STREVA will bring together researchers from universities, research institutes and volcano observatories, to explore methods for reducing the negative consequences of volcanic activity on communities. We will work both with communities facing volcanic threats and with those responsible for monitoring, preparing for and responding to those threats. Our main partners are volcano monitoring agencies and observatories in Colombia, the Caribbean and Ecuador, and through them, disaster managers and disaster researchers throughout the region, as well as residents of communities at risk. We will use a number of techniques to build links between the project and the wider community, including workshops, running scenario exercises, and using social media to report our results. Our aim, by working collaboratively across different disciplines, is to develop and apply a risk assessment framework that will generate better plans to reduce the negative consequences of volcanic activity on people and assets. Volcanic risk is a complex problem, which we shall understand by investigating a number of volcanoes, at-risk communities, emergencies and policy responses across the region. These case studies will help us to identify common issues in volcanic disaster risk and ultimately develop regional risk assessment processes. These will be crucial for long-term planning to reduce exposure to volcanic hazards. The countries in which we will work are all middle income and face multiple volcanic threats, often in close proximity to large towns and cities. The main focus will be on six volcanic sites across the Lesser Antilles, Ecuador and Colombia. We will begin the project by reviewing the secondary literature on three well monitored and active volcanoes, to analyse what has already been done to understand and reduce risk to the surrounding population. Through in-depth empirical research in these volcanic areas we shall begin to develop, test and apply our new risk assessment framework and methods for application. We will then take these lessons and apply them to three high-risk volcanoes where monitoring and understanding is less advanced. STREVA's work will generate improvements in: (i) methods for forecasting the start of eruptions and changes in activity during eruption; (ii) prediction of areas at-risk (the "footprint") from different volcanic hazards; (iii) understanding of the factors that make people and their assets more vulnerable to volcanic threats; (iv) understanding of institutional constraints and capacities and how to improve incentives for risk reduction By the end of the project, our new knowledge will help us to measure volcanic risk more accurately and monitor how that risk is changing. The practical results will be a strengthening in the capacity of stakeholders at different scales (staff in volcano observatories, local and national governments and NGOs) to produce risk assessments for high-risk volcanoes and use them to improve preparedness and response to volcanic emergencies and build resilience in the surrounding communities through long-term planning. In adopting this approach, STREVA will have real impacts in real places, and will significantly advance the fields of volcanic risk analysis and disaster risk reduction.

The SPECTRA programme seeks to enhance the sustainable development of one of the poorest regions of China, Guizhou, through cutting edge critical zone science undertaken by integrated, complementary and multidisciplinary teams of Chinese and UK scientists. The key question for management of the karst landscapes of SW China is "how can the highly heterogeneous critical zone resources be restored, to enable sustainable delivery of ecosystem services?" We know little about the geological, hydrological and ecological processes which control soil fertility and soil function in these landscapes and how best to manage them to maximise ecosystem service delivery. SPECTRA has been designed to address these questions through a suite of 4 interlinked workpackages. The CZ will span a gradient from undisturbed natural vegetation through to human perturbed and highly degraded landscapes. Using cutting-edge approaches we will integrate measurements of: (1) the three-dimensional distribution of plants (including roots), soil, fungi, and microbes; (2) rates of rock weathering, elemental release and soil formation processes; (3) rates of erosion and soil redistribution; and, (4) pools and fluxes of soil organic C (SOC), nitrogen (N) and phosphorus (P). This will allow us to identify the biological controls on nutrient availability, soil formation and loss in the CZ and their response to perturbation, providing the rich evidence base needed to inform land management decision-making in the Guizhou province. In doing so, SPECTRA will directly address the Newton Fund objective of enhancing economic development and social welfare by providing rigorous applied scientific knowledge that will underpin the development of strategies to improve net ecological service delivery from the karst landscape, informing realistic economic and ecological compensation plans to alleviate poverty, particularly for the households that rely on fragile soils for a living. The project is also designed to maximise the benefits to the science communities of both countries, thereby bringing significant institutional benefits to all partners. Training of Chinese Early Career Researchers in state-of-the-art approaches and techniques in leading UK laboratories is an absolute priority of the scientific partnership, and combined with the networking opportunities between project partners in the global CZ community, will contribute significantly to meeting the Newton Fund objective of building the capacity for CZ Science in China. The ultimate beneficiaries of this project will be the people of Guizhou karst region (population 35 million), which is one of the poorest regions in China with a GDP less than 50% of the national average. In response to the environmental deterioration and changing social conditions in the Guizhou karst region, the Chinese government has intervened to promote the abandonment of the most degraded cultivated land and its succession to grassland, shrub and forest. This strategy has met with mixed success and is not yet underpinned by well-developed plans to repay landowners for rational and sustainable use of land resources. This must be informed by science that quantifies current and potential ecosystem service delivery. There is significant potential for our research on the response, resilience and recovery of the karst critical zone to perturbation to inform improved land management strategies that will meet these demands, leading in turn to improved delivery of ecosystem services to the communities in this region and higher environmental quality, addressing poverty and the welfare of the population through development of long-term sustainable economic development.

