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  • Journal article
    Aas TE, Howell JA, Janocko M, Jackson CA-Let al., 2009,

    , Marine and Petroleum Geology, Vol: 27, Pages: 412-434

    It is widely recognized that palaeobathymetry is a key control on the distribution of turbidite deposits. Thus, the utilisation of palaeobathymetric surfaces as an input for numerical turbidity current modelling offers a potentially powerful method to predict the distribution of deep marine sands in ancient (subsurface or outcrop) successions. Such an approach has been tested on an Aptian turbidite deposit from the Buchan Graben, UK Central North Sea, where modelled sand distributions could be quality controlled against available well data. Palaeobathymetric (base Aptian sand) surfaces are re-created from a surface-based 3D model by stepwise backstripping of post-Aptian overburden and removal of the post-depositional structural overprint. Key input parameters such as; (i) initial porosity and compaction factor assigned to the overburden and underburden; (ii) the restoration of structural overprint; and (iii) and the crustal response to removal of overburden (Airy vs. Flexural Isostasy), are associated with significant uncertainty. Thus, to assess this uncertainty, various palaeobathymetric surfaces are re-created by systematically modelling extreme values of individual input parameters. The effects of single input parameter variability on output surface morphology are quantified by spatial comparison of appropriate surfaces. Out of the 20 palaeobathymetric surfaces that were re-created, 3 were selected as input for process-based, numerical turbidity current simulations. The simulation software (Flow 3D™) uses computational fluid-dynamics (CFD) to model depositional patterns, while the effects of flow turbulence are simulated using the Renormalization-Group (RNG) model. The location of flow introduction into the model (sediment input point) as well as flow input parameters (volume of sediment, duration of flow, velocity, height and width) are fixed for all three surfaces to ensure that differences in flow behaviour and sand distribution can be attributed to spa
  • Journal article
    Elbeshausen D, Wuennemann K, Collins GS, 2009,

    , ICARUS, Vol: 204, Pages: 716-731, ISSN: 0019-1035
    • Cite
    • Citations: 173
  • Journal article
    Piggott MD, Farrell PE, Wilson CR, Gorman GJ, Pain CCet al., 2009,

    , PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES, Vol: 367, Pages: 4591-4611, ISSN: 1364-503X
    • Cite
    • Citations: 74
  • Journal article
    Cobden L, Goes S, Ravenna M, Styles E, Cammarano F, Gallagher K, Connolly JADet al., 2009,

    , JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, Vol: 114, ISSN: 2169-9313
    • Cite
    • Citations: 62
  • Conference paper
    Tsiampousi A, Zdravkovic L, Potts DM, 2009,

    Modelling of overconsolidated unsaturated soils

    , 4th Asia Pacific Conference on Unsaturated Soils, Publisher: CRC Press, Pages: 673-678

    Constitutive models for unsaturated soils are most commonly based on conventional critical state type models for saturated soils. The effect of partial saturation is taken into account through the intro-duction of an additional stress variable which depends on soil suction. The modified Cam-Clay surface is usu-ally assumed for the formulation of the yield and the plastic potential surfaces in the mean stress – deviatoric stress space. In this paper an existing model for unsaturated soils is used to simulate drained triaxial tests per-formed on highly overconsolidated unsaturated silt. Even though the model adopts an improved expression for the yield surface that allows a variety of shapes to be introduced, none of them can accurately simulate the observed soil behaviour in the laboratory tests. A new version of the model is, therefore, proposed and pre-sented here. Following the formulation and implementation of these alterations, analyses of laboratory ex-periments on artificial silt are presented demonstrating the improved simulation of soil behaviour.
  • Journal article
    Bland PA, Jackson MD, Coker RF, Cohen BA, Webber JBW, Lee MR, Duffy CM, Chater RJ, Ardakani MG, McPhail DS, McComb DW, Benedix GKet al., 2009,

