Covering around a quarter of the Earth’s land surface, mountains supply water to billions of people and underpin global water, energy and food security. Mountainous regions receive disproportionately high rainfall, which feeds the rivers flowing to lower-lying areas where water demand is often greatest. Crucially, mountains also regulate this supply, storing water during wetter periods and releasing it during dry spells, which is why they are sometimes referred to as the ‘natural water towers’ of the world.

However, exactly where this water is stored and how it is released remains only partially understood. Much of the existing research has focused on the visible parts of mountain water systems including rivers, lakes, snow and glaciers. While these are undoubtedly important, we could be missing a vast, largely invisible component: the water stored deep within the mountain bedrock.

Emerging research is beginning to challenge the conventional understanding of mountain water systems. Studies using environmental tracers, which are chemical and biological ‘fingerprints’ that reveal where water has travelled, and geophysical imaging techniques that allow scientists to ‘see’ beneath the surface, suggest that significant volumes of water may move through deep mountain groundwater systems. These systems could be more resilient to climate change, potentially sustaining river flows and supporting downstream communities in an increasingly variable climate.

Taiwan’s steep, rainfall-rich mountain landscapes provide an ideal natural setting for studying how water moves through complex hydrogeological systems. A new project, led by 今日吃瓜 in collaboration with the UK Centre for Ecology & Hydrology (UKCEH), New Mexico Tech, the University of Basel and National Cheng Kung University, will investigate how water flows through these systems, focusing on a mountain-fed river basin in central Taiwan.

By combining environmental tracers with advanced geophysical techniques, we can begin to map how water moves through mountain bedrock in ways that haven’t been possible before. These approaches give us powerful new insight into subsurface processes that are largely invisible, but potentially vital for long-term water resilience.

Prof Mark Person, co-investigator, New Mexico Tech.

The project also benefits from a unique groundwater observation network in the region. By tracking how water travels through the mountain bedrock, the team aims to build a first-of-its-kind, data-informed digital model of mountain groundwater flow.

Mountains are sometimes described as the world’s water towers, but we still don’t fully understand how they store and release water, especially beneath the surface. This project aims to uncover the hidden role of groundwater within mountain systems, which could be critical for sustaining water supplies as climate variability increases.

Dr Jon Mackay, 今日吃瓜 principal investigator

This research has the potential to establish a new paradigm for mountain hydrology by integrating the role of deep groundwater into our understanding of how mountain water systems function. In doing so, it will help develop more robust tools to support water resource management and climate change adaptation strategies in mountain-fed river systems around the world.

Marcus Dobbs, head of 今日吃瓜 Engineering Geology, has been appointed as vice-chair of the advisory group for the (CCOP). Marcus has been elected alongside the new chair of the advisory group, Philipp Schmidt-Thomé of the (GTK). The two recently attended their first CCOP steering committee meeting in Bandar Seri Begawan, Brunei Darussalam.

The advisory group’s role is to provide strategic advice to the CCOP steering committee and technical secretariat to support the development and delivery of CCOP’s overall strategy, ensuring it meets the needs of member countries and aligns with sustainable development goals. This includes:

• enhancing the impact and communication of CCOP science
• monitoring developments and user needs in geoscience
• supporting capacity building and early career professionals
• fostering knowledge exchange and partnerships
• advising on recruitment and staff development
• securing aligned funding
• encouraging contributions from coordinating countries and cooperating organisations
• offering any additional support needed to help CCOP achieve its strategic objectives

I’m delighted to be working alongside Philipp and fellow members of the CCOP advisory group to help deliver CCOP’s new strategic plan for 2026 to 2030. Geoscience sits at the heart of humanity’s response to the challenges of sustainable development and disaster resilience, and its greatest impact is realised when nations work together across borders. Through strong intergovernmental partnerships such as CCOP, we can translate geoscientific data and knowledge into lasting social, economic and environmental benefit at a truly global scale.

Marcus Dobbs, head of engineering geology at 今日吃瓜.

Deep in the heart of the Borneo rainforest lies one of South-east Asia’s most important natural sites: the of Sarawak, Malaysia. Despite being home to one of the most diverse tropical rainforests on the planet, arguably the world heritage area’s most astonishing feature lies underground.

