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  • This collection brings together five interrelated datasets from the University of Hull research program on the turbulent suspension of sediment in stratified shear flows. It includes: numerical simulations of thermally stratified and sediment-laden channel flows performed using open-source NEK5000 v19, with initial conditions and post processed data; experimental measurements from a novel Stratified Flow Facility (SFF), with raw and processed (insitu) ultrasonic and optical equipment; and a full brief of facility design. The collection also links to a GitHub repository containing a Python-based processing suite for stratified flow simulations and experiments. Together, these datasets provide raw and processed data, experimental metadata, and technical documentation to support the study of turbulence, internal waves, particle transport, and measurement methodologies in stratified fluid dynamics.

  • The research will experimentally test the ice-segregation model of rock fracture in the context of near-surface bedrock. Experiments at the Caen Cold Laboratories will monitor the effects of different thermal regimes, moisture conditions and material properties on rock fracture, ice segregation and frost heave in large blocks of limestone and sandstone. Experimentally-formed fractures and segregated ice will be compared with predictions from two theoretical models of rock fracture and frost heave, and the observed rock fractures compared with contemporary and relict weathering profiles. By integrating curiosity-driven research on important Earth-surface processes (rock fracture, ice segregation) with their practical consequences (rock heave/settlement), the study will have international significance to cold-regions Earth science and engineering.

  • High-presicion Ar- Ar and U-Pb dating of magmatic events in the British Tertiary igneous province is difficult to reconcile with the magnetostratigraphy. The normally maganetised rocks of Mull Centres 2 and 3 are too old for C26N, much too young for C25N, and of too long a duration to fit into normal cryptpchrons in C26R. The most likely reason for this discrepancy is that the accepted time range of C26N (58-57.6 Ma) is too young by at least 0.5m.y. We propose to resolve the problem by re-determining the age of the Palaeocene-Ecocene boundary by Ar-Ar dating of sanidine from ash layers in northern Jutland. Our Ar-Ar dates will be checked against U-Pb ages of zircon and sphen from the Danish ashes and from the Hebrides.

  • To determine the seasonality and inter-annual variability of rainfall from the variations in annual luminescence laminations for multiple samples of recently deposited stalagmites from two monitored cave systems. a) extend this for the last 2000 years of climate change for multiple sites in the UK and continental Europe to establish regional palaeoprecipitation records. Measurement of variations in the structure of laminae luminescence using UV microscope and laser techniques for samples from England and France with parallel monitoring of seasonal variations of luminescence. UV techniques as above with additional samples to extend the project spatially (to Belgium, Scotland, England & France) and temporally (last 2000 years)

  • Since 20 September, 2005, an ~120 km-long segment of the Red Sea rift system in Ethiopia has been rocked by 31 earthquakes detected on seismometers worldwide. Ashes emanating from long, open fissures at the surface have blanketed a much wider area, displacing ~50,000 people and their livestock. Colleagues from Addis Ababa University report new fault scarps, and new displacements along existing fault scarps; these faults provide direct measures of rates of crustal deformation that can only be inferred from routine monitoring. The active rupture zone is much larger than has been associated with other historic sequences in the Afar depression, and other continental rift zones worldwide, suggesting this linked tectonic-volcanic crisis is a major event. Thus, the Boina seismo-volcanic crisis provides a superb opportunity to record directly the processes of continental breakup leading to the formation of a new ocean basin. Routine seismic, volcanic, and geodetic monitoring provides information on the time-averaged deformation, but misses the sometimes catastrophic discrete events that achieve the tectonic processes. This proposal aims to: 1) establish a seismic monitoring network to measure aftershock sequences and lava movement within the plate; 2) investigate reports of new eruptions and measure gas emissions from vents along the length of the rupturing segment and compare them with earlier baseline measurements from Afar; and 3) use space-based radar images acquired prior to, during, and after the crisis to measure the magnitude and extent of deformation across the region. Simple elastic modelling of seismic and radar interferometry results will allow us to estimate the proportion of tectonic vs magmatic deformation associated with continental rupture. Additionally, our measurements will provide a firm basis for hazard mitigation for the Ethiopian government coping with this catastrophe, supplementing the sparse infrastructure established by our Ethiopian colleagues.

