39 research outputs found

    VOLCANS: an objective, structured and reproducible method for identifying sets of analogue volcanoes

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    The definition of a suite of analogue volcanoes, or volcanoes that are considered to share enough characteristics as to be considered exchangeable to a certain extent, is becoming a key component of volcanic hazard assessment. This is particularly the case for volcanoes where data are lacking or scarce. Moreover, volcano comparisons have often been based on similarities and differences inferred through expert judgement and not necessarily informed by volcano characteristics from global datasets. These similarities can be based on a range of features, from very simplified (e.g. statrovolcanoes) to very specific (e.g. detailed eruption chronologies), and may be strongly influenced by the personal experience of individuals or teams conducting the analogue analysis. In this work, we present VOLCANS (VOLCano ANalogues Search)—an objective, structured and reproducible method to identify sets of analogue volcanoes from global volcanological databases. Five overarching criteria (tectonic setting, rock geochemistry, volcano morphology, eruption size and eruption style), and a structured combination of them, are used to quantify overall multi-criteria volcano analogy. This innovative method is complementary to expert-derived sets of analogue volcanoes and provides the user with full flexibility to weigh the criteria and identify analogue volcanoes applicable to varied purposes. Some results are illustrated for three volcanoes with diverse features and significant recent and/or ongoing eruptions: Kı̄lauea (USA), Fuego (Guatemala) and Sinabung (Indonesia). The identified analogue volcanoes correspond well with a priori analogue volcanoes derived from expert knowledge. In some cases, single-criterion searches may not be able to isolate a reduced set of analogue volcanoes but any multi-criteria search can provide high degrees of granularity in the sets of analogue volcanoes obtained. Data quality and quantity can be important factors, especially for single-criterion searches and volcanoes with very scarce data (e.g. Sinabung). Nevertheless, the method gives stable results overall across multi-criteria searches of analogue volcanoes. Potential uses of VOLCANS range from quantitative volcanic hazard assessment to promoting fundamental understanding of volcanic processes

    Investigating Source Conditions and Controlling Parameters of Explosive Eruptions: Some Experimental-Observational- Modelling Case Studies

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    Explosive volcanic eruptions are complex systems that can generate a variety of hazardous phenomena, for example, the injection of volcanic ash into the atmosphere or the generation of pyroclastic density currents. Explosive eruptions occur when a turbulent multiphase mixture, initially predominantly composedf of fragmented magma and gases, is injected from the volcanic vent into the atmosphere. For plume modelling purposes, a specific volcanic eruption scenario based on eruption type, style or magnitude is strictly linked to magmatic and vent conditions, despite the subsequent evolution of the plume being influenced by the interaction of the erupted material with the atmosphere. In this chapter, different methodologies for investigating eruptive source conditions and the subsequent evolution of the eruptive plumes are presented. The methodologies range from observational techniques to large-scale experiments and numerical models. Results confirm the relevance of measuring and observing source conditions, as such studies can improve predictions of the hazards of eruptive columns. The results also demonstrate the need for fundamental future research specifically tailored to answer some of the still open questions: the effect of unsteady flow conditions at the source on the eruptive column dynamics and the interaction between a convective plume and wind

    3D geological models and their hydrogeological applications : supporting urban development : a case study in Glasgow-Clyde, UK

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    Urban planners and developers in some parts of the United Kingdom can now access geodata in an easy-to-retrieve and understandable format. 3D attributed geological framework models and associated GIS outputs, developed by the British Geological Survey (BGS), provide a predictive tool for planning site investigations for some of the UK's largest regeneration projects in the Thames and Clyde River catchments. Using the 3D models, planners can get a 3D preview of properties of the subsurface using virtual cross-section and borehole tools in visualisation software, allowing critical decisions to be made before any expensive site investigation takes place, and potentially saving time and money. 3D models can integrate artificial and superficial deposits and bedrock geology, and can be used for recognition of major resources (such as water, thermal and sand and gravel), for example in buried valleys, groundwater modelling and assessing impacts of underground mining. A preliminary groundwater recharge and flow model for a pilot area in Glasgow has been developed using the 3D geological models as a framework. This paper focuses on the River Clyde and the Glasgow conurbation, and the BGS's Clyde Urban Super-Project (CUSP) in particular, which supports major regeneration projects in and around the City of Glasgow in the West of Scotland

