Wed 05 Jun 17:30: Extreme glacial implies discontinuity of early human occupation of Europe Building doors are card operated, so latecomers may not be able to access the venue.
The oldest known hominin remains in Europe [ca. 1.5 to 1.1 million years ago (Ma)] have been recovered from Iberia, where paleoenvironmental reconstructions have indicated warm and wet interglacials and mild glacials, supporting the view that once established, hominin populations persisted continuously. We report analyses of marine and terrestrial proxies from a deep-sea core on the Portugese margin that show the presence of pronounced millennial-scale climate variability during a glacial period ca. 1.154 to 1.123 Ma, culminating in a terminal stadial cooling comparable to the most extreme events of the last 400,000 years. Climate envelope–model simulations reveal a drastic decrease in early hominin habitat suitability around the Mediterranean during the terminal stadial. We suggest that these extreme conditions led to the depopulation of Europe, perhaps lasting for several successive glacial-interglacial cycles.
Building doors are card operated, so latecomers may not be able to access the venue.
- Speaker: Vasiliki Margari, University College London
- Wednesday 05 June 2024, 17:30-19:00
- Venue: Harker 1, Department of Earth Sciences, Downing Street.
- Series: Quaternary Discussion Group (QDG); organiser: Jinheum Park.
Wed 05 Jun 17:30: Extreme glacial implies discontinuity of early human occupation of Europe Building doors are card operated, so latecomers may not be able to access the venue.
The oldest known hominin remains in Europe [ca. 1.5 to 1.1 million years ago (Ma)] have been recovered from Iberia, where paleoenvironmental reconstructions have indicated warm and wet interglacials and mild glacials, supporting the view that once established, hominin populations persisted continuously. We report analyses of marine and terrestrial proxies from a deep-sea core on the Portugese margin that show the presence of pronounced millennial-scale climate variability during a glacial period ca. 1.154 to 1.123 Ma, culminating in a terminal stadial cooling comparable to the most extreme events of the last 400,000 years. Climate envelope–model simulations reveal a drastic decrease in early hominin habitat suitability around the Mediterranean during the terminal stadial. We suggest that these extreme conditions led to the depopulation of Europe, perhaps lasting for several successive glacial-interglacial cycles.
Building doors are card operated, so latecomers may not be able to access the venue.
- Speaker: Vasiliki Margari, University College London
- Wednesday 05 June 2024, 17:30-19:00
- Venue: Harker 1, Department of Earth Sciences, Downing Street.
- Series: Quaternary Discussion Group (QDG); organiser: Jinheum Park.
Wed 05 Jun 17:30: Extreme glacial implies discontinuity of early human occupation of Europe Building doors are card operated, so latecomers may not be able to access the venue.
The oldest known hominin remains in Europe [ca. 1.5 to 1.1 million years ago (Ma)] have been recovered from Iberia, where paleoenvironmental reconstructions have indicated warm and wet interglacials and mild glacials, supporting the view that once established, hominin populations persisted continuously. We report analyses of marine and terrestrial proxies from a deep-sea core on the Portugese margin that show the presence of pronounced millennial-scale climate variability during a glacial period ca. 1.154 to 1.123 Ma, culminating in a terminal stadial cooling comparable to the most extreme events of the last 400,000 years. Climate envelope–model simulations reveal a drastic decrease in early hominin habitat suitability around the Mediterranean during the terminal stadial. We suggest that these extreme conditions led to the depopulation of Europe, perhaps lasting for several successive glacial-interglacial cycles.
Building doors are card operated, so latecomers may not be able to access the venue.
- Speaker: Vasiliki Margari, University College London
- Wednesday 05 June 2024, 17:30-19:00
- Venue: Harker 1, Department of Earth Sciences, Downing Street.
- Series: Quaternary Discussion Group (QDG); organiser: Jinheum Park.
Wed 05 Jun 17:30: Extreme glacial implies discontinuity of early human occupation of Europe Building doors are card operated, so latecomers may not be able to access the venue.
