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Department of Earth Sciences

 
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A collection of all the seminars going on at the Department, either on the downtown site, or out at the Bullard Laboratories
Updated: 48 min 3 sec ago

Thu 19 May 11:30: Optofluidic hollow-core photonic crystal fibre

Mon, 16/05/2022 - 09:53
Optofluidic hollow-core photonic crystal fibre

Liquid-filled hollow-core photonic crystal fibres (HC-PCF) are excellent optofluidic microreactors in which light propagates in well-defined modes at the centre of a microchannel [1]. They enable efficient photochemistry, photo-switching, and photocatalysis at optical powers that are five orders of magnitude lower than in conventional reactors [1]. In addition, sample volumes in HC-PCF can be as small as a few nL per cm interaction length while meter-long optical paths enable sensitive absorption, fluorescence, and Raman spectroscopy.

In my talk, I will discuss how optofluidic HC-PCF can help improve our understanding of photochemical and electrochemical processes relevant to the green energy transition.

First, we demonstrate an operando Raman spectroscopy method that tracks the chemistry of liquid electrolytes during battery cycling. An optofluidic hollow-core fibre is integrated into a working Li: ion cell and used to analyse sub-microlitre electrolyte samples at different stages of the charge-discharge cycle by background-free Raman spectroscopy. The observed changes in electrolyte composition are related to the solid electrolyte interphase (SEI) formation and can reveal early signs of battery degradation [2].

Second, we use HC-PCF, connected to microfluidic coupling cells, to optimise photocatalytic “solar-fuel” generation in hybrid colloidal systems that combine molecular catalysts with particulate light absorbers. We focus on carbon-nanodots, one of the most promising light-absorber materials, due to their unique combination of scalability, biocompatibility, water solubility, and stable optical properties [3]. Key to improving their performance in solar catalysis are charge-transfer processes that we investigate and optimise through fibre-based absorption [4], fluorescence [8], and Raman spectroscopy [9].

Finally, I will briefly discuss how holographic spatial light modulation techniques can be used to excite higher-order modes in HC-PCFs, with the aim to selectively probe surface- and bulk processes within optofluidic microreactors [7,8].

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Thu 19 May 11:30: Crystallisation fouling from aqueous solutions of clathrate hydrates and CO2 injection into an anticline

Mon, 16/05/2022 - 09:17
Crystallisation fouling from aqueous solutions of clathrate hydrates and CO2 injection into an anticline

Anastasia Karela – Crystallisation fouling from aqueous solutions of clathrate hydrates

Paddy Mortimer – CO2 injection into an anticline

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Thu 16 Jun 11:30: The Geobattery Concept – a sustainable future for shallow geothermal resources?

Wed, 11/05/2022 - 15:18
The Geobattery Concept – a sustainable future for shallow geothermal resources?

Heating the air in our buildings is responsible for almost ¼ of all UK CO2 emissions and is a sector we need to decarbonise quickly to meet net zero targets. Abandoned coal mines have huge potential to provide a low carbon heat resource due to their expected connectivity and transmissivity, readily available warm water, and their co-location with heat demand. However, we need to be careful how we develop these resources to avoid over exploitation because heat demand is often far greater than recharge rate. At the same time industrial processes exhaust ~46 TWh of excess heat per year into the atmosphere squandering an important and valuable resource. In this talk I will present recent work from our group at the University of Edinburgh investigating the energy balance of shallow geothermal resources and thermal energy storage from both an energy and reservoir stability perspective. I will also introduce the Geobattery concept as a possible way of recycling industrial excess heat to maximise mine water heat potential and ensure the effective management of shallow geothermal resources.

Bio

Andrew Fraser-Harris is a post-doctoral research associate in GeoEnergy at the University of Edinburgh. He studied for an MSci in Geology at the University of Birmingham with a year at the University of Auckland which sparked his interest in Geoenergy, particularly geothermal energy. He then did an MScR and PhD in coupled process modelling before continuing onto a post-doc at Edinburgh combining experimental equipment development with numerical modelling to study radioactive waste disposal, conventional and unconventional hydrocarbon recovery, rock mechanics, integrated risk assessments, and geothermal energy. His recent focus is on technologies to decarbonise heating through low temperature resources.

