As a geologist and geophysicist, my research focuses on understanding whether Scotland radiothermal granites could help unlock a new source of sustainable geothermal energy for the UK. In summer 2024, I conducted a three-week field campaign to study the potential for geothermal energy in the Cairngorms with a team of other geoscientists. 

The Cairngorms: more than just mountains

Geothermal energy is often associated with places like Iceland or other volcanic hot spots, but Scotland ancient granites may also be able to supply sustainable heat. The Cairngorm Pluton, part of the East Grampians Batholith, is one of the UK highest heat-producing granites, with intriguing geothermal potential. My work combines geophysical surveying with laboratory experiments to explore this potential, whilst addressing uncertainties about the region geology. 

Using magnetotellurics to explore below the surface

Magnetotellurics (MT) is a deep-sounding geophysical technique that uses the Earth natural electromagnetic field to produce images of the conductivity properties of the rocks in the subsurface. It can also be used to map features like fluid pathways and fractures located several kilometres below the surface. These pathways are critical for geothermal energy because they act as conduits for the fluids transporting heat. 

During my fieldwork in the Cairngorms, we set up 24 MT stations using instruments on loan from the NERC Geophysical Equipment Facility across the region. These were deployed by a team comprising myself and: 

• 51ÁÔÆæ staff members 

• Heriot-Watt University staff 

• other postgraduate researchers 

• a Cairngorm ranger 

• a University of St Andrews undergraduate student 

The MT equipment uses two types of sensor:  (1) non-polarisable electrodes, which measure the ground electric field, and (2) induction coil magnetometers, which measure changes in the magnetic field. The setup at each site required us to bury the sensors to protect them from the fierce weather conditions.

The data collected from the sensors will allow us to produce images of the Earth electrical resistivity below the surface using a mathematical process called data inversion. Ideally, the images could show zones with lower electrical conductivity, where fractures in the rocks are present within the resistive granite. These could be potential geothermal reservoirs from which heat can be extracted.

Fieldwork challenges and discoveries

Conducting fieldwork in the beautiful but bleak Cairngorms is both rewarding and challenging. With no roads in much of the area, we had to carry our equipment, including a 20 kg battery, over many kilometres of hiking paths and sometimes beyond any trails. Navigating deep bogs, steep bouldery terrain and elevations of up to 1250 m while braving sudden weather changes was an adventure in itself. In June 2024 we had seven consecutive days of snow fall on the mountain!

In addition to the MT fieldwork, I surveyed the geological structures and outcrops and collected samples for later laboratory analysis. One memorable moment came when we discovered a zone of extensive hydrothermal alteration of the granite near Stob Coire an t-Sneachda. This is possible evidence of hot fluids chemically changing the rock many millions of years ago. This alteration is significant because it could enhance the porosity and permeability of the rock, which are crucial factors for geothermal reservoirs.

Why it matters

Geothermal energy offers a constant, low-carbon source of heat, making it a promising candidate for the UK renewable energy mix. Additionally, its small land footprint and minimal surface infrastructure requirements mean it can provide sustainable energy with reduced visual impact, preserving the natural landscape. My research aims to de-risk geothermal exploration in Scotland, providing the scientific basis for future projects that could benefit communities and combat climate change.

Next steps

With my first year of fieldwork complete, I’m back in the laboratory, analysing samples and processing the MT data to build a three-dimensional resistivity map of the Cairngorm Pluton. Combining geophysical models with laboratory-based analyses will bring us closer to understanding the geothermal potential of this region of Scotland.

Thanks

Thanks go to Nathaniel Forbes Inskip and Andreas Busch from Heriot-Watt University and Juliane Huebert from BGS.

All images kindly reproduced with permission. For enquiries about the images within this article, please contact the copyright team (IPR@bgs.ac.uk).

Collaboration can provide an exchange of information vital to the advancement of environmental research. One such partnership is the relationship between BGS and the University of Eldoret (UoE) in Kenya. This partnership not only demonstrates the benefits of international collaboration but also highlights the importance of addressing global challenges collectively.  

