phyllosilicate orientation demonstrates early timing of compactional stabilization in calcite cemented concretions in the barnett shale late mississippian fort worth basin texas u s a abstract calcite cemented zones in the prolific gas producing barnett shale ft worth basin texas preserve very early compactional fabrics that contrast markedly with fabrics in the enclosing host rocks the compactional state of these zones based upon alignments of phyllosilicates as determined by high resolution x ray goniometry hrxtg complemented by x ray powder diffraction xrpd back scattered electron imaging and elemental x ray mapping points to a prelithification near syndepositional timing of initial authigenic calcite emplacement thus these carbonate cemented zones are of particular interest for the information they provide on the character of grain assemblages and sediment types at the time of deposition and also on the early post depositional environmental chemistry of the barnett shale strata

intrinsic elasticity of a textured transversely isotropic muscovite aggregate comparisons to the seismic anisotropy of schists and shales 1 the anisotropic properties of phyllosilicate rocks are investigated through the modeling of the pore free intrinsic elasticity of a textured muscovite aggregate the elastic constants were calculated for textures as defined using orientation distribution functions odfs ranging from perfectly aligned to completely random the odfs were described using a gaussian distribution the width of which is controlled by the standard deviation of the orientations of the crystal c axis with respect to the sample foliation plane under the assumption that the sample has hexagonal transversely isotropic symmetry the values were obtained using the widely used voigt reuss hill averaging techniques as well as the geometric mean average gma the gma is more physically meaningful in that it requires that the elastic constants determined in either the stiffness or the compliance domains be invertible comparisons between these different averages indicate that strictly the voigt and reuss values do not necessarily provide the limiting bounds as is expected for the isotropic case despite this some characteristics of the elastic wave p wave anisotropy are only weakly dependent on the averaging procedure employed the calculated elastic constants are converted to the anisotropic and parameters in order to allow for comparison to existing measurements in the literature however these intrinsic results are not intended to provide a measure of the properties of phyllites per se but to provide a reference against which more sophisticated models that incorporate porosity layering and composition may be constructed

an integrated ams structural palaeo and rock magnetic study of eocene marine marls from the jaca pamplona basin pyrenees n spain new insights into the timing of magnetic fabric acquisition in weakly deformed mudrocks

nearshore tsunami inundation model validation toward sediment transport applications model predictions from a numerical model delft3d based on the nonlinear shallow water equations are compared with analytical results and laboratory observations from seven tsunami like benchmark experiments and with field observations from the 26 december 2004 indian ocean tsunami the model accurately predicts the magnitude and timing of the measured water levels and flow velocities as well as the magnitude of the maximum inundation distance and run up for both breaking and non breaking waves the shock capturing numerical scheme employed describes well the total decrease in wave height due to breaking but does not reproduce the observed shoaling near the break point the maximum water levels observed onshore near kuala meurisi sumatra following the 26 december 2004 tsunami are well predicted given the uncertainty in the model setup the good agreement between the model predictions and the analytical results and observations demonstrates that the numerical solution and wetting and drying methods employed are appropriate for modeling tsunami inundation for breaking and non breaking long waves extension of the model to include sediment transport may be appropriate for long non breaking tsunami waves using available sediment transport formulations the sediment deposit thickness at kuala meurisi is predicted generally within a factor of 2

clay fabrics in relation to the burial history of shales quantitative appraisal of compaction strain is essential for the study of the burial history of shales in sedimentary basins the results of a preliminary fabric analysis of westphalian and zechstein shales in the campine basin belgium show that clay fabric analysis using an x ray pole figure goniometer is suitable for this purpose clay fabrics in the range studied are independent of depth and therefore cannot be used as depth indicators this suggests that in the early stages of the burial history a stable clay fabric has to develop which will basically remain unchanged during the subsequent burial history the degree of clay particle preferred orientation not only reflects the compaction strain but is also determined by mineralogical parameters the presence of non platy particles and the relative concentrations of the different clay minerals this degree of preferred orientation furthermore determines the degree of fissility of the shales these mineralogical factors limit the use of clay fabrics as truly quantitative strain markers their use as semi quantitative strain markers remains advantageous mainly because of the common occurrence of clay fabrics in the geological record moreover the relative ease of measurement and the possibility of distinguishing compaction from tectonic strains favour the use of clay fabrics in the quantitative strain analysis of argillaceous rocks

fault related fold kinematics recorded by terrestrial growth strata sant llorenc de morunys pyrenees mountains ne spain abstract foreland basin growth strata are ideal recorders of deformation rates and kinematics in tectonically active regions this study develops a high resolution chronostratigraphic age model to determine folding rates in the eocene oligocene terrestrial growth strata of the berga conglomerate group ne spain the berga conglomerate group was sampled for rock magnetic magnetostratigraphic and magnetic susceptibility cyclostratigraphy analyses analysis of rock magnetic measurements indicate a mixed mineral assemblage with both paramagnetic and ferromagnetic minerals a new magnetic reversal stratigraphy constrains the time frame of folding and is in agreement with previous interpretations time series analysis of variations show statistically significant power at expected orbital frequencies and provides precession scale 20 kyr temporal resolution strain measurements including anisotropy of magnetic susceptibility ams fabrics and bedding plane strain worm burrow distortion are consistent with fixed hinge flexural folding kinematics fault related folding was modeled using cyclostratigraphy timing and strain measurement kinematic constraints the onset of folding was at 33 85 ma and the end of deformation is less constrained but is younger than 31 06 ma deformation and sediment accumulation rates are unsteady at 20 kyr time scales but appear artificially steady at polarity chron time scales

time dependent onshore tsunami response abstract while bulk measures of the onshore impact of a tsunami including the maximum run up elevation and inundation distance are important for hazard planning the temporal evolution of the onshore flow dynamics likely controls the extent of the onshore destruction and the erosion and deposition of sediment that occurs however the time varying dynamics of actual tsunamis are even more difficult to measure in situ than the bulk parameters here a numerical model based on the non linear shallow water equations is used to examine the effects variations in the wave characteristics bed slope and bottom roughness have on the temporal evolution of the onshore flow model results indicate that the onshore flow dynamics vary significantly over the parameter space examined for example the flow dynamics over steep smooth morphologies tend to be temporally symmetric with similar magnitude velocities generated during the run up and run down phases of inundation conversely on shallow rough onshore topographies the flow dynamics tend to be temporally skewed toward the run down phase of inundation with the magnitude of the flow velocities during run up and run down being significantly different furthermore for near breaking tsunami waves inundating over steep topography the flow velocity tends to accelerate almost instantaneously to a maximum and then decrease monotonically conversely when very long waves inundate over shallow topography the flow accelerates more slowly and can remain steady for a period of time before beginning to decelerate these results indicate that a single set of assumptions concerning the onshore flow dynamics cannot be applied to all tsunamis and site specific analyses may be required

fabric and anisotropy of slates from classical studies to new results abstract slates are low grade metamorphic argillaceous rocks which have developed an intense tectonic fabric referred to as slaty cleavage due to their unique properties they have long been used as building materials especially tiles for roofs and floors the fabric characterized by strong alignment of platy phyllosilicate crystals produces extreme anisotropy that has been of great interest in structural geology what different fabric types are observed how do they form here we review crystal preferred orientation cpo and add new information to establish a comprehensive base for future studies slates are composed of fine grained phyllosilicates dominantly white mica and chlorite sometimes chloritoid quartz and accessories texture analyses of these polyphase rocks with high energy synchrotron x ray diffraction and high resolution ebsd reveal strong alignment of mica and chlorite in some cases exceeding any previously reported texture strength including metals interestingly the cpo of quartz with highly flattened grains shape preferred orientation or spo is practically random recrystallization microstructures observed by scanning electron microscopy suggest that the phyllosilicate preferred orientation is largely caused by crystal growth under stress and that quartz was subject to pressure solution and reprecipitation producing an anisotropic shape while phyllosilicates preferred orientation in slates is much higher than reports for shale schists and gneiss elastic seismic anisotropy for slates is similar to shales where a significant component is due to aligned porosity

