Browsing by Author "Petherick, LM"

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    Climate variability over the last 35,000 years recorded in marine and terrestrial archives in the Australian region: an OZ-INTIMATE compilation
    (Elsevier Science Ltd., 2013-08-15) Reeves, JM; Barrows, TT; Cohen, TJ; Kiem, AS; Bostock, HC; Fitzsimmons, KE; Jansen, JD; Kemp, J; Krause, C; Phipps, SJ; Petherick, LM
    The Australian region spans some 600 of latitude and 500 of longitude and displays considerable regional climate variability both today and during the Late Quaternary. A synthesis of marine and terrestrial climate records, combining findings from the Southern Ocean, temperate, tropical and arid zones, identifies a complex response of climate proxies to a background of changing boundary conditions over the last 35,000 years. Climate drivers include the seasonal timing of insolation, greenhouse gas content of the atmosphere, sea level rise and ocean and atmospheric circulation changes. Our compilation finds few climatic events that could be used to construct a climate event stratigraphy for the entire region, limiting the usefulness of this approach. Instead we have taken a spatial approach, looking to discern the patterns of change across the continent. The data identify the clearest and most synchronous climatic response at the time of the Last Glacial Maximum (LGM) (21 +/- 3 ka), with unambiguous cooling recorded in the ocean, and evidence of glaciation in the highlands of tropical New Guinea, southeast Australia and Tasmania. Many terrestrial records suggest drier conditions, but with the timing of inferred snowmelt, and changes to the rainfall/runoff relationships, driving higher river discharge at the LGM. In contrast, the deglaciation is a time of considerable south-east to north-west variation across the region. Warming was underway in all regions by 17 ka. Post-glacial sea level rise and its associated regional impacts have played an important role in determining the magnitude and timing of climate response in the north-west of the continent in contrast to the southern latitudes. No evidence for cooling during the Younger Dryas chronozone is evident in the region, but the Antarctic cold reversal clearly occurs south of Australia. The Holocene period is a time of considerable climate variability associated with an intense monsoon in the tropics early in the Holocene, giving way to a weakened monsoon and an increasingly El Nino-dominated ENSO to the present. The influence of ENSO is evident throughout the southeast of Australia, but not the southwest. This climate history provides a template from which to assess the regionality of climate events across Australia and make comparisons beyond our region.© 2013, Elsevier Ltd.
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    Environmental context for late holocene human occupation of the South Wellesley Archipelago, Gulf of Carpentaria, northern Australia
    (Elsevier, 2015-10-22) Moss, PT; Mackenzie, LL; Ulm, S; Sloss, CR; Rosendahl, D; Petherick, LM; Steinberger, L; Wallis, LA; Heijnis, H; Petchey, F; Jacobsen, GE
    A 2400 year record of environmental change is reported from a wetland on Bentinck Island in the southern Gulf of Carpentaria, northern Australia. Three phases of wetland development are identified, with a protected coastal setting from ca. 2400 to 500 years ago, transitioning into an estuarine mangrove forest from ca. 500 years ago to the 1940s, and finally to a freshwater swamp over the past +60 years. This sequence reflects the influence of falling sea-levels, development of a coastal dune barrier system, prograding shorelines, and an extreme storm (cyclone) event. In addition, there is clear evidence of the impacts that human abandonment and resettlement have on the island's fire regimes and vegetation. A dramatic increase in burning and vegetation thickening was observed after the cessation of traditional Indigenous Kaiadilt fire management practices in the 1940s, and was then reversed when people returned to the island in the 1980s. In terms of the longer context for human occupation of the South Wellesley Archipelago, it is apparent that the mangrove phase provided a stable and productive environment that was conducive for human settlement of this region over the past 1000 years. © 2015 Published by Elsevier Ltd.
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    Holocene sea-level change and coastal landscape evolution in the southern Gulf of Carpentaria, Australia
    (SAGE, 2018-09-01) Sloss, CR; Nothdurft, L; Hua, Q; O'Connor, SG; Moss, PT; Rosendahl, D; Petherick, LM; Nanson, RA; Mackenzie, LL; Sternes, A; Jacobsen, GE; Ulm, S
    A revised Holocene sea-level history for the southern Gulf of Carpentaria is presented based on new data from the South Wellesley Archipelago and age recalibration of previous research. Results confirm that rising sea levels during the most recent post-glacial marine transgression breached the Arafura Sill ca. 11,700 cal. yr BP. Sea levels continued to rise to ca. –30 m by 10,000 cal. yr BP, leading to full marine conditions. By 7700 cal. yr BP, sea-level reached present mean sea-level (PMSL) and continued to rise to an elevation of between 1.5 m and 2 m above PMSL. Sea level remained ca. + 1.5 between 7000 and 4000 cal. yr BP, followed by rapid regression to within ± 0.5 m of PMSL by ca. 3500 cal. yr BP. When placed into a wider regional context results from this study show that coastal landscape evolution in the tropical north of Australia was not only dependent on sea-level change but also show a direct correlation with Holocene climate variability. Specifically, the formation and preservation of beach-rock deposits, intertidal successions, beach and chenier ridge systems hold valuable sea-level and Holocene climate proxies that can contribute to the growing research into lower latitude Holocene sea-level and climate histories. © The Author(s) 2018
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    Holocene sea-level change and coastal landscape evolution in the southern Gulf of Carpentaria, Australia
    (International Union for Quaternary Research (INQUA), 2019-07-30) Sloss, CR; Northdurft, L; Hua, Q; O'Connor, SG; Moss, PT; Rosendahl, D; Petherick, LM; Nanson, RA; Mackenzie, LL; Sternes, A; Jacobsen, GE; Ulm, S
    A Holocene sea-level history for the southern Gulf of Carpentaria has been constructed based on a review of previously published data, combined with data collected for this study from a variety of sea-level proxies. These sea-level proxies include beach ridges, claypans, mangrove swamps, fossilized in situcoral reefs, beachrock and aeolinite deposits. Results confirm that rising sea-levels during the last Post-Glacial Marine transgression beached the Arafura Sill ca. 11,700 years ago (-53 m), resulting in a change from lacustrine to a marine environment. Sea levels continued to rise to ca. -30 m by 10,000 years ago. By 7,700 cal. yr BP sea-level reached PMSL and continued to rise an elevation of between 1.5 and 2 m above present mean sea-level by 7,000 years ago. Elevated sea levels resulted in the development of raised coral reefs, beach-rock and aeolinite deposits, and the initiation of chenier plains and beach ridges. Sea-level remained ca. +1.5 m above PMSL during the Holocene highstand, accompanied by distinct phases of beach-ridge and chenier plain development. The highstand was followed by arapid regression to within ±0.5 m of PMSL by ca. 3,500 cal. yr BP. When placed into a wider regional context results from this study show thatcoastal landscape evolution in the tropical north of Australia was not only dependenton sea-level change but also show a direct correlation with Holocene climatevariability. Specifically, the formation and preservation of beach-rock deposits,intertidal successions, beach and chenier ridge systems hold valuable sea-level and Holoceneclimate proxies that can contribute to the growing research into lowerlatitude Holocene sea-level and climate histories. ©2019 The Authors.