Job Isaboke (UoE) and Sophia Dowell (BGS) are research students at their institutions and have been to measure the rate of soil erosion in western Kenya using novel chemical methods. For their PhD projects, they aimed to understand the effect land management can have on soil erosion using plutonium isotopes (Sophia) and the associated loss of micronutrients from the soil (Job), which is important for crop composition and onward dietary intake for animal and human health.

Soil erosion  

Soil erosion is a widespread environmental issue that poses a significant threat to agricultural productivity, water quality and ecosystem health worldwide. In Kenya, soil erosion is driven by factors such as deforestation, unsustainable land-management practices and climate change. However, quantitative data describing the amounts and patterns of soil erosion and sedimentation can be used to inform sustainable soil conservation practices. This data can also aid in the validation of predictive models for an improved understanding of factors influencing the acceleration of erosion processes.ÌýÌý

Working together 

One of the primary advantages of international cooperation is the sharing of expertise and resources. Bringing together diverse backgrounds benefits research at both BGS and UoE by combining advanced technologies and methodologies, such as specialist mass spectrometry methods to detect ultra-trace plutonium in the UK, with invaluable local knowledge and on-the-ground insights from Kenyan counterparts. This allows for a more comprehensive approach to studying soil erosion, encompassing both scientific rigour and practical applicability.  

Ultimately, the collaboration between BGS and UoE stands as a key step toward securing the sustainable future of this agriculturally crucial region and works towards addressing several of the , including: 

• poverty (SDG 1) 
• life below water (SDG 14) 
• life on land (SDG 15)  
  

Beyond scientific advancements, working together to research soil erosion fosters cultural exchange and capacity building. Through joint research initiatives, Job and Sophia have been able to learn from each others’ perspectives, approaches to research and experiences. This cultural exchange has not only enhanced both their roles as early-career researchers, but has also strengthened relationships between BGS and UoE to promote mutual understanding.  

The international collaboration also contributes to the development of scientific capacity in Kenya. By providing training opportunities, mentorship, networks and technology transfer for members of both UK and Kenyan institutions, early-career researchers are empowered to tackle environmental challenges independently.

The opportunities created by this collaborative project collectively and individually demonstrate the potential for scientific research to address environmental issues whilst developing scientific capacity in Kenya and the UK. The two-way exchange of staff and paired Kenya/UK PhD students, including Job and Sophia, provided an enriching experience for all involved.

Michael Watts, head of the BGS International Geoscience Research and Development programme

So much can be achieved with collaboration and a working international team breaks much more than just academic barriers. The larger body of knowledge would benefit through building collaborations globally, as this work has demonstrated.

Prof Odipo Osano, University of Eldoret, Kenya

Through this partnership, Sophia and Job are working towards informing evidence-based decision making and developing targeted interventions to mitigate against future soil erosion. Through attending workshops and conferences, they have both had the opportunity to engage with stakeholders ranging from policymakers and land managers to farmers and community leaders. These workshops have allowed them to understand the best way to communicate their research to different stakeholders and further their understanding of the usability of the data, working on ways to target future research to ensure the maximum impact.  

Through fostering dialogue and knowledge exchange, the collaboration works towards the eventual adoption of sustainable land-management practices and helps to adopt agricultural practices aimed at preserving soil health and preventing erosion. 

I feel my PhD research wouldn’t have been possible without the support from Kenyan counterparts at the University of Eldoret. Both Job and Prof Odipo Osano in-depth knowledge of the local area and dedication to the research have been invaluable. Without their help, the fieldwork wouldn’t have been possible, especially during the COVID-19 pandemic where I wasn’t able to travel to Kenya to conduct the work myself. But, above all else, I feel this PhD opportunity has allowed me to grow, both professionally and personally, into the scientist I am today and for that I am extremely grateful.

Dr Sophia Dowell

As part of the collaboration, Sophia recently gained her PhD in ‘Utilising plutonium isotopes to evaluate soil erosion in tropical East African agri-systems’ and Job has gained a master degree in environmental science; he is now working towards his PhD in ‘Dynamics of soil micronutrient loss and transfer as influenced by land management’. 

