The geomagnetic field varies on time scales of milliseconds to billions of years, and has sources both inside the Earth, from the dynamo generating the main field in the highly conducting liquid iron core, and outside the Earth, from currents flowing above us in the ionosphere and magnetosphere, reflecting the interaction of the solar wind with our planet. In general, rapid variations (less than one year period) originate outside the Earth, while longer period variations come from inside. Separating signals from one to ten years is a challenge, but also has the potential to tell us much about Earth structure and processes. The most rapid variations generally identified as being of internal origin are so-called "geomagnetic jerks" - rapid changes in the rate of change of the magnetic field. Their structure and evolution can tell us not only about rapid changes in Earth's fluid core (such as waves and upwelling of core fluid) but also about the solid mantle in between. This rocky region is not as electrically conducting as the iron core, but it could still conduct weakly. A strong constraint on this property has recently been provided by another geophysical measurement, the rate of Earth rotation. We have found that sharp changes in the field are matched by almost contemporaneous sharp changes in the rate of Earth rotation. This both gives as clues as to what causes the events, but also strongly restricts the conductivity of the mantle - if this were higher, then the magnetic signal would lag the rotational signal as it would take time for the field to diffuse from its origin at the core-mantle boundary through the solid Earth to be observed at the surface. Mantle conductivity is also constrained by measurements of the induced magnetic field from varying external fields, so-called geomagnetic depth sounding. The combination of this constraint from above the Earth, and the new constraint from the deep mantle, will be used to give a detailed profile of conductivity as a function of depth, which in turn constrains the composition and mineral state of the solid Earth. For example, if a phase change of silicate rock were predicted which gives a sharp rise in conductivity, this phase change could be excluded by the geomagnetic data. The bulk of the work in this study is detailed analysis of both geomagnetic and Earth rotation data to tease out more information as to the signals they contain. A six-year oscillation has been confirmed in both measurements, but more rapid variations are even harder to distinguish, as they overlap with other sources: for the magnetic field, from external current systems, and for Earth rotation from angular momentum exchange with the atmosphere. For example, variations in short period (atmospheric) variations in Earth rotation have been shown to have a strong link to the ENSO climatic signal. A successful outcome of the project will rely on successful separation of the signals. We will construct detailed models of the magnetic field variation in space and time to investigate what is causing these changes. Recently, quantum mechanical calculations of the physical state of materials of the Earth's deep interior have revised our assumed value for the electrical and linked thermal conductivity of the core. These new values have changed our understanding of how the core works - we now believe that instead of full vigorous convection, it is highly likely that there is a stably stratified layer of fluid at the top of the core. This layer will support waves and instabilities rather than large scale convection, as is seen for our atmosphere and oceans, similarly stably stratified, rapidly rotating fluids. A recent simple model of these waves can explain the details of the variation of the dipole field in the Earth, and our preliminary results suggest that they may also explain the geomagnetic jerks. Thus our work should constrain both the structure of Earth's mantle, and the dynamics of its core.

This Global Partnerships Seedcorn bid is focused on developing a new research collaboration primarily between UK and Indian scientists. Its primary aim is to start to address the challenge of better understanding the physical risks and limits to the future habitability of the reef islands of the Lakshadweep Archipelago (LA) in the northern Indian Ocean. As with most reef islands, the islands of the LA are inherently vulnerable to sea-level rise, but the question of future habitability is especially pressing in the LA because they support some of the highest rural densities in India (>2,000 people/km2), this representing the highest population density of coral-reef dependent communities worldwide, with 100% of its community within a few kms of the coast. The reefs surrounding the islands in this region, which provide key coastal protection and island-building sediment supply functions, are increasingly threatened locally by rapid human population growth (>6% increase per year), rapidly growing fishing pressure, and poorly controlled (at the local level) infrastructure development. At the same time, population pressures and development threaten both groundwater resources and water self-sufficiency. Understanding the magnitude of change to these key physical limits to island habitability in the LA is thus critical to guide adaptation planning. In the context of these challenges our aims through this partnership are two-fold. The first is to develop and then establish a framework for understanding the current natural physical limits to island habitability in the LA. We will bring the collective expertise of the PI and international PPs to bear on the question of changing risk from reef ecological change, the consequences for reef growth and island-building sediment supply, and consider the impacts of changing island hydrological regimes. This data will be used to undertake initial mapping of zones of highest physical risk for island habitability. From a longer-term collaborative perspective, we envisage work is this area leading directly to a range of joint PhD and MRes project opportunities for students to work alongside the NCF, as well as the development of grant proposals aligned to exploring, for example, changing coastal wave exposure. Secondly, in collaboration with a range of other international PPs (see CfS Part 1), we are interested to start exploring how local jurisdiction and governance structures may either aid or hinder island adaptation planning options. There are a range of local political structural challenges in this respect within the LA, which lacks the political autonomy of atoll nations like the Maldives. Rather it sits under subnational island jurisdictions where national development aims do not necessarily align to local concerns. To explore the influence (both positive and negative) of different governance structures across the atoll nations of the world, we will host an interdisciplinary workshop towards the end of year two of the project drawing on the experience from the work in the LA, but also bringing in those with adaptation and policy experience across atoll nations and at different levels of governance. In a longer-term context, we are then interested to use this work as a springboard to seek future funding to work with social scientists to examine, for example, how historical and recent physical evidence of land changes align with the lived experience of island vulnerability. The issues we seek to address are highly relevant to global scale questions about reef island resilience and adaptation and are thus high agenda topics both in the LA, and across the atoll nations.