a comparison of the strain of crinoid columnals with that of their enclosing silty and shaly matrix on the appalachian plateau new york abstract a pole figure goniometer was used to measure the preferred orientation of the basal planes of chlorite in 87 samples from the upper devonian clastic rocks of the appalachian plateau new york interpretation of the preferred orientation according to the theory of march yields an estimate of how much an element of the sediment has changed shape since deposition this deformation can be interpreted according to three distinct models for the strain history all begin with compaction followed by one of three types of tectonic strain 1 a plane strain that conserves bedding plane area by compensating for horizontal shortening with horizontal elongation at right angles 2 one that uniaxially shortens a horizontal line normal to the fold axes without compensating elongation and 3 a plane strain again which conserves the area in the vertical plane containing a shortened horizontal direction by stretching it vertically for lack of suitable names we will simply call the three total strains type b u and v from the initials of the distinguishing features of their tectonic increment the horizontal strain components estimated from preferred orientation are compared at a number of localities with those implicit in the principal horizontal diameters of the elliptical outlines of deformed crinoid columnals found on bedding planes expressed for constant bedding plane area or type b total strain the strain in the direction of greatest elongation measured by preferred orientation was found to range from no recorded strain to 0 19 with a median of 0 04 as a rule however the more intensive strains were recorded in shales with a fine grained phyllosilicate content exceeding 85 by volume in which the mean was 0 07 deformed crinoid columnals in the same set of samples have elongations parallel to their long axes that range from 0 04 to 0 10 with a median and average of 0 07 the discrepancy between the two sets of strain measures at least in the coarser and more permeable rock types may either be real and caused by easier flushing of dissolved ions or may be caused by imperfect strain recording in coarse matrix materials

deep seismic expression of a foreland basin taranaki basin new zealand a deep seismic reflection profile shot across the south taranaki basin new zealand indicates up to 10 km of crustal thickening beneath the taranaki boundary fault at the eastern margin of the basin the seismic data also show a broad flexure of the entire crust the locus of the flexure producing load appearing to be in the vicinity of the taranaki boundary fault such crustal thickening and flexure suggest a compressional foreland basin style of late cenozoic development rather than the rift graben origin previously assumed this change in interpretation for the south taranaki basin has implications for evaluating the thermal history of the basin and its possibilities for hydrocarbon prospects the study therefore demonstrates the value of deep seismic exploration of a hydrocarbon bearing basin in its early stage of exploration

reconstructing the pattern and depth of flow onshore in a palaeotsunami from associated deposits the widespread sheets of fine particulate sediment frequently deposited by tsunami constitute valuable evidence from which to reconstruct tsunami inundation this is illustrated with evidence from three sites near montrose in eastern scotland u k where a horizon of mainly sand laid down during the holocene storegga slide palaeotsunami of circa 8000 bp is examined the horizon is remarkably consistent in its distribution morphology stratigraphy and particle size characteristics these properties allow inferences to be made on the nature of tsunami flow onshore and run up it is suggested that estimates can be made of the possible depth of water involved from the characteristics of the sediment and thus of the extent of inundation involved in the tsunami at these sites

fabric anisotropy induced by primary depositional variations in the silt clay ratio in two fine grained slope fan complexes texas gulf coast and northern north sea article i nfo high resolution x ray texture goniometry hrxtg has been used to quantify the alignment anisotropy of phyllosilicate minerals in a series of diagenetically altered mudstone samples from the deep subsurface of the texas gulf coast and the northern north sea the sampled formations have undergone a simple burial history with no overprint of tectonic deformation that may have influenced the phyllosilicate orientation observations have been made in two constrained temperature windows 148 150 c north sea data and 169 210 c texas gulf coast wherein less than 20 smectite remains in the mixed layer phase illite smectite quantitative x ray powder diffraction xrpd shows quartz which is dominantly detrital and phyllosilicate content having an inverse relationship quantified illite smectite fabric intensity phyllosi licate alignments ranges from low alignment values of 2 42 m r d multiples of a random distribution to high alignment values 6 75 m r d and chlorite kaolinite ranges from 1 80 to 6 46 m r d we propose that the broad range of phyllosilicate fabric intensity observed reflects the range of quartz phyllosilicate ratios that are the imprint of depositional setting bedform truncation and initial grain size detrital quartz acts to disrupt fabric intensity by being non platy producing areas sheltered from effective stress pressure shadows and acting as a matrix support there is no evidence that bioturbation is a significant control on phyllosilicate alignment in these quartz phyllosilicate mixtures these findings have important implications for the role of grain scale alignment on seismic anisotropy in mudstone systems fabric intensity in post diagenetic samples can be predicted from 1 quartz content and 2 total clay content where

numerical models of tsunami sediment transport current understanding and future directions abstract researchers who study tsunami deposits share common ultimate goals of their work which are to better assess the magnitude information of paleotsunamis and to contribute to the assessment of future tsunami risks numerical modeling of tsunami sediment transport is an important piece of interdisciplinary research that fills the gap between geological studies and practical utilization of tsunami deposits forward and inverse numerical models that address tsunami transport of sand and boulders have been developed over the last two decades forward models are capable of delineating the time evolution of tsunami hydrodynamics sediment transport and the resulting morphological changes associated with erosion and deposition inverse models estimate tsunami characteristics such as flow speed and depth from deposits numerical modeling can be used not only to quantify paleotsunamis but also to enhance our understanding of tsunami sedimentology and hydrodynamics to make progress towards the ultimate goal of improved tsunami risk assessment development of an in depth mutual understanding between modelers and geologists of the advantages limitations and uncertainties in both numerical modeling and geological records is an important challenge

sediment loading on the western platform of the new zealand continent implications for the strength of a continental margin abstract mechanical properties of the new zealand lithosphere are determined by forward modelling the gravity and isostatic response of a plio pleistocene sediment loaded shelf margin the giant foreset formation on the western platform of new zealand is a 2 km thick 250 km long and 100 km wide sediment package both the downward flexed pliocene miocene boundary beneath the package and a 35 50 mgal peak to trough gravity anomaly over the sediment package are best matched with a flexural rigidity in the region of 5 6 10 22 1 5 10 23 n m effective elastic thickness t e 20 28 km the giant foresets are a particularly important load to model because unlike most sediment loaded passive margins there is a time gap of about 70 80 ma between rifting and subsequent deposition of the sedimentary load furthermore the width of the giant foreset load is sufficiently small to afford a reasonable resolution of t e

platform subsidence behind an active subduction zone numerical models of viscous mantle flow indicate that a broad subsidence should occur above subduction zones1 4 this platform subsidence is predicted to cause an asymmetrical depression 500 1 000 km wide with a maximum depth of 2 km if filled with water direct evidence linking platform subsidence to mantle flow has remained elusive however here we offer evidence from western new zealand for a complete link in both space and time between subduction initiation and platform subsidence because of the broad wavelength 200 km of the observed 1 500 m subsidence it is unlikely that the subsidence is due to a flexural foredeep the observed subsidence does however match in both wavelength and amplitude that predicted by a model of subduction induced mantle flow the occurrence of platform subsidence has implications not only for understanding mantle convection but also for explaining geoid anomalies over active margins5 and patterns of continental submergence6 and sedimentation7 that could otherwise be interpreted as a eustatic sea level change8

field survey and numerical simulations a review of the 1998 papua new guinea tsunami the papua new guinea png tsunami of 1998 is re examined through a detailed review of the field survey as well as numerous numerical computations the discussion of the field survey explores a number of possible misinterpretations of the recorded data the survey data are then employed by a numerical model as a validation tool a boussinesq model and a nonlinear shallow water wave nlsw model are compared in order to quantify the effect of frequency dispersion on the landslide generated tsunami the numerical comparisons indicate that the nlsw model is a poor estimator of offshore wave heights however due to what appears to be depth limited breaking seaward of sissano spit both numerical models are in agreement in the prediction of maximum water elevations at the overtopped spit by comparing three different hot start initial profiles of the tsunami wave it is shown that the initial shape and orientation of the tsunami wave is secondary to the initial displaced water mass in regard to prediction of water elevations on the spit these numerical results indicate that agreement between numerical prediction of runup values with field recorded values at png cannot be used to validate either a nlsw tsunami propagation model or a specific landslide tsunami hot start initial condition finally with the use of traditional tsunami codes a new interpretation of the png runup measurements is presented

