedent magma. Further, magma ascent was associated with efficient gas segregation and transport to the surface along preferential percolation pathways. Efficient degassing in low viscosity magmas typically results in effusive activity; however, this study shows that the high explosivity of the climactic 19th February 1975 eruption was linked to the presence of a coherent, degassed, and hydrothermally altered caprock resulting in accumulation and coalescence of pressurised gas beneath the plug. This study discounts the previously ascribed theory that magma-water interaction controlled the high explosivity of this event. Instead, limited magma-water interaction likely produced the steam observed in the eruption column.

Based on the interpretations outlined above, it is now possible to explain the inner crater stratigraphy. The 1975 inner crater rim deposit is now divided into four facies, A through D, based on textural characteristics and componentry. Facies A (comprising dense sub-angular lapilli and vesicular scoria lapilli) and B (comprising black scoria lapilli/bombs and dense lapilli) were emplaced during vulcanian activity associated with disruption of a caprock, leading up the climactic eruption on the 19th of February 1975. Facies C (comprising loose scoria, dense lapilli, and large irregular domains of densely coalesced/agglutinated pyroclasts) and D (comprising dense lapilli to blocks, scoria lapilli, and bombs) were deposited during the continuous ‘sub-plinian’ eruption on the 19th of February 1975, from strombolian fire-fountaining activity at the base of the large eruption plume. Evidence for this is recorded by the mixture of scoria, agglutinated spatter, and dense clasts throughout these facies; which are indicative of a spatter-fed eruption.

text: Precursory eruptions, magma priming and eruption dynamics associated with the climactic 19th February 1975 eruption of Ngauruhoe Ngauruhoe is an active central North Island composite volcano, located at the south end of the Taupo Volcanic Zone. This basaltic andesite to andesite cone is one of the most active vents of the larger Tongariro Volcanic Complex; the active summit scoria cone (c. 150 m in diameter) was constructed within the older crater (c. 400 m in diameter) during the eruptions of 1954 to 1975. Approximately 9 m of volcanic material was added to the inner crater rim during the 1975 eruption. Past eruptions from Ngauruhoe have been well-documented in various studies; however, these generally lack detailed observation and analyses of the 1975 eruption deposit meaning that pre-eruptive conditions and explosion dynamics associated with this eruption were left poorly constrained.

This research investigates the physical parameters and eruption controls that led up to the 1975 eruption, including the activity observed from 1968. Specifically, this study examines the pre-eruptive conditions, triggers and eruption mechanisms that led to eruption and emplacement of the 1975 inner crater rim deposit. A key part of this study involved identifying the relationship between, and source of, different clast types comprising the deposit, in addition to determining whether a solid plug and/or magma-water interaction contributed to the high explosivity of the 1975 eruption. By improving our understanding of magmatic and volcanic processes associated with this eruption, this study may assist with more reliable interpretation of monitoring data prior to and during such eruptions (not only at Ngauruhoe, but also basaltic-andesitic volcanoes worldwide). Fieldwork involved stratigraphic logging, high-resolution photography, and sample collection, in addition to sub-sample collection of the 1954-75 volcanic ash deposits stored on archive at GNS Science. Outcrop photos were subsequently point-counted to discriminate between the components, and collected samples described and characterised. Further laboratory analyses included optical microscopic petrography, component point counting, vesicularity studies, scanning electron microscopy, electron microprobe analysis, laser sizing, and quantitative software shape analysis.

This study has demonstrated the importance of crystal fractionation and magma mixing in the evolution of the magma that erupted during 1975. In particular, the transporting magma may have interacted with, and entrained, exotic crystals from a cooler, more evolved crystal mush zone formed by an antecedent magma. Further, magma ascent was associated with efficient gas segregation and transport to the surface along preferential percolation pathways. Efficient degassing in low viscosity magmas typically results in effusive activity; however, this study shows that the high explosivity of the climactic 19th February 1975 eruption was linked to the presence of a coherent, degassed, and hydrothermally altered caprock resulting in accumulation and coalescence of pressurised gas beneath the plug. This study discounts the previously ascribed theory that magma-water interaction controlled the high explosivity of this event. Instead, limited magma-water interaction likely produced the steam observed in the eruption column.