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Wed 11 May 16:00: Investigating the Afro-Arabian rift system with passive seismology

Mon, 09/05/2022 - 11:37
Investigating the Afro-Arabian rift system with passive seismology

In this seminar, I will report challenges and achievements related to the management of a portable network of broadband seismic instruments. The presentation has two main parts. In the first part, I will present the motivations for running a passive seismic network in the Olduvai basin, also referred to as the “Cradle of Mankind”, located off the southern tip of the eastern branch of the East African Rift. I will show how our network contributed to the planning of the next round of paleoanthropological investigations in the Olduvai basin and to the general understanding of the East African Rift evolution. In the second part, I will give an overview of the current seismic networks that we run in the western portion of the Arabian plate with the goal of revealing the big mysteries of the Red Sea rift and its collateral elements, such as transform faults, fracture zones and volcanism.

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Tue 31 May 12:00: Title to be confirmed

Sat, 07/05/2022 - 01:53
Title to be confirmed

Abstract not available

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Tue 17 May 12:00: [Geoscience in Context] Skills for sustainable geoscience: evidencing transition in Energy and Higher Education

Sat, 07/05/2022 - 01:53
[Geoscience in Context] Skills for sustainable geoscience: evidencing transition in Energy and Higher Education

Geoscience and engineering play critical roles in tackling the climate crisis and enabling sustainable development. Rapid growth in subsurface technologies such as geological CO2 storage, hydrogen storage and geothermal are anticipated to deliver and live in a Net Zero future. However, there has been a long-term downturn in student uptake of geoscience subjects in higher education. There is already huge demand for engineering graduates which is set to increase. Might our ability for geoscience applications to contribute to Net Zero be hindered by a future skills gap? Further, minority groups and marginalised communities are poorly represented in STEM and particularly in geoscience, and, globally, the energy sector is one of the least diverse. If this isn’t addressed, might growth in subsurface net zero technologies for the energy transition drive inequalities?

In this talk, Jen will explore these challenges and their interaction with the transition to a fair and sustainable future for all. She will also present evidence of recent shifts in geoscience degree programmes towards sustainable geoscience problems (with particular focus on structural geology and the energy transition) to make the discipline more attractive to STEM -engaged students.

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Tue 10 May 12:00: The evolution of the geobiological nitrogen cycle This is a hybrid event. The talk will be given via Zoom (https://zoom.us/j/99984123581), and screened live in the Tilley Lecture Theatre.

Sat, 07/05/2022 - 01:45
The evolution of the geobiological nitrogen cycle

Nitrogen limits biological productivity in large parts of the modern ocean, and it may have constrained the proliferation of life over Earth’s history. This talk will discuss how nitrogen isotopes can be used to reconstruct the evolution of nitrogen availability through time. Furthermore, hydrothermal vents and lightning will be discussed as potentially important nutrient sources that may have helped sustain the early biosphere.

This is a hybrid event. The talk will be given via Zoom (https://zoom.us/j/99984123581), and screened live in the Tilley Lecture Theatre.

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Tue 10 May 12:00: The evolution of the geobiological nitrogen cycle This is a hybrid event. The talk will be given via Zoom (https://zoom.us/j/99984123581), and screened live in the Tilley Lecture Theatre.

Fri, 06/05/2022 - 15:31
The evolution of the geobiological nitrogen cycle

Nitrogen limits biological productivity in large parts of the modern ocean, and it may have constrained the proliferation of life over Earth’s history. This talk will discuss how nitrogen isotopes can be used to reconstruct the evolution of nitrogen availability through time. Furthermore, hydrothermal vents and lightning will be discussed as potentially important nutrient sources that may have helped sustain the early biosphere.

This is a hybrid event. The talk will be given via Zoom (https://zoom.us/j/99984123581), and screened live in the Tilley Lecture Theatre.

