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Journal articleRossetto T, D'Ayala D, Gori F, et al., 2014,
The value of multiple earthquake missions: the EEFIT L'Aquila Earthquake experience
, BULLETIN OF EARTHQUAKE ENGINEERING, Vol: 12, Pages: 277-305, ISSN: 1570-761X- Author Web Link
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- Citations: 16
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Journal articleFitch PJR, Jackson MD, Hampson GJ, et al., 2014,
Interaction of stratigraphic and sedimentological heterogeneities with flow in carbonate ramp reservoirs: impact of fluid properties and production strategy
, Petroleum Geoscience, Vol: 20, Pages: 7-26, ISSN: 1354-0793 -
Journal articlevan Reeuwijk M, Holzner M, 2014,
The turbulence boundary of a temporal jet
, Journal of Fluid Mechanics, Vol: 739, Pages: 254-275, ISSN: 0022-1120We examine the structure of the turbulence boundary of a temporal plane jet at Re=5000 using statistics conditioned on the enstrophy. The data is obtained by direct numerical simulation and threshold values span 24 orders of magnitude, ranging from essentially irrotational fluid outside the jet to fully turbulent fluid in the jet core. We use two independent estimators for the local entrainment velocity vn based on the enstrophy budget. The data show clear evidence for the existence of a viscous superlayer (VSL) that envelopes the turbulence. The VSL is a nearly one-dimensional layer with low surface curvature. We find that both its area and viscous transport velocity adjust to the imposed rate of entrainment so that the integral entrainment flux is independent of threshold, although low-Reynolds-number effects play a role for the case under consideration. This threshold independence is consistent with the inviscid nature of the integral rate of entrainment. A theoretical model of the VSL is developed that is in reasonably good agreement with the data and predicts that the contribution of viscous transport and dissipation to interface propagation have magnitude 2vn and −vn , respectively. We further identify a turbulent core region (TC) and a buffer region (BR) connecting the VSL and the TC. The BR grows in time and inviscid enstrophy production is important in this region. The BR shows many similarities with the turbulent–non-turbulent interface (TNTI), although the TNTI seems to extend into the TC. The average distance between the TC and the VSL, i.e. the BR thickness is about 10 Kolmogorov length scales or half a Taylor length scale, indicating that intense turbulent flow regions and viscosity-dominated regions are in close proximity.
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Journal articleAlves TM, Bell RE, Jackson CA-L, et al., 2014,
Deep-water continental margins: geological and economic frontiers
, Basin Research, Vol: 26, Pages: 3-9Deep-water margins have been the focus of considerable research during the past decade. They comprise vast, underexplored regions, in which only recently have improvements in seismic imaging and drilling technology allowed the discovery of significant hydrocarbon accumulations. This volume comprises of a series of manuscripts based on studies from continental margins bordering India, East Africa, Australia, China, Norway, the United Kingdom, Iberia, Newfoundland, the southern US, West Africa and Brazil, thus offering a global perspective on the evolution and economic significance of deep-water margins. The articles in this volume examine: (i) the quantification of extension and hyperextension in distal parts of continental margins, and their relationship with regional subsidence, (ii) the importance of magmatism in the structural and thermal evolution of rifted continental margins, (iii) the processes driving and the significance of regional exhumation during and after syn-rift stretching, (iv) the tectonic setting of salt basins and (v) depositional patterns along deep-water margins. To complement this work, we present a personal view of some of the specific questions that need to be addressed in the next few years of deep-water continental margin research.