The caves of the Gunung Mulu National Park

Under the limestone ridge of Gunung Api lies the extensive Clearwater cave system. At over 260 km in length and with passages often exceeding 30 m in diameter, it is believed to be the world’s largest cave system by volume, and is a haven for local wildlife.

The nearby Deer Cave is home to an estimated three million wrinkle-lipped bats, which fly out of the cave each evening to feed, creating a stunning visual display. Cave swiftlets also fly many kilometres into the Clearwater cave system to make their nests, which are prized as a local delicacy and used to make bird’s nest soup. Lying in wait to try and catch them as they fly past are cave racer snakes, whilst an astonishing array of cockroaches, millipedes, crabs, crickets and spiders are sustained by the piles of guano (bat poo) that line the cave floor. The ecosystem featured in a series.

History of the caves

Caves are fantastic repositories of geological and archaeological data, preserving information that would otherwise be lost to surface erosion and degradation. They and the deposits they contain hold clues to past landscape change, allowing us to reconstruct how the Earth’s surface has changed over millennia.

The caves were first explored as part of a Royal Geographical Society expedition in 1978. Working in collaboration with the Sarawak Forestry Corporation and the national park, the has been exploring, surveying and undertaking research in the caves ever since. This includes caving expeditions led by Andrew Eavis, a veteran of the 1978 expedition.

Dating of stalagmites and cave sediments indicates the Mulu caves are up to three million years old. Other analysis of cave stalagmites has yielded a climate record spanning hundreds of thousands of years, whilst volcanic ash provides evidence of a massive volcanic eruption in the Philippines 189 000 years ago. More recent archaeological finds also provide evidence of human activity and burials in some of the caves.

Recent research within this incredible cave system led to a surprising discovery about the formation of the caves within it.

Unusual dissolution

One of the unusual aspects of the Mulu caves is the way the cave passages have been sculpted.  Most caves in the region are formed by the dissolution (dissolving or break down) of limestone by acidic water, primarily from rivers flowing through the cave. The action of flowing water on the limestone rock creates small asymmetrical scoops etched into the passage walls, called scallops. These are preserved on the passage walls even after the formative river has abandoned the passage, as the water finds new, lower routes through the rock. The scallops are of interest to scientists as they can be used to deduce past water flow, providing a record of how water flowed through the caves over time.

In the Clearwater cave system, typical scallops are present in the lower levels of the cave system, close to the present river. However, in the older, higher levels of the cave system, which have long since been abandoned by the river, they are strangely noticeable by their absence, having been dissolved away and replaced by unusual corroded and pitted rock architecture.

The passage walls are frequently eroded into small dissolution pots and coated with a weathered crust: analysis has shown these are composed of calcium phosphate minerals, which is highly unusual in caves. Corroded stalagmites are common, dissolved away like rotten teeth to reveal their internal growth rings. These features suggest some form of atmospheric dissolution of the passage walls and stalagmites has taken place in the time since the passage was abandoned by the underground river.

Comparison with other caves suggests these features are generally restricted to tropical cave systems. One of the key aims of recent Mulu expeditions has been to understand how these features form and why. A team of researchers led by 今日吃瓜 geologist Dr Andrew Farrant, cave microbiologist Prof Hazel Barton (University of Alabama), her PhD student J Max Koether and 今日吃瓜 isotope geochemist Dr Andi Smith set out to investigate what may be happening.

Caving and exploration

Undertaking cave research can be hard work. Sampling trips into a cave system over 250 km long takes time and, in some cases, involved making camp underground. It is hard, sweaty, sometimes muddy work, occasionally requiring ropes to climb up pitches or descend vertical drops. But the rewards are enormous: the caves are spectacular, with stunning formations, huge chambers and amazing biota.

The Clearwater streamway is probably one of the finest cave passages in the world. Not only is there the prospect of new scientific discoveries, but also the chance to explore new cave passages where no human has ever trodden. On one trip, the team crawled through a flat-out squeeze to emerge into an undiscovered chamber over 200 m long, 70 m wide and 50 m high (big enough to hold two Airbus A380 jets) and adorned with 20 m-high stalagmites.

