Basaltic lava flows cause significant damage to property and infrastructure on many volcanoes. To improve our understanding of the evolution of lava flows and flow fields, there is a need for an integrated multi-disciplinary study of the physicochemical properties of lava as it moves from the vent to the flow front, and of the complex interactions that take place during flow. Key requirements are: (i) robust methods of predicting how lava rheology changes during flow; and (ii) an improved understanding of how both long- and short-term changes in effusion rates affect the complex range of processes operating during flow emplacement. This project will provide a range of measurements using new field equipment, automated imaging procedures, ground-, helicopter- and satellite-based imagery and innovative laboratory measurements. The combined dataset will be used to develop and constrain the next-generation of lava flow models which will drive future hazard assessment and mitigation strategies on basaltic volcanoes. We propose to focus our research on one or more eruptions of Mount Etna. This collaborative and multi-disciplinary project will be undertaken jointly by the PI and Co-PIs at Lancaster, staff at INGV, Catania, and other colleagues from the USA and the UK. Current flow models assume that rheological changes are driven mainly by surface cooling. However, rheological changes over the entire flow thickness can result from crystallisation due to degassing-related undercooling. To assess the importance of undercooling, we will determine patterns of volatile loss and rates of crystal and bubble nucleation and growth during the emplacement of active lava flows, and make accurate measurements of the rheological properties of lava in different parts of an active lava flow using a new field viscometer. Quenched samples of all lavas measured will be collected and used to determine the crystallinity, vesicularity and composition of residual glass of all samples in collaboration with colleagues at INGV, Catania, and the University of Oregon. Vesicle size distributions, porosity and an assessment of bubble coalescence and connectivity (and hence the potential for gas loss during flow) will be made at Lancaster using a state-of-the-art X-ray tomographic scanner. Measurements of volatile loss during emplacement will be undertaken in a new Magma Volatile Laboratory at Lancaster using a coupled Thermogravimetric Analysis - Differential Scanning Calorimeter - Mass Spectrometer, and these will allow the potential effects of undercooling to be quantified and compared with changes in crystal size distribution. These combined laboratory and field measurements will allow us to reconstruct the entire volatile degassing budget of a lava flow for the first time, and to assess the importance of degassing in controlling the emplacement of lava flows. The above measurements will be used in combination with a comprehensive time-series of thermal images and digital terrain models of an evolving lava flow field to understand and quantify the processes responsible for flow field evolution. Digital terrain models will be created using long range laser scanner data, augmented by oblique photogrammetric data from ground-based imagery from a new network of high-resolution cameras. These will be supplemented by helicopter imagery collected by INGV, Catania, and Hyperion satellite data in collaboration with a colleague at the Jet Propulsion Laboratory. The data acquired using the combined rheological/degassing and imaging measurements will, for the first time, enable the emplacement processes/flow behaviour to be directly linked to the cooling, degassing and crystallisation of the lava in both simple and more complex flow fields. While the work will be undertaken on lavas from Mount Etna, the methodologies developed in this project have major applications for many other volcanoes and are in line with NERC's strategic and scientific priorities 2007-2012.

As we gain ever-greater control of materials on a very small scale, so a new world of possibilities opens up to be studied for their scientific interest and harnessed for their technological benefits. In science and technology nano often denotes tiny things, with dimensions measured in billionths of metres. At this scale structures have to be understood in terms of the positions of individual atoms and the chemical bonds between them. The flow of electricity can behave like waves, with the effects adding or subtracting like ripples on the surface of a pond into which two stones have been dropped a small distance apart. Electrons can behave like tiny magnets, and could provide very accurate timekeeping in a smartphone. Carbon nanotubes can vibrate like guitar strings, and just as the pitch of a note can be changed by a finger, so they can be sensitive to the touch of a single molecule. In all these effects, we need to understand how the function on the nanoscale relates to the structure on the nanoscale. This requires a comprehensive combination of scientific skills and methods. First, we have to be able to make the materials which we shall use. This is the realm of chemistry, but it also involves growth of new carbon materials such as graphene and single-walled carbon nanotubes. Second, we need to fabricate the tiny devices which we shall measure. Most commonly we use a beam of electrons to pattern the structures which we need, though there are plenty of other methods which we use as well. Third, we need to see what we have made, and know whether it corresponds to what we intended. For this we again use beams of electrons, but now in microscopes that can image how individual atoms are arranged. Fourth, we need to measure how what we have made functions, for example how electricity flows through it or how it can be made to vibrate. A significant new development in our laboratory is the use of machine learning for choosing what to