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On September 19, 2021, the Cumbre Vieja volcano on La Palma, in Spain's Canary Islands, erupted after more than half a century of quiescence. Lasting 85 days, the Tajogaite eruption was the longest recorded in the island’s history. Around 12 square kilometres of populated land was inundated with lava, nearly 3,000...

Hot plumes rising from the Earth’s deep mantle are believed to form broad plume heads beneath lithospheric plates, causing uplift, rifting, and volcanism. However, the mechanisms governing plume-lithosphere interactions remain poorly understood. Using seismic waveform tomography, we image interconnected corridors of hot, partially molten rock beneath the East Africa-Arabia region. These corridors, underlying zones of uplift, rifting, and dispersed volcanism, form an active plume head shaped like a three-pointed star. Eruption ages, seismic anisotropy, and plate reconstructions suggest this plume head evolved from south to north, fed by three deep mantle upwellings beneath Kenya, Afar, and the Levant. The resulting large-scale mantle flow, combined with subduction-driven forces, drives the lateral motion of the Anatolian microplate and the dynamic evolution of the Zagros orogen. Our findings demonstrate how plate tectonics and mantle dynamics together govern regional kinematics and surface deformation. Star-shaped plume heads in thin-lithosphere corridors are essential features of plume-continent interactions, shedding light on the dispersed volcanism observed in large igneous provinces, both past and present.

• Speaker: Chiara Civiero, University of Trieste
• Wednesday 05 February 2025, 14:00-15:00
• Venue: Wolfson Lecture Theatre.
• Series: Bullard Laboratories Wednesday Seminars; organiser: Tom Merry.

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Around the beginning of the Late Holocene (4,200 years BP) across the western Mediterranean regions, Bronze Age societies developed unique socio-economic and political complexity reflected in the construction of monumental stone architecture. New geoarchaeological and chronostratigraphic research in Sardinia, Italy, exposes for the first time the environmental underpinnings of the expansion and decline of the Nuragic Bronze Age monument-building society. These findings also highlight the role of prehistoric societies in shaping the landscape of the Mediterranean region over the Holocene. Multi-proxy geoarchaeological analyses—including soil micromorphology, XRD mineralogy, magnetic susceptibility, and geochemistry—reveal that the Bronze Age climax soil type of basaltic mesas in Sardinia was a dark Vertisol rich in primary nutrients and montmorillonite clay. These fertile soils sustained grassland ecosystems and played a key role in the distribution of early Middle Bronze Age Nuragic monuments across Sardinia’s basaltic landscapes. However, prolonged and intensified land use, particularly animal herding and agriculture, to support monument construction led to soil erosion and, ultimately, the replacement of deep, nutrient-rich Vertisol cover with a thin, oxidised and vertic Cambisol one. These processes resulted in a significant increase in sediment supply in the catchment east of the mesa, causing a new major phase of alluviation in the valley bottoms during the Late Holocene. These landscape changes triggered a socio-environmental crisis marked by the abandonment of the mesa at the end of the Middle Bronze Age, hence excluding the influence of a climate change in causing the local societal collapse.

• Speaker: Gian Battista Marras (British School at Rome)
• Wednesday 19 March 2025, 17:30-19:00
• Venue: Latimer Room, Clare College.
• Series: Quaternary Discussion Group (QDG); organiser: sr632.

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Around the beginning of the Late Holocene (4,200 years BP) across the western Mediterranean regions, Bronze Age societies developed unique socio-economic and political complexity reflected in the construction of monumental stone architecture. New geoarchaeological and chronostratigraphic research in Sardinia, Italy, exposes for the first time the environmental underpinnings of the expansion and decline of the Nuragic Bronze Age monument-building society. These findings also highlight the role of prehistoric societies in shaping the landscape of the Mediterranean region over the Holocene. Multi-proxy geoarchaeological analyses—including soil micromorphology, XRD mineralogy, magnetic susceptibility, and geochemistry—reveal that the Bronze Age climax soil type of basaltic mesas in Sardinia was a dark Vertisol rich in primary nutrients and montmorillonite clay. These fertile soils sustained grassland ecosystems and played a key role in the distribution of early Middle Bronze Age Nuragic monuments across Sardinia’s basaltic landscapes. However, prolonged and intensified land use, particularly animal herding and agriculture, to support monument construction led to soil erosion and, ultimately, the replacement of deep, nutrient-rich Vertisol cover with a thin, oxidised and vertic Cambisol one. These processes resulted in a significant increase in sediment supply in the catchment east of the mesa, causing a new major phase of alluviation in the valley bottoms during the Late Holocene. These landscape changes triggered a socio-environmental crisis marked by the abandonment of the mesa at the end of the Middle Bronze Age, hence excluding the influence of a climate change in causing the local societal collapse.