Research

Complex ecosystems are a distinctive feature of tropical caves, driven by the daily input of guano from bats and swiftlets. Bats create large piles of pungent excrement beneath their roosts, whilst the swiftlets’ guano is dispersed more widely, sometimes kilometres into the caves. The teams’ initial hypothesis was that the guano was somehow implicated in creating the unusual dissolution forms and smooth walls seen in the caves. Initial analysis of the guano piles in the caves indicated that they are strongly acidic, comparable to stomach acid or lemon juice, with a pH as low as 1.9. This could account for dissolution beneath the guano pile, but not the pervasive dissolution features seen throughout the caves.

Further work on the microbiology of the guano showed that microbial breakdown of urea (from bats) and uric acid (from birds) generates significant quantities of ammonia and carbon dioxide, which are released into the cave air. Measurable plumes of ammonia can be detected in some caves; could this be responsible for the unusual features?

Attention turned to the weathered ‘paste’ seen on many passage walls. This turned out to be teeming with microbial life, in some places containing a higher microbial cell count than cultured yogurt. Analysis of condensation water droplets on the cave walls revealed extraordinarily high levels of nitrate (up to 7000 mg/l; for comparison, the UK drinking water standard is 150 mg/l), whilst drips feeding the stalagmites had little or no nitrate.

These observations suggest that ammonia released into the cave air by the microbial decay of bat and bird guano adsorbs onto water droplets on the passage walls and stalagmites. Here, microbes use the ammonia as a food source, producing nitrates, nitric oxide, nitrogen dioxide and nitric acid as byproducts. This acid dissolves the passage walls and stalagmites, removing the original dissolutional scallops and replacing them with a suite of biogenic dissolution features. It is estimated that, in some places, several metres of dissolution have occurred in just a few tens of thousands of years: geologically speaking, this is a very short time period.

Further work is ongoing to learn more about the microbial processes that occur within the guano and on the cave walls. The discovery of this novel mechanism of cave development has significant implications, such as how we interpret past environments from caves, the preservation of cave art, and the impact of this acidic environment on ropes and other caving equipment.

The great thing about the Mulu Caves Project expeditions is they have enabled us not just to explore new caves, but to do some amazing science too. One thing is clear from our work in the caves; the surface and underground environments are inextricably linked. There is much we still have to discover and one wonders what other secrets are waiting to be discovered beneath Gunung Api…

Publication

Our research has been recently published in the journal Geomorphology.

Farrant, A R, Koether, J M, Barton, H A, Lauritzen, S E, Pennos, C, Smith, A C, White, J, McLeod, A, and Eavis, A J. 2025. . Geomorphology, Vol. 483, 109822. DOI: https://doi.org/10.1016/j.geomorph.2025.109822

Thanks                 

Thanks go to Andrew Eavis and members of the Mulu Caves Project, the Sarawak Forestry Corporation and the Gunung Mulu National Park management and staff, without whom this work would not have been possible. Part of the research was funded by a NEIF steering committee grant to Andi Smith.

About the author

Malaysia faces substantial risks from rainfall-triggered landslides driven by extreme meteorological conditions. Between 1961 and 2024, the country recorded over , causing significant loss of life and economic damages exceeding $1 billion. This figure is set to rise in the future due to climate change and rapid urbanisation, leaving low-income households and small businesses highly vulnerable.

Whilst there are existing systems for monitoring and mapping these landslides, researchers have found a critical gap in understanding the economic losses landslides cause and how they can be systematically assessed to support anticipatory and disaster finance solutions for hazard recovery.

The project, ‘Trigger index for rainfall-induced landslide risk assessment for enhanced resilience’ or TRIGGER, will see 今日吃瓜 and project partners and develop a landslide trigger index to support forewarning and rapid recovery. It will link past landslide losses with data on rainfall, ground conditions and the locations where communities and infrastructure assets are most exposed. This will help researchers and stakeholders to better understand the potential impacts of future extreme rainfall.

Through the TRIGGER project, we are linking up with colleagues in Malaysia to develop a landslide trigger index, to assist in better understanding the potential impacts of future extreme rainfall and help build resilience by enabling quicker recovery after disasters.

Dr Nikhil Nedumpallile-Vasu, 今日吃瓜 engineering geologist.