measure next. We have set ourselves the goal that within five years the machine will decide what the next experiment should be to the standard of a second-year graduate student. The Platform Grant renewal 'From Nanoscale Structure to Nanoscale Function' will provide underpinning support for a remarkable team of researchers who bring together exactly the skills set which is needed for this kind of research. It builds on the success of the current Platform Grant 'Molecular Quantum Devices'. This grant has given crucial support to the team and to the development of their careers. The combination of skills, and the commitment to working towards shared goals, has empowered the team to make progress which would not have been possible otherwise. For example, our team's broad range of complementary skills were vital in allowing us to develop a method, now patented, for making nanogaps in graphene. This led to reproducible and stable methods of making molecular quantum devices, the core subject of that grant. The renewal of the Platform Grant will underpin other topics that also build on achievements of the current grant, and which require a similar set of skills to determine how function on the nanoscale depends on structure on the nanoscale. You can get a flavour of the research to be undertaken by the questions which motivate the researchers to be supported by the grant. Here is a selection. Can we extend quantum control to bigger things? Can molecular scale magnets be controlled by a current? How do molecules conduct electricity? How can we pass information between light and microwaves? How can we measure a thousand quantum devices in a single experiment? Are the atoms in our devices where we want them? Can computers decide what to measure next? As we make progress in questions like these, so we shall better understand how structure on the nanoscale gives rise to function on the nanoscale. And that understanding will in turn provide the basis for new discoveries and new technologies.

Over the past two decades, improving seismic and geodetic data have revealed that many faults accumulate their slip via a suite of phenomena that are not predicted by conventional friction laws: via slow earthquakes, or fault slip events whose average slip rates are between 0.1 microns/s and 1 mm/s, a factor of 1 thousand to 10 million slower than the 1 m/s slip rates typical of earthquakes. Slow earthquakes are now found at most subduction zones, where they accommodate about half of the plate interface slip in the region down-dip of the seismogenic zone. But currently, we do not know which fault zone processes generate the aseismic slip we observe in slow earthquakes. It is important to improve our understanding of slow earthquakes because they occur next to the seismogenic zone. They are capable of triggering large and damaging earthquakes. In this project, we focus on the smallest but most abundant slow earthquakes: tremor. Tremor consists of hundreds to millions of small, closely spaced, slow earthquakes. The earthquakes can be rapidly observed and could be used to track larger-scale aseismic slip variations and to assess whether that slip could trigger hazardous seismic slip. But like other slow earthquakes, tremor remains poorly understood. The goal of this project is to determine which physical process creates tremor and limits its slip rates to around 1 mm/s. Several explanations of tremor's low slip rates have been proposed. It is possible that tremor is governed by the same frictional sliding process that governs normal earthquakes. Tremor may be slow only because the fault's frictional strength or normal stress is low, and thus is unable to drive rapid slip. Alternatively, a more novel physical process could limit tremor's slip speeds. Changes in pore fluid pressure might pull the fault shut, inhibiting rapid slip. Or tremor could be a collection of failed earthquake nucleations, which arise because of stress perturbations on a nominally stable fault. In the proposed work, we will use targeted seismological analysis to assess five proposed models of tremor generation. We will test specific model predictions using high-quality seismic data from some of the best-observed tremor in the world: that near Parkfield, CA. To test our model predictions, we will first examine how tremor is related to shorter and longer slow earthquakes. If tremor is governed by the same novel fault zone physics that governs larger slow earthquakes, there should be a continuum of slow earthquakes with a wide range of sizes and slip rates. The presence or absence of the continuum will be important for constraining the processes governing large and small slow earthquakes, as only a few of the proposed models of large slow earthquakes are consistent with the continuum's wide-ranging slip rates. We will search for 0.05 to 1-second-long events in this continuum using recently developed seismic analysis techniques. And we will examine the clustering of tremor, in order to (1) identify larger, hours-long slow earthquakes potentially within the continuum and (2) to constrain the relationship between tremor and larger-scale slip. Finally, to further test the models, we will move into the details of individual tremor events and probe the evolution of slip in individual tremor earthquakes. We will closely examine the seismic signals produced by tremor in order to determine how tremor's earthquakes' durations, sizes, and complexities vary from event to event. These data will let us determine how much of tremor's properties are controlled by particular rheologies and how much is due to local fault zone structure. By pursuing a suite of features that can test our models, we will be able to determine which physical processes generate the numerous small earthquakes that constitute tremor, so that we may better understand slow earthquake slip and more confidently use tremor to track large-scale slip at depth.