title: On the doctoral journey: An introduction to articles in this issue

authors: Newcombe, Nicolina Isabel

abstract: We are pleased to contribute to the ongoing work of Waikato Journal of Educationin growingknowledge and understanding of educational research and the experiences of researchers. Wehope you find value in the articles in this special issue.

text: On the doctoral journey: An introduction to articles in this issue We are pleased to contribute to the ongoing work of Waikato Journal of Educationin growingknowledge and understanding of educational research and the experiences of researchers. Wehope you find value in the articles in this special issue.

year: 2022-09-08

title: Southwest Pacific Absolute Plate Kinematic Reconstruction Reveals Major Cenozoic Tonga-Kermadec Slab Dragging

authors: van de Lagemaat, Suzanna H.A.

subjects: Science & Technology

abstract: Tectonic plates subducting at trenches having strikes oblique to the absolute subducting plate motion undergo trench‐parallel slab motion through the mantle, recently defined as a form of “slab dragging.” We investigate here long‐term slab‐dragging components of the Tonga‐Kermadec subduction system driven by absolute Pacific plate motion. To this end we develop a kinematic restoration of Tonga‐Kermadec Trench motion placed in a mantle reference frame and compare it to tomographically imaged slabs in the mantle. Estimating Tonga‐Kermadec subduction initiation is challenging because another (New Caledonia) subduction zone existed during the Paleogene between the Australia and Pacific plates. We test partitioning of plate convergence across the Paleogene New Caledonia and Tonga‐Kermadec subduction zones against resulting mantle structure and show that most, if not all, Tonga‐Kermadec subduction occurred after ca. 30 Ma. Since then, Tonga‐Kermadec subduction has accommodated 1,700 to 3,500 km of subduction along the southern and northern ends of the trench, respectively. When placed in a mantle reference frame, the predominantly westward directed subduction evolved while the Tonga‐Kermadec Trench underwent ~1,200 km of northward absolute motion. We infer that the entire Tonga‐Kermadec slab was laterally transported through the mantle over 1,200 km. Such slab dragging by the Pacific plate may explain observed deep‐slab deformation and may also have significant effects on surface tectonics, both resulting from the resistance to slab dragging by the viscous mantle.

Plain Language Summary
In studying subduction zones, where one plate dives below another back into the mantle, we tend to focus on the relative motion between the two plates, normally by assuming that the upper plate is fixed relative to the underlying mantle. Plate reconstructions in an “absolute” mantle frame of reference show, however, that trenches often migrate parallel to their trend relative to the mantle. In this paper, we study the southwestern Pacific Tonga‐Kermadec Trench and demonstrate (1) that it is likely much younger than often assumed, and accommodated most if not all of its subduction after ~30 million years ago and (2) that even in this short time period, it moved as much as 1,200 km northward relative to the mantle, parallel to its strike. By comparing this history with the subducted plate that is seismically imaged in the mantle, we show that the subducted Pacific lithosphere underwent major northward slab dragging through the mantle. This dragging explains enigmatic deep earthquakes and seismological observations of mantle structure. Realizing the role of slab dragging may provide novel constraints for deep‐time geological reconstructions as well as natural hazards assessment.

text: Southwest Pacific Absolute Plate Kinematic Reconstruction Reveals Major Cenozoic Tonga-Kermadec Slab Dragging Tectonic plates subducting at trenches having strikes oblique to the absolute subducting plate motion undergo trench‐parallel slab motion through the mantle, recently defined as a form of “slab dragging.” We investigate here long‐term slab‐dragging components of the Tonga‐Kermadec subduction system driven by absolute Pacific plate motion. To this end we develop a kinematic restoration of Tonga‐Kermadec Trench motion placed in a mantle reference frame and compare it to tomographically imaged slabs in the mantle. Estimating Tonga‐Kermadec subduction initiation is challenging because another (New Caledonia) subduction zone existed during the Paleogene between the Australia and Pacific plates. We test partitioning of plate convergence across the Paleogene New Caledonia and Tonga‐Kermadec subduction zones against resulting mantle structure and show that most, if not all, Tonga‐Kermadec subduction occurred after ca. 30 Ma. Since then, Tonga‐Kermadec subduction has accommodated 1,700 to 3,500 km of subduction along the southern and northern ends of the trench, respectively. When placed in a mantle reference frame, the predominantly westward directed subduction evolved while the Tonga‐Kermadec Trench underwent ~1,200 km of northward absolute motion. We infer that the entire Tonga‐Kermadec slab was laterally transported through the mantle over 1,200 km. Such slab dragging by the Pacific plate may explain observed deep‐slab deformation and may also have significant effects on surface tectonics, both resulting from the resistance to slab dragging by the viscous mantle.

Plain Language Summary
In studying subduction zones, where one plate dives below another back into the mantle, we tend to focus on the relative motion between the two plates, normally by assuming that the upper plate is fixed relative to the underlying mantle. Plate reconstructions in an “absolute” mantle frame of reference show, however, that trenches often migrate parallel to their trend relative to the mantle. In this paper, we study the southwestern Pacific Tonga‐Kermadec Trench and demonstrate (1) that it is likely much younger than often assumed, and accommodated most if not all of its subduction after ~30 million years ago and (2) that even in this short time period, it moved as much as 1,200 km northward relative to the mantle, parallel to its strike. By comparing this history with the subducted plate that is seismically imaged in the mantle, we show that the subducted Pacific lithosphere underwent major northward slab dragging through the mantle. This dragging explains enigmatic deep earthquakes and seismological observations of mantle structure. Realizing the role of slab dragging may provide novel constraints for deep‐time geological reconstructions as well as natural hazards assessment.

year: 2018

title: My journey with te reo Māori: From primary schooling in the mid 20th century to retirement from full-time academic service in the early years of the 21st Century

authors: Houia-Roberts, Ngaere

subjects: New Zealand

abstract: This is not an academic article in the traditional sense. It is a personal account of my experiences, as a first language speaker of te reo Māori, of New Zealand's educational system from the middle of the 20th century to the early years of the 21st century, from the early days of my primary schooling, through my service as a teacher, teacher trainer and academic researcher until my retirement from full-time academic service in 2005. A great deal has been written about the ways in which attitudes and approaches to te reo Māori have changed over that period of time but very little has been written about how it felt to be part of these changes. Our society is based on facts and feelings. If our mokopuna are to understand the fabric of our society, they need to have access to feelings as well as to facts. In this paper, weft and warp, facts and feelings, are woven together. This personal account is dedicated to our mokopuna, to all of our mokopuna, whatever their origin and whatever their colour. The future of our society depends upon their understanding.

text: My journey with te reo Māori: From primary schooling in the mid 20th century to retirement from full-time academic service in the early years of the 21st Century This is not an academic article in the traditional sense. It is a personal account of my experiences, as a first language speaker of te reo Māori, of New Zealand's educational system from the middle of the 20th century to the early years of the 21st century, from the early days of my primary schooling, through my service as a teacher, teacher trainer and academic researcher until my retirement from full-time academic service in 2005. A great deal has been written about the ways in which attitudes and approaches to te reo Māori have changed over that period of time but very little has been written about how it felt to be part of these changes. Our society is based on facts and feelings. If our mokopuna are to understand the fabric of our society, they need to have access to feelings as well as to facts. In this paper, weft and warp, facts and feelings, are woven together. This personal account is dedicated to our mokopuna, to all of our mokopuna, whatever their origin and whatever their colour. The future of our society depends upon their understanding.

year: 2006-02