The oldest known hominin remains in Europe [ca. 1.5 to 1.1 million years ago (Ma)] have been recovered from Iberia, where paleoenvironmental reconstructions have indicated warm and wet interglacials and mild glacials, supporting the view that once established, hominin populations persisted continuously. We report analyses of marine and terrestrial proxies from a deep-sea core on the Portugese margin that show the presence of pronounced millennial-scale climate variability during a glacial period ca. 1.154 to 1.123 Ma, culminating in a terminal stadial cooling comparable to the most extreme events of the last 400,000 years. Climate envelope–model simulations reveal a drastic decrease in early hominin habitat suitability around the Mediterranean during the terminal stadial. We suggest that these extreme conditions led to the depopulation of Europe, perhaps lasting for several successive glacial-interglacial cycles.
Building doors are card operated, so latecomers may not be able to access the venue.
- Speaker: Vasiliki Margari, University College London
- Wednesday 05 June 2024, 17:30-19:00
- Venue: Harker 1, Department of Earth Sciences, Downing Street.
- Series: Quaternary Discussion Group (QDG); organiser: Jinheum Park.
Wed 05 Jun 17:30: Extreme glacial implies discontinuity of early human occupation of Europe Building doors are card operated, so latecomers may not be able to access the venue.
The oldest known hominin remains in Europe [1.5 to 1.1 million years ago (Ma)] have been recovered from Iberia, where paleoenvironmental reconstructions have indicated warm and wet interglacials and mild glacials, supporting the view that once established, hominin populations persisted continuously. We report analyses of marine and terrestrial proxies from a deep-sea core on the Portugese margin that show the presence of pronounced millennial-scale climate variability during a glacial period 1.154 to 1.123 Ma, culminating in a terminal stadial cooling comparable to the most extreme events of the last 400,000 years. Climate envelope–model simulations reveal a drastic decrease in early hominin habitat suitability around the Mediterranean during the terminal stadial. We suggest that these extreme conditions led to the depopulation of Europe, perhaps lasting for several successive glacial-interglacial cycles.
Building doors are card operated, so latecomers may not be able to access the venue.
- Speaker: Vasiliki Margari, University College London
- Wednesday 05 June 2024, 17:30-19:00
- Venue: Harker 1, Department of Earth Sciences, Downing Street.
- Series: Quaternary Discussion Group (QDG); organiser: Jinheum Park.
Wed 05 Jun 17:30: Extreme glacial implies discontinuity of early human occupation of Europe Building doors are card operated, so latecomers may not be able to access the venue.
The oldest known hominin remains in Europe [1.5 to 1.1 million years ago (Ma)] have been recovered from Iberia, where paleoenvironmental reconstructions have indicated warm and wet interglacials and mild glacials, supporting the view that once established, hominin populations persisted continuously. We report analyses of marine and terrestrial proxies from a deep-sea core on the Portugese margin that show the presence of pronounced millennial-scale climate variability during a glacial period 1.154 to 1.123 Ma, culminating in a terminal stadial cooling comparable to the most extreme events of the last 400,000 years. Climate envelope–model simulations reveal a drastic decrease in early hominin habitat suitability around the Mediterranean during the terminal stadial. We suggest that these extreme conditions led to the depopulation of Europe, perhaps lasting for several successive glacial-interglacial cycles.
Building doors are card operated, so latecomers may not be able to access the venue.
- Speaker: Vasiliki Margari, University College London
- Wednesday 05 June 2024, 17:30-19:00
- Venue: Harker 1, Department of Earth Sciences, Downing Street.
- Series: Quaternary Discussion Group (QDG); organiser: Jinheum Park.
Wed 05 Jun 17:30: Extreme glacial implies discontinuity of early human occupation of Europe Building doors are card operated, so latecomers may not be able to access the venue.
The oldest known hominin remains in Europe [1.5 to 1.1 million years ago (Ma)] have been recovered from Iberia, where paleoenvironmental reconstructions have indicated warm and wet interglacials and mild glacials, supporting the view that once established, hominin populations persisted continuously. We report analyses of marine and terrestrial proxies from a deep-sea core on the Portugese margin that show the presence of pronounced millennial-scale climate variability during a glacial period 1.154 to 1.123 Ma, culminating in a terminal stadial cooling comparable to the most extreme events of the last 400,000 years. Climate envelope–model simulations reveal a drastic decrease in early hominin habitat suitability around the Mediterranean during the terminal stadial. We suggest that these extreme conditions led to the depopulation of Europe, perhaps lasting for several successive glacial-interglacial cycles.