microfracturing and microporosity in shales shales are ubiquitous rocks in sedimentary basins where their low permeability makes them efficient seals for conventional oil and gas reservoirs and underground waste storage repositories waste waters co2 nuclear fuels moreover when they contain organic matter they form source rocks for hydrocarbons that may escape towards a more porous reservoir during burial a process referred to as primary migration and when the hydrocarbons cannot escape these rocks can be exploited as oil or shale gas reservoirs while the presence of fractures at the outcrop scale has been described the existence of fractures at smaller scales their link with microporosity the mechanisms that created them their persistence over geological times and their effect on the petrophysical properties of shales represent scientific challenges for which drillings in various sedimentary basins over the past decades may hold timely key data here we review and synthetize the current knowledge on how microfractures and micropores in shales can be imaged and characterized and how they control their anisotropic mechanical properties and permeability one question is whether such microfractures when observed in outcrops or in drilled core samples extracted from boreholes are related to decompaction and do not exist at depth another question is whether veins observed in shales represent microfractures that were open long enough to have acted as flow paths across the formation the mechanisms of microfracture development are described some have an internal origin fracturing by maturation of organic matter dehydration of clays while others are caused by external factors tectonic loading importantly the amount of microfracturing in shales is shown to depend strongly on the content in 1 organic matter and 2 strong minerals the nucleation of microfractures depends on the existence of mechanical heterogeneities down to the nanometer scale their propagation and linkage to create a percolating network will depend on the presence of heterogeneities at the meso to macro scales such percolating microfracture networks could control both the long term sealing capabilities of cap rocks and the further propagation of hydraulic fracturing cracks finally possible areas of research for describing the mechanism of microfracture formation in greater detail and how this impacts the transport and mechanical properties of shales are also discussed

two dimensional stratigraphic forward modeling reconstructing high relief clinoforms in the northern taranaki basin clinoforms the basic large scale architectural form within which sediments are stored and eventually fed down depositional dip in clastic wedges exist in many shapes and sizes understanding how they form evolve and degrade is critical to understanding how transport mechanisms affect the shelf margin and sediment partitioning and distribution and their implications on the presence of a working petroleum system the neogene stratigraphic succession of the taranaki basin in new zealand contains clinoform packages that display a variety of architectures well imaged on seismic data quantitative characterization of this interval was performed to unravel the processes by which clinoforms evolve under the influence of tectonic and isostatic driven subsidence sea level change and sediment supply fluctuations nine different clinoform packages were identified on the basis of changes in their seismic stratigraphic characteristics two dimensional stratigraphic forward modeling was used to conduct a sensitivity analysis and determine the relative importance of different geologic controls on their genesis our results show that during the early to late pliocene clinoform architectures were influenced by the opening of a back arc rifting structure in the taranaki basin northern graben which controlled sediment redistribution and partitioning at the same time a drop in global sea level allowed sediment bypass to distal parts of the basin during the late pliocene changes in the australian pacific subduction zone forced rapid uplifting of the southern alps generating a significant increase in sediment supply model simulations suggest that clinoform architectures during the late pliocene were controlled by this increase in sediment supply and associated loading

preferred orientation of phyllosilicates effects of composition and stress on resedimented mudstone microfabrics abstract development of a preferred orientation of clay minerals is investigated in response to changes in vertical effective stress and composition in resedimented material boston blue clay boston blue clay bbc an illitic glacio marine clay composed of 57 clay sized particles

the tsunami phenomenon abstract with human activity increasingly concentrating on coasts tsunamis from japanese tsu harbour nami wave are a major natural hazard to today s society stimulated by disastrous tsunami impacts in recent years for instance in south east asia 2004 or in japan 2011 tsunami science has significantly flourished which has brought great advances in hazard assessment and mitigation plans based on tsunami research of the last decades this paper provides a thorough treatise on the tsunami phenomenon from a geoscientific point of view starting with the wave features tsunamis are introduced as long shallow water waves or wave trains crossing entire oceans without major energy loss at the coast tsunamis typically show wave shoaling funnelling and resonance effects as well as a significant run up and backflow tsunami waves are caused by a sudden displacement of the water column due to a number of various trigger mechanisms such are earthquakes as the main trigger submarine and subaerial mass wastings volcanic activity atmospheric disturbances meteotsunamis and cosmic impacts as is demonstrated by giving corresponding examples from the past tsunamis are known to have a significant sedimentary and geomorphological off and onshore response so called tsunamites form allochthonous high energy deposits that are left at the coast during tsunami landfall tsunami deposits show typical sedimentary features as basal erosional unconformities fining upward and landward a high content of marine fossils rip up clasts from underlying units and mud caps all reflecting the hydrodynamic processes during inundation the on and offshore behaviour of tsunamis and related sedimentary processes can be simulated using hydro and morphodynamic numerical models the paper provides an overview of the basic tsunami modelling techniques including discretisation guidelines for appropriate temporal and spatial resolution as well as the nesting method furthermore the boussinesq approximation a simplification of the three dimensional navier stokes equations is presented as a basic theory behind numerical tsunami models which adequately reflects the non linear dispersive wave behaviour of tsunamis the fully non linear boussinesq equations allow the simulation of tsunamis e g in the form of n waves based on the various subtopics presented recommendations for future multidisciplinary tsunami research are made it is especially discussed how the combination of sedimentary and geomorphological tsunami field traces and numerical modelling techniques can contribute to derive locally relevant tsunami sources and to improve the assessment of tsunami hazards considering the individual pre history and physiogeographical setting of a specific region

strike variability of clastic depositional systems does it matter for sequence stratigraphic analysis current sequence stratigraphic models are two dimensional in nature and predict variability in depositional dip sections strike and dip variability of sediment supply to clastic depositional systems causes significant changes to sequence architecture so that contrasting yet coeval stacking patterns result these changes ultimately affect prediction potential based on fixed systems tract stacking patterns and relation to relative sea level curves identification of key surfaces in sequences rather than stacking patterns is the most reliable indicator of relative sea level history

efficient computation of surf zone waves using the nonlinear shallow water equations with non hydrostatic pressure abstract a numerical method for non hydrostatic free surface irrotational flow governed by the nonlinear shallow water equations including the effects of vertical acceleration is presented at the aim of studying surf zone phenomena a vertical boundary fitted grid is used with the water depth divided into a number of layers a compact finite difference scheme is employed for accurate computation of frequency dispersion requiring a limited vertical resolution and hence capable of predicting the onset of wave breaking a novel wet dry algorithm is applied for a proper handling of moving shoreline mass and momentum are strictly conserved at discrete level while the method only dissipates energy in the case of wave breaking the numerical results are verified with a number of tests and show that the proposed model using two layers without ad hoc assumptions enables to resolve propagating nonlinear shoaling breaking waves and wave run up within the surf and swash zones in an efficient manner

shelf edge deltas along structurally complex margins a case study from eastern offshore trinidad a 15 000 km2 5792 mi2 three dimensional seismic data survey that covers the shelf slope transition of the eastern offshore trinidad continental margin reveals the geometry and depositional history of the last maximum glacial lowstand shelf margin succession despite the lack of well information at these shallow depths the quality and continuity of the seismic data allow us to pursue a detailed seismic stratigraphic interpretation of the last lowstand margin succession the basin fill stratal architecture of the studied stratigraphic interval shows a great deal of lateral and vertical variability along the continental margin during the pleistocene to holocene three geomorphological elements controlled the character of the accommodation within the basin and were crucial in transporting delivering and storing sediment supply from shelf to slope areas 1 the columbus sedimentary pathway on the shelf 2 bypass zones in the shelf break region and 3 deep water depocenters the location and geometry of these geomorphological elements within the basin are clearly controlled by underlying structures transpressional to the north and gravity driven to the south migration of the paleo orinoco delta system across the shelf was also a key factor in defining the stratigraphic geometries that are observed within the shelf break development of shelf edge versus outer shelf deltaic systems on the continental margin was controlled by the nature of sediment supply at specific times as well as by the availability of accommodation although to a lesser extent to relative sea level fluctuations the interpretation also showed that for time equivalent units parts of the shelf edge region could develop as an erosional margin sediment bypass zones whereas other parts of the shelf edge could behave as an accretionary margin sediment accumulation the sequence stratigraphic interpretation that was attempted in this work also demonstrated that the characteristics of systems tracts can abruptly change along strike in the shelf edge region for time equivalent units these changes can be misleading if a genetic interpretation is pursued only on the basis of the definition of system tracts in the shelf edge region without the consideration of a complete regional framework

