title: Far-flung markers

authors: Lowe, David J.

abstract: Tephras are fragmentary materials that are blasted explosively into the air during volcanic eruptions. Distributed throughout Zealandia, tephras provide useful markers for connecting and dating land surfaces, sediment layers, and archaeological sites.

text: Far-flung markers Tephras are fragmentary materials that are blasted explosively into the air during volcanic eruptions. Distributed throughout Zealandia, tephras provide useful markers for connecting and dating land surfaces, sediment layers, and archaeological sites.

year: 2008

title: Biogeochemical feedbacks to ocean acidification in a cohesive photosynthetic sediment

authors: Vopel, Kay

subjects: Science & Technology

abstract: Ecosystem feedbacks in response to ocean acidification can amplify or diminish diel pH oscillations in productive coastal waters. Benthic microalgae generate such oscillations in sediment porewater and here we ask how CO₂ enrichment (acidification) of the overlying seawater alters these in the absence and presence of biogenic calcite. We placed a 1-mm layer of ground oyster shells, mimicking the arrival of dead calcifying biota (+Calcite), or sand (Control) onto intact silt sediment cores, and then gradually increased the pCO₂ in the seawater above half of +Calcite and Control cores from 472 to 1216 μatm (pH 8.0 to 7.6, CO₂:HCO₃⁻ from 4.8 to 9.6 × 10⁻⁴). Porewater [O₂] and [H⁺] microprofiles measured 16 d later showed that this enrichment had decreased the O₂ penetration depth (O₂-pd) in +Calcite and Control, indicating a metabolic response. In CO₂-enriched seawater: (1) sediment biogeochemical processes respectively added and removed more H+ to and from the sediment porewater in darkness and light, than in ambient seawater increasing the amplitude of the diel porewater [H⁺] oscillations, and (2) in darkness, calcite dissolution in +Calcite sediment decreased the porewater [H⁺] below that in overlying seawater, reversing the sediment–seawater H⁺ flux and decreasing the amplitude of diel [H⁺] oscillations. This dissolution did not, however, counter the negative effect of CO₂ enrichment on O₂-pd. We now hypothesise that feedback to CO₂ enrichment—an increase in the microbial reoxidation of reduced solutes with O₂—decreased the sediment O₂-pd and contributed to the enhanced porewater acidification.

text: Biogeochemical feedbacks to ocean acidification in a cohesive photosynthetic sediment Ecosystem feedbacks in response to ocean acidification can amplify or diminish diel pH oscillations in productive coastal waters. Benthic microalgae generate such oscillations in sediment porewater and here we ask how CO₂ enrichment (acidification) of the overlying seawater alters these in the absence and presence of biogenic calcite. We placed a 1-mm layer of ground oyster shells, mimicking the arrival of dead calcifying biota (+Calcite), or sand (Control) onto intact silt sediment cores, and then gradually increased the pCO₂ in the seawater above half of +Calcite and Control cores from 472 to 1216 μatm (pH 8.0 to 7.6, CO₂:HCO₃⁻ from 4.8 to 9.6 × 10⁻⁴). Porewater [O₂] and [H⁺] microprofiles measured 16 d later showed that this enrichment had decreased the O₂ penetration depth (O₂-pd) in +Calcite and Control, indicating a metabolic response. In CO₂-enriched seawater: (1) sediment biogeochemical processes respectively added and removed more H+ to and from the sediment porewater in darkness and light, than in ambient seawater increasing the amplitude of the diel porewater [H⁺] oscillations, and (2) in darkness, calcite dissolution in +Calcite sediment decreased the porewater [H⁺] below that in overlying seawater, reversing the sediment–seawater H⁺ flux and decreasing the amplitude of diel [H⁺] oscillations. This dissolution did not, however, counter the negative effect of CO₂ enrichment on O₂-pd. We now hypothesise that feedback to CO₂ enrichment—an increase in the microbial reoxidation of reduced solutes with O₂—decreased the sediment O₂-pd and contributed to the enhanced porewater acidification.

year: 2021

title: Te Mata Ono-The six faces of Māori broadcasting

authors: Kaire-Melbourne, Kimiora

subjects: Māori broadcasting

abstract: Māori have always been involved in media communication and from a traditional viewpoint karanga, whaikōrero, taonga pūoro, haka, waiata and mōteatea are all mediums used to share messages across a mass audience. Since the arrival of European settlers, we have seen Māori content disseminated through platforms such as newspaper, radio, and more recently via the medium of television. This particular study is concerned with the way that Māori are represented and information is shared via indigenous broadcaster, Māori Television. Using a theoretical model made up of six key components, this thesis asserts that Te Mata Ono could not only help to improve the production of Māori content but also reshape and modify the medium of television itself, to become more culturally appropriate. Ultimately, this model could guide Māori Television, outlining a Māori specific approach to broadcasting. This study is one part of a two-part study. Due to the limitations of a four-paper masters thesis, I will only be examining three elements of Te Mata Ono, which are Mata Māori, Mata ō-tua and Mata Pākehā. Another thesis that was conducted simultaneously by Te Aorere Pewhairangi explores the remaining three elements of the same model, Mata Iwi, Mata Ako and Mata Tikanga. Te Mata Ono could be applied to Māori Television, making a positive contribution to the future development of Māori broadcasting.

text: Te Mata Ono-The six faces of Māori broadcasting Māori have always been involved in media communication and from a traditional viewpoint karanga, whaikōrero, taonga pūoro, haka, waiata and mōteatea are all mediums used to share messages across a mass audience. Since the arrival of European settlers, we have seen Māori content disseminated through platforms such as newspaper, radio, and more recently via the medium of television. This particular study is concerned with the way that Māori are represented and information is shared via indigenous broadcaster, Māori Television. Using a theoretical model made up of six key components, this thesis asserts that Te Mata Ono could not only help to improve the production of Māori content but also reshape and modify the medium of television itself, to become more culturally appropriate. Ultimately, this model could guide Māori Television, outlining a Māori specific approach to broadcasting. This study is one part of a two-part study. Due to the limitations of a four-paper masters thesis, I will only be examining three elements of Te Mata Ono, which are Mata Māori, Mata ō-tua and Mata Pākehā. Another thesis that was conducted simultaneously by Te Aorere Pewhairangi explores the remaining three elements of the same model, Mata Iwi, Mata Ako and Mata Tikanga. Te Mata Ono could be applied to Māori Television, making a positive contribution to the future development of Māori broadcasting.

year: 2019