Building doors are card operated, so latecomers may not be able to access the venue.
- Speaker: Vasiliki Margari, University College London
- Wednesday 05 June 2024, 17:30-19:00
- Venue: Harker 1, Department of Earth Sciences, Downing Street.
- Series: Quaternary Discussion Group (QDG); organiser: Jinheum Park.
Wed 05 Jun 17:30: Extreme glacial implies discontinuity of early human occupation of Europe Building doors are card operated, so latecomers may not be able to access the venue.
The oldest known hominin remains in Europe [1.5 to 1.1 million years ago (Ma)] have been recovered from Iberia, where paleoenvironmental reconstructions have indicated warm and wet interglacials and mild glacials, supporting the view that once established, hominin populations persisted continuously. We report analyses of marine and terrestrial proxies from a deep-sea core on the Portugese margin that show the presence of pronounced millennial-scale climate variability during a glacial period 1.154 to 1.123 Ma, culminating in a terminal stadial cooling comparable to the most extreme events of the last 400,000 years. Climate envelope–model simulations reveal a drastic decrease in early hominin habitat suitability around the Mediterranean during the terminal stadial. We suggest that these extreme conditions led to the depopulation of Europe, perhaps lasting for several successive glacial-interglacial cycles.
Building doors are card operated, so latecomers may not be able to access the venue.
- Speaker: Vasiliki Margari, University College London
- Wednesday 05 June 2024, 17:30-19:00
- Venue: Harker 1, Department of Earth Sciences, Downing Street.
- Series: Quaternary Discussion Group (QDG); organiser: Jinheum Park.
Wed 24 Apr 14:00: Carbon subduction and mid-ocean ridge emissions modulate icehouse-greenhouse climates
The cycling of carbon between the deep Earth and the atmosphere plays a significant role in modulating global climate. While carbon degassing at volcanic arcs are generally assumed to be the main contributor to atmospheric carbon, our research reveals that mid-ocean ridge degassing surpasses arc emissions before 50 Ma. Combining thermodynamic modelling of subducting carbon reservoirs with reconstructions of remobilised crustal carbon through the Phanerozoic, we show that volcanic arc emissions reduce to merely ~12% of mid-ocean ridge outflux before 120 Ma. This reflects the absence of deep-sea carbonate sediments entering subduction zones, leaving less voluminous metamorphic degassing of continental carbonate platforms next to convergent margins as the main mechanism for arc CO2 degassing. We find that the balance between oceanic volcanic outgassing and removal of carbon via subduction tracks major climate shifts, including the Late Palaeozoic, Late Cretaceous and Cenozoic icehouse climates.
- Speaker: Ben Mather, University of Sydney
- Wednesday 24 April 2024, 14:00-15:00
- Venue: Wolfson Lecture Theatre.
- Series: Bullard Laboratories Wednesday Seminars; organiser: Megan Holdt.
Wed 24 Apr 14:00: Carbon subduction and mid-ocean ridge emissions modulate icehouse-greenhouse climates
The cycling of carbon between the deep Earth and the atmosphere plays a significant role in modulating global climate. While carbon degassing at volcanic arcs are generally assumed to be the main contributor to atmospheric carbon, our research reveals that mid-ocean ridge degassing surpasses arc emissions before 50 Ma. Combining thermodynamic modelling of subducting carbon reservoirs with reconstructions of remobilised crustal carbon through the Phanerozoic, we show that volcanic arc emissions reduce to merely ~12% of mid-ocean ridge outflux before 120 Ma. This reflects the absence of deep-sea carbonate sediments entering subduction zones, leaving less voluminous metamorphic degassing of continental carbonate platforms next to convergent margins as the main mechanism for arc CO2 degassing. We find that the balance between oceanic volcanic outgassing and removal of carbon via subduction tracks major climate shifts, including the Late Palaeozoic, Late Cretaceous and Cenozoic icehouse climates.
- Speaker: Ben Mather, University of Sydney
- Wednesday 24 April 2024, 14:00-15:00
- Venue: Wolfson Lecture Theatre.