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Journal articleMagee C, Jackson CAL, Schofield N, 2014,
Diachronous sub-volcanic intrusion along deep-water margins: insights from the Irish Rockall Basin
, Basin Research, Vol: 26, Pages: 85-105The movement of magma in sedimentary basins often occurs through an extensive and interconnected complex of sills. Field-, modelling-, and seismic reflection-based studies indicate that the emplacement of shallow-level sills is commonly accommodated by the formation of forced folds, which may be expressed at the free surface and onlapped by younger strata. If the age of these onlapping strata can be constrained, important insights can be gained into the timing of magma emplacement and associated regional, tectono-magmatic events. Previous studies have focused on isolated intrusions that are overlain by an individual forced fold formed during a single tectono-magmatic event. However, the structure and evolution of ‘compound’ folds developed above stacked, interconnected sills, and what they may reveal about polyphase intrusive events has not been investigated. In this study, we use 3D seismic reflection data from the Irish Rockall Basin, offshore western Ireland, to constrain the structural style and emplacement history of a sill complex that contains 82 seismically resolved intrusions. Individual forced folds, <41 km2 in plan view and with mean fold amplitudes of 111 m, are developed above single intrusions. However, where sills are stacked, broader (100–244 km2), larger amplitude (mean of 296 m) compound folds occur following the coalescence of individual folds. Stratigraphic onlap and truncation observed within the folds throughout the Palaeocene-to-Middle Eocene succession, indicates that emplacement and forced folding initiated at the end Maastrichtian and lasted for ca. 15 Ma, before ceasing near the end of the Ypresian. We demonstrate (i) intrusion-induced forced folds evolve dynamically and can form broad areas of sustained local uplift, and (ii) that the formation of sill complexes within the upper crust may occur over prolonged time periods. This study also highlights the importance of seismic reflection data to understanding the struct
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Journal articleBell RE, Jackson CAL, Elliott GM, et al., 2014,
Insights into the development of major rift-related unconformities from geologically constrained subsidence modelling: Halten Terrace, offshore mid Norway
, Basin Research, Vol: 26, Pages: 203-224Due to the effects of sediment compaction, thermal subsidence and ‘post-rift’ fault reactivation, the present-day geometry of buried, ancient rift basins may not accurately reflect the geometry of the basin at any stage of its syn-rift evolution. An understanding of the geometry of a rift basin through time is crucial for resolving the dynamics of continental rifting and in assessing the hydrocarbon prospectivity of such basins. In this study, we have restored the Late Jurassic–Early Cretaceous geometry of the southern Halten Terrace, offshore mid Norway, using a combination of well log- and core-derived, sedimentological and stratigraphic data, seismic-stratigraphic observations and reverse subsidence modelling. This integrated geological and geophysical approach has allowed the large number of input parameters involved in flexural backstripping and post-rift thermal subsidence modelling to be constrained. We have thus been able to determine the regional structure of the basin at the end of the Late Jurassic–Early Cretaceous rift phase and the associated amount of crustal stretching. Our basin geometry reconstructions reveal that, during the latest syn-rift period in the Late Jurassic–Early Cretaceous, the Halten Terrace was characterized by a series of isolated depocentres, located between footwall islands, which were not connected into a single depocentre until the Late Cretaceous (Coniacian). We show that two major unconformities, which are now vertically offset by ca. 2 km and located ca. 60 km apart, formed at similar subaerial elevations in the Late Jurassic–Early Cretaceous and were subsequently vertically offset by thermally induced tilting of the basin margin. Cretaceous sediments were deposited in a single, relatively unconfined basin in water depths of 1–1.5 km. The β profile that best restores palaeobathymetry to match our geological constraints is the same as that derived from summing visible post-Late Tri
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Journal articleD'Arcy M, Whittaker AC, 2014,
Geomorphic constraints on landscape sensitivity to climate in tectonically active areas
, Geomorphology, Vol: 204, Pages: 366-381The geomorphology of fluvial landscapes is known to record information about uplift rate, spatial patterns of faulting, and tectonic history. Data is far less available when addressing the sensitivity of common geomorphological metrics, such as channel steepness, to climatic boundary conditions. We test the relationship between channel steepness and precipitation rate by measuring a large number of channels in different mountainous areas. These regions exhibit a tenfold variation in precipitation rate between them (~ 100-1000 mm y- 1) but have similar uplift rates, allowing the tectonic variable to be controlled. By accounting for the orographic coupling of rainfall with uplifted topography, we find that channel steepness is significantly suppressed by higher precipitation rates in a measurable way that conforms to simple stream power erosion laws and empirical constraints on their parameters. We demonstrate this using modern and estimated glacial precipitation rates; and climate emerges as an important, quantifiable control on channel geometry. These findings help to explain why highly variable measurements of channel steepness are reported from different locations and provide important empirical constraints on how climate shapes tectonically active landscapes.