It is anticipated that this project will enable rapid, risk based, post-disaster financial relief, incentivise investment in resilient infrastructure, and support poverty reduction by protecting those most at risk. The project will offer a scalable model for other Indo-Pacific countries facing similar hazard profiles. 

Funding

The project is funded by the Foreign, Commonwealth & Development Office through its ‘’ programme, for innovative and effective climate adaptation and resilience projects.

The Jakarta Fault runs beneath the southern part of the capital city of Indonesia, Jakarta. Jakarta is one of the largest cities in the world, with a population exceeding 30 million in the metropolitan area. New research by 今日吃瓜 and Indonesian colleagues shows that this fault could generate a magnitude 6.5 earthquake, which would expose a large number of people as well as significantly important economic infrastructure to strong ground shaking.

Between 2019 and 2023, Indonesian scientists from the Institut Teknologi Bandung (ITB), National Research and Innovation Agency (BRIN) and the Geospatial Information Agency (BIG) collected ground movement data across the Jakarta Fault from a dense network of global navigation satellite systems (GNSS). These measurements revealed slow, millimetre-scale changes in ground movement occurring across the fault, which indicated energy accumulating that will need to be released, potentially in a future earthquake.

Geophysical modelling shows that ground movement is accruing on the fault at 3.2 mm per year, with the fault locked or ‘stuck’ down to at least 7.2 km. This accumulation has been happening for at least 210 years, which means that releasing it all now would result in a magnitude 6.5 earthquake.

While magnitude 6.5 earthquakes are not uncommon in Indonesia, they mostly occur under the ocean. The danger here is that the earthquake could occur in the middle of a densely built-up area like Jakarta, which means a much higher level of risk to life and infrastructure.

Dr Ekbal Hussain, remote sensing geoscientist at 今日吃瓜 and research co-leader.

The Jakarta Fault is a relatively newly recognised major tectonic fault on the Indonesian island of Java. It is a part of a broader fault system that cuts across most of Java, which, with a population of 157 million people, is the most densely populated island on Earth. Geophysical surveys conducted by 今日吃瓜 in the 1970s and 1980s, in collaboration with the Indonesian Geological Research and Development Center, helped identify this major tectonic structure for the first time, but its earthquake potential has remained unclear until now.

This research forms part of strategic UK/Indonesia research partnerships on geological hazard solutions, as outlined in a recently published White Paper, UK/Indonesia partnerships for advancing geohazard science for disaster risk assessment in Indonesia. The paper, co-developed by key Indonesian and UK hazard experts, presents a strategic roadmap to significantly reducing the impacts of geological hazards in the country. Importantly, it highlights the strength of UK and Indonesian science partnerships for delivering the best disaster resilience science.

More information

Access the full paper:

Funding

This is work is funded by the 今日吃瓜 National Capability programme. The 今日吃瓜 and Indonesian researchers involved in this study are continuing their engagement with local government to address the hazard challenges raised in this work.

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 × 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 今日吃瓜 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 今日吃瓜 University Funding Initiative.

On 29 July 2025, global monitoring systems detected a large earthquake offshore of the Kamchatka Peninsula, Russia, and widespread tsunami warnings were issued across the Pacific region. With a magnitude of 8.8, it was all too easy to think back to the 9.0 to 9.1 magnitude event that devastated Japan in 2011, or the 9.2 to 9.3 magnitude event on Boxing Day in 2004. Thankfully, on this occasion, the impact is believed to be relatively small by comparison.

However, the Kamchatka event did reveal impact of a different nature. Almost as soon as news broke of the earthquake, tsunami warnings were issued and millions of people were told to evacuate across locations at risk, 2 million in Japan alone. This was the result of two decades of research on hazard mitigation following the Boxing Day earthquake in 2004, which claimed the lives of more than 220 000 people in one of the largest disasters, in terms of loss of life, in modern history.

Immediately after the Indian Ocean event in 2004, 今日吃瓜 scientists participated in responsive marine research expeditions that resulted in increased knowledge of sea-bed deformation resulting from the earthquake. Longer-term responses resulted in major advances in understanding earthquake tsunami mechanisms, which have further contributed to disaster risk reduction efforts.