- Series: Bullard Laboratories Wednesday Seminars; organiser: Megan Holdt.
Wed 22 May 14:00: Title to be confirmed
Abstract not available
- Speaker: Arwen Deuss - Utrecht University
- Wednesday 22 May 2024, 14:00-15:00
- Venue: Wolfson Lecture Theatre.
- Series: Bullard Laboratories Wednesday Seminars; organiser: Lisanne Jagt.
Wed 22 May 14:00: Title to be confirmed
Abstract not available
- Speaker: Arwen Deuss - Utrecht University
- Wednesday 22 May 2024, 14:00-15:00
- Venue: Wolfson Lecture Theatre.
- Series: Bullard Laboratories Wednesday Seminars; organiser: Lisanne Jagt.
Tue 30 Apr 12:00: Fresh perspectives on the origins of major animal groups: insights from the late Ediacaran of Namibia
Abstract not available
- Speaker: Alex Lui, Department of Earth Sciences, University of Cambridge
- Tuesday 30 April 2024, 12:00-13:00
- Venue: Department of Earth Sciences, Tilley Lecture Theatre.
- Series: Department of Earth Sciences Seminars (downtown); organiser: Dr Rachael Rhodes.
Tue 30 Apr 12:00: Fresh perspectives on the origins of major animal groups: insights from the late Ediacaran of Namibia
Abstract not available
- Speaker: Alex Lui, Department of Earth Sciences, University of Cambridge
- Tuesday 30 April 2024, 12:00-13:00
- Venue: Department of Earth Sciences, Tilley Lecture Theatre.
- Series: Department of Earth Sciences Seminars (downtown); organiser: Dr Rachael Rhodes.
Wed 24 Apr 14:00: Carbon subduction and mid-ocean ridge emissions modulate icehouse-greenhouse climates
The cycling of carbon between the deep Earth and the atmosphere plays a significant role in modulating global climate. While carbon degassing at volcanic arcs are generally assumed to be the main contributor to atmospheric carbon, our research reveals that mid-ocean ridge degassing surpasses arc emissions before 50 Ma. Combining thermodynamic modelling of subducting carbon reservoirs with reconstructions of remobilised crustal carbon through the Phanerozoic, we show that volcanic arc emissions reduce to merely ~12% of mid-ocean ridge outflux before 120 Ma. This reflects the absence of deep-sea carbonate sediments entering subduction zones, leaving less voluminous metamorphic degassing of continental carbonate platforms next to convergent margins as the main mechanism for arc CO2 degassing. We find that the balance between oceanic volcanic outgassing and removal of carbon via subduction tracks major climate shifts, including the Late Palaeozoic, Late Cretaceous and Cenozoic icehouse climates.
- Speaker: University of Sydney
- Wednesday 24 April 2024, 14:00-15:00
- Venue: Wolfson Lecture Theatre.
- Series: Bullard Laboratories Wednesday Seminars; organiser: Megan Holdt.
Wed 24 Apr 14:00: Carbon subduction and mid-ocean ridge emissions modulate icehouse-greenhouse climates
The cycling of carbon between the deep Earth and the atmosphere plays a significant role in modulating global climate. While carbon degassing at volcanic arcs are generally assumed to be the main contributor to atmospheric carbon, our research reveals that mid-ocean ridge degassing surpasses arc emissions before 50 Ma. Combining thermodynamic modelling of subducting carbon reservoirs with reconstructions of remobilised crustal carbon through the Phanerozoic, we show that volcanic arc emissions reduce to merely ~12% of mid-ocean ridge outflux before 120 Ma. This reflects the absence of deep-sea carbonate sediments entering subduction zones, leaving less voluminous metamorphic degassing of continental carbonate platforms next to convergent margins as the main mechanism for arc CO2 degassing. We find that the balance between oceanic volcanic outgassing and removal of carbon via subduction tracks major climate shifts, including the Late Palaeozoic, Late Cretaceous and Cenozoic icehouse climates.
- Speaker: University of Sydney
- Wednesday 24 April 2024, 14:00-15:00
- Venue: Wolfson Lecture Theatre.
