It has been known since Rhodes Fairbridge's first attempt to establish a global pattern of Holocene sea-level change by combining evidence from Western Australia and from sites in the northern hemisphere that the details of sea-level history since the Last Glacial Maximum vary considerably across the globe. The Australian region is relatively stable tectonically and is situated in the 'far-field' of former ice sheets. It therefore preserves important records of post-glacial sea levels that are less complicated by neotectonics or glacio-isostatic adjustments. Accordingly, the relative sea-level record of this region is dominantly one of glacio-eustatic (ice equivalent) sea-level changes. The broader Australasian region has provided critical information on the nature of post-glacial sea level, including the termination of the Last Glacial Maximum when sea level was approximately 125 m lower than present around 21,000-19,000 years BP, and insights into meltwater pulse 1A between 14,600 and 14,300 cal. yr BP. Although most parts of the Australian continent reveals a high degree of tectonic stability, research conducted since the 1970s has shown that the timing and elevation of a Holocene highstand varies systematically around its margin. This is attributed primarily to variations in the timing of the response of the ocean basins and shallow continental shelves to the increased ocean volumes following ice-melt, including a process known as ocean siphoning (i.e. glacio-hydro-isostatic adjustment processes). Several seminal studies in the early 1980s produced important data sets from the Australasian region that have provided a solid foundation for more recent palaeo-sea-level research. This review revisits these key studies emphasising their continuing influence on Quaternary research and incorporates relatively recent investigations to interpret the nature of post-glacial sea-level change around Australia. These include a synthesis of research from the Northern Territory, Queensland, New South Wales, South Australia and Western Australia. A focus of these more recent studies has been the re-examination of: (1) the accuracy and reliability of different proxy sea-level indicators; (2) the rate and nature of post-glacial sea-level rise; (3) the evidence for timing, elevation, and duration of mid-Holocene highstands; and, (4) the notion of mid-to late Holocene sea-level oscillations, and their basis. Based on this synthesis of previous research, it is clear that estimates of past sea-surface elevation are a function of eustatic factors as well as morphodynamics of individual sites, the wide variety of proxy sea-level indicators used, their wide geographical range, and their indicative meaning. Some progress has been made in understanding the variability of the accuracy of proxy indicators in relation to their contemporary sea level, the inter-comparison of the variety of dating techniques used and the nuances of calibration of radiocarbon ages to sidereal years. These issues need to be thoroughly understood befor...

A revised Holocene sea-level curve for the southeast coast of New South Wales, Australia, is presented based on a review of previously published geochronological results for fossil molluscs, organic-rich mud, mangrove roots and fixed biological indicators. It is supplemented by new radiocarbon and amino acid racemization-derived ages on fossil molluscs from transgressive sandsheet facies in back-barrier settings within shallow incised valleys along the southern coast of New South Wales. This data base has been limited to fossils with accurate descriptions of their facies associations and stratigraphic relationships to present mean sea level. Results show that sea level during the Holocene marine transgression rose to between −15 and −11 m at 9400—9000 cal. yr BP. Sea level then rose to approximately −5 m by 8500 cal. yr BP and to approximately −3.5 m between 8300 and 8000 cal. yr BP inundating shallow incised valleys resulting in the deposition of shell-rich transgressive sandsheets within shallow incised bedrock valleys. Present sea level was attained between 7900 and 7700 cal. yr BP, approximately 700—900 years earlier than previously proposed. Sea level continued to rise to between +1 and +1.5 m between 7700 and 7400 cal. yr BP, followed by a sea-level highstand that lasted until about 2000 cal. yr BP followed by a gradual fall to present. A series of minor negative and positive oscillations in relative sea level during the late-Holocene sea-level highstand appear to be superimposed over the general sea-level trend. However, the precise nature of the oscillations are difficult to quantify because of problems associated with accurately determining palaeotidal and wave regimes, climatic conditions and the antecedent morphology of the shallow marine environments during the mid Holocene.

The South Asian Monson (SAM) is one of the most intense climatic elements yet its initiation and variations are not well established. Dating the deposits of SAM wind-driven currents in IODP cores from the Maldives yields an age of 12. 9 Ma indicating an abrupt SAM onset, over a short period of 300 kyrs. This coincided with the Indian Ocean Oxygen Minimum Zone expansion as revealed by geochemical tracers and the onset of upwelling reflected by the sediment’s content of particulate organic matter. A weaker ‘proto-monsoon’ existed between 12.9 and 25 Ma, as mirrored by the sedimentary signature of dust influx. Abrupt SAM initiation favors a strong influence of climate in addition to the tectonic control, and we propose that the post Miocene Climate Optimum cooling, together with increased continentalization and establishment of the bipolar ocean circulation, i.e. the beginning of the modern world, shifted the monsoon over a threshold towards the modern system.