Pyroclastic density currents (PDCs) are clouds of ash and rock, generated during eruptions, which propagate down volcanoes at high speed. They are the major hazard at many active volcanoes and have killed thousands of people. Our current ability to predict their behaviour and plan for their effects is limited, in part, by our incomplete knowledge of their flow dynamics. The proposed research will revolutionise our understanding of PDCs by obtaining, for the first time ever, measurements of position in time, hence velocity, of the dense core of moving PDCs using an advanced custom-built radar system (GEODAR). GEODAR has been developed and successfully used on snow avalanches, dramatically improving our knowledge of their dynamics. The project will build and deploy three GEODAR systems that have a spatial range resolution of 0.375 m and will image the dense core flow at 100 Hz: a spatial and time resolution never achieved before in studies of PDCs. GEODAR will easily penetrate the ash cloud to image the dense, destructive underflow, and can observe all particles larger than 30 mm. This novel system will be able to track PDCs along their flow paths and will allow us to image internal surges, roll-waves and flow fronts and reconstruct the velocity structure of moving PDCs. This data will enable the rigorous testing of PDC flow models and provide fundamental insights into their flow so that improved models can be developed. In addition, the flow path and deposits of the PDCs will be digitally mapped by a drone at 30 mm resolution in order to resolve the lateral extent and location of the flow. Features in the digital terrain maps will be directly matched with the features observed in the radar data and this will greatly add to the understanding of PDC emplacement mechanisms. For some flows we expect to have high resolution DTMs both before and after the event, and we will produce erosion and deposition maps. This data feeds in to the final part of the project which is the computer simulation of PDCs. The simulation code produces will be useful for predicting the path and forces of PDCs which is necessary for saving lives and protecting infrastructure. The code will be made freely available and a workshop run on its use. The DTM will be used for running the SHALTOP code and the results will be compared with GEODAR data and the erosion and deposition maps. SHALTOP is a simulation code developed, over the past fifteen years, by a French team partner in this project. It can be run with a variety of flow laws and we will determine which flow law best matches the data and from there we develop improvements. Such a detailed comparison has never been done before due to the lack of data from flowing PDCs. We have chosen Santiaguito volcano, Guatemala, as the test site. It is one of the world's most active volcanoes, which has been erupting since 1922 and dozens of PDCs are generated every year. The team has extensive experience working at this site and the local volcano observatory is an enthusiastic participant in the project. In addition, the terrain around the volcano is ideally suited for the location of GEODAR, with nearly complete sight-lines to the likely flow paths. The systems will be remotely triggered using a combination of infrasound and seismic signals. The three GEODAR systems will be stand- alone solar-powered units and communicate via a satellite-phone data link. The data storage will be on SSDs mounted in fireproof crash boxes so that they can withstand inundation. This research will produce the first ever high resolution position, and hence velocity, data for the dense core of flowing PDCs and the first ever model comparison with such data. The project will develop improved theoretical and computational models for PDCs and improve the accuracy of hazard assessments around volcanoes. The ultimate aim is to improve physical knowledge of these destructive natural hazards with the potential to save hundreds of lives.

