title: Using paleoseismology and tephrochronology to reconstruct fault rupturing and hydrothermal activity since c. 40 ka in Taupo Rift, New Zealand

authors: Loame, Remedy C.

subjects: Science & Technology

abstract: The Taupo Volcanic Zone (TVZ) in North Island, New Zealand, is the on-land continuation of the Tonga-Kermadec arc formed in the Quaternary at the obliquely convergent boundary of the Pacific and Australian tectonic plates. The central TVZ is a region of intense silicic volcanism and active rifting with a very high heat flux. Within this zone is a dynamic landscape affected by a dense, active fault network, the Taupo Rift. In this rift, the Ngakuru graben hosts fossil hydrothermal systems in an area parallel to numerous active faults including the east strand of Whirinaki Fault that forms a major structure. Using various geoscientific techniques including mapping, stratigraphy, paleoseismic trenching, and tephrostratigraphy, in conjunction with LiDAR-derived DEMs, we reconstruct and date the fault's rupture history along with hydrothermal activity (including silica-sinter development) since c. 40,000 calendar years ago (40 cal. ka) at a site near Hossack Road called “Meade”. Ages for Kawakawa (c. 25.4 cal. ka), Okareka (c. 21.8 cal. ka), Rotorua (c.15.6 cal. ka), Rotoma (c. 9.4 cal. ka), and Taupo (c. 1.7 cal. ka) tephras enabled us to date five identified fault rupture events using the Meade trench excavation. Slip rates of 2.66 ± 0.77 mm/yr (pre-Kawakawa tephra), 0.28 ± 0.04 mm/yr (between c. 25.4 ka and Taupo) and 0.51 ± 0.19 mm/yr (post-Taupo), and the recurrence interval of ∼5500 cal. yr during the last c. 25.4 cal. kyr, all correlate with events of similar ages determined from studies on other trenches on Whirinaki Fault. Intercalated with Tahuna tephra (c. 39.3 cal. ka) and additionally dated at c. 38.9 cal. ka using radiocarbon, the hydrothermal sinter began developing at the Meade site at c. 39 cal. ka and ceased by c. 21.8 cal. ka (marked by Okareka tephra). We examine the causative relationship between fault activity and the development of sinter by comparing the chronology of volcanic eruptions and fault rupturing events with that of sinter formation as recorded in three neighbouring sites, Mangatete, Matthews, and Fitzpatrick. The findings improve understanding of the complex rupture behaviour of faulting and provide evidence for relationships between tectonic and hydrothermal activities, which were additionally influenced by the impacts of climatic change and geomorphic processes on landscape evolution, within the late Quaternary period. The study also exemplifies the unique value of tephrochronology in helping to disentangle complex geological deposits and events in an extremely dynamic part of the Earth's surface (the Taupo Rift).

text: Using paleoseismology and tephrochronology to reconstruct fault rupturing and hydrothermal activity since c. 40 ka in Taupo Rift, New Zealand The Taupo Volcanic Zone (TVZ) in North Island, New Zealand, is the on-land continuation of the Tonga-Kermadec arc formed in the Quaternary at the obliquely convergent boundary of the Pacific and Australian tectonic plates. The central TVZ is a region of intense silicic volcanism and active rifting with a very high heat flux. Within this zone is a dynamic landscape affected by a dense, active fault network, the Taupo Rift. In this rift, the Ngakuru graben hosts fossil hydrothermal systems in an area parallel to numerous active faults including the east strand of Whirinaki Fault that forms a major structure. Using various geoscientific techniques including mapping, stratigraphy, paleoseismic trenching, and tephrostratigraphy, in conjunction with LiDAR-derived DEMs, we reconstruct and date the fault's rupture history along with hydrothermal activity (including silica-sinter development) since c. 40,000 calendar years ago (40 cal. ka) at a site near Hossack Road called “Meade”. Ages for Kawakawa (c. 25.4 cal. ka), Okareka (c. 21.8 cal. ka), Rotorua (c.15.6 cal. ka), Rotoma (c. 9.4 cal. ka), and Taupo (c. 1.7 cal. ka) tephras enabled us to date five identified fault rupture events using the Meade trench excavation. Slip rates of 2.66 ± 0.77 mm/yr (pre-Kawakawa tephra), 0.28 ± 0.04 mm/yr (between c. 25.4 ka and Taupo) and 0.51 ± 0.19 mm/yr (post-Taupo), and the recurrence interval of ∼5500 cal. yr during the last c. 25.4 cal. kyr, all correlate with events of similar ages determined from studies on other trenches on Whirinaki Fault. Intercalated with Tahuna tephra (c. 39.3 cal. ka) and additionally dated at c. 38.9 cal. ka using radiocarbon, the hydrothermal sinter began developing at the Meade site at c. 39 cal. ka and ceased by c. 21.8 cal. ka (marked by Okareka tephra). We examine the causative relationship between fault activity and the development of sinter by comparing the chronology of volcanic eruptions and fault rupturing events with that of sinter formation as recorded in three neighbouring sites, Mangatete, Matthews, and Fitzpatrick. The findings improve understanding of the complex rupture behaviour of faulting and provide evidence for relationships between tectonic and hydrothermal activities, which were additionally influenced by the impacts of climatic change and geomorphic processes on landscape evolution, within the late Quaternary period. The study also exemplifies the unique value of tephrochronology in helping to disentangle complex geological deposits and events in an extremely dynamic part of the Earth's surface (the Taupo Rift).

