It is a common assumption that flooding arises as a result of intense rainfall. Whilst this is true in many cases, another common cause is actually groundwater flooding, where groundwater emerges at the surface. Groundwater flooding can occur in a variety of geological settings and poses a significant risk around the UK. In England and Wales alone, it’s estimated that groundwater flooding accounts for around £530 million in damages per year (ESI, 2016). The impacts can be devastating for farmers, local businesses and homeowners, and cause significant disruption across regional transport routes.

½ñÈÕ³Ô¹Ï geologists have started a four-year project that will enhance knowledge of ground conditions and undertake flood-pattern investigations around the River Tweed. This survey will provide crucial geological data for local authorities, organisations and others involved in land-management initiatives to the benefit of the 450 000 people who live in or around the flood-prone Borders region.

Much of the region was last surveyed in the 1920s (or earlier) and this latest project forms a central part of ½ñÈճԹϒs current national geological mapping programme. The picturesque landscapes so synonymous with the famous salmon river have been formed over millions of years. Most recently, they were sculpted by ice during the last glaciation, which ended around 19 000 years ago in the Tweed catchment.

Existing maps indicate that the area is dominated either by glacial till or bedrock but, in reality, it is a lot more complex than this, with a continuum from bedrock through weathered bedrock, slope deposits and till. These nuances will be a particular focus for geologists as they are likely to have an effect on how groundwater moves through the shallow subsurface, due to the more open pore space of slope deposits compared to till or bedrock. This enhanced understanding will help to provide baseline data for flood monitoring and forecasting for those in the environmental modelling and policy communities, as well as landowners, to make more informed decisions about the management of land in the catchment area.

Our understanding of glacial systems has evolved enormously in the hundred years since the Tweed catchment was last surveyed. In the 1920s, geological surveys were performed solely by walkover surveys, but now we are able to take advantage of high-resolution Earth observation data to understand and model these systems.

Creating new maps using a modern understanding of how ice sheets develop combined with this new data will improve our understanding of this crucial waterway and may enable us to use additional knowledge of ground conditions to assist with land-planning initiatives that will help manage flooding.

Sam Roberson, ½ñÈÕ³Ô¹Ï Quaternary geologist and Tweed project lead.

The Tweed project is exploring new technologies to create geological maps, combining artificial intelligence, high-resolution terrain data and field observations to understand how the different deposits affect the shape of our landscapes. Field studies began in the Cheviot Hills in spring 2025, before heading to the Tweedsmuir Hills during summer 2025 and around Melrose and Galashiels during autumn 2025. All fieldwork is completed on foot, making observations about the sedimentary exposures and the form of the landscape.

Geological maps produced from this work will form part of the national geological map, which can be freely accessed on the ½ñÈÕ³Ô¹Ï maps portal or via the on the ½ñÈÕ³Ô¹Ï website. Research papers and reports will also be accessible via the ½ñÈÕ³Ô¹Ï website and the service.

The lowland rainforests of south-east Asia are renowned for their exceptional biodiversity but are among the most threatened ecosystems on Earth. Mass flowering events in lowland tropical rainforests are generally triggered by environmental cues, particularly climatic changes such as drought or temperature fluctuations. However, there is increasing evidence that nutrient availability, particularly phosphorus, may also play a critical role in regulating these events and, through them, forest development. Phosphorus is an essential macronutrient for plant growth and productivity, but it is often a limited nutrient in tropical rainforest soils, which are highly weathered and nutrient poor.

In lakes, particles from a diverse range of inorganic, organic and biogenic detritus and volcanic ash can settle through the water column and onto the lake floor. Over time, layers of particles accumulate that can contain a wealth of information about the past environmental conditions in the lake and its watershed. My research aims to answer fundamental questions about how concentrations of essential nutrients, particularly phosphorus, derived from volcanic ash affect tropical forest composition, structure and flowering dynamics. In May 2025, I conducted a two-week fieldtrip to collect lake sediment cores and fresh soil and water samples at the Bulusan Volcano Natural Park, Sorsogon Province, Philippines.  

Lake Bulusan

Bulusan Volcano Natural Park is located in Sorsogon Province, Philippines, and stretches over 3673 hectares. It was first designated as a National Park in 1935. It consists of mixed forests, giant ferns and other plant species including ground orchids. Lake Bulusan itself is a 0.28 km² lake lying at the foothills of Mt Bulusan and has no inlets or outlets; instead it comprises a closed system fed primarily by precipitation and groundwater. The lake’s location and its ability to catch volcanic ash from volcanic eruptions over time makes it the perfect study site for my PhD project.