As a PhD student from Kenya, I am grateful for the collaboration between UoE and BGS, which provided me with both laboratory training and financial resources. I appreciate the support from my UK supervisors, Dr Michael Watts and Dr Olivier Humphrey, and the entire BGS inorganic chemistry department team.

To be a successful scientist, one must undergo extensive training using advanced instrumentation and learn laboratory etiquette. Within the framework of my PhD research, I am currently working with Dr Sophia Dowell to determine soil erosion dynamics in tropical locations and link this to micronutrients in soils.

Job Isaboke

Acknowledgements  

This research was conducted with the financial support of the following funders:  

• 51ÁÔÆæ/NERC grant NE/R000069/1, entitled ‘Geoscience for Sustainable Futures’  
• 51ÁÔÆæ Centre for Environmental Geochemistry programmes 
• NERC National Capability International Geoscience programme, entitled ‘Geoscience to tackle global environmental challenges’ (NE/X006255/1)  

Additional financial support from:  

• The Royal Society International Collaboration Awards 2019 grant ICA/R1/191077, entitled ‘Dynamics of environmental geochemistry and health in a lake-wide basin’ 
• Natural Environment Research Council ARIES Doctoral Training Partnership (grant number NE/S007334/1)  
• 51ÁÔÆæ University Funding Initiative (GA/19S/017)  

Additional support from:  

• British Academy Early Career Researchers Writing Skills Workshop (WW21100104) 

About the authors 

Sophia Dowell is an analytical geochemist working within the BGS Inorganic Geochemistry Facility in Keyworth. Prior to this, she was a BUFI PhD student funded by the NERC ARIES doctoral training programme. This PhD was in collaboration with BGS, the University of Plymouth and the University of Eldoret in Kenya. 

Job Isaboke is a PhD researcher funded by BUFI/The Royal Society in collaboration with BGS and the University of Eldoret. He has had the opportunity to work within the UK alongside BGS during his PhD but is mainly based in Eldoret, Kenya.  

My name is Christopher Bengt and I am first-year PhD student enrolled at Lancaster University and I am being hosted at the BGS by the Stable Isotope Facility. My PhD is funded through the and the 51ÁÔÆæ University Funding Initiative. My research aims to understand fundamental questions about how tropical forest composition, structure and flowering dynamics are affected by the concentrations of essential nutrients, importantly phosphorus, in the soil. 

My previous research 

Prior to taking this post, I completed my master degree (MRes) in biological science at Birkbeck, University of London, where I studied the extraction of DNA from archaeological animal bones. This work involved using a number of analytical methods to assess the level of damage to the bones, indicating the extent of preservation of ancient DNA. Whilst studying, I also worked on immune response to vaccines and infectious diseases as a laboratory technician at the World Health Organisation Pneumococcal Serology Reference Laboratory at University College, London. All these skills stand me in good stead for my PhD, which will have significant laboratory and fieldwork requirements.  

Tropical rainforests 

Tropical rainforests are the oldest living and most complex ecosystems on Earth, with evidence from fossils and pollen dating back 70 million years. Being in the tropics, the rainforests have a stable climate consisting of warm temperatures, high precipitation levels and high levels of solar irradiation, providing essential conditions for highly productive forests. The stable climate, abundant resources and millions of years of evolution mean biodiversity in tropical rainforests has flourished, resulting in countless species with specialised adaptations.  

The effect of volcanoes on tropical ecosystems 

Unexpectedly for such diverse and productive ecosystems, rainforest soils are often of poor quality, with low concentrations of nutrients including carbon, nitrogen, potassium, and phosphorus. However, in areas such as the Philippines (my study area), volcanic eruptions can deposit nutrient-rich ash directly into the tropical rainforest environment. Volcanic ash is composed of fine rock particles that can be expelled and then deposited over vast areas, many kilometres from the original site of eruption. These particles contain essential nutrients such as potassium and phosphorus, and it is hypothesised that these may be critical for soil enrichment.  

Whilst volcanic eruptions can pose an immediate threat to local ecosystems, the aftermath may help foster these fertile environments. The relationship between volcanoes and nutrient-rich soils underscores the dual nature of these natural phenomena that are both destructive and transformative.  