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Journal articleMonroy R, Zdravkovic L, Ridley AM, 2014,
Evaluation of an Active System to Measure Lateral Stresses in Unsaturated Soils
, GEOTECHNICAL TESTING JOURNAL, Vol: 37, ISSN: 0149-6115- Author Web Link
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- Citations: 7
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Journal articleKamal RH, Coop MR, Jardine RJ, et al., 2014,
The post-yield behaviour of four Eocene-to-Jurassic UK stiff clays
, GEOTECHNIQUE, Vol: 64, Pages: 620-634, ISSN: 0016-8505- Author Web Link
- Open Access Link
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- Citations: 30
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Journal articleZhang C, Yang ZX, Nguyen GD, et al., 2014,
Theoretical breakage mechanics and experimental assessment of stresses surrounding piles penetrating into dense silica sand
, GEOTECHNIQUE LETTERS, Vol: 4, Pages: 11-16, ISSN: 2049-825X- Author Web Link
- Open Access Link
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- Citations: 34
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Journal articleNeal WD, Appleby-Thomas GJ, Collins GS, 2014,
Meso-scopic deformation in brittle granular materials
, 18TH APS-SCCM AND 24TH AIRAPT, PTS 1-19, Vol: 500, ISSN: 1742-6588- Author Web Link
- Open Access Link
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- Citations: 6
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Conference paperTsiampousi A, Vitsios I, Zdravkovic L, et al., 2014,
Effect of previous stress history and vegetation on the coefficient of earth pressure at-rest, K-0, in London clay
, 8th European Conference on Numerical Methods in Geotechnical Engineering (NUMGE), Publisher: CRC PRESS-TAYLOR & FRANCIS GROUP, Pages: 209-214- Author Web Link
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- Citations: 1
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Conference paperJacobs CT, Collins GS, Piggott MD, et al., 2014,
MULTIPHASE FLOW MODELLING OF EXPLOSIVE VOLCANIC ERUPTIONS USING AN ADAPTIVE UNSTRUCTURED MESH-BASED APPROACH
, 11th World Congress on Computational Mechanics (WCCM) / 5th European Conference on Computational Mechanics (ECCM) / 6th European Conference on Computational Fluid Dynamics (ECFD), Publisher: INT CENTER NUMERICAL METHODS ENGINEERING, Pages: 7406-7417 -
Conference paperZdravkovic L, Potts DM, Tsiampousi A, 2014,
Obtaining factors of safety from a finite element analysis of unsaturated soils
, 6th International Conference on Unsaturated Soils (UNSAT), Publisher: CRC PRESS-TAYLOR & FRANCIS GROUP, Pages: 553-559 -
Journal articleDeveugle PEK, Jackson MD, Hampson GJ, et al., 2014,
A comparative study of reservoir modeling techniques and their impact on predicted performance of fluvial-dominated deltaic reservoirs
, AAPG Bulletin, Vol: 98, Pages: 729-763, ISSN: 0149-1423Multiple techniques are available to construct three-dimensional reservoir models. This study uses comparative analysis to test the impact of applying four commonly used stochastic modcling techniques to capture geologic heterogeneity and fluid-flow behavior in fluvial-dominated deltaic reservoirs of complex facies architecture: (1) sequential indicator simulation; (2) object-based modeling; (3) multiple-point statistics (MPS); and (4) spectral component geologic modeling. A reference for comparison is provided by a high-resolution model of an outcrop analog that captures facies architecture at the scale of parasequences, delta lobes, and fades-association belts. A sparse, pseudosubsurface data set extracted from the reference model is used to condition models constructed using each stochastic reservoir modeling technique. Models constructed using all four algorithms fail to match the facies-association proportions of the reference model because they are conditioned to well data that sample a small, unrepresentative volume of the reservoir. Simulated sweep efficiency is determined by the degree to which the modeling algorithms reproduce two aspects of fades architecture that control sand-body connectivity: (1) the abundance, continuity, and orientation of channelized fluvial sand bodies; and (2) the lateral continuity of barriers to vertical flow associated with flooding surfaces. The MPS algorithm performs best in this regard. However, the static and dynamic performance of the models (as measured against facies-association proportions, facies architecture, and recovery factor of the reference model) is more dependent on the quality and quantity of conditioning data and on the interpreted geologic scenario(s) implicit in the models than on the choice of modeling technique. Copyright ©2014. The American Association of Petroleum Geologists. All rights reserved.