Fieldtrip

Conducting the fieldwork in the Philippines was not without challenges. Firstly, all necessary agreements and permits needed to be in place beforehand; this process was carried out during the first 15 months of the PhD project. In the week leading up to the trip, the volcano, which is located close to the fieldtrip site, erupted briefly and put the whole fieldtrip in jeopardy. Luckily the eruption did not cause any danger to the public or surrounding areas.

Our first stop was Manila, where the correct wildlife permit was provided by the Department of the Environment and Natural Resources — Biodiversity Management Bureau (DENR-BMB) to allow us to collect the samples. We then travelled down to Sorsogon Province, where we met up with our local collaborator Dr Ellen Funesto (University of the Philippines — Cebu) and lake coring expert Dr Wes Farnsworth (University of Iceland). After a day of recovery, the team headed into the Bulusan Volcano Natural Park to access Lake Bulusan for lake coring and sampling activities.

The lake coring was done on a semi-luxury 4 Ã— 3 m raft equipped with a table to sit at and an umbrella for shade, and we were assisted by six local fishermen who were all interested in the research and lake coring processes. Two local guides also helped the team navigate around the lake and through the forest, finding the best spots to collect fresh soil samples from the forest surrounding the lake.

Learning about the culture

As we collected samples, we also had time to enjoy some of the Filipino cuisine. With recommendations from our local collaborator, we tasted a range of dishes that are must-tries (at least in our opinion!) when visiting the Philippines, ranging from local fish bangus, through pork sisig to chicken teriyaki from the local chicken shop.

Additionally, the Philippines’ landscape offers scenery unlike anything I have seen before:  beautiful beaches, waterfalls, volcanoes and forest. Beyond the incredible food and stunning environment, the local people in the rural parts of the Philippines are some of the friendliest people I have met. They were welcoming and those who joined us on site to collect samples brought joy to the fieldwork at the natural park.

Next steps

The samples are now back at the ½ñÈÕ³Ô¹Ï headquarters in Keyworth and, over the next few months, we plan to explore the palaeo-nutrient histories hidden within the lake sediments, using core scanning alongside geochemical and stable isotope methods. In addition, there will be a trip to the University of Copenhagen, Denmark, later this year to extract ancient environmental DNA, which will help us understand how nutrient inputs from volcanic ash affect the tropical rainforest system.

Thanks

Thanks to our collaborators Dr Ellen Funesto and Dr Wes Farnsworth; without your assistance and expertise to the team the fieldwork would not have been possible. A special thanks also goes to Eleanor Lacsi De La Cruz from the Provincial Environment and Natural Resources Office (PENRO), who was on site all day and worked hard in both helping coring and securing all the necessary permits to export the samples back to Keyworth.

The work would not have been possible without the support of a huge number of people, especially the DENR-BMB, PENRO and DENR regional offices who issued the permits and have supported the project over the last two years.

About the author

Christopher Bengt is a second-year PhD student enrolled at Lancaster University. His PhD is funded through the Envision Doctoral Training Partnership and the ½ñÈÕ³Ô¹Ï University Funding Initiative.

As a geologist and geophysicist, my research focuses on understanding whether Scotland’s 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’s ancient granites may also be able to supply sustainable heat. The Cairngorm Pluton, part of the East Grampians Batholith, is one of the UK’s 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’s geology. 

Using magnetotellurics to explore below the surface

Magnetotellurics (MT) is a deep-sounding geophysical technique that uses the Earth’s 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: 

• ½ñÈÕ³Ô¹Ï 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’s 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’s 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 ½ñÈÕ³Ô¹Ï.

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

A re-survey of Strathmore, eastern Scotland, has been commissioned under ½ñÈճԹϒs national mapping programme. The area was last surveyed in the 1880s and the re-survey will provide updated geological data and information for the region. 

Field studies will be conducted between Montrose and Alyth from May to June 2024 and in September 2024 and spring 2025. The field survey will be done on foot, making observations of rock exposures, soils and the form of the landscape. Geological maps will then be drawn up using the field observations alongside analyses of borehole records, historic maps and remote-sensing datasets, such as digital terrain models and aerial photos.