The Asian Hornet (Vespa velutina nigrithorax) [AH] is an invasive alien species that is rapidly spreading through Europe. It is an important emerging threat to wild and managed pollinators, as it is a voracious predator of insects. Over 50% of its diet has been reported to consist of honeybees, wild bees and wasps. The AH live in large nests producing 5,000-20,000 individuals and the workers hawk for prey at bees' nest entrances, and flower patches, picking off foragers and shutting down foraging activity to the detriment of the colony. AH have caused significant damage to honeybee colonies in France and Italy with increased mortality of 5-80% where AH has established, threatening the viability of beekeeping and honey production. Of additional and immediate concern is the damage it could cause to wild bee and wasp populations, and the pollination services they provide to crops and wild flowers, but these effects have not been quantified. An AH nest was first found in UK in September 2016, another nest found in 2017, and a third found in September 2018, signalling that establishment in the UK is imminent. The only means of halting the spread, or limiting it, is to find and destroy nests as soon as possible. There is thus an urgent need to develop a method to locate nests efficiently for management of this pest. In a ground-breaking pilot project (funded by Defra) we have radio-tracked individual AH flying back to their (previously un-discovered) nests. Our first aim is to test the range of use of radiotelemetry, and combine it with a new acoustic monitor giving early warning of AH attacks at bee hives. We will design a protocol using these technologies to reduce the speed of AH invasion (Objective 1). Our second aim is to measure the potential impact of AH as a pest of managed and wild pollinators in three ways: measuring the impact of AH predating at bee colonies (Objective 2); measure the proportions of different pollinator species in the AH diet using DNA sequencing (Objective 3) and measure whether AH disrupt pollinator networks at flower patches (Objective 4). Work will be carried out in France and the Channel Islands which are at different stages of the invasion timeline. Data on AH foraging and predation rates will be used to forecast the likely impact of these predators on managed and wild pollinators in the UK, and estimate impacts on crop pollination (Objective 5) using our models of bee colony and population dynamics, BEEHAVE and bumbleBEEHAVE. It is essential that this research takes place as soon as possible: the best opportunity to slow a UK invasion is during the next few years. EU governments are looking for methods to slow the spread of AH, and beekeepers strongly advocate the need for investment in this work, (see Supporting Letters from Defra, DoE Jersey, and beekeepers). The ~250,000 honeybee hives in the UK are estimated to be worth £150 mill to the economy in honey and pollination provision. The AH could trigger losses of £30-45 mill per year, and our technology to detect nests early could reduce AH economic impact by at least £10-15 mill per year. This will be achieved by sharing our protocol and evidence with policy makers: to help manage the invasion and increase knowledge and skills amongst beekeepers, agencies and pest controllers. These actions, together with raised public awareness, will boost chances of early nest detection at the AH invasion front. The reduction in environmental impact will also be significant, because wild bees are under threat already, so that a further reduction in these communities is likely to affect their vitally important ecological function as pollinators. The assembled team of researchers at Univ. of Exeter (Osborne, Tyler, Kennedy & Chaput) and partners (French researchers, Defra, Dept of Environment Jersey, the BBKA & Jersey beekeepers) have experience in animal tracking, pollinator science, molecular ecology and practical AH management to succeed in these goals.