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Sediments cored along the southwestern Iberian margin during Integrated Ocean Drilling Program Expedition 339 provide constraints on Mediterranean Outflow Water (MOW) circulation patterns from the Pliocene epoch to the present day. After the Strait of Gibraltar opened (5.33 million years ago), a limited volume of MOW entered the Atlantic. Depositional hiatuses indicate erosion by bottom currents related to higher volumes of MOW circulating into the North Atlantic, beginning in the late Pliocene. The hiatuses coincide with regional tectonic events and changes in global thermohaline circulation (THC). This suggests that MOW influenced Atlantic Meridional Overturning Circulation (AMOC), THC, and climatic shifts by contributing a component of warm, saline water to northern latitudes while in turn being influenced by plate tectonics.

Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Zealand archipelago: the northern North Island (including Northland, Auckland, and the Coromandel 13 Peninsula); the southwest coast of the North Island; the Canterbury coast (South Island); and the 14 Otago coast (South Island). In the North Island the RSL highstand commenced c. 8,100-7,2400 cal yr 15 BP when present mean sea-level (PMSL) was first attained. This is c. 600-1,400 years earlier than has 16 been previously indicated for the New Zealand region as a whole, and is consistent with recent 17Holocene RSL reconstructions from Australia. In North Island locations the early-Holocene sea-level 18 highstand was quite pronounced, with RSL up to 2.75 m higher than present. In the South Island the 19 onset of highstand conditions was later, with the first attainment of PMSL being between 7,000-20 6,400 cal yr BP. In the mid-Holocene the northern North Island experienced the largest sea-level 21 highstand, with RSL up to 3.00 m higher than present. This is demonstrably higher than the 22 highstand recorded for the southwest North Island and Otago regions. A number of different drivers 23 region, while research from Australia has suggested that north-south variations in Holocene RSL 32 changes due to hydro-isostatic influences are limited or non-existent. At the regional-to local-scale, 33 post-glacial meltwater loading on the continental shelf around New Zealand is predicted by GIA 34 modelling to have a significant effect on the timing and magnitude of RSL changes through the 35 phenomenon of continental levering. The spatial variation in continental levering is controlled by the 36 configuration of the coast and the width of the adjacent continental shelf, with continental levering 37 providing a robust explanation for the observed spatial and temporal variations in RSL changes. 38Further research is required to characterise the regional and local effects of different tectonic 39 regimes, wave climates, and sediment regimes. These are potentially very significant drivers of RSL 40 variability at the regional-to local-scale. However, the magnitude of their potential effects remains 41 equivocal. 42Highlights 43  RSL histories were reconstructed for four regions in the New Zealand archipelago 44  Northern sites experience RSL rise earlier compared to southern sites 45  Northern sites experience a higher-magnitude highstand compared to southern sites 46  Long-wavelength signals from Antarctica cannot explain the observed variation in RSL 47  A range of processes potentiall...

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Based on high-resolution reflection seismic and core data from IODP Expedition 359 we present a new channel-related drift type attached to a carbonate platform slope, which we termed delta drift. Like a river delta, it is comprised of several stacked lobes and connected to 3 3 a point source. The delta drifts were deposited at the exit of two gateways that connect the Inner Sea of the Maldives carbonate platform with the open ocean. The channels served as conduits focusing and accelerating the water flow; Entrained material was deposited at their mouth where the flows relaxed. The lobe-shaped calcareous sediment drifts must have formed under persistent water through flow. Sediment supply was relatively high and continuous, resulting in an average sedimentation rate of 17 cm ka-1. The two delta drifts occupy 342 and 384 km 2 , respectively; with a depositional relief of approximately 500 m. They have a sigmoidal clinoform reflection pattern with a particular convex upward bending of the foresets. In the Maldives the drift onset marks the transition from a sea-level controlled to a progressively current dominated depositional regime. This major event occurred in the Serravallian about 13 Ma ago, leading to the partial drowning of the carbonate platform and the creation of shallow seaways. The initial bank-enclosed topography resembles an "empty bucket" geometry which is rapidly filled by the drift sediments that aggrade and prograde into the basin. Thereby the depositional environment of the delta drifts changes from deep water (>500) to shallow-water conditions at their topsets, indicated by the overall coarsening upward trend in grain size and the presence of shallow water large benthic foraminifers at their top.