• Speaker: Gian Battista Marras (British School at Rome)
• Wednesday 19 March 2025, 17:30-19:00
• Venue: Latimer Room, Clare College.
• Series: Quaternary Discussion Group (QDG); organiser: sr632.

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tbc – landscape evolution and climate

• Speaker: Dr Matthew Fox - UCL
• Monday 03 February 2025, 18:00-19:00
• Venue: Harker 1 lecture room, Department of Earth Sciences, Downing Site.
• Series: Sedgwick Club talks; organiser: Susannah Scott.

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The compositions of Earth materials are usually described in terms of specific components, normalised to a whole. This means that individual components must always be positive, and their sum cannot exceed 100%. While these properties are obvious, their wider implications are often misunderstood. In this talk, I will first show how most geochemical datasets are not nearly as amenable to standard statistical analysis and interpretation as they may initially appear. I will then show how the magic of log-ratios can help us to address these difficulties. Finally, I will discuss the physico-chemical meaning of log-ratios and give some examples of how they can be used to better describe, understand, and model various geochemical fractionation processes. This will inevitably raise questions regarding the standard, classical approaches still used for these tasks.

• Speaker: Dr Max Frenzel - Helmholtz-Zentrum Dresden-Rossendorf
• Monday 27 January 2025, 18:00-19:00
• Venue: Harker 1 lecture room, Department of Earth Sciences, Downing Site.
• Series: Sedgwick Club talks; organiser: ss2849.

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tbc – metamorphic petrology

• Speaker: Dr Barbara Kunz - The Open University
• Monday 17 March 2025, 18:00-19:00
• Venue: Harker 1 lecture room, Department of Earth Sciences, Downing Site.
• Series: Sedgwick Club talks; organiser: Susannah Scott.

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tbc – geochemistry and technology metals

• Speaker: Dr Eva Marquis - University of Exeter
• Monday 10 March 2025, 18:00-19:00
• Venue: Harker 1 lecture room, Department of Earth Sciences, Downing Site.
• Series: Sedgwick Club talks; organiser: ss2849.

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tbc – glaciers and sedimentology

• Speaker: Dr Claus-Dieter Hillenbrand
• Monday 03 March 2025, 18:00-19:00
• Venue: Harker 1 lecture room, Department of Earth Sciences, Downing Site.
• Series: Sedgwick Club talks; organiser: ss2849.

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Abstract not available

• Speaker: Sarah Humbert (University of Cambridge)
• Monday 17 February 2025, 18:00-19:00
• Venue: Harker 1 lecture room, Department of Earth Sciences, Downing Site.
• Series: Sedgwick Club talks; organiser: ss2849.

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tbc – paleobotany

• Speaker: Dr Tim Astrop - Brymbo Fossil Forest
• Monday 10 February 2025, 18:00-19:00
• Venue: Harker 1 lecture room, Department of Earth Sciences, Downing Site.
• Series: Sedgwick Club talks; organiser: ss2849.

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The Fenlands of eastern England are known as the breadbasket of Britain, producing around a third of the nations’ vegetables and employing roughly 80,000 people in the agricultural food chain. Historically, the Fens were an extensive maze of wetlands and snaking rivers. Today, this landscape is maintained as productive and...

The simulation of the last deglaciation (about 20.000 years before present to present) represents a hitherto unsolved challenge for comprehensive state-of-the-art climate models. During my presentation, I will introduce our novel coupled atmosphere-ocean-vegetation-ice sheet-solid earth model that is used to simulate the transient climate. An ensemble of transient model simulations successfully captures the main features of the last deglaciation, as depicted by proxy estimates. In addition, our model simulates a series of abrupt climate changes, which can be attributed to different drivers that will be discussed throughout the presentation. I will furthermore show, how the model can be applied for simulations of the long-term future. The future simulations show, that parts of the Antarctic ice sheet become unstable even under low-emission scenarios, with significant implications for the modelled climate response. Sensitivity experiments additionally show that, the Greenland ice sheet may exhibit multiple steady-states under pre-industrial climate conditions. This has significant implications for a potential regrowth, once disintegrated entirely.

• Speaker: Marie-Luise Kapsch (Max Planck Institute for Meteorology)
• Wednesday 12 February 2025, 17:30-19:00
• Venue: Latimer Room, Clare College.
• Series: Quaternary Discussion Group (QDG); organiser: wb350.

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Volcanism is known to act as a driver of change to the Earth system on a range of scales. Degassing of greenhouse gases may act to drive global warming, whilst the weathering of fresh volcanic material may enhance the silicate weathering feedback and aid cooling of Earth’s climate. At the same time, the intensity of volcanism responds to other aspects of the Earth system. For example, low sea levels and low ice volumes may both act to increase levels of volcanic activity through the release of pressure on magma chambers. These interactions in turn may control the level of impact volcanism has as a driver of change. To fully understand the interaction between volcanic activity and climate, however, reliable records of changing volcanic intensity through time are required. Such records have been, to date, either regional or of low resolution. Here, I will discuss two approaches to this problem, firstly through the compilation of volcanic material occurrence in deep sea sediment cores. Secondly, I will present the application of inversion of atmospheric carbon dioxide records as an approach to reconstructing periods of imbalance and likely volcanic activity in the carbon cycle. Both approaches highlight a shift in the late Pleistocene at around 400 ka, whereby more volcanic activity is reconstructed, and the activity becomes cyclical in nature. This may be linked to Mid Brunhes Transition, a period of strengthening in amplitude of glacial-interglacial cycles, and indicates how Earth system changes may impact volcanic intensity.