texture and diagenesis of ordovician shale from the canning basin western australia implications for elastic anisotropy and geomechanical properties texture and diagenesis of ordovician shale from the canning basin western australia implications for elastic anisotropy and geomechanical properties

subduction evolution and mantle dynamics at a continental margin central north island new zealand 1 central north island new zealand provides an unusually complete geological and geophysical record of the onset and evolution of subduction at a continental margin whereas most subduction zones are innately two dimensional north island of new zealand displays a distinct three dimensional character in the back arc regions specifically we observe mariana type subduction in the back arc areas of central north island in the sense of back arc extension high heat flow prolific volcanism geothermal activity and active doming and exhumation of the solid surface evidence for emplacement of a significant percent of new lithosphere beneath the central north island comes from heat flux of 25 mw km of strike of volcanic zone and thinned crust underlain by rocks with a seismic wave speed consistent with underplated new crust seismic attenuation qp 1 is high 240 and rhyolitic and andesitic volcanism are widespread almost complete removal of mantle lithosphere is inferred here in pliocene times on the basis of the rock uplift history and upper mantle seismic velocities as low as 7 4 0 1 km s in contrast southwestern north island exhibits chilean type back arc activity in the sense of compressive tectonics reverse faulting low heat flow thickened lithosphere and strong coupling between the subducted and overriding plates this rapid switch from mariana type to chilean type subduction occurs despite the age of the subducted plate being constant under north island moreover stratigraphic evidence shows that processes that define the extensional back arc area the central volcanic region are advancing southward into the compressional system wanganui basin at about 10 mm yr we link the progression from one system to another to a gradual and viscous removal of thickened mantle lithosphere in the back arc regions thickening occurred during the miocene within the taranaki fault zone the process of thickening and convective removal is time and temperature dependent and has left an imprint in both the geological record and geophysical properties of central north island which we document and describe

development testing and applications of site specific tsunami inundation models for real time forecasting 1 the study describes the development testing and applications of site specific tsunami inundation models forecast models for use in noaa s tsunami forecast and warning system the model development process includes sensitivity studies of tsunami wave characteristics in the nearshore and inundation for a range of model grid setups resolutions and parameters to demonstrate the process four forecast models in hawaii at hilo kahului honolulu and nawiliwili are described the models were validated with fourteen historical tsunamis and compared with numerical results from reference inundation models of higher resolution the accuracy of the modeled maximum wave height is greater than 80 when the observation is greater than 0 5 m when the observation is below 0 5 m the error is less than 0 3 m the error of the modeled arrival time of the first peak is within 3 of the travel time the developed forecast models were further applied to hazard assessment from simulated magnitude 7 5 8 2 8 7 and 9 3 tsunamis based on subduction zone earthquakes in the pacific the tsunami hazard assessment study indicates that use of a seismic magnitude alone for a tsunami source assessment is inadequate to achieve such accuracy for tsunami amplitude forecasts the forecast models apply local bathymetric and topographic information and utilize dynamic boundary conditions from the tsunami source function database to provide site and event specific coastal predictions only by combining a deep ocean assessment and reporting of tsunami constrained tsunami magnitude with site specific high resolution models can the forecasts completely cover the evolution of earthquake generated tsunami waves generation deep ocean propagation and coastal inundation wavelet analysis of the tsunami waves suggests the coastal tsunami frequency responses at different sites are dominated by the local bathymetry yet they can be partially related to the locations of the tsunami sources the study also demonstrates the nonlinearity between offshore and nearshore maximum wave amplitudes

the relationship of phyllosilicate orientation x ray diffraction intensity ratios and c b fissility ratios in metasedimentary rocks of the helvetic zone of the swiss alps and the caledonides of jamtland central western sweden phyllosilicate preferred orientations x ray diaraction intensity ratios and c b fissility ratios were determined from 23 metasedimentary rocks from the helvetic zone of the swiss alps and from the caledonides of jamtland sweden the relationships between these parameters of phyllosilicate orientation depend strongly on the lithology and the cleavage morphology diaerences in orientation direction and in degree of preferred orientation reflect both deformation intensities and lithologies whereas polyphase deformed fine grained samples generally have phyllosilicates that are oriented parallel to cleavage showing high orientation intensities phyllosilicates in less deformed and or coarse grained rocks are oriented parallel to bedding with low orientation intensities weak orientation intensities in samples with phyllosilicates that are oriented parallel to bedding reflect compaction strain the higher strain in samples with micas and chlorites that are parallel to cleavage is a combination of compaction and tectonic strain due to the development of crenulation cleavage 2000 elsevier science ltd all rights reserved

tsunami induced morphological change a model based impact assessment of the 1755 tsunami in ne atlantic from the morocco coast abstract tsunamis can be responsible for coastal geomorphic crises extensively inundated coasts can suffer widespread and dramatic changes in their morphology due to sediment erosion transport and deposition processes in this paper we investigate the tsunami induced morphological changes on coasts prone to inundation and how sediment transport is controlled by both tsunami and sediment characteristics we focus on a tsunami prone coast in the ne atlantic tangier morocco that experienced the 1755 lisbon tsunami we use a coupled hydrodynamic and morphodynamic numerical model together with high resolution digital elevation and sedimentary models to simulate the impact of tsunamis on the morphology and sediment distribution of tangier bay due to the uncertainty on the source and effects of the 1755 event we consider two 1755 like tsunamigenic scenarios that have the potential to cause different levels of inundation results show that the coastal zone of tangier can undergo substantial changes in morphology and sediment distribution following the tsunami impact for the selected scenarios the volume of sediments mobilized at both the offshore and onshore zones of the tangier site ranges from 30 000 to 200 000 m3 moreover the presence of mobile sediments and conditions favoring tsunami shoaling lead to an increase in wave impact on the coastal configuration conversely the presence of the breakwaters helps to protect the tangier coast by limiting the extent of the affected area the results of this study suggest that the assessment of tsunami induced coastal impact should include the effect on morphology

integral flow properties of the swash zone and averaging the swash zone is that part of a beach over which the instantaneous shoreline moves back and forth as waves meet the shore this zone is discussed using the nonlinear shallow water equations which are appropriate for gently sloping beaches a weakly three dimensional extension of the two dimensional solution by carrier greenspan 1958 of the shallow water equations for a wave reflecting on an inclined plane beach is developed and used to illustrate the ideas thereafter attention is given to integrated and averaged quantities the mean shoreline might be defined in several ways but for modelling purposes we find the lower boundary of the swash zone to be more useful a set of equations obtained by integrating across the swash zone is investigated as a model for use as an alternative boundary condition for wave resolving studies comparison with sample numerical computations illustrates that they are effective in modelling the dynamics of the swash zone and that a reasonable representation of swash zone flows may be obtained from the integrated variables the longshore flow of water in the swash zone is in many ways similar to the stokes drift of propagating water waves further averaging is made over short waves to obtain results suitable as boundary conditions for longer period motions including the effect of incident short waves in order to clearly present the work a few simplifications are made the main result is that in addition to the kinematic type of boundary condition that occurs on a simple e g rigid boundary two further conditions are found in order that both the changing position of the swash zone boundary and the longshore flow in the swash zone may be determined models of the short waves both outside and inside the swash zone are needed to complete a full wave averaged model only brief indication is given of such modelling

kinematic and metamorphic aspects of cleavage formation in very low grade metamorphic slates abstract fabric studies on first cleavages in very low grade metamorphic slates from the rheinisches schiefergebirge and other very low grade metamorphic fold belts reveal two types of slaty cleavage 1 1 cleavage without syntectonic phyllosilicate recrystallization these are generally crenulation cleavages 2 2 cleavage with syntectonic phyllosilicate recrystallization with increasing syntectonic metamorphism the crenulation fabric is modified by solution of grains along cleavage planes and precipitation of material within the cleavage lamellae with further increase of metamorphism the crenulation fabric is gradually obliterated the finite fabric results from progressive solution crystallization and recrystallization superimposed with bending kinking and internal rotation achieved by slip parallel to the basal planes of phyllosilicates