Past records of climate 

To better understand the relationship between volcanoes and tropical ecosystems, we must explore past records of volcanic activity and forest productivity. These are often best found within lake sediment archives.  

Lakes serve as repositories of environmental history through the sediments that accumulate at their bottoms. The sediments are composed of organic and inorganic materials and encapsulate a wealth of information, telling us about crucial nutrients (including phosphorus) and serving as archives of ecological changes. My project will analyse both the nutrient makeup of the lake sediments and the ancient DNA preserved within them. In combination, these records will allow us to investigate the links between nutrient dynamics, ecosystem productivity and plant and tree diversity.  

For my project, I will undertake a fieldtrip to Lake Bulusan at Mount Bulusan, one of the most active volcanoes in the Philippines, which is surrounded by rainforest. Cores of the sediment from the lake will be brought back to the UK to interrogate the geochemical signatures trapped within them. The sediment cores will also be sent to the University of Copenhagen, Denmark, to extract and analyse modern and ancient DNA.  

These records should tell us more about how climate, volcanic activity and biological history are linked throughout the last 2000 years. This multiproxy approach will uncover critical information regarding the modern phosphorus cycle and soil limitations, as well as the true impact volcanic events have had on the phosphorus cycle in the palaeorecord and, in turn, the development and flowering of the surrounding tropical forest. The findings could potentially offer a ‘step change’ in our understanding of tropical forest development in volcanically active regions.  

About the author

Christopher Bengt is a first-year PhD student enrolled at Lancaster University. His PhD is funded through the and the 51ÁÔÆæ University Funding Initiative.

My name is Maureene Auma Ondayo and I am a 51ÁÔÆæ-funded PhD candidate at the University of Eldoret, Kenya, and BGS, with a background in environmental and public health. In this blog I will share my PhD research, investigating major and trace element exposure in the environment. This includes ores, soils, sediment and waters, locally grown staple food crops (maize, leafy vegetables, pulses and tubers), and human samples (hair, nails and urine). My research also incorporates risk factors of exposure to potentially harmful elements (PHEs) and associated health implications among artisanal and small-scale gold mining workers and local residents.  

What is artisanal and small-scale gold mining?  

Artisanal and small-scale gold mining (ASGM) is an informal mining sector that provides subsistence-level livelihoods for many rural communities across the world. In Kenya, ASGM occurs in Migori, Narok, Siaya, Vihiga, Kakamega, Nandi, Kisumu, Turkana, West Pokot, Marsabit, Homa Bay and Kericho counties. It is estimated that ASGM production yields around 5 metric tons per year (worth around £250 million), employing 250 000 workers with more than 1 million dependents. The main environmental and health risks associated with ASGM relate to poor conditions at mining camps and mining operations, which include the extensive misuse of mercury in the production process.   

Mining the gold 

Miners often rely on local knowledge when prospecting for gold after which agricultural land and pristine forests are cleared to make way for the mine. Ores are excavated and broken into smaller pieces using sledgehammers and mills, dispersing large volumes of contaminated dust across nearby environments and communities. Milled ore powder is then wetted and sluiced to extract the gold particles. Panning separates gold-associated sediment particles, then liquid mercury is added, which joins together with the gold to form an amalgam and separates it from the sediment. The amalgam is then burnt on open flames, vaporising the mercury and leaving behind the gold, whilst tailings and wastewater from ASGM are disposed of in nearby farms, residences, playgrounds and waterways. 

These activities expose the workers and local populations to extreme health and safety hazards, with injuries, diseases and premature deaths reported in ASGM areas.  

Hazards of ASGM 

Exposure to potentially toxic elements (PTEs), physical hazards, gaseous emissions, overexertion, physical injuries and poor ventilation inside the mines are the key hazards to human health in ASGM. This exposure results in a wide range of health disorders including:  

• cancers 
• immunity suppression 
• neurological disorders 
• developmental health effects  

Socio-economic issues related to mining activities are also present in local areas, including alcohol and addiction, violence and HIV/AIDs.  

My research 

During my PhD, I investigated the environmental and human exposure and health implications among nineteen ASGM communities in Kakamega and Vihiga counties, Kenya. 