    , EARTH AND PLANETARY SCIENCE LETTERS, Vol: 287, Pages: 559-568, ISSN: 0012-821X
    • Cite
    • Citations: 133
  • Journal article
    Fang F, Pain CC, Navon IM, Gorman GJ, Piggott MD, Allison PA, Goddard AJHet al., 2009,

    , International Journal for Numerical Methods in Fluids, Vol: 63, Pages: 185-206, ISSN: 1097-0363

    The approach for designing an error measure to guide an adaptive meshing algorithm proposed in Power et al. (Ocean Modell. 2006; 15:3-38) is extended to use a POD adjoint-based method, thus facilitating efficient primal and adjoint integration in time. The aim is to obtain a new mesh that can adequately resolve all the fields at all time levels, with optimal (w.r.t. the functional) efficiency. The goal-based method solves both the primal and adjoint equations to form the overall error norms, in the form of a metric tensor. The tetrahedral elements are then optimized so that they have unit size in Riemannian space defined with respect to the metric tensor.This is the first attempt to use POD to estimate an anisotropic error measure. The metric tensor field can be used to direct anisotropic mesh adaptivity. The resulting mesh is optimized to efficiently represent the solution fields over a given time period. The calculation of the error measures is carried out in the reduced space. The POD approach facilitates efficient integration backwards in time and yields the sensitivity analysis necessary for the goal-based error estimates. The accuracy of both the primal and adjoint-reduced models is thus optimized (through the use of anisotropic mesh adaptivity). In addition, the functional for optimizing meshes has been designed to be consistent with that for 4D Var data assimilation.
  • Journal article
    Zhu B, Jardine RJ, Foray P, 2009,

    , SOILS AND FOUNDATIONS, Vol: 49, Pages: 675-688, ISSN: 0038-0806
    • Cite
    • Citations: 52
  • Journal article
    Jardine RJ, Zhu B, Foray P, Dalton CPet al., 2009,

    , SOILS AND FOUNDATIONS, Vol: 49, Pages: 661-673, ISSN: 0038-0806
    • Cite
    • Citations: 33
  • Journal article
    Kenkmann T, Collins GS, Wittmann A, W眉nnemann K, Reimold WU, Melosh HJet al., 2009,

    , Geological Society of America Special Paper, Vol: 458, Pages: 571-586
  • Journal article
    Getsinger A, Rushmer T, Jackson MD, Baker Det al., 2009,

    , JOURNAL OF PETROLOGY, Vol: 50, Pages: 1935-1954, ISSN: 0022-3530
    • Cite
    • Citations: 31
  • Journal article
    Sech RP, Jackson MD, Hampson GJ, 2009,

    , AAPG Bulletin, Vol: 93, Pages: 1155-1181, ISSN: 0149-1423

    <jats:title>Abstract</jats:title> <jats:p>Conventional reservoir modeling approaches are developed to account for uncertainty associated with sparse subsurface data but are not equipped for detailed reconstruction of high-resolution geologic data sets. We present a surface-based modeling procedure that enables explicit representation of heterogeneity across a hierarchy of length scales. Numerous surfaces are used to construct complex facies-body geometries and distributions prior to generating a grid, allowing sampled and conceptual data to be fully incorporated within field-scale models. Our approach is driven by the improved efficiency that surfaces introduce to reservoir modeling through their geologically intuitive design, rapid construction, and ease of manipulation. Cornerpoint gridding of the architecture defined by the surfaces reduces the number of cells required to represent complex geometries, thus preserving geologic detail and rendering upscaling unnecessary for fluid-flow simulations.</jats:p> <jats:p>The application of surface-based modeling is demonstrated by reconstructing the detailed three-dimensional facies architecture of a wave-dominated shoreface-shelf parasequence from a rich outcrop data set. The studied outcrop data set describes reservoir architecture in a generic analog for many shallow-marine reservoirs. The process of model construction has demonstrated the function of (1) shoreface-shelf clinoforms, (2) paleogeographic changes in shoreline orientation, and (3) storm-event-bed amalgamation in controlling facies architecture. These subtle geometric features cannot be accurately represented using conventional stochastic reservoir modeling algorithms, which results in poor estimation of facies proportions and associated hydrocarbon volumes in place. In contrast, the surface-based modeling approach honors all data and captures subtle geometric facies relationships, thus allowin
  • Conference paper
    Barmpopoulos IH, Ho TYK, Jardine RJ, Anh-Minh Net al., 2009,