  • The 'snowball Earth' theory has been the subject of widespread media attention, particularly its lively defence by key proponent, Prof. Paul Hoffman. This period of earth history from 750 to 540 million years ago contained perhaps as many as 5 extreme events of climatic fluctuation. During the coldest of these the globe may have been entirely covered in ice. Until recent years research into the rocks of this age had focussed mainly on cold or hot desert areas of the world with very good outcrop and undeformed piles of sediments, but some of the most complete, but poorly exposed rock sections of this age are in more accessible areas such as Scotland and Ireland. Sediments are extremely difficult to date and ages of these rock sequences rely on the rare occurences of volcanic rocks. There is now the makings of a global framework of these glacial periods based on the isotopes of carbon in limestones, but without other dating evidence this can only say that the rocks are related to a glacial event, not which one. The isotopes of sulphur are constrained during this period by the rapid increase in the oxygen content of earth's oceans and atmosphere which resulted in the rapid evolution of many species and the development of vertebrate animals. This sulphur signal changed rapidly after the largest 'snowball Earth' event and recent studies suggest that this distinct signal might be globally recognisable. In Scotland and Ireland 3 glacial periods have been recognised in a seqence of rocks aged approximately 800 million years old at the base, 600 million about 75% of the way up from the base and containing 540-520 million year old vertebrate fossils close to the top. Linking the glacial periods to a particular global event in this 260 million year period has proved difficult. Combining new sulphur isotope data for the mineral pyrite from limestone and black shale rocks, with carbon isotope data and organic carbon content will allow these glacial events in Scotland and Ireland to be correlated and put into global context. This new data will place better age constraints on these rocks in Scotland and Ireland and improve the global understanding of this period of Earth history. Man's influence on the planet might have destabilised the climate system, so it is important that we understand the causes and effects of extreme climate variation in the past.

  • Vegetation plays an important role in landscapes that are shaped by wind-driven (aeolian) sand transport, such as coastal dunes and semi-arid regions. We have a good knowledge of how and why different types of desert dunes and dune fields form without the presence of vegetation, but our understanding of the effects of vegetation in the formation of coastal foredunes, parabolic dunes, blowouts, and nebkha's (shrub hummocks) is limited to descriptive observations and reasoning. This is especially true for vegetated dune fields on a landscape scale, and the effects of various plant species on the evolution and dynamics of such environments are not quantified. This research project aims to develop a computer simulation model based on moving around slabs of sand across a grid of cells that represents a landscape surface including varying amounts of vegetation in each cell. These movements are controlled by a set of simple rules that dictate interactions between the existing surface, the vegetation in each cell, and the propagation of the sand slabs. This allows simulating the evolution of aeolian landscapes through self-organisation into different types of dune fields without actually modelling the complex airflow dynamics and sand transport patterns. Simulations will be compared with our current descriptive understanding of vegetated aeolian landscape development to ensure that the model generates realistic results. The model is then used to systematically investigate exactly how and why various kinds of plant species and vegetation patterns influence the dynamics of dune development in aeolian environments.

  • One of the primary processes shaping Earth's surface is the stretching and eventual break-up of continents to create new ocean basins. The processes of stretching and heating of -150 km-thick plates, or layers of rock, are made evident at Earth's surface via earthquakes, volcanoes, hot springs, landslides and rockfalls that occur within and along the margins of narrow, long basins flanked by steep mountain ranges (e.g., East African rift, Gulf of Corinth). Ancient areas of stretching are more difficult to decipher, since the physical processes we wish to understand have since stopped, and competing processes of erosion, sedimentation, and subsidence of the rift zones makes them difficult to image. Finally, studies of continental break-up require an understanding of margins on both sides of ocean basins, which may now be 1000's of km apart (e.g., N. Atlantic). We propose to determine the evolution of continental rifting leading to break-up in the Gulf of Aden, where break-up occurred <20 My ago, and both margins are within a day's shiptime from one another. The short time interval since break-up means that sedimentary strata overlying the stretched, fractured, and heated rock layers of the plate are thin, and we can image clearly using geophysical methods. Our experiment involves the analyses of the travel times of seismic waves through the rock layers of the plates and underlying mantle where rocks are hotter, and where pockets of molten rock may have accumulated. Electronic devices capable of measuring vibrations from earthquakes worldwide (seismometers) will be buried along onshore continuations of profiles across the Gulf of Aden. We intend to use both man-made sound sources generated onboard the French seismic research vessel Marie Dufresne, which will travel along 3 profiles of the Gulf of Aden sending airblasts into the water every 50 metres. Our instruments will also record earthquakes occurring in the Himalayas, the Atlantic mid-ocean ridge, the Mediterranean sea, and the East African rift system. Variations in the arrival times of these sound waves recorded across our array allow us to map out velocity structure of the rocks beneath the array and across the width of the Gulf of Aden. Our aims are to map the geometry of the stretched layers within the plates, as well as their variations in velocity and physical properties. The velocity variations help us detect small variations in temperature and/or composition of the rocks, and help us determine the mechanical properties of the plates as they are stretched. Do the plates come apart along one large fracture, or fault zone, or does the stretching move continually inward to a narrow zone of necking, much like one finds stretching blue tack? Has some of the hot mantle rock which passively rises up to fill the place previously occupied by the plate depressurise and melt to form lavas? Where do these lavas form and rise up? Are these properties continuous along the length of the rift zone, or is the process three-dimensional? All of this information is vitally important to 1) oil explorationists trying to improve predictive models for oil and gas generation and migration 2) planners and government officials who need to evaluate seismic and volcanic hazards in areas of active rifting 3) earth scientists who wish to understand the physical properties of rocks so that we can adequately describe the physics of continental break-up and predict the onset of seafloor spreading. Funds are requested to cover travel to and from Oman to deploy instruments, to download data every 6 weeks (3 months) and every 12 weeks (9 months), plus travel to partner institutions to confer and integrate research results.