title: History of oceanic front development in the New Zealand sector of the Southern Ocean during the Cenozoic--a synthesis

authors: Nelson, Campbell S.

subjects: New Zealand

abstract: The New Zealand sector of the Southern Ocean (NZSSO) has opened about the Indian-Pacific spreading ridge throughout the Cenozoic. Today the NZSSO is characterised by broad zonal belts of antarctic (cold), subantarctic (cool), and subtropical (warm) surface-water masses separated by prominent oceanic fronts: the Subtropical Front (STF) c. 43deg.S, Subantarctic Front (SAF) c. 50deg.S, and Antarctic Polar Front (AAPF) c. 60deg.S. Despite a meagre database, the broad pattern of Cenozoic evolution of these fronts is reviewed from the results of Deep Sea Drilling Project-based studies of sediment facies, microfossil assemblages and diversity, and stable isotope records, as well as from evidence in onland New Zealand Cenozoic sequences. Results are depicted schematically on seven paleogeographic maps covering the NZSSO at 10 m.y. intervals through the Cenozoic. 
During the Paleocene and most of the Eocene (65-35 Ma), the entire NZSSO was under the influence of warm to cool subtropical waters, with no detectable oceanic fronts. In the latest Eocene (c. 35 Ma), a proto-STF is shown separating subantarctic and subtropical waters offshore from Antarctica, near 65deg.S paleolatitude. During the earliest Oligocene, this front was displaced northwards by development of an AAPF following major global cooling and biotic turnover associated with ice sheet expansion to sea level on East Antarctica. Early Oligocene full opening (c. 31 Ma) of the Tasmanian gateway initiated vigorous proto-circum-Antarctic flow of cold/cool waters, possibly through a West Antarctic seaway linking the southern Pacific and Atlantic Oceans, including detached northwards "jetting" onto the New Zealand plateau where condensation and unconformity development was widespread in cool-water carbonate facies. Since this time, a broad tripartite division of antarctic, subantarctic, and subtropical waters has existed in the NZSSO, including possible development of a proto-SAF within the subantarctic belt. In the Early-early Middle Miocene (25-15 Ma), warm subtropical waters expanded southwards into the northern NZSSO, possibly associated with reduced ice volume on East Antarctica but particularly with restriction of the Indonesian gateway and redirection of intensified warm surface flows southwards into the Tasman Sea, as well as complete opening of the Drake gateway by 23 Ma allowing more complete decoupling of cool circum-Antarctic flow from the subtropical waters. During the late Middle-Late Miocene (15-5 Ma), both the STF and SAF proper were established in their present relative positions across and about the Campbell Plateau, respectively, accompanying renewed ice buildup on East Antarctica and formation of a permanent ice sheet on West Antarctica, as well as generally more expansive and intensified circum-Antarctic flow. 
The ultimate control on the history of oceanic front development in the NZSSO has been plate tectonics through its influence on the paleogeographic changes of the Australian-New Zealand-Antarctic continents and their intervening oceanic basins, the timing of opening and closing of critical seaways, the potential for submarine ridges and plateaus to exert some bathymetric control on the location of fronts, and the evolving ice budget on the Antarctic continent. The broad trends of the Cenozoic climate curve for New Zealand deduced from fossil evidence in the uplifted marine sedimentary record correspond well to the principal paleoceanographic events controlling the evolution and migration of the oceanic fronts in the NZSSO.

text: History of oceanic front development in the New Zealand sector of the Southern Ocean during the Cenozoic--a synthesis The New Zealand sector of the Southern Ocean (NZSSO) has opened about the Indian-Pacific spreading ridge throughout the Cenozoic. Today the NZSSO is characterised by broad zonal belts of antarctic (cold), subantarctic (cool), and subtropical (warm) surface-water masses separated by prominent oceanic fronts: the Subtropical Front (STF) c. 43deg.S, Subantarctic Front (SAF) c. 50deg.S, and Antarctic Polar Front (AAPF) c. 60deg.S. Despite a meagre database, the broad pattern of Cenozoic evolution of these fronts is reviewed from the results of Deep Sea Drilling Project-based studies of sediment facies, microfossil assemblages and diversity, and stable isotope records, as well as from evidence in onland New Zealand Cenozoic sequences. Results are depicted schematically on seven paleogeographic maps covering the NZSSO at 10 m.y. intervals through the Cenozoic. 
During the Paleocene and most of the Eocene (65-35 Ma), the entire NZSSO was under the influence of warm to cool subtropical waters, with no detectable oceanic fronts. In the latest Eocene (c. 35 Ma), a proto-STF is shown separating subantarctic and subtropical waters offshore from Antarctica, near 65deg.S paleolatitude. During the earliest Oligocene, this front was displaced northwards by development of an AAPF following major global cooling and biotic turnover associated with ice sheet expansion to sea level on East Antarctica. Early Oligocene full opening (c. 31 Ma) of the Tasmanian gateway initiated vigorous proto-circum-Antarctic flow of cold/cool waters, possibly through a West Antarctic seaway linking the southern Pacific and Atlantic Oceans, including detached northwards "jetting" onto the New Zealand plateau where condensation and unconformity development was widespread in cool-water carbonate facies. Since this time, a broad tripartite division of antarctic, subantarctic, and subtropical waters has existed in the NZSSO, including possible development of a proto-SAF within the subantarctic belt. In the Early-early Middle Miocene (25-15 Ma), warm subtropical waters expanded southwards into the northern NZSSO, possibly associated with reduced ice volume on East Antarctica but particularly with restriction of the Indonesian gateway and redirection of intensified warm surface flows southwards into the Tasman Sea, as well as complete opening of the Drake gateway by 23 Ma allowing more complete decoupling of cool circum-Antarctic flow from the subtropical waters. During the late Middle-Late Miocene (15-5 Ma), both the STF and SAF proper were established in their present relative positions across and about the Campbell Plateau, respectively, accompanying renewed ice buildup on East Antarctica and formation of a permanent ice sheet on West Antarctica, as well as generally more expansive and intensified circum-Antarctic flow. 
The ultimate control on the history of oceanic front development in the NZSSO has been plate tectonics through its influence on the paleogeographic changes of the Australian-New Zealand-Antarctic continents and their intervening oceanic basins, the timing of opening and closing of critical seaways, the potential for submarine ridges and plateaus to exert some bathymetric control on the location of fronts, and the evolving ice budget on the Antarctic continent. The broad trends of the Cenozoic climate curve for New Zealand deduced from fossil evidence in the uplifted marine sedimentary record correspond well to the principal paleoceanographic events controlling the evolution and migration of the oceanic fronts in the NZSSO.