    The large displacement shear characteristics of granular media against concrete and steel interfaces

    , Amsterdam, Research Symposium on the Characterization and Behavior of Interfaces (CBI), Publisher: IOS Press, Pages: 17-24
  • Journal article
    Jackson MD, Hampson GJ, Sech RP, 2009,

    , AAPG BULLETIN, Vol: 93, Pages: 1183-1208, ISSN: 0149-1423
    • Cite
    • Citations: 61
  • Journal article
    Jackson CA-L, Johnson HD, 2009,

    , Sedimentary Geology, Vol: 219, Pages: 77-96

    The Temburong Fm (Early Miocene), Labuan Island, offshore NW Borneo, was deposited in a lower-slope to proximal basin-floor setting, and provides an opportunity to study the deposits of sustained turbidity currents and their interaction with debrite-related slope topography. Two main gravity-flow facies are identified; (i) slump-derived debris-flow deposits (debrites) - characterised by ungraded silty mudstones in 1.5 to >60 m thick beds which are rich in large (>5 m) lithic clasts; and (ii) turbidity current deposits (turbidites) - characterised by medium-grained sandstone in beds up to 2 m thick, which contain structureless (Ta) intervals alternating with planar-parallel (Tb) and current-ripple (Tc) laminated intervals. Laterally discontinuous, cobble-mantled scours are also locally developed within turbidite beds. Based on these characteristics, these sandstones are interpreted as having been deposited from sustained turbidity currents. Cobble-mantled scours indicate periods of intense turbidity current waxing. The sustained turbidity currents are interpreted to have been derived from retrogressive collapse of sand-rich mouth bars (breaching) or directly from river effluent (hyperpycnal flow). Analysis of the stratal architecture of the two facies indicates that routing of the turbidity currents was influenced by topographic relief developed at the top of underlying debrite Turbidite beds are locally eroded at the base of an overlying debrite, possibly due to clast-related substrate ‘ploughing’ during the latter flow event. This study highlights the difficulty in constraining the origin of sustained turbidity currents in ancient sedimentary sequences. In addition, this study documents the importance large debrites may have in generating topography on submarine slopes and influencing routing of subsequent turbidity current and the geometry of their associated deposits.
  • Book
    Liu JG, Mason P, 2009,

    Essential Image Processing and GIS for Remote Sensing

    , UK 9780470510322, Publisher: Wiley, ISBN: 9780470510322

    Essential Image Processing and GIS for Remote Sensing is an accessible overview of the subject and successfully draws together these three key areas in a ...
  • Conference paper
    Davison TM, Collins GS, Ciesla F, 2009,

    Quantifying heating in porous planetesimal collisions

    , 72nd Annual Meeting of the Meteoritical-Society, Publisher: Meteoritical Society, Pages: A58-A58, ISSN: 1086-9379
  • Conference paper
    Ciesla FJ, Davison TM, Collins GS, 2009,

    Cooling of porous planetesimals after impacts: Implications for the thermal evolution of primitive bodies

    , 72nd Annual Meeting of the Meteoritical-Society, Publisher: Meteoritical Society, Pages: A51-A51, ISSN: 1086-9379
  • Conference paper
    Collins GS, Wuennemann K, 2009,

    NUMERICAL MODELING OF IMPACT EJECTION PROCESSES IN POROUS GEOLOGIC MATERIALS

    , 72nd Annual Meeting of the Meteoritical-Society, Publisher: METEORITICAL SOC, Pages: A53-A53, ISSN: 1086-9379
  • Journal article
    Hwang YK, Ritsema J, Goes S, 2009,

    , JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, Vol: 114, ISSN: 2169-9313
    • Cite
    • Citations: 17

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