Based on the interpretations outlined above, it is now possible to explain the inner crater stratigraphy. The 1975 inner crater rim deposit is now divided into four facies, A through D, based on textural characteristics and componentry. Facies A (comprising dense sub-angular lapilli and vesicular scoria lapilli) and B (comprising black scoria lapilli/bombs and dense lapilli) were emplaced during vulcanian activity associated with disruption of a caprock, leading up the climactic eruption on the 19th of February 1975. Facies C (comprising loose scoria, dense lapilli, and large irregular domains of densely coalesced/agglutinated pyroclasts) and D (comprising dense lapilli to blocks, scoria lapilli, and bombs) were deposited during the continuous ‘sub-plinian’ eruption on the 19th of February 1975, from strombolian fire-fountaining activity at the base of the large eruption plume. Evidence for this is recorded by the mixture of scoria, agglutinated spatter, and dense clasts throughout these facies; which are indicative of a spatter-fed eruption.

year: 2019

title: Domestic Violence and Systemic Deception in the Family Legal  System: A Compelling Case for Truthful Reform

authors: Nakarawa, Jalesi

subjects: domestic violence

abstract: This thesis investigates the law and legal philosophy behind New Zealand’s response to domestic violence. As a feature of common law reasoning, legal fiction, asserting something to be true when it is not true, persists as an important mechanism in judicial fact finding. In family law, the convenient and crucially unrecognised fiction of the “ideal family” which may never have existed continues to drive the family justice system. The failure to be aware of the fiction may undo the justifications for its existence and undermine its utility.
Treating this fiction as true rather than treating it as “if true” drives a wedge between the normative intent of the law and the behavioural issues that underlie human interpersonal relationships. The resulting gap between the realities of the family experience we live with and the “ideal family” we live by underwrites the vague and imprecise objectives of our responses to domestic violence. Apart from the uncertainty of what we are trying to achieve, the fiction assumes that deception and aggression are pathologies in human behaviour. The law’s reliance on these fictions to pursue just ends requires careful considerations to avoid causing real world pathologies.
Despite New Zealand’s reputation for innovative responses to domestic violence, the Family Justice System as a whole has failed to produce the anticipated result. The expansion of the continuum of conduct classified as domestic violence has criminalised instances of ordinary human aggression. This expansion under the Domestic Violence Act was intended to provide victims greater protection from domestic violence, but it has not had the intended result. While success in police management terms may be evaluated in higher rates of reported incidents, arrests and convictions, success for victims ought to be assessed regarding the reduction in incidences of violence over time. This has not happened. For this reason, the application of statistical data to support a specific agenda often distorts our assessment of domestic violence.
The thesis proposes a holistic approach based on domestic violence as fundamentally a behavioural issue. It is important first to ascertain the nature of violence in the world and our lives and to unpack human behaviour for a better understanding of why we do the things we do. Secondly, statistical data should be properly analysed to provide an accurate picture of human behaviour and domestic violence as it is on the ground, the reality of family life we live with. This and only this can provide a sound basis for developing explicit goals to guide our legal responses or interventions, bridging the divide between the aspirational objectives of the law and the human reality we live with.