grain assemblages and strong diagenetic overprinting in siliceous mudrocks barnett shale mississippian fort worth basin texas porosity permeability and total organic carbon toc in a heterogeneous suite of 21 high maturity samples vitrinite reflectance 1 52 2 15 from the barnett shale in the eastern fort worth basin display few correlations with parameters of rock texture fabric and composition these factors being mostly obscured by the effects of a protracted history of diagenesis diagenesis in these rocks includes mechanical and chemical modifications that occurred across a wide range of burial conditions compaction and cementation have mostly destroyed primary intergranular porosity the porosity average 5 vol by gas research institute helium porosimetry and pore size 8 nm median pore throat diameter are reduced to a degree such that pores are difficult to detect even by imaging ar ion milled surfaces with a field emission scanning electron microscope the existing porosity that can be imaged is mostly secondary and is localized dominantly within organic particulate debris and solid bitumen the grain assemblage is highly modified by replacement a weak pattern of correlation survives between bulk rock properties and the ratio of extrabasinal to intrabasinal sources of siliciclastic debris higher porosity permeability and toc are observed in samples representing the extreme end members of mixing between extrabasinal siliciclastic sediment and intrabasinal derived biosiliceous debris reservoir quality in these rocks is neither more strongly nor more simply related to variations in primary texture and composition because the interrelationships between texture and composition are complex and importantly the diagenetic overprint is too strong

nine unusually large tsunami deposits from the past 4000 years at kiritappu marsh along the southern kuril trench abstract large earthquakes along the kuril subduction zone in northern japan are known to have caused damaging tsunami although there is a little information on historical earthquakes and tsunami in this area because no documents exist before the 19th century that might refer to tsunami events to determine the likely timing and size of future events we need information on their recurrence intervals and to do this for the prehistoric past we have investigated sediments located in the kiritappu marsh in eastern hokaido that we interpret as laid down by tsunami using reliable multiple lines of evidence from sedimentological geomorphological micropaleontological and chronological results we identify 13 tsunami sands two of these lie within a peat bed above a historical tephra ta a ad 1739 the upper one probably corresponds to the ad 1843 tempo tokachi oki earthquake m 8 2 tsunami and the lower to either the ad 1952 tokachi oki earthquake m 8 2 tsunami or the ad 1960 chilean earthquake m 9 5 tsunami underlying are 11 prehistoric tsunami sand beds nine large sand beds and two smaller sand beds deposited during the past 4000 years because of the wide spatial distribution of the large sand beds and inundation distances inland of between 1200 to 3000 m we suggest that they record unusually large tsunamis along the kuril subduction zone according to our analyses these tsunami sands were derived from the coastal area and although they do not show clear graded bedding they commonly have gradational upper boundaries and erosional bases and include internal sedimentary structures such as plane beds dunes and current ripples reflecting bedload transportation based on our results we calculate the recurrence interval of unusually large earthquakes probably m 8 6 along the kuril subduction zone as about 365 553 years and estimate the youngest large event to have occurred in the 17th century

a turbulent bore on a beach a theoretical model is developed giving a moderately detailed description of the flow in a turbulent bore the velocity profiles the shear stresses the energy dissipation etc an analysis of the flow conditions at the toe of the turbulent front indicates significant differences from the usual description based on the finite amplitude shallow water equations and it is shown that the present model gives a closer description of the actual physical conditions finally numerical results are presented that illustrate how the model works and test its validity on an example with known properties

wave characteristic and morphologic effects on the onshore hydrodynamic response of tsunamis abstract while the destruction caused by a tsunami can vary significantly owing to near and onshore controls we have only a limited quantitative understanding of how different local parameters influence the onshore response of tsunamis here a numerical model based on the non linear shallow water equations is first shown to agree well with analytical expressions developed for periodic long waves inundating over planar slopes more than 13 000 simulations are then conducted to examine the effects variations in the wave characteristics bed slopes and bottom roughness have on maximum tsunami run up and water velocity at the still water shoreline while deviations from periodic waves and planar slopes affect the onshore dynamics the details of these effects depend on a combination of factors in general the effects differ for breaking and non breaking waves and are related to the relative shift of the waves along the breaking non breaking wave continuum variations that shift waves toward increased breaking such as steeper wave fronts tend to increase the onshore impact of non breaking waves but decrease the impact of already breaking waves the onshore impact of a tsunami composed of multiple waves can be different from that of a single wave tsunami with the largest difference occurring on long shallow onshore topographies these results demonstrate that the onshore response of a tsunami is complex and that using analytical expressions derived from simplified conditions may not always be appropriate

a numerical model for tsunami induced morphology change we describe the development of a time resolved model for tsunami induced morphology change based on an existing boussinesq model for weakly dispersive free surface waves coupled to a depth integrated model for sediment concentration and an equation for bed level change the model allows for spatial variability in bottom friction coefficients and accounts for the presence of non erodible beds or finite depths of available sediment the model is verified using one laboratory data set and against field observations of morphology change in the crescent city ca harbor during the 2011 tohoku tsunami event the model is then applied to a hypothetical example illustrating the impact of tsunami inundation on an undeveloped barrier island

runup of solitary waves on a circular island this is a study of the interactions of solitary waves climbing up a circular island a series of large scale laboratory experiments with waves of different incident height to depth ratios and different crest lengths is described detailed two dimensional run up height measurements and time histories of surface elevations around the island are presented a numerical model based on the two dimensional shallow water wave equations including runup calculations was developed numerical model predictions agreed very well with the laboratory data and the model was used to study wave trapping and the effect of slope under certain conditions enhanced runup and wave trapping on the lee side of the island were observed suggesting a possible explanation for the devastation reported by field surveys in babi island off flores indonesia and in okushiri island japan

2004 indian ocean tsunami inflow and outflow at phuket thailand at bangtao beach phuket the 2004 indian ocean tsunami produced a repeated sequence in which rapid inflow of turbulent water was followed by ponding and then by gradual outflow photographs and eyewitness accounts show an initial withdrawal followed by series of inflows the tsunami left behind a sand sheet as much as 25 cm thick that contains parallel inclined landward and seaward lamina in addition to the normal grading commonly reported from tsunami deposits the sheet contains evidence for two times of vigorous inflow each of these is marked by mud rip ups medium to coarse sand that grades upward to fine landward inclined laminae and a sharp basal contact the top of the sand sheet when observed in the first days after the tsunami abounded in current dune and ripple bedforms of mostly landward orientation the tsunami s first positive wave left noonshore sedimentary record in this pitting area the second wave deposited sand that is much less extensive and slightly finer than that of the third wave the deposit of both these waves contains multiple fining upward sequences possibly due to multiple surges in one wave train the depth averaged flow velocity estimated from thickness and grain size are in the range 7 21 m s whereas a near bottom threshold velocity calculated from bedforms reveals the order of magnitude difference from 1 74 to 1 03 m s 2007 elsevier b v all rights reserved

phyllosilicate preferred orientation in relation to strain path determination in the lower paleozoic stavelot venn massif ardennes belgium abstract phyllosilicate preferred orientation measured by means of an x ray pole figure goniometer allows a quantitative exploration of the slaty cleavage development the relationship between phyllosilicate preferred orientation and strain as demonstrated in the march model furthermore enables the application of phyllosilicate pole figures in a strain determination in slate belts both applications are illustrated in this paper in which the results are presented of a crystallographic fabric analysis of argillites in the southern domain of the lower paleozoic stavelot venn massif belgium in these argillites the development of a phyllosilicate preferred orientation is primarily defined by the low grade metamorphism and the deformation history the metamorphism causing recrystallisation to be active during cleavage development assures the development of a high degree of preferred orientation on the other hand the deformation history defines the type of phyllosilicate pole figure pattern based on the distinction of different pole figure patterns a possible strain path for the argillites in the southern domain of the stavelot venn massif is proposed an axially symmetric pole figure pattern indicates a caledonian cleavage development in a pure flattening regime the variscan cleavage development on the other hand is characterised by an additional extensional component in the cleavage plane if the primary phyllosilicate fabric due to a pre deformational compaction or a caledonian cleavage development underwent a complete reorientation caused by syntectonic recrystallisation a typical orthorhombic pole figure pattern is formed otherwise a transition pole figure pattern develops reflecting the superposition of the variscan cleavage development on a pre existing caledonian cleavage fabric the general deformation history of the southern domain of the stavelot venn massif differs substantially from that described for the northern domain contrary to the northern domain the southern domain seems to have undergone considerable variscan deformation