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Tue 10 May 12:00: Title to be confirmed This is a hybrid event. The talk will be given via Zoom (https://zoom.us/j/99984123581), and screened live in the Tilley Lecture Theatre.

Fri, 06/05/2022 - 14:53
Title to be confirmed

Abstract not available

This is a hybrid event. The talk will be given via Zoom (https://zoom.us/j/99984123581), and screened live in the Tilley Lecture Theatre.

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Wed 11 May 16:00: Title to be confirmed

Thu, 05/05/2022 - 12:59
Title to be confirmed

Abstract not available

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Tue 07 Jun 12:00: Title to be confirmed

Thu, 05/05/2022 - 00:55
Title to be confirmed

Abstract not available

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Tue 17 May 12:00: Title to be confirmed

Thu, 05/05/2022 - 00:54
Title to be confirmed

Abstract not available

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Tue 14 Jun 12:00: Title to be confirmed

Thu, 05/05/2022 - 00:49
Title to be confirmed

Abstract not available

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Tue 24 May 12:00: Crust formation and deformation on the rapidly rotating early Earth

Thu, 05/05/2022 - 00:46
Crust formation and deformation on the rapidly rotating early Earth

The last event in the main stage of Earth’s accretion is thought to be the Moon-forming giant impact. A planet-sized body slammed into the proto-Earth, injecting material into orbit out of which the Moon formed. The huge torques exerted during the impact meant that the early Earth was rapidly rotating, with a day between ~ 5 and 2.5 hrs. As a result, Earth was significantly oblate, with a ratio of polar to equatorial radii between 0.9 and 0.5, with a very different physical structure (e.g., internal pressure, surface gravity) than at present. As the Moon receded from Earth, the planet’s spin period increased and its shape changed dramatically, becoming roughly spherical within a few 10s Myrs. This is a key period of Earth’s history in which the first crust formed, the initial atmospheric composition was set, and the conditions for Earth’s subsequent evolution established. However, little work has been done to understand the role that Earth’s rapid rotation played during this epoch.

We used petrological, tidal evolution, and planetary structure calculations to determine the effect of Earth’s distorted and changing shape on the early crust. We find that the composition and thickness of a terrestrial crust formed by decompression melting of the primitive mantle varied with latitude due to the varying surface gravity. We demonstrate that the change in shape of Earth caused by lunar tidal recession drove extensive deformation of this early crust during the first few 10s Myr after the giant impact. There would have been extension in polar regions and convergent tectonics in the equatorial regions at rates potentially higher than those forming the Himalayas today. Such substantial deformation could have forced hydrated crust to depth, driving secondary melting and the production of more evolved magmas. A tectonically active early Earth could explain the diversity of lithologies recorded in the early zircon and rock records.

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Wed 18 May 16:00: Earthquake ground-motion assessment and rupture behaviours of induced seismicity from deep geothermal production

Wed, 04/05/2022 - 15:16
Earthquake ground-motion assessment and rupture behaviours of induced seismicity from deep geothermal production

With UK’s net-zero carbon emissions goal for 2050, geothermal energy has become a promising renewable energy source with its low carbon footprint. In 2020, it stood for 4.5% of UK’s renewable energy, and there are several geothermal projects planned for the near future. However, one of the risks associated with geothermal production is induced seismicity. Although small microseismic events are natural at geothermal sites, a few recent cases of larger earthquakes overseas have alarmed the public, caused damage, and paused or halted the energy development. Thus, as UK is developing its geothermal sites, it is important to analyse the first earthquakes available from each location to better understand how the regions respond to ground motions and how the earthquakes behave.

Using a local Raspberry Shakes seismic network, we examined the induced earthquakes from the United Downs geothermal site in Cornwall, UK, and found that the region experiences more high-frequency content than expected based on relevant models. We also concluded that low-cost Raspberry Shakes are a suitable alternative for preliminary seismic hazard analysis in regions lacking seismic networks. Additionally, we investigated the first induced earthquakes from the Helsinki, Finland, deep geothermal site to get a closer look at the rupture behaviour of the earthquakes, identifying clear rupture directivity and complex behaviour similar to larger, natural earthquakes.