text: Domestic Violence and Systemic Deception in the Family Legal  System: A Compelling Case for Truthful Reform This thesis investigates the law and legal philosophy behind New Zealand’s response to domestic violence. As a feature of common law reasoning, legal fiction, asserting something to be true when it is not true, persists as an important mechanism in judicial fact finding. In family law, the convenient and crucially unrecognised fiction of the “ideal family” which may never have existed continues to drive the family justice system. The failure to be aware of the fiction may undo the justifications for its existence and undermine its utility.
Treating this fiction as true rather than treating it as “if true” drives a wedge between the normative intent of the law and the behavioural issues that underlie human interpersonal relationships. The resulting gap between the realities of the family experience we live with and the “ideal family” we live by underwrites the vague and imprecise objectives of our responses to domestic violence. Apart from the uncertainty of what we are trying to achieve, the fiction assumes that deception and aggression are pathologies in human behaviour. The law’s reliance on these fictions to pursue just ends requires careful considerations to avoid causing real world pathologies.
Despite New Zealand’s reputation for innovative responses to domestic violence, the Family Justice System as a whole has failed to produce the anticipated result. The expansion of the continuum of conduct classified as domestic violence has criminalised instances of ordinary human aggression. This expansion under the Domestic Violence Act was intended to provide victims greater protection from domestic violence, but it has not had the intended result. While success in police management terms may be evaluated in higher rates of reported incidents, arrests and convictions, success for victims ought to be assessed regarding the reduction in incidences of violence over time. This has not happened. For this reason, the application of statistical data to support a specific agenda often distorts our assessment of domestic violence.
The thesis proposes a holistic approach based on domestic violence as fundamentally a behavioural issue. It is important first to ascertain the nature of violence in the world and our lives and to unpack human behaviour for a better understanding of why we do the things we do. Secondly, statistical data should be properly analysed to provide an accurate picture of human behaviour and domestic violence as it is on the ground, the reality of family life we live with. This and only this can provide a sound basis for developing explicit goals to guide our legal responses or interventions, bridging the divide between the aspirational objectives of the law and the human reality we live with.

year: 2016

title: The Research Data Landscape in Aotearoa New Zealand: A report undertaken in partnership with the Aotearoa New Zealand Committee on Data in Research (CoDiR)

authors: Sterling, Rogena

abstract: Data and datasets are often described as a core strategic asset for Aotearoa New Zealand (Aotearoa) and indispensable for the government’s ambition of being a small nation with an advanced, adaptive, and inclusive economy. In the context of our research, science and innovation (RSI) ecosystem, the value of data cannot be overstated. 
The purpose of this report is to provide a review (the Review) of Aotearoa’s research data landscape. Research data are data that are used as primary sources to support technical or scientific enquiry, research, or artistic activity; as evidence in the research process; and/or are commonly accepted in the
research community as necessary to provide a foundation for, or validate research findings and results. The Review covers four core areas:

• Te Tiriti o Waitangi and data sovereignty
• research data ecosystems
• research data infrastructure
• research data cultures.

Although informed by international data landscape reviews, this Review emphasises the unique considerations and structural features of the Aotearoa data landscape. Based on our analysis and observations from a series of targeted workshops, we provide a set of recommendations on how to strengthen the system and advance shared aspirations for better outcomes. The recommendations are organised under the five headings from Nosek’s Pyramid of Social Change, setting out a phased strategy for culture and behaviour change. In implementing these recommendations, we recognise that the articles of Te Tiriti should be embedded throughout, consistent with sector requirements (MBIE, 2023d).

text: The Research Data Landscape in Aotearoa New Zealand: A report undertaken in partnership with the Aotearoa New Zealand Committee on Data in Research (CoDiR) Data and datasets are often described as a core strategic asset for Aotearoa New Zealand (Aotearoa) and indispensable for the government’s ambition of being a small nation with an advanced, adaptive, and inclusive economy. In the context of our research, science and innovation (RSI) ecosystem, the value of data cannot be overstated. 
The purpose of this report is to provide a review (the Review) of Aotearoa’s research data landscape. Research data are data that are used as primary sources to support technical or scientific enquiry, research, or artistic activity; as evidence in the research process; and/or are commonly accepted in the
research community as necessary to provide a foundation for, or validate research findings and results. The Review covers four core areas:

• Te Tiriti o Waitangi and data sovereignty
• research data ecosystems
• research data infrastructure
• research data cultures.

Although informed by international data landscape reviews, this Review emphasises the unique considerations and structural features of the Aotearoa data landscape. Based on our analysis and observations from a series of targeted workshops, we provide a set of recommendations on how to strengthen the system and advance shared aspirations for better outcomes. The recommendations are organised under the five headings from Nosek’s Pyramid of Social Change, setting out a phased strategy for culture and behaviour change. In implementing these recommendations, we recognise that the articles of Te Tiriti should be embedded throughout, consistent with sector requirements (MBIE, 2023d).

year: 2023