Mon 03 Mar 18:00: Context from marine geological records for present West Antarctic Ice Sheet dynamics and implications for future change
Satellite and field observations show that the West Antarctic Ice Sheet (WAIS) is currently undergoing rapid ice loss, thereby increasingly contributing to global sea-level rise. The direct observational record, however, spans just a few decades, raising the question whether this “snapshot” of ice-sheet changes is representative or exceptional in a longer-term context. The only reliable method to establish the long-term framework of WAIS variability and, thus, to evaluate, if present ice loss is related to human-induced global warming, is the reconstruction of past ice-sheet configurations from the geological record. Here I will demonstrate how research on the marine geological imprint left by the ice sheet on the West Antarctic continental margin has improved our understanding of past and present WAIS dynamics. This newly acquired knowledge will help to evaluate the reliability of numerical models in simulating WAIS dynamics and, thus, improve model-based predictions of future ice loss and associated global sea-level rise.
- Speaker: Dr Claus-Dieter Hillenbrand, British Antarctic Survey
- 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.
Wed 26 Feb 14:00: What small earthquakes can teach us about large earthquakes at caldera ring faults
Magnitude ~ 5 earthquakes are often observed at caldera volcanoes undergoing unrest. These earthquakes stand out in regional and teleseismic moment tensor catalogues for their shallow depths and non-double-couple source mechanisms. Intriguingly, the orientation of the moment tensor (vertical-dilatational or vertical-compressional) appears to correlate with the stage of volcanic unrest (inflation building up to eruption, or deflation as magma leaves the edifice), but we don’t yet have a general understanding of what source processes lead to their distinctive nature.
In this talk I will explore how local measurements of such earthquakes at Bárðarbunga caldera, central Iceland, can be used to investigate this further. Bárðarbunga has hosted the longest sequence of such anomalous earthquakes observed at any volcano globally, and in 2014-15 hosted a spectacular eruption that featured more than 70 of these Mw 5+ events over a period of just 6 months. Analysis of detailed observations of seismicity and ground deformation delivered important new constraints on models of the caldera system and ring faults, but also new questions. Since 2015 the edifice has been re-inflating, accompanied by around 1-2 large earthquakes per year. We have sought to exploit this by supplementing the long-running regional network with temporary dense deployments of seismometers above the ice-filled caldera, to provide further improved constraints on earthquake locations and focal mechanisms. I will describe the 10’s of thousands of earthquakes we have located from these few months of data, and the new insights they provide into caldera ring fault seismicity at Bárðarbunga.
- Speaker: Tom Winder ( University of Iceland)
- Wednesday 26 February 2025, 14:00-15:00
- Venue: Wolfson Lecture Theatre.
- Series: Bullard Laboratories Wednesday Seminars; organiser: ChuanChuan Lu.
The coral whisperer
Duygu Sevilgen has built a coral lab in the basement of an old Zoology building. Here, 10 experimental tanks host multicoloured miniature forests, with each tank representing a different marine environment. Duygu uses extremely small sensors to record the fine details of coral skeletons and listen to their dialogue with algae. In doing so, she determines how much change corals can bear, and improves our chances of saving them in the wild.
The coral whisperer
Duygu Sevilgen has built a coral lab in the basement of an old Zoology building. Here, 10 experimental tanks host multicoloured miniature forests, with each tank representing a different marine environment. Duygu uses extremely small sensors to record the fine details of coral skeletons and listen to their dialogue with algae. In doing so, she determines how much change corals can bear, and improves our chances of saving them in the wild.
The tale of the tomb of Thutmose II
Cambridge University's Dr Judith Bunbury is Deputy Mission Director of the archaeological project in the Theban Mountain area that found the lost tomb of Thutmose II.
The tale of the tomb of Thutmose II
Cambridge University's Dr Judith Bunbury is Deputy Mission Director of the archaeological project in the Theban Mountain area that found the lost tomb of Thutmose II.
Thu 06 Mar 11:30: Reactions in Porous Rocks
Abstract not available
- Speaker: Sam Clarke, IEEF
- Thursday 06 March 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.
Thu 27 Feb 11:30: Green Carbon for the Chemical Industry: Decoupling Polymers from Fossil Resources
Reducing reliance on fossil carbon is central to the concepts of sustainable development and material stewardship. Whereas decarbonization of the energy sector is feasible through the development of renewable energy, the chemicals sector needs carbon as a building block. The lasting and growing demand for this embedded carbon, especially for production of polymers, must be met in the future through utilization of renewable feedstocks such as biomass, CO2 and recycling of carbon-containing waste. In this context, the transition from fossil to renewable polymers provides a major challenge. Advances in renewable polymers will be exemplified through case studies of two of the most promising bio-based platforms for plastics: lactic acid (LA) and hydroxymethylfurfural (HMF).
- 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.