The geology of the region includes the sandstones, siltstones and conglomerates of the ’Old Red Sandstone’, which were deposited by rivers in hot and dry conditions some 400 million years ago in the Devonian Period. The reddish colour of these rocks and the rich soils derived from them are characteristic of the region. The higher ground of the Ochil Hills is underlain by volcanic rocks, which are typically associated with acidic soils.

The survey will address questions about the arrangement of the sandstones, conglomerates and volcanic units and develop new understanding of how they have been deformed by faulting and folding.

The results will also help ½ñÈÕ³Ô¹Ï to better understand ground conditions and the pathways for groundwater flow, supporting groundwater management and assessments of geothermal resource potential. In the future, this will help farmers and other rural businesses identify more reliable groundwater sources and make decisions around investment in ground-source heat pumps.  Geological maps produced from this work will form part of the national geological map, which can be freely viewed on the ½ñÈÕ³Ô¹Ï maps portal or on the on the ½ñÈÕ³Ô¹Ï website. Research papers and reports will also be accessible via the ½ñÈÕ³Ô¹Ï website and services.

The Strathmore area was last surveyed nearly 100 years before we knew about plate tectonics and before there were aerial photos. With this re-survey, we can re-shape our understanding of a key part of Scotland’s geological past by looking at these rocks and structures with new eyes, both in the field and using modern digital data resources.

Katie Whitbread, ½ñÈÕ³Ô¹Ï Survey Geologist and Strathmore project lead.

For further information about ½ñÈÕ³Ô¹Ï and the Strathmore project, please contact ½ñÈÕ³Ô¹Ï enquiries (enquiries@bgs.ac.uk) or telephone 0115 9363100.

I have recently returned from a couple of weeks of fieldwork on Mount St Helens volcano in the Cascades, US, with Julia Eychenne from Laboratoire Magmas et Volcans (LMV) Volcanology, France and David Damby from the United States Geological Survey, and in collaboration with the Cascades Volcano Obervatory. The focus of our fieldwork was the , which produced the largest debris avalanche in recorded history as much of the northern flank of the volcano was removed. This avalanche led to a powerful blast which stripped much of the surrounding area of trees and produced a plume of ash that lofted to more than 30 km above sea level. Ash was dispersed many hundreds of kilometres away from the volcano. Plinian plumes, pyroclastic density currents and lahars (mixtures of volcanic material and water) followed and continued over the following months.

Given the scale and the range of eruptive behaviour that occurred during this eruption, it presents a case study that enables scientific investigation from a range of perspectives. Across our field team, interests ranged from eruption dynamics, human health impacts and ash resuspension. We dug holes through the deposits to allow us to access the whole sequence of the eruption, collecting blast samples and ash deposits from several locations across the blast area.

While we initially focused on the 18 May 1980 blast deposits, a day in the field with Cascades Volcano Observatory scientist Heather Wright introduced us to deposits from several older eruptions from Mount St Helens which also piqued our interest.

Over the coming months, the team will conduct geophysical and chemical analyses to improve understanding of the deposits, providing further insights into the eruption.

The fieldwork was made possible through collaboration with Cascades Volcano Observatory. Many thanks to Alexa Van Eaton, Heather Wright and Richard Waitt for providing lots of context on the eruption, deposits and field relationships, and ensuring we had a great trip!

About author

In early September 2022, eight geologists from different disciplines across ½ñÈÕ³Ô¹Ï completed the applied glacial geology field-based training course in north Norfolk, led by ½ñÈճԹϒs Emrys Phillips and Jonathan Lee. The course benefits geoscientists working on applied projects where glacial geology will affect ground conditions and properties of the shallow subsurface, such as offshore windfarms.

During the course we visited Sheringham, West and East Runton, Happisburgh and Weybourne. We were able to develop skills to describe and interpret glacial sediments and deformed materials, and their influence on ground conditions both on and offshore.

Day 1: Happisburgh and Weybourne

On the first training day, we drove to Happisburgh. We were lucky with the weather not only on the first day but also throughout the field course. With a beautiful sea view, Emrys and Jon introduced us to the topic of glacial geology and explained the history of coastal erosion at the site. At Happisburgh, we examined several cliff sections through the , the Ostend Clay Member and the .