Chemical weathering mediates Earth's carbon cycle and hence global climate over geological time-scales. Ca and Mg from silicate minerals are released to the solute phase during dissolution with carbonic acid. This solute Ca and Mg gets subsequently buried as Ca and Mg carbonates in ocean basins transferring carbon from the atmosphere to the carbonate rock reservoir. This simple reaction has provided the climatic feedback that has maintained Earth's climate equable and inhabitable over the entire history of the Earth. To understand how Earth's climate functions, it is therefore vital to understand silicate weathering and to estimate the flux carbon dioxide associated with modern chemical weathering. Modern day silicate weathering fluxes are estimated from the chemistry of rivers or natural waters. Natural waters contain positively charged elements or cations such as Ca, Mg, Na and K, and it has been understood for decades that the relative and absolute concentrations of these elements depend of the type of rocks that are drained. For example, Ca is mainly derived from the weathering of limestones, whereas Na and K are mainly derived from the weathering of silicate minerals such as feldspar. This distinction is important because only the Ca derived from silicate weathering is important for carbon dioxide consumption. Therefore, the Ca flux from silicate weathering is usually estimated based on Na, which has been thought to a more reliable estimate of silicate weathering. However, chemical weathering is more complex than simple mineral dissolution and a series of other chemical reactions also occur such as cation exchange. This is a process whereby the positively charged cations in solution are attracted to negatively charged mineral surfaces on clays, a process known to buffer groundwaters. One of the key chemical exchanges is Ca for Na, meaning that Na may not provide a true estimate of silicate weathering at all. Recent isotopic data suggests that cation exchange might be more significant that previously thought, which until now has been very hard to fingerprint. One method is to use naturally occurring tracers or isotopes, that allow chemical reactions to be tracked. In this work, it is proposed to examine the naturally occurring isotopes of the elements Li and Mg to examine the role of cation exchange in global budgets. However, to be able to do this successfully, a series of experimental work is proposed to examine the behaviour of the isotopes of Mg and Li during cation exchange. Once we understand how our tracers work we can use them to re-evaluate our understanding of natural waters, and better estimate fluxes of carbon dioxide associated with chemical weathering, with the ultimate aim of better understanding Earth's climate.

Chemical weathering mediates Earth's carbon cycle and hence global climate over geological time-scales. Ca and Mg from silicate minerals are released to the solute phase during dissolution with carbonic acid. This solute Ca and Mg gets subsequently buried as Ca and Mg carbonates in ocean basins transferring carbon from the atmosphere to the carbonate rock reservoir. This simple reaction has provided the climatic feedback that has maintained Earth's climate equable and inhabitable over the entire history of the Earth. To understand how Earth's climate functions, it is therefore vital to understand silicate weathering and to estimate the flux carbon dioxide associated with modern chemical weathering. Modern day silicate weathering fluxes are estimated from the chemistry of rivers or natural waters. Natural waters contain positively charged elements or cations such as Ca, Mg, Na and K, and it has been understood for decades that the relative and absolute concentrations of these elements depend of the type of rocks that are drained. For example, Ca is mainly derived from the weathering of limestones, whereas Na and K are mainly derived from the weathering of silicate minerals such as feldspar. This distinction is important because only the Ca derived from silicate weathering is important for carbon dioxide consumption. Therefore, the Ca flux from silicate weathering is usually estimated based on Na, which has been thought to a more reliable estimate of silicate weathering. However, chemical weathering is more complex than simple mineral dissolution and a series of other chemical reactions also occur such as cation exchange. This is a process whereby the positively charged cations in solution are attracted to negatively charged mineral surfaces on clays, a process known to buffer groundwaters. One of the key chemical exchanges is Ca for Na, meaning that Na may not provide a true estimate of silicate weathering at all. Recent isotopic data suggests that cation exchange might be more significant that previously thought, which until now has been very hard to fingerprint. One method is to use naturally occurring tracers or isotopes, that allow chemical reactions to be tracked. In this work, it is proposed to examine the naturally occurring isotopes of the elements Li and Mg to examine the role of cation exchange in global budgets. However, to be able to do this successfully, a series of experimental work is proposed to examine the behaviour of the isotopes of Mg and Li during cation exchange. Once we understand how our tracers work we can use them to re-evaluate our understanding of natural waters, and better estimate fluxes of carbon dioxide associated with chemical weathering, with the ultimate aim of better understanding Earth's climate.