full scale cfd simulation of tsunamis part 2 boundary layers and bed shear stresses abstract this paper presents results from numerical simulations of the propagation and run up of full scale tsunamis using a reynolds averaged navier stokes model with emphasis on the resulting boundary layers and bed shear stresses spatial distributions of the shields and rouse parameters during run up and draw down show that for the tsunamis considered with a sediment grain size corresponding to medium sand considerable sediment transport shields parameter o 10 o 100 can be expected during run up and that the sediment transport can be expected to be dominated by suspended load the results likewise show that the expected sediment transport during draw down will similarly be considerable and dominated by suspension the tsunami induced boundary layers are monitored in time and the observed boundary layer thickness ranges from spanning only a small fraction of the water depth to spanning the entire depth the velocity profiles beneath the tsunamis are shown to have good correspondence with a logarithmic profile within the boundary layer similarly the bed shear stresses beneath the tsunamis are investigated and a new and simple engineering model is developed for predicting the temporal variation of the bed shear stress based only on a free stream velocity signal the new engineering model is shown give better predictions for the bed shear stress than a standard manning approach and is likewise shown in the appendix to produce reasonable predictions for shorter wind scale waves it is finally also shown how the temporal evolution of the boundary layer thickness can be predicted based on the free stream velocity signal alone the results presented here are part 2 of a larger study where part 1 presents the model validation and detailed descriptions of the run up process

rapid locking of tectonic magnetic fabrics in weakly deformed mudrocks abstract the anisotropy of magnetic susceptibility ams has provided important insights into early deformation conditions in compressive settings through characterization of tectonic fabrics in mudrocks that appear otherwise undeformed the validity of these insights relies on the assumption that tectonic fabrics are rapidly locked shortly after sediment deposition however the time lag between deposition and the tectonic overprint has yet to be quantified to verify this assumption here we present ams data from late holocene sediments recovered in two cores from lake issyk kul in the kyrgyz tien shan fold and thrust belt these sediments in which magnetic fabrics reflect the preferred orientation of phyllosillicates have typical tectonic magnetic fabrics with varying degrees of tectonic overprint likely controlled by small scale active faults the mean orientation of the susceptibility maxima parallels neighbouring active thrust faults and is perpendicular to the geodetically derived local shortening direction the age model for one of the studied cores which is based on 7 calibrated accelerator mass spectrometer radiocarbon dates indicates that sediments as young as 25 yr record this clear tectonic fabric which is locked within sediments older than 1180 cal yr bp our demonstration of rapid locking of tectonic fabrics in weakly deformed mudrocks shortly after deposition provides the required validation of their reliability for tectonic studies and opens new opportunities for providing quantitative insights into the relationship between magnetic ellipsoids shortening rates and stress directions in compressive settings

tsunami run up and draw down on a plane beach tsunami run up and draw down motions on a uniformly sloping beach are evaluated based on fully nonlinear shallow water wave theory the nonlinear equations of mass conservation and linear momentum are first transformed to a single linear hyperbolic equation to solve the problem with arbitrary initial conditions we apply the fourier bessel transform and inversion of the transform leads to the green function representation the solutions in the physical time and space domains are then obtained by numerical integration with this semi analytic solution technique several examples of tsunami run up and draw down motions are presented in particular detailed shoreline motion velocity field and inundation depth on the shore are closely examined it was found that the maximum flow velocity occurs at the moving shoreline and the maximum momentum flux occurs in the vicinity of the extreme draw down location the direction of both the maximum flow velocity and the maximum momentum flux depend on the initial waveform it is in the inshore direction when the initial waveform is predominantly depression and in the offshore direction when the initial waves have a dominant elevation characteristic

segmentation and growth of an obliquely reactivated normal fault abstract detailed kinematic analysis of a large 1800 m maximum displacement reactivated normal fault in the taranaki basin new zealand has been conducted using high quality 3d seismic data the parihaka fault is approximately north south striking in basement where it accrued late cretaceous to early eocene displacements in response to east west extension and was obliquely reactivated by nw se extension in the pliocene reactivation resulted in upward propagation newly formed segmentation and up dip clockwise rotation of the fault surface by up to 20 from the strike of the basement fault fault segmentation and map view soft linkage by relay zones in post miocene strata was synchronous with the formation of antithetic faults in late miocene strata at bends in the fault surface fault segment lengths antithetic faults and relay zone dimensions were formed geologically instantaneously during initial reactivation of the main fault at 3 7 3 4 ma i e within the first 10 of faulting rapid formation of pliocene fault segments is followed by displacement accumulation without an increase in fault segment length until eventual relay breaching when continued ramp rotation is unsustainable this evolutionary history is consistent with a model in which arrays of fault segments are from inception components of a single coherent structure

subduction platform subsidence and foreland thrust loading the late tertiary development of taranaki basin new zealand borehole seismic and gravity data are used to investigate deformation of continental lithosphere at a miocene collisional zone deformation is manifested in the three following principal forms a long wavelength 500 km platform subsidence ascribed to mantle convection flexural deformation on a scale of 100 200 km due to crustal thrusting at the eastern boundary of the taranaki basin and a ductile thickening evident on the deep seismic section of taranaki basin that occurs on a scale of 10 km evidence for flexural deformation principally comes from the deep seismic section that shows a 150 km wavelength bending of the moho down toward the major zone of thrusting within the taranaki fault zone paleowater depths however provide evidence for an initial early miocene regional subsidence that is too long in wavelength to be explained by flexure induced from thrust sheet loading instead we propose that this broad platform subsidence was driven by loading from a deep source probably subduction induced flow in the mantle by 22 19 ma 1 2 km of water existed over most of the area now occupied by south taranaki basin by 19 17 ma the water depth in the zone east of the taranaki basin the taranaki fault zone had been replaced by rock due to submarine thrusting and crustal thickening this build up of submarine topography in the taranaki fault zone constitutes part of the load 25 8 mpa that created and maintains south taranaki basin gravity data place further constraints on loading at the thrust front and point to an additional intracrustal loading equivalent to 15 7 mpa over a 50 km wide zone this intracrustal load is explained as being due to thick skinned thrusting bringing denser lower crustal rocks nearer to the surface in the thrust zone the complete load on the taranaki foreland is therefore in three parts the submarine topographic load the intracrustal load and the loading of infilling sediments

automatic calibration of stratigraphic forward models for predicting reservoir presence in exploration understanding and predicting reservoir presence and characteristics at regional to basin scales is important for evaluating risk and uncertainty in hydrocarbon exploration simulating reservoir distribution within a basin by a stratigraphic forward model enables the integration of available prior information with fundamental geologic processes embedded in the numerical model stratigraphic forward model predictions can be significantly improved by calibrating the models to independent constraints such as thicknesses from seismic or well data a three dimensional basin scale stratigraphic forward modeling tool is coupled with an inversion algorithm the inversion algorithm is a modification of the neighborhood algorithm a type of genetic algorithm which is designed to sample complex multimodal objective functions and is parallelized on computer clusters to accelerate convergence the process generates a set of representative geological models that are consistent with prior ranges for uncertain parameters calibration constraints and associated tolerance thresholds the workflow is first demonstrated on two data sets a synthetic example based on a clastic passive margin and a real hydrocarbon exploration example for slope and basin floor stratigraphic traps in the neocomian lower cretaceous of the west siberian basin the analysis of calibrated models provides constraints on stratigraphic controls and allows prediction of locations with higher potential to develop stratigraphic traps these locations are related to complex interactions between paleobathymetry subsidence eustatic fluctuations characteristics of sediment input sources and sediment transport parameters results show the potential of stratigraphic forward modeling combined with inverse methods as an additional tool to support conventional play based exploration and reservoir presence prediction

stratigraphy of the southern norfolk ridge and the reinga basin a record of initiation of tonga kermadec northland subduction in the southwest pacific abstract seismic stratigraphic interpretations of a large new 2d seismic reflection dataset from the reinga basin region northwest of new zealand constrain the history of cretaceous fragmentation of gondwana and cenozoic initiation of tonga kermadec northland subduction the southern norfolk ridge system lay in a proximal location to plate boundaries that were active during both cretaceous and cenozoic events and persistent marine conditions led to a relatively complete record of sedimentation cretaceous extension was followed by regional subsidence and transgression two cenozoic contractional events are separated by substantial 1 km subsidence late eocene contraction led to reverse faulting and folding between new caledonia and the southern norfolk ridge system and topographic highs created in the north western sector were locally eroded by wave abrasion reinga basin was located at the southern tip of this event which had only limited impact in adjacent northern new zealand regional oligocene and miocene subsidence was contemporaneous with late oligocene and early miocene emplacement of nappes in northern new zealand and the onset of arc volcanism early miocene contraction in the reinga basin led to formation of the wanganella ridge these events can be related to calculated plate motions and are shown to be consistent with models of induced subduction nucleation that require c 150 km of convergence the first contraction is associated with regional inception of tonga kermadec subduction whereas oligocene to miocene events and the onset of hikurangi northland subduction were in response to a local change in plate boundary displacement rate and consequent linkage between subduction north of new zealand with alpine fault formation farther south