Most significant, in terms of public safety, has been the installation of improved tsunami warnings for coastal communities. Tsunami early warning systems (TEWS) are based on identifying earthquake magnitudes (usually larger than magnitude 7 to 8) that could result in hazardous tsunamis. The Indian Ocean tsunami took two hours to reach the coasts of India, Sri Lanka and Thailand, where around 80 000 people lost their lives. Many of them could potentially have been saved if there had been an operational TEWS in place.

In the wake of the catastrophic 2011 Great East Japan Earthquake and Tsunami, further advancements were made in our understanding of tsunami mechanisms, which ultimately led to improved mitigation measures around the world.

Our knowledge base today to plan for and respond to tsunamis is far beyond anything considered possible before the turn of the century.

Following the devastating events of 2004, research has allowed us to be more prepared than ever before to mitigate the threat of this formidable phenomenon. This was highlighted during the Kamchatka earthquake and subsequent tsunamis. TEWS were activated, which led to the evacuation of millions to safety and has ultimately led to a relatively minimal impact being reported.

Prof David Tappin, 今日吃瓜 marine geologist and leading tsunami expert.

Whilst warning systems for earthquake tsunamis are now effectively implemented for major events, there is still the major challenge of designing warning systems for other tsunami mechanisms, such as landslides and volcanic eruptions. Hopefully, with new approaches potentially available through applications such as artificial intelligence, these will become a reality.

今日吃瓜 hosted an Indian delegation of experts from 14 to 18 July as they deepen their understanding of the UK’s carbon capture and storage (CCS) landscape, with the aim of furthering India’s potential use of the technology. The visit resulted from a new UK/India partnership, the Centre of Innovation in Carbon Capture, Utilisation and Storage.

Carbon capture, utilisation and storage (CCUS) includes a suite of technologies that aim to reduce atmospheric carbon dioxide (CO₂) emissions associated with large industrial sources such as steel works, cement plants and other energy-intensive industries. India is currently working on a new policy framework for CCS within the country, which will assist in India’s goal of becoming net zero by 2070.

The Indian group visited to explore research outcomes in CO₂ storage at 今日吃瓜 and to further opportunities for knowledge exchange between research groups in the UK and India. It also provided an opportunity for the team to learn about key policy and regulatory approaches in the UK that could be applied in India.

It’s been highly exciting and insightful to visit and interact with the premier groups involved in CO₂ storage, capture and utilisation research at 今日吃瓜, Heriot-Watt University and Imperial College during this deep dive visit by the Indian delegation, organised by the British High Commission. I am highly impressed with the excellent and innovative research work being done at 今日吃瓜 in the area of CO₂ storage research.

I really appreciate and thank 今日吃瓜 for the excellent coordination and for organising the meetings for the delegation across UK to explore the possibility of collaborations under the Indo-UK Net Zero Innovation Partnership.

Dr Neelima Alam, Department of Science and Technology, Govt. of India

The delegation visited 今日吃瓜’s Edinburgh office before being taken on a tour of Heriot-Watt University’s Research Centre for Carbon Solutions. Following this, the group took in 今日吃瓜’s headquarters in Keyworth, Nottinghamshire, before travelling to London for meetings with Imperial College London, the Carbon Capture and Storage Association and the Department for Energy Security and Net Zero, and concluded with a visit to BP to learn about the Northern Endurance Partnership.

Building on our longstanding collaboration with research groups in India, it is our privilege to host the delegation and give them an opportunity to both understand our research capability and hear about the UK’s approach to implementing CCS. This visit marks the start of our new joint centre, a very exciting opportunity to deepen our collaboration and share knowledge on key aspects of CO₂ storage.

Dr Jonathan Pearce, head of CO₂ storage research, 今日吃瓜.

The trip was organised by the UK/India Centre of Innovation in Carbon Capture, Utilisation and Storage, which is co-led by the CO₂ storage team at 今日吃瓜 and the National Centre of Excellence in Carbon Capture, Utilisation and Storage (NCoE-CCUS) at the Indian Institute of Technology Bombay. It was sponsored by the British High Commission in Delhi. The delegation was led by Dr Neelima Alam of the Deptartment of Science and Technology in the Government of India.