year: 2019

title: Motives for luxury seafood consumption in first-tier cities in China

authors: Wang, Ou

subjects: Science & Technology

abstract: This study explored Chinese consumers’ choice motives, motive dimensions, segmentation, and species preferences on luxury seafood consumption. A web-based survey was administered to 967 luxury seafood eaters from three cities: Beijing, Shenzhen, and Shanghai. The data were analysed by descriptive analysis, principal component analysis (PCA), cluster analysis, and linear regression analysis. A two-dimensional construct was obtained for Chinese consumers’ choice motives for luxury seafood: food value and symbolic value. The most important specific motives attached to these two dimensions included umami, delicious, fresh, like to eat, show status, face consciousness, high quality life, and networking. Luxury seafood consumption by Chinese consumers was more significantly influenced by the symbolic value motivation dimension than the food value dimension. Two consumer segments were found: food value seeker (42.4%) and dual value seeker (57.6%). Lobster and salmon were the most common luxury seafood species consumed in China.

text: Motives for luxury seafood consumption in first-tier cities in China This study explored Chinese consumers’ choice motives, motive dimensions, segmentation, and species preferences on luxury seafood consumption. A web-based survey was administered to 967 luxury seafood eaters from three cities: Beijing, Shenzhen, and Shanghai. The data were analysed by descriptive analysis, principal component analysis (PCA), cluster analysis, and linear regression analysis. A two-dimensional construct was obtained for Chinese consumers’ choice motives for luxury seafood: food value and symbolic value. The most important specific motives attached to these two dimensions included umami, delicious, fresh, like to eat, show status, face consciousness, high quality life, and networking. Luxury seafood consumption by Chinese consumers was more significantly influenced by the symbolic value motivation dimension than the food value dimension. Two consumer segments were found: food value seeker (42.4%) and dual value seeker (57.6%). Lobster and salmon were the most common luxury seafood species consumed in China.

year: 2020

title: Te mātauranga whakatere waka

authors: Tuaupiki, Jackie Whetumarama

abstract: Hei tēnei tuhinga e whai ake nei, ka tirohia te hangarau waka a ngā tūpuna o Te Moana nui a Kiwa i whakawhiti ai rātou ki ō rātou moutere tae atu ki te mātauranga whakatere waka me te arotahi o te titiro ki te whakatinanatanga o aua mātauranga. Ka tāmutu i konā, ka pūhia te titiro i runga i ngā huarere o Poronīhia e kite ai tātou i ngā āhuatanga o Tāwhirimātea i ōna moutere me ngā wero ki te whakatere waka i ērā huarere.

text: Te mātauranga whakatere waka Hei tēnei tuhinga e whai ake nei, ka tirohia te hangarau waka a ngā tūpuna o Te Moana nui a Kiwa i whakawhiti ai rātou ki ō rātou moutere tae atu ki te mātauranga whakatere waka me te arotahi o te titiro ki te whakatinanatanga o aua mātauranga. Ka tāmutu i konā, ka pūhia te titiro i runga i ngā huarere o Poronīhia e kite ai tātou i ngā āhuatanga o Tāwhirimātea i ōna moutere me ngā wero ki te whakatere waka i ērā huarere.

year: 2017