- Series: Bullard Laboratories Wednesday Seminars; organiser: Megan Holdt.
Thu 02 May 11:30: A molecular-level description of the oxygen evolution reaction using in situ spectroscopy
Water electrolysis stands as a cornerstone technology for green hydrogen production from renewable energy and consists of two half-cell reactions: the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). The sluggish kinetics of the state-of-the-art OER electrocatalysts based on iridium oxide severely limit the overall efficiency of the process and, consequently, its economic viability. An in-depth comprehension of the atomic-level mechanisms governing this reaction is considered essential for designing enhanced materials and advancing the transition to a sustainable and resilient energy sector. In situ structural characterization techniques, such as X-ray absorption spectroscopy and X-ray photoelectron spectroscopy, serve this purpose well as they enable real-time monitoring of the chemical composition, structural phase, and electronic configuration of the species at the gas/liquid/solid interface during the interfacial electrocatalytic turnover. In this talk, I will present an overview of the experimental approaches developed in our group and by others to probe the reactive interface during OER , as well as our current understanding of the reaction mechanism on Ir-O-based systems gained using both soft and hard X-ray spectroscopic techniques.
References
1) R Arrigo, M H ävecker, ME Schuster, C Ranjan, E Stotz, A Knop-Gericke et al.,
In situ study of the gas-phase electrolysis of water on platinum by NAP -XPS,
Angewandte Chemie International Edition 52 (2013), 11660-11664
2) JJ Velasco‐Velez, V Pfeifer, M H ävecker, RS Weatherup, R Arrigo et al., Photoelectron spectroscopy at the graphene–liquid interface reveals the electronic structure of an electrodeposited cobalt/graphene electrocatalyst, Angewandte Chemie International Edition 54 (2015), 14554-14558
3) A Knop-Gericke, V Pfeifer, JJ Velasco-Velez, T Jones, R Arrigo et al., In situ X-ray photoelectron spectroscopy of electrochemically active solid-gas and solid-liquid interfaces, Journal of Electron Spectroscopy and Related Phenomena 221 (2017), 10-17
4) V Pfeifer, TE Jones, JJV V élez, R Arrigo, S Piccinin, M H ävecker et al., In situ observation of reactive oxygen species forming on oxygen-evolving iridium surfaces, Chemical science 8 (2017), 2143-2149 5) V Pfeifer, TE Jones, S Wrabetz, C Massué, JJV V élez, R Arrigo et al., Reactive oxygen species in iridium-based OER catalysts, Chemical science 7 (2017), 6791-6795
6) JJ Velasco-Vélez, EA Carbonio, CH Chuang, CJ Hsu, JF Lee, R Arrigo, et al., Surface electron-hole rich species active in the electrocatalytic water oxidation, Journal of the American Chemical Society 143 (2021), 12524-12534
7) JJV V élez, D Bernsmeier, TE Jones, P Zeller, E Carbonio, CH Chuang, et al., The rise of electrochemical NAPXPS operated in the soft X-ray regime exemplified by the oxygen evolution reaction on IrO x electrocatalysts, Faraday discussions 236 (2022), 103-125 8) J Ruiz Esquius, DJ Morgan, G Algara Siller, D Gianolio, M Aramini et al., Lithium-directed transformation of amorphous iridium (oxy) hydroxides to produce active water oxidation catalysts, Journal of the American Chemical Society 145 (2023), 6398-6409 9) M Falsaperna, R Arrigo, F Marken, SJ Freakley Alkali Containing Layered Metal Oxides as Catalysts for the Oxygen Evolution Reaction, ChemElectroChem 2024, e202300761
- Speaker: Rosa Arrigo, Uni of Salford
- Thursday 02 May 2024, 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.
