9 research outputs found

    Can sand dunes be used to study historic storm events?

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    Knowing the long-term frequency of high magnitude storm events that cause coastal inundation is critical for present coastal management, especially in the context of rising sea levels and potentially increasing frequency and severity of storm events. Coastal sand dunes may provide a sedimentary archive of past storm events from which long-term frequencies of large storms can be reconstructed. This study uses novel portable optically stimulated luminescence (POSL) profiles from coastal dunes to reconstruct the sedimentary archive of storm and surge activity for Norfolk, UK. Application of POSL profiling with supporting luminescence ages and particle size analysis to coastal dunes provides not only information of dunefield evolution but also on past coastal storms. In this study, seven storm events, two major, were identified from the dune archive spanning the last 140 years. These appear to correspond to historical reports of major storm surges. Dunes appear to be only recording (at least at the sampling resolution used here) the highest storm levels that were associated with significant flooding. As such the approach seems to hold promise to obtain a better understanding of the frequency of large storms by extending the dune archive records further back to times when documentation of storm surges was sparse

    Instant luminescence chronologies? High resolution luminescence profiles using a portable luminescence reader

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    Establishing a robust chronology is fundamental to most palaeoenvironmental studies. However, the number and positioning of dated points is critical. Using a portable luminescence reader, it is possible to rapidly generate high resolution down core relative age profiles. Profiles of portable luminescence data from two coastal dunes were evaluated and compared with the results of particle size analysis, stratigraphy, and an independent historical chronology. Results show that, even in young samples, portable luminescence data is dominated by an age related signal which in homogeneous sediment need not be corrected for moisture, feldspar content changes or grain size. Profiles therefore provide relative chronologies from which accumulation phases can be established, and from which better targeted sampling and comparison to other sites could be undertaken. Even though they do not provide instant absolute chronologies, field-based portable luminescence profiling of Late Quaternary sites hold much potential to improve the resultant chronologies

    Last glacial dynamics of the Vale of York and North Sea lobes of the British and Irish Ice Sheet

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    During the Last Glacial Maximum, the Vale of York and North Sea lobes of the British and Irish Ice Sheet extended to within 10 km of each other, impounding a series of pro-glacial lakes. Such an interplay of ice lobes provides a useful analogue for elsewhere in the North Sea basin. This paper focusses on reconstructing the Vale of York and North Sea Ice lobes using a regional suite of 25 luminescence ages in combination with stratigraphical and geomorphic evidence. Results extend and revise the chronology of the Dimlington LGM typesite, showing that the North Sea Ice lobe advanced between 20.9–17.1 ka and 17.1–15.1 ka before present. Initially this lobe impounded a proto Lake Humber which likely covered parts of Holderness as well as the southern part of the Vale of York. Later stages of Lake Humber within the Vale of York show continued blockage of the Humber Gap by the North Sea Ice lobe. The Vale of York Ice extended briefly at ∌18.7 ± 0.63 ka across Lake Humber into South Yorkshire and North Lincolnshire before retreating to and forming the Escrick and York moraines. Both glacier lobes appear to have been short-lived, comprising relatively dynamic ice, especially when moving into areas of deformable lacustrine sediments, which allowed them to rapidly advance and over-extend their margins due to low basal shear stress. Topographic control of the extent and spatial positioning of both Ice lobes also appears to have been significant

    Factors Affecting the Successful Realisation of Benefits from Systems Development Projects: Findings from Three Case Studies

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    This article was published in the Journal of Information Technology [© Palgrave Macmillan] and the definitive version is available at: http://dx/doi.org/10.1057/jit.2011.8The return that organisations derive from investments in information systems and technology continues to disappoint. While there is a very significant body of literature on the factors that should facilitate a successful outcome from systems development, there is growing concern that these prescriptions are not having their desired effect. In this paper, we argue that the success of a systems development project should be measured in terms of its ability to deliver meaningful benefits, rather than the timely delivery of a technical artefact, and therefore organisations should adopt an explicit and proactive benefits realisation approach when investing in IT. Consequently, we sought to explore those actionable factors that might facilitate the effective realisation of benefits from systems development initiatives. Three organisations were identified that claimed to adopt a proactive approach to benefits realisation, and detailed studies of their systems development practices were conducted. Our analysis found that whilst one organisation had been successful in its adoption of a benefits realisation perspective, the other two had not, and this allowed us to identify those factors that helped to explain this difference in outcomes. In short, this paper makes an important contribution by identifying how a sub-set of traditional systems success factors might be enhanced, to give them a more explicit benefits realisation orientation. Moreover, it presents a coherent set of principles that can be used for deriving other factors and practices
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