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Conference paperVire A, Spinneken J, Piggott MD, et al., 2014,
MODELLING OF WAVES AND WAVE-STRUCTURE INTERACTIONS USING NON-LINEAR NUMERICAL MODELS
, 11th World Congress on Computational Mechanics (WCCM) / 5th European Conference on Computational Mechanics (ECCM) / 6th European Conference on Computational Fluid Dynamics (ECFD), Publisher: INT CENTER NUMERICAL METHODS ENGINEERING, Pages: 2138-2148 -
Journal articleMatmon A, Fink D, Davis M, et al., 2014,
Unraveling rift margin evolution and escarpment development ages along the Dead Sea fault using cosmogenic burial ages
, Quaternary Research (United States), Vol: 82, Pages: 281-295, ISSN: 0033-5894The Dead Sea fault (DSF) is one of the most active plate boundaries in the world. Understanding the Quaternary history and sediments of the DSF requires investigation into the Neogene development of this plate boundary. DSF lateral motion preceded significant extension and rift morphology by ~10Ma. Sediments of the Sedom Formation, dated here between 5.0±0.5Ma and 6.2-2.1+infMa, yielded extremely low 10Be concentrations and 26Al is absent. These reflect the antiquity of the sediments, deposited in the Sedom Lagoon, which evolved in a subdued landscape and was connected to the Mediterranean Sea. The base of the overlying Amora Formation, deposited in the terminal Amora Lake which developed under increasing relief that promoted escarpment incision, was dated at 3.3-0.8+0.9Ma. Burial ages of fluvial sediments within caves (3.4±0.2Ma and 3.6±0.4Ma) represent the timing of initial incision. Initial DSF topography coincides with the earliest Red Sea MORB's and the East Anatolian fault initiation. These suggest a change in the relative Arabian-African plate motion. This change introduced the rifting component to the DSF followed by a significant subsidence, margin uplift, and a reorganization of relief and drainage pattern in the region resulting in the topographic framework observed today. © 2014 University of Washington.
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Journal articleBierman PR, Corbett LB, Graly JA, et al., 2014,
Preservation of a preglacial landscape under the center of the greenland ice sheet
, Science, Vol: 344, Pages: 402-405, ISSN: 0036-8075Continental ice sheets typically sculpt landscapes via erosion; under certain conditions, ancient landscapes can be preserved beneath ice and can survive extensive and repeated glaciation. We used concentrations of atmospherically produced cosmogenic beryllium-10, carbon, and nitrogen to show that ancient soil has been preserved in basal ice for millions of years at the center of the ice sheet at Summit, Greenland. This finding suggests ice sheet stability through the Pleistocene (i.e., the past 2.7 million years). The preservation of this soil implies that the ice has been nonerosive and frozen to the bed for much of that time, that there was no substantial exposure of central Greenland once the ice sheet became fully established, and that preglacial landscapes can remain preserved for long periods under continental ice sheets.
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Journal articleHiester HR, Piggott MD, Farrell PE, et al., 2014,
Assessment of spurious mixing in adaptive mesh simulations of the two-dimensional lock-exchange
, Ocean Modelling, Vol: 73, Pages: 30-44, ISSN: 1463-5003 -
Journal articleJackson CA-L, Rodriguez CR, Rotevatn A, et al., 2014,
Geological and geophysical expression of a primary salt weld; an example from the Santos Basin, Brazil. In press
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