Mon 24 Feb 14:00: What small earthquakes can teach us about large earthquakes at caldera ring faults
Magnitude ~ 5 earthquakes are often observed at caldera volcanoes undergoing unrest. These earthquakes stand out in regional and teleseismic moment tensor catalogues for their shallow depths and non-double-couple source mechanisms. Intriguingly, the orientation of the moment tensor (vertical-dilatational or vertical-compressional) appears to correlate with the stage of volcanic unrest (inflation building up to eruption, or deflation as magma leaves the edifice), but we don’t yet have a general understanding of what source processes lead to their distinctive nature.
In this talk I will explore how local measurements of such earthquakes at Bárðarbunga caldera, central Iceland, can be used to investigate this further. Bárðarbunga has hosted the longest sequence of such anomalous earthquakes observed at any volcano globally, and in 2014-15 hosted a spectacular eruption that featured more than 70 of these Mw 5+ events over a period of just 6 months. Analysis of detailed observations of seismicity and ground deformation delivered important new constraints on models of the caldera system and ring faults, but also new questions. Since 2015 the edifice has been re-inflating, accompanied by around 1-2 large earthquakes per year. We have sought to exploit this by supplementing the long-running regional network with temporary dense deployments of seismometers above the ice-filled caldera, to provide further improved constraints on earthquake locations and focal mechanisms. I will describe the 10’s of thousands of earthquakes we have located from these few months of data, and the new insights they provide into caldera ring fault seismicity at Bárðarbunga.
- Speaker: Tom Winder, University of Iceland
- Monday 24 February 2025, 14:00-15:00
- Venue: Wolfson Lecture Theatre.
- Series: Bullard Laboratories Wednesday Seminars; organiser: ChuanChuan Lu.
Tue 18 Mar 12:00: Direct observations of sub-ice environments immediately after large calving event off George VI Ice Shelf, West Antarctica To meet with the speaker, contact Ali Mashayek (am3158@cam.ac.uk)
Abstract not available
To meet with the speaker, contact Ali Mashayek (am3158@cam.ac.uk)
- Speaker: Dr Sasha Montelli
- Tuesday 18 March 2025, 12:00-13:00
- Venue: Department of Earth Sciences, Tilley Lecture Theatre.
- Series: Department of Earth Sciences Seminars (downtown); organiser: Ali Mashayek.
Wed 19 Feb 18:00: I know what you did last summer Pt3 version
Come along to hear some of your favourite Part III students talk about what they did on internships and research placements this summer. From corals to chondrites we’ve got it all! Also an excellent way to find out about opportunities you could apply for when you’re not trudging through the rain on field trips. Speakers are: Alex C, Jenny D, Susannah S, Rosa W, Gio B, Rory M, Erica M, Zara C and Pippa L!
- Speaker: Part 3 students
- Wednesday 19 February 2025, 18:00-19:00
- Venue: Harker 1 lecture room, Department of Earth Sciences, Downing Site.
- Series: Sedgwick Club talks; organiser: ss2849.
Tue 11 Mar 12:00: From Sediment to Spodumene
In this talk I’ll synthesize recent research interrogating how variations in weathering regimes and sediment deposition have impacted the chemistry of igneous rocks. In particular, I will focus on a particular class of granites (often termed “S-type”) which form via partial melting of siliciclastic sedimentary rocks and are uniquely suited to capture how the chemical consequences of sedimentary incorporation into magmas have varied throughout Earth history. I will focus on how enhanced organic matter and clay deposition at various periods in Earth history are reflected in the chemistry of the granites and the implications these variations have for our understanding of the oxygenation of Earth’s atmosphere and the occurrence of Li mineral deposits.
- Speaker: Claire Bucholz, Caltech
- Tuesday 11 March 2025, 12:00-13:00
- Venue: Department of Earth Sciences, Tilley Lecture Theatre.
- Series: Department of Earth Sciences Seminars (downtown); organiser: Dr Rachael Rhodes.
Tue 18 Mar 12:00: Title to be confirmed To meet with the speaker, contact Ali Mashayek (am3158@cam.ac.uk)
Abstract not available
To meet with the speaker, contact Ali Mashayek (am3158@cam.ac.uk)
- Speaker: Dr Sasha Montelli
- Tuesday 18 March 2025, 12:00-13:00
- Venue: Department of Earth Sciences, Tilley Lecture Theatre.
- Series: Department of Earth Sciences Seminars (downtown); organiser: Ali Mashayek.
Wed 19 Mar 14:00: Fault orientation in earthquake seismic precursors: Insights from the laboratory
Faults in the brittle crust lie at any orientation to the far-field stress. However, laboratory experiments designed to investigate earthquake physics commonly simulate favorably oriented faults, potentially overlooking the complexity of natural fault behavior. Here, we assess the role of stress field orientation in fault reactivation and earthquake precursors by conducting triaxial sawcut experiments with laboratory faults oriented at different angles to the maximum principal stress, ranging from 30° to 70°. The samples were instrumented with strain gauges and piezoelectric sensors. Laboratory well-oriented faults describe a rather simple system in which the elastic energy is stored via the deformation of the surrounding host rock during the inter-seismic period and released via on-fault slip during the co-seismic phase with associated precursor acoustic activity. Consistent with previous laboratory data, an abrupt increase in the on-fault acoustic emission rate occurs shortly before the laboratory earthquake. A more complex picture emerges when deforming laboratory misoriented faults. Particularly, acoustic emissions and strain gauge data indicate that when the fault is misoriented, off-fault permanent deformation occurs well before fault reactivation. The stress state in the host rock surrounding the fault is indeed far beyond the one required for the onset of inelastic deformation. In this case, acoustic activity distributed in the rock volume during the pre-seismic phase is associated with permanent deformation in the critically stressed host rock and is not a direct precursor to the following laboratory earthquake. Unlike well-oriented faults, laboratory misoriented faults lack detectable seismic precursors. The laboratory-observed increase in acoustic activity prior to, but not precursor of, misoriented fault reactivation impacts our understanding of earthquake precursors in natural faults.
