sedimentology

Spatial variability of wave signatures and profile morphotypes of beaches in estuaries and bays across different tidal regimes

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Map showing the Ría de Vigo and Pittwater estuaries with the locations of eight studied beaches and wave measurement sites.

This study compares sandy beaches within estuaries and bays in a microtidal system (Pittwater, Sydney) and a mesotidal system (Ría de Vigo, Spain) to understand how waves, tides and sediment shape beach profiles. Swell waves dominate wave energy in both settings, but their relative contribution decreases further from the estuary entrance, where wind and infragravity … Read more…

Impact of Cenozoic sea-level fluctuations on passive margin stratigraphic architecture: Implications for underground hydrogen storage potential

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Global map showing passive margins with thick sedimentary successions and greenhouse–icehouse regime shifts relevant to hydrogen storage potential.

This study used forward stratigraphic modelling of the Hunter offshore margin in New South Wales to examine how Cenozoic sea-level changes shaped the layering of sediments on passive continental margins. The results show that warm 'greenhouse' periods produced thick, continuous sediment layers good for storing gases, while colder 'icehouse' periods produced thinner, stacked layers that … Read more…

Indian Ocean carbonate compensation depth since the Late Oligocene

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The carbonate compensation depth (CCD), defined as the depth in the ocean where the supply rate of pelagic carbonate is balanced by its dissolution, provides an important parameter for estimating the amount of calcium carbonate-bound carbon that is stored in deep-sea sediments. The CCD is reasonably well-constrained across the Atlantic and Pacific oceans; however, our … Read more…

Mars attracts: how Earth’s planetary interactions drive deep-sea circulation

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12 March 2024, The University of Sydney Media Release Giant whirlpools in warming oceans could mitigate Gulf Stream stagnation Geoscientists at Sydney and Sorbonne have identified a 2.4-million-year cycle in the geological record that show the energy of deep-sea currents wax and wane as oceans cool and warm. Earth’s distance to Mars varies between 55 … Read more…

When the Earth warms, the ocean speeds up

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Sixty-six million years of geological data suggests that heating makes ocean currents stronger. By Ellen McPhiddian, Cosmos Ocean currents play a big role in floods, droughts, and other large-scale weather patterns. We know that ocean circulation will be affected by global warming – but figuring out exactly how it will be affected is much more difficult. Will there be … Read more…

Nature Commmunications: Impact of green clay authigenesis on element sequestration in marine settings

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Retrograde clay mineral reactions (reverse weathering), including glauconite formation, are first-order controls on element sequestration in marine sediments. Here, we report substantial element sequestration by glauconite formation in shallow marine settings from the Triassic to the Holocene, averaging 3 ± 2 mmol·cm−²·kyr−1 for K, Mg and Al, 16 ± 9 mmol·cm−²·kyr−1 for Si and 6 ± 3 mmol·cm−²·kyr−1 for Fe, which is ~2 orders of magnitude higher … Read more…

Geology: Deep-sea hiatuses track the vigor of Cenozoic ocean bottom currents

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The deep-sea stratigraphic record is full of gaps. These hiatuses track changes in ocean circulation and chemistry, but determining their timing and causes has been limited by sparse data and incomplete knowledge of ocean gateway evolution in earlier studies. We combine a significantly expanded, age-calibrated deep-sea stratigraphic database with a global tectonic and paleo–water depth … Read more…

PhD scholarship in Deep-Sea Sediments and Paleoclimate

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This PhD project with Dr. Adriana Dutkiewicz in the Univ. of Sydney EarthByte Group is aimed at reconstructing the evolution of the deep-sea carbon reservoir and its impact on the long-term global carbon cycle as part of an ARC-funded Future Fellowship. It includes a stipend allowance of $28,854 per annum for three years (with an … Read more…