Thu 02 May 11:30: A molecular-level description of the oxygen evolution reaction using in situ spectroscopy
Water electrolysis stands as a cornerstone technology for green hydrogen production from renewable energy and consists of two half-cell reactions: the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER). The sluggish kinetics of the state-of-the-art OER electrocatalysts based on iridium oxide severely limit the overall efficiency of the process and, consequently, its economic viability. An in-depth comprehension of the atomic-level mechanisms governing this reaction is considered essential for designing enhanced materials and advancing the transition to a sustainable and resilient energy sector. In situ structural characterization techniques, such as X-ray absorption spectroscopy and X-ray photoelectron spectroscopy, serve this purpose well as they enable real-time monitoring of the chemical composition, structural phase, and electronic configuration of the species at the gas/liquid/solid interface during the interfacial electrocatalytic turnover. In this talk, I will present an overview of the experimental approaches developed in our group and by others to probe the reactive interface during OER , as well as our current understanding of the reaction mechanism on Ir-O-based systems gained using both soft and hard X-ray spectroscopic techniques.
References
1) R Arrigo, M H ävecker, ME Schuster, C Ranjan, E Stotz, A Knop-Gericke et al.,
In situ study of the gas-phase electrolysis of water on platinum by NAP -XPS,
Angewandte Chemie International Edition 52 (2013), 11660-11664
2) JJ Velasco‐Velez, V Pfeifer, M H ävecker, RS Weatherup, R Arrigo et al., Photoelectron spectroscopy at the graphene–liquid interface reveals the electronic structure of an electrodeposited cobalt/graphene electrocatalyst, Angewandte Chemie International Edition 54 (2015), 14554-14558
3) A Knop-Gericke, V Pfeifer, JJ Velasco-Velez, T Jones, R Arrigo et al., In situ X-ray photoelectron spectroscopy of electrochemically active solid-gas and solid-liquid interfaces, Journal of Electron Spectroscopy and Related Phenomena 221 (2017), 10-17
4) V Pfeifer, TE Jones, JJV V élez, R Arrigo, S Piccinin, M H ävecker et al., In situ observation of reactive oxygen species forming on oxygen-evolving iridium surfaces, Chemical science 8 (2017), 2143-2149 5) V Pfeifer, TE Jones, S Wrabetz, C Massué, JJV V élez, R Arrigo et al., Reactive oxygen species in iridium-based OER catalysts, Chemical science 7 (2017), 6791-6795
6) JJ Velasco-Vélez, EA Carbonio, CH Chuang, CJ Hsu, JF Lee, R Arrigo, et al., Surface electron-hole rich species active in the electrocatalytic water oxidation, Journal of the American Chemical Society 143 (2021), 12524-12534
7) JJV V élez, D Bernsmeier, TE Jones, P Zeller, E Carbonio, CH Chuang, et al., The rise of electrochemical NAPXPS operated in the soft X-ray regime exemplified by the oxygen evolution reaction on IrO x electrocatalysts, Faraday discussions 236 (2022), 103-125 8) J Ruiz Esquius, DJ Morgan, G Algara Siller, D Gianolio, M Aramini et al., Lithium-directed transformation of amorphous iridium (oxy) hydroxides to produce active water oxidation catalysts, Journal of the American Chemical Society 145 (2023), 6398-6409 9) M Falsaperna, R Arrigo, F Marken, SJ Freakley Alkali Containing Layered Metal Oxides as Catalysts for the Oxygen Evolution Reaction, ChemElectroChem 2024, e202300761
- Speaker: Rosa Arrigo, Uni of Salford
- Thursday 02 May 2024, 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.
Tue 23 Apr 11:00: Sedgwick Club Conference 2024
Six talks from a variety of areas of Earth Sciences; large igneous provinces, ice core climate records, modern ocean climate systems, earthquake dynamics, geoscience communication and the Earth’s magnetic field. Also featuring highlights from industry and a Part III poster presentation session.
- Speaker: N/A
- Tuesday 23 April 2024, 11:00-16:00
- Venue: Common Room, Department of Earth Sciences.
- Series: Sedgwick Club talks; organiser: Lucas Measures.
Tue 23 Apr 11:00: Sedgwick Club Conference 2024
Six talks from a variety of areas of Earth Sciences; large igneous provinces, ice core climate records, modern ocean climate systems, earthquake dynamics, geoscience communication and the Earth’s magnetic field. Also featuring highlights from industry and a Part III poster presentation session.
- Speaker: N/A
- Tuesday 23 April 2024, 11:00-16:00
- Venue: Common Room, Department of Earth Sciences.
- Series: Sedgwick Club talks; organiser: Lucas Measures.