reliability of magnetic fabric of weakly deformed mudrocks as a palaeostress indicator in compressive settings abstract in this work we compare the results of anisotropy of magnetic susceptibility ams with palaeostress analysis at local scale the ams data refer to 14 sites from weakly deformed mudrocks lower and middle miocene lacustrine sediments from two areas of the internal part of the ebro foreland basin the bardenas reales and monegros areas nine sites display a magnetic fabric related to a subtle tectonic overprint showing a roughly e w magnetic lineation whereas the rest of sites most of them located at the monegros area show a sedimentary fabric without a well defined magnetic lineation palaeostress data result from fault populations and joint sets exposed in the limestone beds interbedded with the mudrocks at the nearest possible outcrop from the ams site the origin of the magnetic lineation is related to a n s compression coeval with the earliest diagenesis of the studied sediments prior to consolidation the comparison between magnetic fabric and palaeostress data demonstrates the coaxiality between the ams and palaeostress ellipsoids both at local and regional scales thereby validating the reliability of ams as palaeostress indicator in compressive settings

texture and anisotropy analysis of qusaiba shales scanning and transmission electron microscopy synchrotron x ray diffraction microtomography and ultrasonic velocity measurements were used to characterize microstructures and anisotropy of three deeply buried qusaiba shales from the rub alkhali basin saudi arabia kaolinite illite smectite illite mica and chlorite show strong preferred orientation with 001 pole figure maxima perpendicular to the bedding plane ranging from 2 4 6 8 multiples of a random distribution m r d quartz feldspars and pyrite crystals have a random orientation distribution elastic properties of the polyphase aggregate are calculated by averaging the single crystal elastic properties over the orientation distribution assuming a nonporous material the average calculated bulk p wave velocities are 6 2 km s maximum and 5 5 km s minimum resulting in a p wave anisotropy of 12 the calculated velocities are compared with those determined from ultrasonic velocity measurements on a similar sample in the ultrasonic experiment which measures the effects of the shale matrix as well as the effects of porosity velocities are smaller p wave maximum 5 3 km s and minimum 4 1 km s the difference between calculated and measured velocities is attributed to the effects of anisotropic pore structure and to microfractures present in the sample which have not been taken into account in the matrix averaging

real time experimental forecast of the peruvian tsunami of august 2007 for u s coastlines 1 at 23 41 utc on 15 august 2007 an offshore earthquake of magnitude 8 0 severely damaged central peru and generated a tsunami severe shaking by the earthquake collapsed buildings throughout the region and caused 514 fatalities the tsunami resulted in three casualties and a representative maximum runup height of 7 m in the near field the first real time tsunami data available came from a deep ocean tsunami detection buoy within 1 hour of tsunami generation these tsunami data were used to produce initial experimental forecasts within 2 hours of tsunami generation the far field forecasts indicated that the tsunami would not flood any of the 14 u s communities comparison with real time tide gage data showed very accurate forecasts

the relationship of strain and preferred orientation of phyllosilicate grains in rocks a review abstract the calculation of strain from the preferred orientation of platy phyllosilicate grains taking strain to be homogeneous is surprisingly often successful from a pragmatic point of view although numerous theoretical objections to this procedure can be and have been raised for the calculation to succeed the original distribution of mica or clay mineral grains must be known or assumed the usual assumption that the starting distribution was random and therefore nearly uniform implies that the strain history of pelitic sediments is taken to start when the watery sediment was last stirred by waves or bioturbation or if it was laid down in still anoxic waters from the moment of first deposition it therefore includes compaction as part of the strain history which is usually neglected by structural geologists originally random distribution of clay flake orientations has been observed in recently deposited sediments in many instances and has been theoretically explained in various ways exceptions probably exist but their frequency has not been estimated biologically disturbed sediments may be brought nearer to a state of random orientation of clay flakes than they were at deposition with the exception of whole beds or concretions in which pores are early filled with cement mudrocks are almost always compacted by the weight of later deposits the strain so induced is axially symmetric about the vertical and thus about the pole of the bedding planes compaction acts on soft unconsolidated rocks but may continue with increasing overburden on rocks strengthened by cementation and by increasing interlocking of grains tectonic deformation may start early before the rock is fully compacted or it may begin only much later and the mechanisms of deformation increase in complexity with the increasing temperature and hydrostatic stress of deeper burial up to a certain level of mild metamorphism however phyllosilicate grains seem to be rather permanent if not as mineral species then at least by preservation of their constituent sheets of silica tetrahedra given this permanence the mechanisms of rock deformation whether intergranular slip cataclasis or dissolution and reprecipitation and various intragranular processes in the non phyllosilicate matrix hardly matter as far as the recording of strain is concerned even a certain amount of stress solution at especially heavily loaded points of the phyllosilicate grains themselves does not destroy their value as strain markers as long as the dissolved material is disposed of mainly by crystallographically continuous overgrowth on existing grains the same holds for local dissolution of phyllosilicates in portions of old grains that have become thermodynamically unstable by bending widespread irregular or random nucleation and growth of newly nucleated phyllosilicate grains at intermediate or high grades of metamorphism can reduce the reliability of the strain record and so can domainal structure of the deformed rock if both the volume fraction of phyllosilicate grains and the intensity of total strain differ sharply from one domain to another if distinct domains are not equant and have themselves a strong preferred orientation of shape nevertheless rocks containing an anastomosing network of zones rich in phyllosilicate grains as slates and other deformed mudrocks commonly do have in many cases been found to have average preferred orientations of mica or chlorite which if used to estimate the strain give results similar to those obtained from independent strain markers in the same rocks thus the most significant verification of the usefulness of strain estimates by measurement of preferred orientation is the mutual confirmation with independently determined strain the limit to such verification is the rarity of strain markers so that the coexistence of two independent ones is exceptionally rare for this reason however it is important to make full use of the orientation of phyllosilicate grains where they are available the alternative to have no strain measurements at all causes structural geologists to miss potential information

2004 indian ocean tsunami flow velocity measurements from survivor videos 1 the tsunami of 26th december 2004 severely affected banda aceh along the north tip of sumatra indonesia at a distance of 250 km from the epicenter of the magnitude 9 0 earthquake this tsunami flow velocity analysis focused on two survivor videos recorded within banda aceh more than 3 km from the open ocean the exact locations of the tsunami eyewitness video recordings were revisited by the survey team between february 22 and 25 2005 to record camera calibration ground control points the motion of the camera during the recordings was determined the individual video images were rectified with a direct linear transformation dlt assuming a planar water surface at the level finally a cross correlation based particle image velocimetry piv analysis was applied to the rectified video images to determine instantaneous tsunami flow velocity fields the measured tsunami flow velocities were within the range of 2 to 5 m s

