title: Anomalous mid-twentieth century atmospheric circulation change over the South Atlantic compared to the last 6000 years

authors: Turney, Chris S.M.

subjects: southern annular mode (SAM)

abstract: Determining the timing and impact of anthropogenic climate change in data-sparse regions is a considerable challenge. Arguably, nowhere is this more difficult than the Antarctic Peninsula and the subantarctic South Atlantic where observational records are relatively short but where high rates of warming have been experienced since records began. Here we interrogate recently developed monthly-resolved observational datasets from the Falkland Islands and South Georgia, and extend the records back using climate-sensitive peat growth over the past 6000 years. Investigating the subantarctic climate data with ERA-Interim and Twentieth Century Reanalysis, we find that a stepped increase in precipitation across the 1940s is related to a change in synoptic atmospheric circulation: a westward migration of quasi-permanent positive pressure anomalies in the South Atlantic has brought the subantarctic islands under the increased influence of meridional airflow associated with the Amundsen Sea Low. Analysis of three comprehensively multi-dated (using 14C and 137Cs) peat sequences across the two islands demonstrates unprecedented growth rates since the mid-twentieth century relative to the last 6000 years. Comparison to observational and reconstructed sea surface temperatures suggests this change is linked to a warming tropical Pacific Ocean. Our results imply ‘modern’ South Atlantic atmospheric circulation has not been under this configuration for millennia.

text: Anomalous mid-twentieth century atmospheric circulation change over the South Atlantic compared to the last 6000 years Determining the timing and impact of anthropogenic climate change in data-sparse regions is a considerable challenge. Arguably, nowhere is this more difficult than the Antarctic Peninsula and the subantarctic South Atlantic where observational records are relatively short but where high rates of warming have been experienced since records began. Here we interrogate recently developed monthly-resolved observational datasets from the Falkland Islands and South Georgia, and extend the records back using climate-sensitive peat growth over the past 6000 years. Investigating the subantarctic climate data with ERA-Interim and Twentieth Century Reanalysis, we find that a stepped increase in precipitation across the 1940s is related to a change in synoptic atmospheric circulation: a westward migration of quasi-permanent positive pressure anomalies in the South Atlantic has brought the subantarctic islands under the increased influence of meridional airflow associated with the Amundsen Sea Low. Analysis of three comprehensively multi-dated (using 14C and 137Cs) peat sequences across the two islands demonstrates unprecedented growth rates since the mid-twentieth century relative to the last 6000 years. Comparison to observational and reconstructed sea surface temperatures suggests this change is linked to a warming tropical Pacific Ocean. Our results imply ‘modern’ South Atlantic atmospheric circulation has not been under this configuration for millennia.

year: 2016

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: Editorial

authors: Bray, Peter

abstract: The Volume 43(1) editorial of the "New Zealand Journal of Counselling" reflects on the past year, highlighting local and global concerns such as COVID-19's impact, civil unrest, conflicts, and climate change. Looking ahead, the editorial stresses acknowledging climate change's reality and ongoing conflicts while seeking optimism.

The editorial notes the privilege of witnessing innovative research by counseling students and colleagues that addresses global crises' effects. It underscores the importance of informed practitioners backed by robust research and theory.

The issue presents five research pieces showcasing diverse counseling methodologies. These include Māori approaches to trauma, Pākehā exploration through pepeha, clients' spirituality in adversity, mind-body interactions in counseling, and supervision amid events like pandemics.

One article discusses Māori trauma approaches, reconnecting wairua (spirit) and whakapapa (ancestral lineage) to address trauma. Another explores how Pākehā can confront colonization roles using pepeha.

Clients' spiritual experiences during challenging events are analyzed in another article, employing Māori and Celtic metaphors.

Mind-body interactions in counseling education and practice are investigated, emphasizing integrating body-oriented psychotherapies and nutrition.

Lastly, supervision during COVID-19 is studied, exploring its impact on relationships and suggesting growth opportunities.

The editorial concludes by noting the New Zealand Association of Counselling's website improvements, aiming to enhance journal access. It acknowledges Dr. Jan Wilson's passing, a significant contributor to New Zealand's counseling research, and encourages engagement with research and journal contributions.

text: Editorial The Volume 43(1) editorial of the "New Zealand Journal of Counselling" reflects on the past year, highlighting local and global concerns such as COVID-19's impact, civil unrest, conflicts, and climate change. Looking ahead, the editorial stresses acknowledging climate change's reality and ongoing conflicts while seeking optimism.

The editorial notes the privilege of witnessing innovative research by counseling students and colleagues that addresses global crises' effects. It underscores the importance of informed practitioners backed by robust research and theory.

The issue presents five research pieces showcasing diverse counseling methodologies. These include Māori approaches to trauma, Pākehā exploration through pepeha, clients' spirituality in adversity, mind-body interactions in counseling, and supervision amid events like pandemics.

One article discusses Māori trauma approaches, reconnecting wairua (spirit) and whakapapa (ancestral lineage) to address trauma. Another explores how Pākehā can confront colonization roles using pepeha.

Clients' spiritual experiences during challenging events are analyzed in another article, employing Māori and Celtic metaphors.

Mind-body interactions in counseling education and practice are investigated, emphasizing integrating body-oriented psychotherapies and nutrition.

Lastly, supervision during COVID-19 is studied, exploring its impact on relationships and suggesting growth opportunities.

The editorial concludes by noting the New Zealand Association of Counselling's website improvements, aiming to enhance journal access. It acknowledges Dr. Jan Wilson's passing, a significant contributor to New Zealand's counseling research, and encourages engagement with research and journal contributions.

year: 2023