Mediterranean societies were characterised by multiple and shifting frontiers during the Middle Ages, a formative period for modern Europe. These frontiers were created by periods of conflict between opposing societies defined, above all, by religious differences - between Christians, Muslims and Jews, but also between different groups of Christians. All these frontiers absorbed existing communities and supplemented them with migrants. They were governed by authorities from imposing castles, whose remit was to ensure security and promote the ideology of the conquerors. As the most striking material legacy of the former frontiers, today these castles are the focus of regional and national tourism, tied into narratives of cultural struggles. However, they remain disconnected from their associated territories, both in the academic and public domains. As frontiers, these territories encompassed multicultural communities and articulated tensions between the conquering authorities and conquered populations. This project will address this disconnection between frontier castles and their cultural landscapes, with two aims. Firstly, to broaden regional and international interest in the full spectrum of medieval heritage in South West Europe, building on existing interest in iconic monuments. Secondly, to develop public awareness of past multiculturalism as an essential context for the current debate on migration and multiculturalism, especially since traditional historical narratives are regularly used to validate political and social agendas. This will entail a comparative investigation of three different frontier regions in Spain and Pyrenean France. The key questions we will ask are how did conquering authorities deal with the creation of multicultural societies in these frontiers, how did they relate to central authorities and how did conquered communities respond to the imposition of new political and social norms? Drawing on a range of archaeological, environmental and historical data, we will investigate changes in settlements, religious, commercial and political centres alongside environmental changes, assessing whether territorial reorganisation resulted in intensified resource exploitation, or to what extent earlier trends continued and can be linked to established practices and worldviews. We will then consider how much freedom there was to move across these frontiers, traditionally linked to the widespread practice of transhumance. Finally, we will bring all this information together and produce a comparative map of what we will define as cultural resilience - the ability of conquered communities to adapt to the imposition of a new regime. Environmental exploitation is an increasingly used index of this resilience. We will then develop a visual and digital infrastructure to enable visitors to engage with the cultural landscapes associated with the iconic monuments of frontier authorities.

The North Sea is one of the most industrialised marine environments on the planet, with thousands of man-made structures (MMS) including oil and gas platforms, pipelines, subsea cable routes, and marine renewable energy installations. Much of the infrastructure relating to the oil and gas industry has been in place for decades and is coming to the end of its economic life. In contrast, the marine renewable energy industry is expanding with many windfarms planned for construction in the near future. Current legislation requires that MMS in the North Sea should be removed from the marine environment after their operational lifespan is complete. With the decline of the oil and gas sector, the UK decommissioning operation will cost around £50 billion, with almost half of the financial burden falling on the taxpayer. These forthcoming changes in the North Sea landscape may have a significant impact on marine life. There is mounting evidence that the effects of MMS on the local marine environment are complex, and depend on the age, type, and operational status of the MMS. Once installed, MMS can host artificial reefs supporting diverse communities of marine life. Further, the exclusion of shipping and fishing in the vicinity of many MMS may provide refuges for fish and predators such as sharks, seals or porpoises (de facto Marine Protected Areas). However, the true extent of the effects of MMS on the ecosystem are unclear. To ensure effective decision-making about removal and installation of such structures in the future, there is an urgent need to better understand the impact of MMS on the North Sea ecosystem. EcoSTAR (Ecosystem-level importance of STructures as Artificial Reefs) is a collaborative project combining the expertise of marine ecologists from the Sea Mammal Research Unit (SMRU) at the University of St Andrews and the Centre for Environment, Fisheries and Aquaculture Science (Cefas). EcoSTAR aims to fill in the key knowledge gaps on the impact of MMS across the entire marine ecosystem. This ecosystem-wide approach is critical to fully understand the breadth of possible interactions between MMS and marine species. To achieve this, EcoSTAR will measure impacts of MMS from the bottom of the food chain (the benthic community) all the way to the top (marine mammals). EcoSTAR will 1) improve our understanding of the importance of MMS as habitat for benthic communities such as mussels, anemones and starfish; 2) measure how MMS influence the distribution and movement patterns of marine mammals in the North Sea; 3) determine how many seals and porpoises forage at MMS, and how often, and estimate the associated benefits or costs of MMS to individual animals; and 4) estimate the consumption of fish by seals and porpoises feeding around MMS. Critically, the knowledge gained from this project will be combined with existing data and knowledge of fish, food webs and fisheries, to predict the impacts of MMS on the whole ecosystem using cutting-edge ecosystem models. This will allow the prediction of the impacts of removing old structures (such as oil and gas platforms) and installing new structures (including wind turbines) on the marine ecosystem and on commercial fisheries The findings of EcoSTAR will facilitate the development of environmentally sustainable management strategies for the North Sea as whole, and specifically with regard the addition and removal of MMS.