I collected soil, sediment, water, locally grown food and human biomarker samples (hair, nails and urine) from ASGM workers and residents of ASGM villages and analysed them for major and trace elements at BGS Inorganic Geochemistry Facility in Keyworth. Further risk factors from PTE exposure and potential health effects among the studied ASGM communities were assessed through interviews.  

Study results 

Kakamega and Vihiga counties are naturally enriched with macro- and micro-elements and the ASGM activities primarily disperse them across surrounding environments and communities. The results show that:  

• soils, sediments and water sources in the ASGM villages were highly polluted by PTEs, including arsenic, mercury, chromium, lead and nickel 
• soil concentrations of arsenic, chromium and nickel in the studied ASGM villages were 154, 9 and 4 times higher than background concentrations, respectively 
• drinking-water samples in the ASGM villages, including springs, shallow wells and mine shafts, were heavily polluted with arsenic, lead and chromium. Very worryingly, we observed mine workers and residents drinking mine-shaft water, the most contaminated water at the ASGMs, when they were extracting the ore!  
• locally grown staple food crops were also contaminated with arsenic, nickel, lead, chromium, cadmium, mercury and aluminium, and were not considered safe for consumption  

The inhalation of gaseous PHEs like mercury during amalgam burning, the consumption of locally grown staple food crops and drinking water, and ingesting PTE-contaminated dust and soils (especially children and pregnant women that exhibit pica, that is, eating non-food items like soil) were the main exposure pathways found in our study. Self-reported potential pollution-related health effects included cancers, neurological effects, respiratory infections, musculoskeletal effects, infectious diseases including HIV/AIDS, and malaria.    

Working with the ASGM community 

A key aspect of my PhD was the multidisciplinary research approach taken to understand the relationships between the environment, diet and public health to effectively assess and communicate human exposure and health risks. We continue to collaborate with ASGM workers, local communities and local health practitioners while sharing our findings.  

On 2 December 2023, we met with county public health administrators to understand how best to present and share the data for interpretation with our key stakeholders. These include: 

• politicians 
• broader county employees 
• the departments of mining, environment, and law enforcement 
• community health workers 
•  the studied ASGM communities in both Kakamega and Vihiga counties 

Additional meetings with public health officers, medical practitioners, environment and agricultural departments and other key stakeholders are planned. This will let us share our results and recommendations on reducing PTE exposure through environmental, occupational and public health safety controls, such as: 

• providing safer drinking water to ASGM communities 
• relocating residences and schools away from ASGM activities  
• controlling dust transfer 
• encouraging regular personal protective equipment (PPE) use 
• alternatives to mercury 
• safer cyanidation operations 
• wet milling 
• technological interventions in ore exploration, excavation, processing and recovery 
• targeted education and training on industrial hygiene 
• public health policy formulation in ASGM in Kenya 

This study characterised PHE exposure pathways and health risks among ASGM communities in the Kakamega gold belt. Our findings are valuable to public health authorities as they inform them of the mitigation actions that are needed to research further, reduce exposure, improve ASGM processes, and protect the environment, food sources and the health of ASGM workers and residents, including policy formulation. 

About the author 

Maureene Auma Ondayo is a 51ÁÔÆæ-funded PhD candidate at the University of Eldoret, Kenya, and BGS, with a background in environmental and public health. 

Co-authors  

Prof Odipo Osano is an environmental toxicologist at the University of Eldoret, Kenya. He has a background in veterinary medicine, public health, and community and laboratory-based environmental epidemiological research.   

Clive Mitchell, BGS Industrial Minerals Geologist.   

Dr Olivier Humphrey, BGS Environmental Chemist.   

Dr Michael Watts, BGS Head of Inorganic Geochemistry and lead for BGS International Geoscience Research and Development.   

Soil erosion processes present the greatest risk to land degradation worldwide and, due to fertile soil being an essential resource, there is increasing concern around the world regarding accelerated soil erosion, particularly in developing countries.

The analysis of plutonium (Pu) in soil samples can inform the understanding of soil erosion processes globally. However, there are specific challenges associated with such analysis in tropical soils, so an optimal analytical methodology that ensures the best sensitivity is critical.

Why use plutonium?