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Wed 04 May 11:30: The Generic Mapping Tools and Community-Maintained Open Source Software

Tue, 03/05/2022 - 15:56
The Generic Mapping Tools and Community-Maintained Open Source Software

The Generic Mapping Tools (GMT; www.generic-mapping-tools.org) is a well-known set of software for the geosciences, in particular in the marine and solid earth disciplines. GMT is also a prerequisite for many other well-known software infrastructures, including USGS ’s ShakeMap for near-real-time maps of ground motion and shaking intensity following significant earthquakes, MBARI /LDEO’s MB-System for multibeam processing and mapping of the seafloor, and Scripps Institution of Oceanography’s GMTSAR for radar interferometric analysis and imaging of crustal deformation. Today, GMT has tens of thousands of users all over the world and remains essential for many terrestrial and planetary data processing and map-making workflows. GMT began its life over 30 years ago when I was a graduate student, and it has enjoyed continuous US National Science Foundation funding since 1993. Leveraging this funding, GMT has succeeded in establishing itself as a collaborative Open Source community resource from the start. Many scientists globally, particularly European scientists, have been instrumental in designing, maintaining, and improving GMT since the early 2000s. As I and several of our core developers approach the end of our academic careers, the GMT team has been pondering how to preserve these collective investments and position GMT to remain an essential geoinformatics infrastructure well into the future. In response, we have made fundamental changes to how GMT works, enabling access to GMT modules from external interfaces such as MATLAB /Octave, Python, and Julia, simplifying user access to large global datasets, and extending our support for the Google Earth platform. However, the biggest impact delivered by the Fall 2019 release of GMT 6 is likely “modern mode”. Modern mode coexists with classic mode (the only previous mode) so that thousands of GMT 4 and 5 scripts will still run as expected. Furthermore, new users will start with modern mode and experience a much-simplified GMT scripting syntax. A new aspect of GMT made possible by modern mode is a greatly simplified animation production. It is clear to all scientists that animations make it easier to elucidate temporal or spatial changes, yet very few scientists create animations as they are traditionally the domain of experts. The GMT team aspires to make animations a task every scientist can do with ease. In this lecture, I will discuss the latest news on GMT , outline modern mode and the external environment access to our modules, highlight a few GMT animations, and present other aspects of our succession planning for strengthening the GMT community.

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Thu 09 Jun 11:30: The Geobattery Concept – a sustainable future for shallow geothermal resources?

Tue, 03/05/2022 - 15:46
The Geobattery Concept – a sustainable future for shallow geothermal resources?

Heating the air in our buildings is responsible for almost ¼ of all UK CO2 emissions and is a sector we need to decarbonise quickly to meet net zero targets. Abandoned coal mines have huge potential to provide a low carbon heat resource due to their expected connectivity and transmissivity, readily available warm water, and their co-location with heat demand. However, we need to be careful how we develop these resources to avoid over exploitation because heat demand is often far greater than recharge rate. At the same time industrial processes exhaust ~46 TWh of excess heat per year into the atmosphere squandering an important and valuable resource. In this talk I will present recent work from our group at the University of Edinburgh investigating the energy balance of shallow geothermal resources and thermal energy storage from both an energy and reservoir stability perspective. I will also introduce the Geobattery concept as a possible way of recycling industrial excess heat to maximise mine water heat potential and ensure the effective management of shallow geothermal resources.

Bio

Andrew Fraser-Harris is a post-doctoral research associate in GeoEnergy at the University of Edinburgh. He studied for an MSci in Geology at the University of Birmingham with a year at the University of Auckland which sparked his interest in Geoenergy, particularly geothermal energy. He then did an MScR and PhD in coupled process modelling before continuing onto a post-doc at Edinburgh combining experimental equipment development with numerical modelling to study radioactive waste disposal, conventional and unconventional hydrocarbon recovery, rock mechanics, integrated risk assessments, and geothermal energy. His recent focus is on technologies to decarbonise heating through low temperature resources.

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