Earthquakes are a very destructive and yet unpredictable manifestations of the Earth internal dynamics. They correspond to a rapid motion along geological faults, generating seismic waves as they propagate along the fault strands. The propagation of ruptures along faults induces dramatic stresses and deformation of the rocks hosting the fault, which become increasingly damaged (i.e, degraded) as multiple earthquakes occur along a fault over geological timescales. In turn, this damage of the off-fault rocks has an impact on the dynamic rupture processes: damage generation and earthquake rupture are coupled phenomena. A better knowledge of the dynamic damage processes can thus truly improve our understanding of the physics of earthquakes, and hence help to better predict strong motion and earthquake hazard. It is the goal of this proposal to investigate how dynamic ruptures can induce damage in the surrounding rocks, the specific characteristics of this damage, how it affects the rocks properties, and finally to build an earthquake rupture model which includes the couplings between rupture propagation and off-fault damage. The proposed approach is multidisciplinary, and includes: (1) field characterisation of naturally damaged samples around the San Jacinto fault in South California; (2) laboratory rock deformation experiments at very high deformation rates; and (3) the development of a numerical modeling approach, tested against experimental data, which will allow simulations of fully coupled earthquake rupture processes to be performed. By far the most challenging aspect of the study of dynamic damage is to perform rock deformation experiments at deformation rates and pressure conditions relevant to earthquake ruptures. To achieve this, our proposal includes the design and construction of a novel deformation apparatus which will allow high speed compression and decompression tests to be performed on rock samples. This apparatus will be unique in Europe and will cover an unprecedented range of deformation conditions.

Plate tectonics has been a fundamental tenet of Earth Science for nearly 50 years, but fundamental questions remain, such as where is the base of the plate and what makes a plate, "plate-like?" A better understanding of the transition from the rigid lithospheric plate to the weaker mantle beneath has important implications for the driving forces of plate tectonics, natural hazards, and climate change. There are many proxies used to estimate the depth and nature of the base of tectonic plates, but to date no consensus has been reached. For example, temperature is known to have a strong effect on the mechanical behaviour of rocks, and if this were the sole process governing the definition of the plate, then we would expect to see a thin plate near a mid ocean ridge and a very thick plate beneath old seafloor. However numerous geophysical studies observe what are interpreted as nearly constant thickness plate at all seafloor ages. This has led scientists to propose other mechanisms, such as dehydration of the mantle to strengthen the mantle to form a rigid plate. Similarly, observations of very strong anomalies have led others to suggest that melt might exist to weaken the mantle beneath the plates. However many of these observations come from only one ocean, the Pacific, from indirect, remote observations, at different areas and scales, and with different sensitivities to earth properties. Although results have been promising, comparisons among studies are challenging, hindering a complete understanding of the tectonic plate. We will systematically image the entire length of an oceanic plate, from its birth at the Mid Atlantic Ridge to its oldest formation on the African margin. This is a large-scale focused effort with multiple scales of resolution and sensitivity, from a metre to kilometre scale using seismic and electromagnetic methods. This scale, focus, and interdisciplinary approach will finally determine the processes and properties that make a plate strong and define it. The project will be accomplished through a large, focused international collaboration that involves EU partners (3.5 M euro) and industry (6.4M euro), both already funded.

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.

Chemical weathering is the process by which rocks dissolve in rainwater, which is naturally acidic. This is because atmospheric carbon dioxide dissolves in rain to form carbonic acid, and the rainwater interacts with rocks making them dissolve. The dissolved carbon dioxide becomes trapped in river and seawater, as bicarbonate (present in all natural waters such as mineral water for example), where it resides stably for thousands, or tens of thousands of years, and is then stored permanently in a mineral form as calcium carbonate (like limescale) and deposited as limestone in the oceans. Rock dissolution or chemical weathering is a major process in the global carbon cycle and it is thought that this terrestrial chemical weathering of rocks, and subsequent burial of carbon as calcium carbonate, acts as the feedback which has controlled the carbon cycle and thus climate over Earth history. The carbon fluxes associated with chemical weathering are commonly estimated from river chemistry, assuming that the river composition can be matched to the type of rock dissolving. This is a simplification because chemical reactions mean that a river doesn't simply have the same chemical composition as a rock which dissolves. One suite of chemical reactions are referred to as cation exchange reactions. They occur rapidly as a chemical equilibrium develops between charged mineral surfaces and a water. One of the most important mineral groups which have charged surfaces are clays. These rapid reactions are well studied in soils and aquifers, but the scientific community working on river chemistry has largely neglected these reactions. We have generated a suite of preliminary data that shows that once the cation exchange process is taken into account it changes significantly the chemistry of natural waters and the total amount of carbon consumption through chemical weathering. We have developed a new tool kit that can address the significance of cation exchange. Our tools are 1) isotope geochemistry, that can trace the rapid chemical reactions, 2) nuclear magnetic resonance that can characterise the mineral surfaces where exchange is occurring and 3) X-ray diffraction that is sensitive to the specific compositions of exchangeable sites in minerals. We have planned a series of experimental studies to quantify the processes in well constrained controlled examples, coupled to a study on the largest rivers in the world (on an archive collection of samples) to determine the global importance of the problem.

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.