Due to their long retention times and minimal spatial variability, Pu isotopes have proven useful as an alternative fallout radionuclide tracer for determining soil erosion rates. To utilise Pu as an effective soil erosion tracer in the southern hemisphere, separation techniques and analyses need to be optimised to establish a robust analytical method for the determination of ultra-trace level Pu isotopes. This method must also have sufficient sensitivity for African soil samples, which typically have very low Pu concentrations compared to the northern hemisphere.

This research aimed to accurately establish fallout Pu activity concentrations in tropical soils in order to determine soil erosion rates with an improved separation and analysis method for ultra-trace Pu determination. To achieve this aim we had to:

• adapt and optimise a separation method using trialkyl methylammonium nitrate (TEVA) cartridges to remove matrix interferences with pre-concentration of ultra-trace Pu isotopes (this reduced waste and increased throughput)
• establish a robust analytical method for the determination of ultra-trace level Pu isotopes with sufficient sensitivity for African soil samples using oxygen as a reaction gas for inductively coupled plasma mass spectrometry (ICP-MS)

The development of robust analytical methods to determine rates of soil erosion and its effect on land degradation is vital to advise mitigation strategies, ultimately ensuring the future sustainability of soils.

Sophia Dowell, PhD student at BGS.

Where does the plutonium come from?

Pu is present in the environment primarily because of nuclear weapons testing. Between 1945 and 1980, 520 atmospheric tests were conducted worldwide; however, only 10 per cent of these experiments were conducted in the southern hemisphere. This resulted in significantly less fallout in the tropics than in the mid-latitudes of the northern hemisphere, which makes the analysis of ultra-trace Pu isotopes in tropical soils challenging.

The challenge of plutonium analysis

Due to their long retention time and minimal spatial variability, Pu isotopes have recently been used as an alternative fallout radionuclide tracer for determining soil erosion rates. As a result of the long half-lives of ²³⁹Pu and ²⁴⁰Pu (24 110 and 6561 years, respectively), approximately 99 per cent of the original activity remains in soils. This means they are suitable as stable, long-term tracers compared to, for example, 137 caesium (Cs), despite Cs’s significantly higher activity in the environment, as Cs only has a half-life of 30 years. Additionally, more than six times as many atoms of ²³⁹Pu and ²⁴⁰Pu were initially dispersed compared to ¹³⁷Cs. This combination of long half-life and higher atom content makes mass spectrometry (MS) techniques better suited to Pu isotopes, whereas radiometric decay counting techniques are more appropriate for the higher specific activity ¹³⁷Cs.

Consequently, recent developments in mass spectrometry techniques have the potential to increase the sensitivity of Pu isotope quantification and subsequently the availability of analytical methods applicable to tropical soils. This raises the potential of using Pu as a soil erosion tracer in the tropics, where the risk of soil degradation is increasing due to extreme weather patterns.

A powerful tool

This method presents a simple, cost-effective, robust sequence with reduced laboratory waste disposal, which is vital to ensure the separation method is applicable to low-resource laboratories. Along with the low detection limits that are comparable to alternative MS methods, this outcome makes the method applicable to the detection of ultra-trace fallout Pu in African soils.

Due to increasing concern regarding accelerated soil erosion and its impact on sustainable intensification of agriculture in developing countries, this work provides advancements in the detection of Pu. The new method is also a powerful tool for the analysis of ultra-trace Pu in African soils, ultimately improving the determination of soil erosion rates in tropical soils to better inform mitigation strategies.

This method has the potential to improve access to advanced soil erosion measurements that could be produced faster than traditional laboratory techniques to enable analyses at scale, yet with greater accuracy than machine learning predictions based on remote sensing data in developing countries which are most at risk to land degradation.

Sophia Dowell, PhD student at BGS.

Funding

51ÁÔÆæ led the research in conjunction with the University of Plymouth and the University of Eldoret in Kenya.

Sophia PhD was supported by the NERC funded ARIES doctoral training programme (grant number NE/S007334/1), and from the NERC International National Capability grants to BGS (NE/R000069/1 and NE/X006255/1), Royal Society International Collaboration grant (ICA/R1/191077), British Academy (WW21100104) and BGS University Funding Initiative (GA/19S/017).

