Kilauea volcano, in Hawaii, is one of the most active volcanoes in the world. Since 2008, there has been an eruptive vent at the summit of the volcano, with a lava lake. Further down the volcano, there has been another vent erupting lava since 1985. In April 2018, magma supply stopped at these two places, and travelled under the ground to the residential region of Puna, where it erupted in 24 different fissures. Over 2000 people have been evacuated from their homes and up to 700 buildings have been destroyed by lava flows. The last time there was an eruption in this area was 1960. When magma pushes its way through the rock, it causes lots of small earthquakes. Earthquake waves can be polarised in a similar way to the way light is polarised. Rock polarises earthquake waves when it is under pressure and tiny cracks line up in one direction. This causes earthquake waves to travel faster in one direction (along the cracks) than the other (across the cracks). Therefore, we can use the polarisation of the earthquake waves to understand how the rock gets pressurised as the magma travels through it. This new eruptive activity at Kilauea means that we can investigate areas that we previously couldn't because there were not enough earthquakes. We will set up four new stations to measure the new earthquakes and use data from the existing monitoring network. We will use the new earthquakes to make images of the pressure in the rocks during this eruption and will be able to see what happens to the pressure when the eruption stops. This information will be useful to understand the eruptive behaviour of Kilauea, will help monitoring and forecasting changes in eruptive activity, and will also be applied to other volcanic systems around the world. To do this, we have made a team of excellent researchers from the University of East Anglia and the US Geological Survey.

The beds of most alluvial river channels are not flat, but comprise a series of undulating sedimentary accumulations termed 'bedforms' that include ripples and dunes. These bedforms exist over a range of scales, and are constantly moving and changing their shape, size and form in response to changes in flow discharge. These bedforms are the primary roughness elements that provide resistance to the water flow. The response of bedforms to a changing discharge is therefore critical for predicting flood inundation levels. Changes in flow discharge are more rapid than changes in the bedforms, such that bedforms are commonly out of equilibrium with the flow. This is very important as the vast majority of our bed-phase diagrams (stability field predictors that relate flow velocity and sediment size to the bedform types likely to be present), morphodynamic simulations, and numerical model predictions assume simplified bed morphologies that are based on equilibrium bed states and constant discharges. Consequently, many feedbacks within our models and predictions are either ignored or highly simplified. This is a significant shortcoming as it is these models that are used, especially in more populated and urban areas, to meet demands on safety against flooding, navigation, hydropower, aggregate mining and water supply. The astute management of these rivers is paramount, putting high demands on accuracy in design, implementation and monitoring. If such models are to be improved, then new fundamental understanding is required of the processes that underlie the dynamics of bedform adjustment to unsteady flow and ways of integrating such knowledge into modelling practice. As a step towards this goal, there is a need to link hydraulic controls, the response of sediment transport processes and morphological adjustment, and the changes in form drag and bed resistance to a range of unsteady flows. Once established, these relations can be used to help improve our understanding of these dynamic processes and predict better the river stage for a set of given discharge changes. This project will delineate these processes using a combination of (i) novel laboratory investigations in a state-of-the-art flume that will quantify the flow structure and sediment transport over fixed and mobile beds as stage varies, (ii) intense fieldwork during flood events in the Mississippi River that will map and quantify changes in bed morphology, flow structure and sediment transport, and (iii) development and application of an innovative numerical model of unsteady flow over a deformable 3D boundary. This modelling work will ensure that the results are generic and have a wider appeal, notably in the improvement of models that provide flood predictions and inform environmental management decisions. All data and output will be made freely available via scientific outlets but also through public dissemination events, the internet and via a GoogleEarth based XML interface.

It is vitally important to anticipate the run-out behaviour of geophysical mass flows and thus anticipate their impact area and peak destructive power, to develop effective strategies to improve the safety of "at risk" populations throughout the world. Geophysical mass flows encompass a wide range of natural hazards including snow avalanches, debris-flows, pyroclastic flows and lahars. They are all examples of either wet or dry granular flows in which "large" particles segregate towards the surface, where the velocity is greatest, and are preferentially transported towards flow fronts. Here they may be over-run, rise up by segregation, and be recirculated to produce bouldery flow fronts. These tend to be more resistive to motion than the finer grained interior, either because the grains are rougher or because in debris- and pyroclastic flows they dissipate the internal pore pressures that confer mobility. These segregation-mobility feedback effects can lead to the development of damaging high-mass-concentration surge fronts and can cause spreading flows to spontaneously develop lobes and leveed channels that transfer the mass readily for long distances (run-out). Such self-organization has important implications for hazard assessment and risk mitigation, because large surges can be highly destructive and the channelizing effect of levees can significantly alter an impact area. In our previous research we developed a depth-averaged theory for segregation that allowed segregation-mobility feedback effects to be incorporated easily into existing geophysical mass flows models. Numerical simulations showed that these captured the morphology of leveed fingers, as well as complex nonlinear coarsening, splitting and merging behaviour, but there was also an unexpected problem indicating that some important physics, related to dissipation, is missing in the model. We aim to identify the physical dissipation mechanisms involved. Small-scale analogue experiments and large-scale flume tests with our United States Geological Survey (USGS) partners will be used to study key flows that yield important insights into the nature of the dissipation, e.g. (i) the size of large particle recirculation cells (ii) the evolution of bouldery flow fronts (iii) the inception and coarsening dynamics of roll-waves and (iv) the velocity profile between levee walls. We will also go to the Pumice Plain of Mount St Helens, which is a virtually unique natural laboratory rich with information on the processes and conditions that led to both strongly leveed flows as well as spreading flows. These deposits have now been cross-cut by streams, which will allow detailed transects to be examined and sampled to establish the size and density of pumice clasts that were deposited by the various phases of June, July and August 1980 eruptions. Our multi-fronted approach of theory, computation, large- and small-scale experiments and field work is extremely powerful and will shed critical light on the controlling physical conditions and processes, and lead to major advances in our understanding of these complex nonlinear flows.