In the afternoon we drove up the coast to Weybourne, where we encountered the , which overlies bedrock. The shallow marine sands and gravels of the Wroxham Crag directly overlie a brecciated chalk unit, which exhibits evidence of periglacial features such as frost heave, soft-sediment deformation and hydrofracturing.

Day 2: East Runton and the West Runton Mammoth

On Day 2, we visited East Runton, where we learned more about glacitectonic chalk rafts (massive blocks of glacially displaced chalk bedrock), their direction of emplacement and the development of ice-marginal sand basins. We also examined the preglacial deposits that are exposed to the east of West Runton, including the Wroxham Crag Formation (shallow marine) and the West Runton Freshwater Bed, which is an organic deposit. Since the 19th century, the latter has become well-renowned with amateur and professional fossil collectors, because it yields both floral and faunal fossil remains and provides much information on the climate and environment during a preglacial interglacial period. The remains of the world-famous West Runton Mammoth were also discovered at the site in the early 1990s.

Day 3: West Runton

On the third day, we visited the coastal section to the west of West Runton, where we continued to learn about chalk raft emplacement and preglacial and glacial stratigraphy and started to think about how glaciers interact with sediments beneath and in front of them. Cliff sections at West Runton record the transition from proglacial through ice-marginal to subglacial environments, which produces distinctive styles of sedimentation and deformation. We also compared the resultant glacitectonic mélange and structure to interpreted seismic cross-sections from the Dogger Bank area of the North Sea, which shows similar features offshore.

Day 4: Sheringham and Skelding Hill

Our fourth and final day started off dry and bright as we started with an ascent of Skelding Hill, which offers a stunning panoramic viewpoint of the coastline between Cromer and Weybourne. From our vantage point, we were able to get a better view of the geomorphology of the area, helping us piece together the broader glacial history.

We then walked down the hill to the beach, where we found some natural beach analogues in the sand that we were able to relate to the glacial activity, including a miniature braided river system.

We walked along the coast to the see the cliff face directly under the summit of Skelding Hill. Here we split into teams and were set challenges to describe the structural geology, geomorphology and unitisation of the glacial sediments we could see in the cliff face.

In the afternoon, we had to dodge several very dramatic-looking rainstorms. However, they quickly passed and this meant members of the team could enjoy a quick pasty and cake in one of Sheringham’s local bakeries. At the end of the day, Jon and Emrys provided a summary of the week and presented a geological model for the history and direction of glaciation in north Norfolk. All members of the team thoroughly enjoyed the trip and look forward to applying our new skills going forward!

This course was one of many scientific and technical support activities funded and organised by ½ñÈÕ³Ô¹Ï Learning and Development.

About the authors

As with many people suddenly finding themselves working at home, my natural flow of work has been disrupted. When I got the opportunity to get out into the fresh air recently to undertake some fieldwork, I wanted to share the benefits this had on me and my team at ½ñÈÕ³Ô¹Ï, and to talk a bit about the work we’ve been up to.  

Missing fieldwork

Lockdown has been a tough journey for most of us. I’m sure I’m not alone in saying that working from home has had some advantages and some disadvantages. It’s certainly cut down on things like petrol use and spending money, but a major disadvantage is missing out on bumping into colleagues in the office and having those organic, face-to-face conversations, exploring ideas and discussing the research we’re working on. And, for geologists especially, being unable to go out on fieldwork and learn more about the world around us has been very affecting.

Trialling Tromino

My role at ½ñÈÕ³Ô¹Ï is mostly office-based, but I love being in the outdoors generally (I’m a massive nature nerd!) so I thoroughly enjoy any fieldwork I can take part in. I am part of the Shallow Drilling Facility at ½ñÈÕ³Ô¹Ï Keyworth, along with Helen Smith and Dave Morgan, who are both pushing forward a passive seismic technology called Tromino. Their fieldwork proposal came at the perfect time to lift my spirits, allowing me to feel part of a team again, as well as providing me with some more experience with the Tromino technology.

The Tromino is a small box that measures the natural rumblings of the Earth and can be deployed really easily. It takes 8–12 minute readings in one spot; then you can move on to a new spot for more readings and continue thus to complete a transect of several points. Once the data is downloaded and run through the software it can provide a cross-section type view of the geology, with a particular emphasis on picking out changes in velocity between geological units. It’s a really neat piece of equipment and a great addition to ½ñÈճԹϒs geophysics team.