More information

The full research paper is available: .

In south England and the Midlands, about 70 per cent of drinking water is sourced from groundwater. This groundwater is home to a wide variety of microscopic organisms that have interactive relationships with the surrounding abiotic and biotic environments, together constituting the groundwater microbial ecosystem. These microbes provide useful services, including pathogenic microbe inactivation and pollutant biodegradation: essentially, the microbes help maintain the quality of the groundwater we consume.

With increasing scientific understanding of groundwater ecosystem services, the water supply companies and Government agencies that are responsible for environmental and public health are paying more attention and investigating the best ways to protect undisturbed groundwater ecosystems. However, this can be difficult because the groundwater and microorganisms are out of sight, making it very tricky to study them. There is also no clear knowledge about what an undisturbed baseline microbial ecosystem should look like or how it can be protected.

This problem is the focus of my PhD, which I am working on at the BGS office in Wallingford, Oxfordshire. For fieldwork, I need to travel all over the Midlands to collect microbial samples from groundwater, which is why I recently travelled to Nottinghamshire and buddied up with Ankita Bhattacharya, another BUFI student who is based at BGS headquarters in Keyworth.

Our fieldwork was carried out at the groundwater pumping stations of Severn Trent Water, where raw groundwater is pumped before it is sent to the supply chain. We collected samples to determine environmental DNA (eDNA), nutrients and the age of the groundwater and we recorded different physiochemical parameters like pH, conductivity, dissolved oxygen and groundwater temperature in as many as 11 locations in and around Nottingham.

Having a field buddy made the otherwise exhausting fieldwork experience truly enjoyable for both of us. We got a chance to explore Nottinghamshire in a different way and have seen huge farmlands, chaotic animal farms, dense forests, peaceful villages, quiet lanes and busy roads. We drove on roads with both smooth concrete and no concrete at all, across landscapes with gentle, sloping floodplains and up steep hill roads with hairpin bends, all of which made the experience memorable.

The eDNA we collected will be sequenced to identify the different microbial species present in groundwater. I will then compare the ecosystem collected from the groundwaters of different regions to find variations in undisturbed ecosystems. As part of my project, I will also address the reasons for microbial ecosystem variations and take samples for environmental variables through sampling for chemical analysis of dissolved organic matter, dissolved nitrogen and dissolved carbon.

Funding

Both of Archita and Ankita are studying under the .

About the authors

Archita Bhattacharyya (Wallingford) and Ankita Bhattacharya (Keyworth) are both BUFI PhD students studying at BGS.

Human activity has led to excess phosphorus concentrations and the continued over-enrichment of coastal and fresh waters across the United States. Alongside colleagues from Union College in New York and Lancaster University, BGS scientists are researching the biogeochemical cycling (how specific chemicals cycle through the biological and geological components of the Earth) of .

What is eutrophication?

Eutrophication is the process by which water becomes progressively enriched with minerals and nutrients, for example phosphorus and nitrogen. It can affect both coastal and fresh waters and can be caused by excess phosphorus entering the water system. Natural eutrophication is a very slow process, but it can occur much more rapidly when pollution accumulates from human sources such as sewage and fertilisers. Eutrophication can cause harmful algal blooms, leading to oxygen depletion in the water and damage to local ecosystems.

Previous and new research

This new research follows on from studies initially undertaken in the UK in 2016 (Gooddy et al., 2015; Ascott et al., 2016) that looked at mains water leakage and the associated inputs of phosphate that this causes. However, these studies only considered mains water leakage: the new study employs an innovative way of determining previously unaccounted-for phosphorus sources at a much bigger scale. It estimates, for the first time, the amount of phosphorus that enters the environment from the US public water supply.

Phosphorus in US public water supplies

Public water systems across the United States widely dose water with phosphate (PO₄) to control the corrosion of lead and copper within water distribution networks. When pipes leak or people water their lawns, this phosphate enters the environment and can find its way into rivers and groundwater. About 5 to 17 per cent of this phosphate-dosed water leaks out of water mains, whilst 5 to 21 per cent is used outdoors. In some parts of the US, the amount of phosphorus entering the environment from the water supply exceeds that coming from point sources like wastewater treatment plants, or from agriculture and fertilisers.