- Speaker: Carolina Giorgetti, ENS Paris
- Wednesday 19 March 2025, 14:00-15:00
- Venue: Wolfson Lecture Theatre.
- Series: Bullard Laboratories Wednesday Seminars; organiser: Adriano Gualandi.
Wed 19 Feb 14:00: Catastrophic failure: sound and vision
Catastrophic failure is the end result of progression and localisation of damage towards brittle failure on a variety of system scales in the Earth. However, the factors controlling this evolution, and that of the resulting seismicity, are not well constrained. We address the question of how to relate the two, and the extent to which they can be controlled by feedback on the seismicity rate in a scale model experiment on a small rock sample deformed in a synchrotron. We image the underlying damage using x-rays and detect acoustic emissions, and show how they change during localisation, from distributed tensile cracking to a localised shear band containing a mixture of tensile cracking, grain rotation, and grain boundary shear, with shear becoming increasingly dominant and ultimately frictional sliding on a contiguous fault. We confirm that using continuous servo-control based on acoustic emission event rate not only slows down deformation compared to standard constant strain rate loading, but also suppresses events of all sizes, including extreme events. We use this evolution to develop a mixture model for the stress history from damage mechanics, and find it is independently consistent with the observed stress history and acoustic emission statistics. Our results imply that including seismic event rate control may improve risk management of induced seismicity compared to feedback on the maximum magnitude alone.
- Speaker: Ian Main, University of Edinburgh
- Wednesday 19 February 2025, 14:00-15:00
- Venue: Wolfson Lecture Theatre.
- Series: Bullard Laboratories Wednesday Seminars; organiser: Adriano Gualandi.
Wed 19 Feb 14:00: Catastrophic failure: sound and vision
Catastrophic failure is the end result of progression and localisation of damage towards brittle failure on a variety of system scales in the Earth. However, the factors controlling this evolution, and that of the resulting seismicity, are not well constrained. We address the question of how to relate the two, and the extent to which they can be controlled by feedback on the seismicity rate in a scale model experiment on a small rock sample deformed in a synchrotron. We image the underlying damage using x-rays and detect acoustic emissions, and show how they change during localisation, from distributed tensile cracking to a localised shear band containing a mixture of tensile cracking, grain rotation, grain boundary shear, with shear becoming increasingly dominant and ultimately frictional sliding on a contiguous fault. We confirm that using continuous servo-control based on acoustic emission event rate not only slows down deformation compared to standard constant strain rate loading, but also suppresses events of all sizes, including extreme events. We use this evolution to develop a mixture model for the stress history from damage mechanics, and find it is independently consistent with the observed stress history and acoustic emission statistics. Our results imply that including seismic event rate control may improve risk management of induced seismicity compared to feedback on the maximum magnitude alone.
- Speaker: Ian Main, University of Edinburgh
- Wednesday 19 February 2025, 14:00-15:00
- Venue: Wolfson Lecture Theatre.
- Series: Bullard Laboratories Wednesday Seminars; organiser: Adriano Gualandi.
Thu 20 Feb 11:30: Bubble growth in alkaline electrolysis
In the production of hydrogen via electrolysis, bubbles of hydrogen and oxygen must grow and detach from the electrode. Discussion of factors effecting rate of bubble growth and final detachment volume, and their contribution to overall efficiency.
- 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.
Mon 03 Mar 13:00: Volcanoes, Rhinoceros and Cabbage
Abstract not available
- Speaker: Professor Matthew Watson (University of Bristol)
- Monday 03 March 2025, 13:00-14:00
- Venue: Tilley Lecture Theatre, Department of Earth Sciences, Downing Street.
- Series: Cambridge Volcanology Seminar; organiser: Matthew Morris.
Research pinpoints triggers and impacts of catastrophic lake outburst flood
Researchers from the University of Cambridge were involved in a global study that pieced together events leading up to the devastating Sikkim Flood in India. The results show that human activity played a key role in the multihazard sequence. On October 3 rd , 2023, a large glacial lake in Sikkim, northeastern India, broke...
Fri 09 May 16:00: The Magmatic Origin of the North Atlantic V-Shaped Ridges and Fractured Crust
Abstract not available
- Speaker: Callum Pearman
- Friday 09 May 2025, 16:00-17:00
- Venue: Tea Room, Old House.
- Series: Bullard Laboratories Tea Time Talks; organiser: David Al-Attar.