• Speaker: Jack Longman (Northumbria University)
• Wednesday 19 February 2025, 17:30-19:00
• Venue: Latimer Room, Clare College.
• Series: Quaternary Discussion Group (QDG); organiser: wb350.

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A team of astronomers and earth scientists from Cambridge have found that Venus has never been habitable, despite decades of speculation that our closest planetary neighbour was once much more like Earth than it is today. The researchers studied the chemical composition of the Venusian atmosphere and inferred that its...

The Arctic is warming nearly four times faster than the rest of Earth’s surface (Rantanen et al., 2022). Consequently, permafrost areal extent is projected to decrease (24 ± 16% by 2100, RCP2 .6, Chadburn et al., 2017) and Arctic precipitation is projected to increase (50 – 60 % by 2100, RCP2 .6, Bitanja and Andry, 2017). Permafrost contains ~ two times as much carbon as Earth’s atmosphere (Hugelius et al., 2014). Upon thaw, permafrost organic carbon is a) stored in soils and sediments, b) transferred from soils to aquatic bodies, c) broken down to inorganic carbon in soils and aquatic bodies. A fraction of this inorganic carbon is released as greenhouse gases to the atmosphere which could amplify Arctic warming (the permafrost carbon feedback, Schuur et al., 2015). A portion of permafrost organic carbon is associated with minerals (e.g., Garcia-Palacios et al., 2023) which contribute to modulating if carbon is stored in the land or released into the atmosphere (e.g., Patzner et al., 2020). Our work seeks to understand the environmental controls on how, where and when minerals contribute to carbon release from these vulnerable landscapes. To do this we couple in-field measurements (e.g., precipitation and water table depth) with geochemical measurements (e.g., isotopes, microscopy, spectroscopy. I will present findings from large and small Arctic catchments and ongoing ideas for future research.

• Speaker: Catherine Hirst, University of Durham
• Tuesday 11 February 2025, 12:00-13:00
• Venue: Department of Earth Sciences, Tilley Lecture Theatre.
• Series: Department of Earth Sciences Seminars (downtown); organiser: Dr Rachael Rhodes.

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Abstract not available

• Speaker: James Morris, IEEF
• Thursday 20 February 2025, 11:30-12:30
• Venue: Open Plan Area, Institute for Energy and Environmental Flows, Madingley Rise CB3 0EZ.
• Series: Institute for Energy and Environmental Flows (IEEF); organiser: Catherine Pearson.

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Abstract not available

• Speaker: Professor Matthew Davidson, Bath Institute of Sustainability and Climate Change
• Thursday 27 February 2025, 11:30-12:30
• Venue: Open Plan Area, Institute for Energy and Environmental Flows, Madingley Rise CB3 0EZ.
• Series: Institute for Energy and Environmental Flows (IEEF); organiser: Catherine Pearson.

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Abstract not available

• Speaker: Speaker to be confirmed
• Thursday 23 January 2025, 11:30-12:30
• Venue: Open Plan Area, Institute for Energy and Environmental Flows, Madingley Rise CB3 0EZ.
• Series: Institute for Energy and Environmental Flows (IEEF); organiser: Catherine Pearson.

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The simulation of the last deglaciation (about 20.000 years before present to present) represents a hitherto unsolved challenge for comprehensive state-of-the-art climate models. During my presentation, I will introduce our novel coupled atmosphere-ocean-vegetation-ice sheet-solid earth model that is used to simulate the transient climate. An ensemble of transient model simulations successfully captures the main features of the last deglaciation, as depicted by proxy estimates. In addition, our model simulates a series of abrupt climate changes, which can be attributed to different drivers that will be discussed throughout the presentation. I will furthermore show, how the model can be applied for simulations of the long-term future. The future simulations show, that parts of the Antarctic ice sheet become unstable even under low-emission scenarios, with significant implications for the modelled climate response. Sensitivity experiments additionally show that, the Greenland ice sheet may exhibit multiple steady-states under pre-industrial climate conditions. This has significant implications for a potential regrowth, once disintegrated entirely.

• Speaker: Marie-Luise Kapsch (Max Planck Institute for Meteorology)
• Wednesday 12 February 2025, 17:30-19:00
• Venue: Latimer Room, Clare College.
• Series: Quaternary Discussion Group (QDG); organiser: wb350.

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