    Developing the specifications of an Open Angle Glaucoma screening intervention in the United Kingdom : a Delphi approach

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    PMID: 23216983 [PubMed - indexed for MEDLINE] PMCID: PMC3563574 Free PMC Article Acknowledgements We thank all the glaucoma specialists who took part in the Delphi process. We thank the Glaucoma screening Platform Study advisory panel including R Bativala, D Crabb, D Garway-Heath, M Griffiths, R Hitchings; S McPherson, A Tuulonen, A Viswanathan, H Waterman, R Wormald, D Wright for their guidance and contribution to the Delphi process and Luke Vale and Rodolfo Hernandez for their advice on development of the Delphi questionnaires. This paper was developed from the first phase of a project funded by the MRC (project reference G0701759) Developing the intervention & outcome components of a proposed randomized controlled trial of screening for open angle glaucoma. The Health Services Research Unit is core funded by the Chief Scientist Office of the Scottish Government Health Directorates. The views expressed in this report are those of the authors and not necessarily those of the funders.Peer reviewedPublisher PD

    Narrative theology in Religious Education

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    This is an Author's Accepted Manuscript of an article published in British Journal of Religious Education, 20 March 2013. Copyright © 2013 Taylor & Francis. Available online at: http://www.tandfonline.com/10.1080/01416200.2013.785931This article advocates a pedagogy of Religious Education (RE) based upon a narratival framework informed by both narrative theology and narrative philosophy. Drawing on the work of narrative theologians including Stanley Hauerwas, the article outlines the nature of the framework, describes the four phases of learning that comprise the pedagogy, and explains how such an approach can overcome existing difficulties in how biblical texts are handled within RE. Working from the narrative assumption that individuals and communities are formed by reading, sharing and living within stories, it suggests that the pedagogy might encourage pupils to think about how the lives of Christians are shaped by their interpretations of biblical narratives, to offer their own interpretations of biblical and other texts, and to consider the stories – religious, non-religious or both – which shape their own lives. In so doing, the article moves away from a ‘proof-texting’ approach to the Bible towards one in which pupils are enabled to think about the significance of biblical narratives for both Christians and themselves

    Textural and geochemical constraints on andesitic plug emplacement prior to the 2004–2010 vulcanian explosions at Galeras volcano, Colombia

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    Hazardous sequences of vulcanian explosions are thought to result from the repeated emplacement and destruction of degassed, highly crystalline magma plugs in the shallow conduit of arc volcanoes. The processes governing the timing and magnitude of these explosions are thought to be related to magma ascent rate and efficiency of degassing and crystallisation. We study a rare suite of time-constrained ballistic bombs from the 2004–2010 period of activity of Galeras volcano to reconstruct magma plug architecture prior to six individual vulcanian explosions. We find that each plug was vertically stratified with respect to crystallinity, vesicularity and melt volatile content, melt composition and viscosity. We interpret this structure as resulting from multiple bubble nucleation events and degassing-driven crystallisation during multi-step ascent of the magma forming the plug, followed by spatially variable crystallisation within the plug under contrasting conditions of effective undercooling created by degassing. We propose that the shallow conduit evolved from more open degassing conditions during 2004–2008 to more closed conditions during 2009–2010. This resulted in explosions becoming smaller and less frequent over time during 2004–2008, then larger and more frequent over time during 2009–2010. This evolution was controlled by changing average ascent rates and is recorded by systematic changes in plagioclase microlite textures. Our results suggest that small volume vulcanian explosions (~ 105 m3) should generally be associated with longer repose times (hundreds of days) and produce ballistics characterised by small numbers of large, prismatic plagioclase microlites. Larger volume vulcanian explosions (~ 106 m3) should be associated with shorter repose times (tens of days) and produce ballistics characterised by high numbers of small, more tabular plagioclase microlites
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