year: 2001-12-01

title: Moving beyond panaceas in fisheries governance

authors: Young, Oran R.

subjects: Science & Technology

abstract: In fisheries management—as in environmental governance more generally—regulatory arrangements thatare thought to be helpful in some contexts frequently become panaceas or, in other words, simpleformulaic policy prescriptions believed to solve a given problem in a wide range of contexts, regardlessof their actual consequences. When this happens, management is likely to fail, and negative side effectsare common. We focus on the case of individual transferable quotas to explore the panacea mindset, a setof factors that promote the spread and persistence of panaceas. These include conceptual narratives thatmake easy answers like panaceas seem plausible, power disconnects that create vested interests in pan-aceas, and heuristics and biases that prevent people from accurately assessing panaceas. Analysts havesuggested many approaches to avoiding panaceas, but most fail to conquer the underlying panaceamindset. Here, we suggest the codevelopment of an institutional diagnostics toolkit to distill the vastamount of information on fisheries governance into an easily accessible, open, on-line database of check-lists, case studies, and related resources. Toolkits like this could be used in many governance settings tochallenge users’understandings of a policy’s impacts and help them develop solutions better tailored totheir particular context. They would not replace the more comprehensive approaches found in the liter-ature but would rather be an intermediate step away from the problem of panaceas.

text: Moving beyond panaceas in fisheries governance In fisheries management—as in environmental governance more generally—regulatory arrangements thatare thought to be helpful in some contexts frequently become panaceas or, in other words, simpleformulaic policy prescriptions believed to solve a given problem in a wide range of contexts, regardlessof their actual consequences. When this happens, management is likely to fail, and negative side effectsare common. We focus on the case of individual transferable quotas to explore the panacea mindset, a setof factors that promote the spread and persistence of panaceas. These include conceptual narratives thatmake easy answers like panaceas seem plausible, power disconnects that create vested interests in pan-aceas, and heuristics and biases that prevent people from accurately assessing panaceas. Analysts havesuggested many approaches to avoiding panaceas, but most fail to conquer the underlying panaceamindset. Here, we suggest the codevelopment of an institutional diagnostics toolkit to distill the vastamount of information on fisheries governance into an easily accessible, open, on-line database of check-lists, case studies, and related resources. Toolkits like this could be used in many governance settings tochallenge users’understandings of a policy’s impacts and help them develop solutions better tailored totheir particular context. They would not replace the more comprehensive approaches found in the liter-ature but would rather be an intermediate step away from the problem of panaceas.

year: 2018-09-11

title: The arguing genre and the explaining genre: A comparison in terms of discourse relational analyses of texts written in English and texts written in Maori

authors: Crombie, Winifred

subjects: linguistics

abstract: There is a commonly held belief that those who are immersed in indigenous cultures have a tendency, when constructing academic texts, to avoid sequential, deductive argumentation. We report here on a comparison of two groups of texts exhibiting two different genres – explaining and arguing. One group of texts was written in Māori by indigenous authors, the other group was written in English by non-indigenous authors. Our findings are that although the percentage use of logico-deductive relationships is roughly equivalent for both groups of texts/ writers in the case of the explaining genre, the Māori texts/ writers use almost twice the percentage of logicodeductive relationships as do the English texts/ writers.

text: The arguing genre and the explaining genre: A comparison in terms of discourse relational analyses of texts written in English and texts written in Maori There is a commonly held belief that those who are immersed in indigenous cultures have a tendency, when constructing academic texts, to avoid sequential, deductive argumentation. We report here on a comparison of two groups of texts exhibiting two different genres – explaining and arguing. One group of texts was written in Māori by indigenous authors, the other group was written in English by non-indigenous authors. Our findings are that although the percentage use of logico-deductive relationships is roughly equivalent for both groups of texts/ writers in the case of the explaining genre, the Māori texts/ writers use almost twice the percentage of logicodeductive relationships as do the English texts/ writers.

year: 2005