Helen and I undertook the fieldwork and she was a perfect field partner! She did all the hard work by getting the various COVID-19 forms filled out and approved, arranging the actual work and liaising with various landowners to get access. The fieldwork lasted two weeks and, in that time, we got some very mixed weather, but even two days of constant rain in the second week still didn’t dampen our spirits! We completed seven transects involving more than 400 points (roughly 50 points per day). We saw some wonderful scenery and could take pleasure in the nature around us, which for me helps to keep me grounded and gives me the freedom to think.

The opportunity to go on fieldwork with ½ñÈÕ³Ô¹Ï colleagues and reignite the sense of community and teamwork is one I feel very grateful for.

Collaborating and integrating other data

We also caught up on a water borehole being drilled by another company. This was fantastic as it gave Helen and I the opportunity to see a bigger rig in action. We will be able to use the geological data from the other rig to calibrate our Tromino results because it gives us a better understanding of the ground. This was a great bit of collaborative work! At the end of all this we’ve hopefully created some useful data for the project to take into the 3D environment, which can be used to constrain the geological ground model.

We are really keen to encourage people to use the Tromino kit, as it can provide some good data to feed into 3D modelling, for example, but the data should be tied into borehole data in order to calibrate the results. The Tromino data needs to be processed before it can be visualised properly; to do this you need to understand a bit about the ground before you start. Borehole data can provide those measurements, which can be input to create the velocity measurements and conversions inside the software. For this reason, Tromino and our drilling rig are a perfect partnership!

If you want to find out more about the Tromino or the Shallow Drilling Facility then please get in touch.

About the author

The demand for battery raw materials, such as lithium and cobalt, is increasing rapidly as we transition to a low-carbon economy and work towards net zero. The COVID-19 pandemic has disrupted normal working activities, including some of the ‘real-world’ geological fieldwork essential to the research that will help accelerate the shift towards zero-emission electric vehicles.

Geological research is a highly collaborative activity but, under current UK restrictions, fieldwork outside of the local area is very difficult to undertake. Focusing on lithium exploration, this article explains how virtual field reconnaissance can help maintain research momentum.

Virtual field reconnaissance

During the pandemic, ½ñÈÕ³Ô¹Ï and have been working in partnership with Yacimientos de Litio Bolivianos (YLB)  on the -funded project, which aims to better understand the lithium resource in the salt flats (salars) of South America. The research aim is not only to understand the sources of lithium in the volcanic rocks of the Andes Mountains, but also how it is liberated from these rocks and then transported, by surface water and underground water, to the salars.

Once the lithium is in the salar, we want to understand how it is deposited in the salt as the water evaporates. In addition, we seek to better understand how it can be moved around and concentrated by salt-rich brines. This research will lead to a better knowledge of lithium resource efficiency.

‘Resource efficiency means using the Earth’s limited resources in a sustainable manner while minimising impacts on the environment. It allows us to create more with less and to deliver greater value with less input.’

Geological mapping using satellite imagery

Remotely sensed satellite imagery and data play an important part in mapping the geology. Different rocks reflect different amount of sunlight in different regions of the electromagnetic spectrum; the satellites are able to record this information in infrared areas that the human eye cannot see. The imagery can therefore be processed to highlight reflections that characterise different rocks and minerals, meaning the geologist can see these subtle differences.

Understanding the geometric relationships between different geologies is crucial to understanding their ages and position in the succession. High-resolution terrain models, when combined with the processed satellite imagery in the GeoVisionary 3D environment, allow these relationships to be easily understood.

Some of the key questions in Bolivia concern where the lithium originates and also where it is most likely to be picked up by water to be transported to a salar. Geological processes and understanding tell us that it is the ignimbrites (deposits of ash, glass and rock particles following explosive pyroclastic flows), rather than the extrusive lavas, that will be richer in lithium. However, the majority of the lithium will reach the surface and groundwater from modern sediments (sands and gravels) that have eroded from the ignimbrites.

GeoVisionary was already a proven environment for more effective and targeted fieldwork. In this case it proved to be an excellent means by which the entire project team could collaborate effectively and clearly, overlaying and analysing multiple datasets all within a single context-rich tool.

The outcomes of using GeoVisionary for virtual reconnaissance fieldwork have been to identify:

• geometrical relationships and hence relative ages of different rock types
• ignimbrites
• sediments derived from the ignimbrites

About the author

More information

Find out more about or contact ½ñÈÕ³Ô¹Ï Enquiries.