Recent developments in satellite geodesy are providing a new perspective on volcanic processes and continental tectonics through observations of largely aseismic processes such as interseismic strain accumulation and magma intrusion. Scientists are interested in these measurements since they can identify the mechanisms controlling continental deformation and quantify the constitutive laws controlling rheology, but practical applications include seismic and volcano hazard assessment and geothermal resources. InSAR has been used to study volcanic deformation in a wide variety of situations but the interferometic coherence is reduced by changes in the appearance of the ground surface (e.g vegetation, steep slopes) and the accuracy is limited by variations in the path delays caused by tropospheric water vapour. Our research group, part of the National Centre for Earth Observation (NCEO) has developed algorithms (Poly-interferogram rate and time-series estimator; known as PIRATE) which are designed to measure fault-related processes such as interseismic strain accumulation (Biggs et al, 2007; Elliott et al, 2008; Wang et al, 2009) and postseismic relaxation (Biggs et al, 2009) in similar conditions (e.g. Alaska, Tibet). The USGS Cascades Volcano Observatory is keen for us to adapt this and other codes to study volcanic deformation. The aims will be to apply these methods to their extensive archive of radar data and set up an operational system for near real-time monitoring for the Cascades Range. This project is truly collaborative, the universities will provide the algorithm development from scientific applications while the CASE partner will provide access to the dataset and a practical application for the results. Together the partners will provide training which cuts across purely scientific algorithm development to practical hazard monitoring. The existing data archive and infrastructure of the USGS make this the ideal environment to transfer recent technological developments, yet the project will also have impact globally and to the UK. Numerous other volcanoes around the world sit in similar environmental conditions and we have established links with several other observatories who would benefit, as will the global-interests of the UK-insurance industry. The student will receive training in a wide range of areas, including satellite geodesy, image analysis, volcanology and computing. They will also receive guidance in the preparation and presentation of their research to both academic and hazard monitoring audiences. During the project the student will spend at least 6 months based at CVO, participating in the day-to-day monitoring activities of the volcano observatory and incorporating the InSAR observations into ground-based measurements. A background in geophysics, physics, mathematics or engineering is required for this project. Upon completion, the student will be very well prepared for a career in industry or academia, including research in topics as diverse as volcanology, earth observation, risk and hazard management and insurance.

All rivers across the globe that exit to the ocean contain a zone, which can be 100s of kilometres long, which is transitional between river and tidal environments (termed here the Tidally-Influenced Fluvial Zone, or TIFZ). This zone is one of the most complex environments on the surface of the Earth because it is an area where both river flow and tidal currents are significant, and these competing forces vary daily, seasonally and annually. These regions are important to mankind and form some of the areas of highest population density: they are strategically important in the present day because these zones are at the interface of competing demands for shipping, aquaculture, land reclamation and nature conservation. Thus in order to better maintain, manage and protect these fragile zones, we must understand how and why these regions change and what factors control such change. Additionally, the sediments of ancient TIFZs may contain significant volumes of hydrocarbons which are increasingly the target for many energy companies. For example, the Athabasca oil sands form the largest petroleum deposit on Earth and these bitumen tars are locked up with ancient TIFZ sediments. Understanding the internal nature of such TIFZ sediments is thus of paramount importance when attempting to extract the maximum quantity of oil (or gas) from such ancient hydrocarbon reservoirs - we need to know what controls the geometry and internal characteristics of these reservoirs, and thus better plan efficient and maximal hydrocarbon extraction strategies. Thus all of these interests in both modern and ancient TIFZ environments depend on a detailed knowledge of the fluid flows in these areas, how such flows transport their sediment and critically how the form (or morphology) of these environments changes through time. However, due to the extraordinary challenges of working in such a complex and dynamic environment, few high-resolution, spatially-representative, field datasets exist and remarkably little work has been undertaken on the diagnostic internal sedimentary structure of such TIFZ deposits. Additionally, whilst there has been progress on the mathematical modelling of estuarine flow and sediment transport, these models remain largely untested. There is therefore a pressing need to link the processes and deposits of the TIFZ through an integrated study of their flow, morphology and sediment movement to quantify the key processes and how these are represented within the subsurface sedimentary record. This proposal outlines an integrated field and mathematical modelling study that seeks to achieve a step-change in our understanding of the TIFZ, using the very latest techniques in field survey and mathematical modelling. These techniques will yield unrivalled high-resolution datasets of bathymetry, flow, sediment transport and sedimentary structure that will then be used to construct and validate new numerical models of the TIFZ. This will ultimately allow evaluation of key unknowns with respect to the TIFZ, such as how such environments evolve under changing scenarios of tidal and fluvial contributions associated with sea-level change, and whether it is possible to differentiate between 'fluvial' and 'tidally' influenced deposits. Such results will transform our understanding of how such TIFZ zones behave in modern environments and critically how these changes may be recognized within ancient sedimentary successions.