Developing a more effective phosphorus management policy requires a comprehensive understanding of phosphorus sources and routes into the environment, which are known as fluxes. These fluxes should be considered in relation to other sources of phosphorus in the aquatic environment (Gooddy et al., 2017) and can inform localised phosphorus management practices.

Future work

The next step is to look at carbon cycling and greenhouse gas emissions from water use in the US. A sister study, which was published by the same authors in 2022, looked at how water supply processes are responsible for significant nitrogen fluxes (Flint et al., 2022).

Researchers and funding

51ÁÔÆæ is the lead on this research with PhD candidate Elizabeth Flint supervised by Dr Matthew Ascott and Prof Daren Gooddy. There has also been input to the work from Dr Mason Stahl from Union College, NY, USA and Dr Ben Surridge at Lancaster University, UK.

This work has been funded through ENVISION DTP with supervisor support provided through the BGS BUFI programme and National Capability funding through Groundwater Processes.

Further reading

References

For my PhD project I am using laboratory experiments to investigate when roofs may collapse under tephra loads. ‘Tephra’ comprises all the material ejected during an explosive volcanic eruption, including ash and larger particles. Buildings close to an eruptive source are at risk but, on pitched roofs, the tephra deposit will sometimes slide off and this is what I am testing. My results will help emergency planners to identify buildings most at risk from tephra fall and allow designers to take account of tephra loads when planning new buildings.

The eruption of Cumbre Vieja on La Palma, which started in September 2021, provided a great opportunity to ground truth the results from my lab work. I was very pleased to be invited to spend a few days at the beginning of December with the emergency team from the Instituto Geológico y Minero de España (IGME, the Spanish geological service) to assess building damage. Time is of the essence when collecting data during an eruption and so, after a hectic day getting a risk assessment approved, booking flights and accommodation and completing all the COVID-related paperwork, I was on my way to the Canary Islands.

Arriving at the hotel in Breña Baja, I could see black ash dusting the pavements in the town and the white volcanic plume (of water vapour) rising above the hills, but there was no disruption to day-to-day life. The hotel guests were a strange mix of tourists and emergency workers, including teams of firefighters who were clearing the roofs of houses to make sure tephra did not build up to dangerous depths.

On my first day with IGME, we travelled into the exclusion zone. This was a tightly controlled area: my name had to be on an approved list and we were signed in and out every day. IGME geologists took readings at key checkpoints to monitor how much tephra had fallen in the past week, as well as lava samples for lab analysis. We inspected roofs in Las Manchas where the tephra depth was around 1 m; the roofs of some outbuildings and weaker structures had collapsed but houses where the tephra had been cleared were undamaged. The roof of the large wrestling arena had completely collapsed.

On my second day we visited Tacande, a village being subsumed by lava, where lava flows were up to 10 m deep. We again took tephra depth measurements and collected samples to measure density and porosity of the deposit, which both affect the load and so the likelihood of roof collapse. In the evening, one of the houses we had surveyed was completely destroyed by a new lava flow. The power of the eruption was awe inspiring.

For my final day in the field, we visited the villages of Tajuya and La Laguna. Here there were vast greenhouses of bananas but the crops were dying as ash had got inside the structures. It is likely to be two years before new crops can be harvested. This highlighted the devastating impact of the eruption on the local economy.

The Cumbre Vieja eruption is now over and the residents of La Palma are assessing the damage and starting to plan for the future. I am using the field data to refine estimates of loads that lead to roof collapse, which will assist emergency responders in future eruptions. There is still much to learn about the impact of volcanic eruptions, but each survey of an affected area increases our knowledge and enables us to reduce the risk to people living in volcanic areas.

I owe huge thanks to the IGME staff: Inés Galindo Jiménez for arranging my visit and Julio López Gutiérriez and Javier Martnez Martnez for taking me with them on their field work.

About the author

Sara Osman is a BGS BUFI student at the University of Leeds. Her BGS supervisor is Dr Julia Crummy, a volcanologist at the BGS office in the Lyell Centre, Edinburgh.