microfabric and rock properties of experimentally compressed silt clay mixtures abstract oedometric mechanical compaction tests were performed on brine saturated synthetic samples consisting of silt clay mixtures to study changes in microfabric and rock properties as a function of effective stress the silt consisted of crushed quartz 100 with grain size range between 4 and 40 m whereas the clay consisted of 81 kaolinite 14 mica illite and 5 microcline of grain size between 0 4 and 30 m five sample pairs ranging in composition from pure silt to pure clay were compacted to 5 and 50 mpa effective stress respectively sem studies were carried out to investigate microfabric changes in the mechanically compacted silt clay mixtures the degree of alignment of the different minerals present quartz mica illite and kaolinite were computed by using an image analysis software experimental compaction have measured the changes in the rock properties such as porosity and velocity as a function of effective stress for different mixtures of clay and silt clay rich samples showed a higher degree of mineral orientation and lower porosity compared to silt dominated samples as a function of effective stress pure clay sample had 11 porosity at 50 mpa effective stress whereas the pure silt sample retained about 29 porosity at the same effective stress the experiments showed that low porosity down to 11 is possible by mechanical compaction only a systematic increase in strain was observed in the silt clay mixtures with increasing clay content but the porosity values found for the 50 50 silt clay mixture were lower than that of 25 75 silt clay mixture no preferential mineral orientation is expected before compaction owing to the high initial porosity suggesting that the final fabric is a direct result of the effective stress both p and s wave velocities increased in all silt clay mixtures with increasing effective stress the maximum p and s wave velocities were observed in the 25 75 silt clay mixture whereas the minimum vp and vs were recorded in the pure silt mixture at 50 mpa effective stress p wave velocities as high as 3 km s resulted from experimental mechanical compaction alone the results show that fine grained sediment porosity and velocity are dependent on microfabric which in turn is a function of grain size distribution particle shape sediment composition and stress at 5 mpa effective stress quartz orientation increased as a function of the amount of clay indicating that clay facilitate rotation of angular quartz grains adding clay from 25 to 75 in the silt clay mixtures at 50 mpa effective stress decreased the quartz alignment the clay mineral orientation increased by increasing both the amount of clay and the effective stress the mica illite fabric alignment being systematically higher than that of kaolinite even small amount of silt 25 added to pure clay reduced the degree of clay alignment significantly this study demonstrates that experimental compaction of well characterized synthetic mudstones can be a useful tool to understand microfabric and rock properties of shallow natural mudstones where mechanical compaction is the dominant process

clinoform development by advection diffusion of suspended sediment modeling and comparison to natural systems clinoforms are the building blocks of prograding stratigraphic sequences these sig moid shaped surfaces can be found forming today on modem deltas sedimentation rate profiles over the clinoform surface of these deltas show low rates of sediment accumulation on both topset and bottomset regions with a maximum accumulation rate on the upper foreset region we pres ent a model for the formation of clinoforms that relies on the interpretation of modem clinoform sedimentation as a result of the distribution of shear stresses at the mouth of a river model clino form surfaces are generated using an equation for the conservation of suspended sediment concentration together with a conservation of fluid equation for simple time averaged flow velocity fields in the model suspended sediment is advected horizontally into a basin and gravitational settling of sediment particles is counteracted by vertical turbulent diffusion in shallow water shear stresses are too large to allow deposition and sediment bypasses the topset region with increasing water depth near bed shear stresses decrease and sediment is allowed to deposit at the foreset region with gradually decreasing rates toward deeper water this sedimentation pattern leads to progradation of the clinoform surfaces through time the clinoform surfaces produced by the model capture the fundamental morphological characteristics of natural clinoforms these include the gradual slope rollover at the topset and bottomset steeper foreset slopes with increased grain size and an increase in foreset slope through time as clinoforms prograde into deeper water because the parameters controlling the model clinoforms have a direct relation to physical quantities that can be measured in natural systems the model is an important step toward unraveling the physical processes associated with these deposits

laboratory experiments of tsunami runup on a circular island laboratory experiments of a 7 2 m diameter conical island were conducted to study three dimensional tsunami runup the 62 5 cm tall island had 1 on 4 side slopes and was positioned in the center of a 30 m wide by 25 m long flat bottom basin solitary waves with height to depth ratios ranging from 0 05 to 0 20 and source lengths ranging from 0 30 to 7 14 island diameters were tested in water depths of 32 and 42 cm twenty seven capacitance wave gages were used to measure surface wave elevations at incident and four radial transects on the island slope maximum vertical runup measurements were made at 20 locations around the perimeter of the island using rod and transit a new runup gage was located on the back or lee side of the island to record runup time series

determining flow patterns and emplacement dynamics from tsunami deposits with no visible sedimentary structure in the absence of eyewitness reports or clear sedimentary structures it can be difficult to interpret tsunami deposits or reconstruct tsunami inundation patterns the emplacement dynamics of two historical tsunami deposits were investigated at seven transects in okains bay new zealand using a combined geospatial geomagnetic and sedimentological approach the tsunami deposits are present as layers of sand and silt intercalated between soils and become finer and thinner with distance inland the deposits are attributed to the 1960 and possibly the 1868 tsunamis based on radiometric dating and correlation with historical records measurements of magnetic fabric mf anisotropy of magnetic susceptibility and particle size were used to reconstruct the evolution of flow dynamics laterally and vertically a combination of statistical methods including spatial autocorrelation testing spearman s rank order correlation principal component analysis pca and k means cluster analysis was applied to examine relationships between mf parameters and sediment texture and infer depositional hydrodynamics flow patterns deduced from mf show the estuary channel acted as a conduit for inundation with flow commonly aligned sub perpendicular to the estuary bed mf and sediment data suggest deposition occurred from settling during laminar flow evidence of both uprush and backwash deposition as well as wave reflection from infrastructure was found statistical analysis of data showed significant relationships between grain size parameters and mf parameters associated with flow speed and magnetic fabric type pca and cluster analysis differentiated samples into two primary hydrodynamic groups 1 samples deposited from laminar flow and 2 samples deposited close to the limit of inundation which includes samples deposited further inland those affected by flow convergence and those in the upper part of tsunami deposits this approach has potential as a tool for reconstructing hydrodynamic conditions for palaeotsunamis and by combining spatial and statistical analyses large scale investigations can be more easily performed this article is protected by copyright all rights reserved

large scale stratigraphic architecture eustatic variation and unsteady tectonism a theoretical evaluation we incorporate a process based depositional model with basin subsidence models to predict stratigraphic records this allows us to investigate the importance of subsidence geometry on coastal stratigraphy and thus to characterize and compare the stratigraphic architecture of two categories of tectonic basins the models demonstrate that the correlation of stratigraphic sequences to eustatic cycles is not the same in passive margin basins as in foreland basins and that in a foreland basin the record of episodic tectonism is distinct from that of eustatic sea level change in the model sediment transport is approximated by slope controlled diffusion nonmarine transport is treated as more efficient diffusion than marine transport three different subsidence and sediment supply models are examined a simple passive margin basin a simple foreland basin and then a foreland basin for which vertical motions are driven by thrust shortening that is compensated flexurally and for which sediment supply is related to relief predicted passive margin stratigraphies for cases of varying eustatic sea level are similar to those of natural basins and include progradational packages and subaerial unconformities which are used to define sequence boundaries that form during sea level fall we explore the timing relationships between stratigraphic features and a sinusoidal sea level history showing that the phase relationship depends on subsidence sediment flux efficiency of sediment transport and period and amplitude of sea level when the basic geometry of the basin is inverted placing the sediment supply on the side with maximum subsidence as is the case in foreland basins the sequence character changes markedly subaerial erosion does not generate unconformities in the models of a dynamic foreland basin sediment supply and subsidence are linked to the structure of the flanking thrust belt and are not necessarily constant for steady thrusting and variable sea level unconformities that define sequence boundaries form only on the distal or forebulge side of the basin and the ages of the sequence boundaries correlate to limes of rising sea level in cases of constant sea level but variable thrusting subaerial unconformities are cut locally on both the proximal margin of the basin and the distal margin of the basin yet the ages of the proximal margin and distal margin unconformities are out of phase in the tectonic cycle erosion is most pronounced during quiescence on the proximal side and during thrusting on the distal side

constraints on the amplitude of mid pliocene 3 6 2 4 ma eustatic sea level fluctuations from the new zealand shallow marine sediment record ice volume calibrations of the deep ocean foraminiferal delta18o record imply orbitally influenced sea level fluctuations of up to 30m amplitude during the mid pliocene and up to 30 per cent loss of the present day mass of the east antarctic ice sheet eais assuming complete deglaciation of the west antarctic ice sheet wais and greenland these sea level oscillations have driven recurrent transgressions and regressions across the world s continental shelves wanganui basin new zealand contains the most complete shallow marine late neogene stratigraphic record in the form of a continuous cyclostratigraphy representing every 41 and 100ka sea level cycle since ca 3 6ma this paper presents a synthesis of faunally derived palaeobathymetric data for shallow marine sedimentary cycles corresponding to marine isotope stages m2 100 ca 3 4 2 4ma our approach estimates the eustatic sea level contribution to the palaeobathymetry curve by placing constraints on total subsidence and decompacted sediment accumulation the sea level estimates are consistent with those from delta18o curves and numerical ice sheet models and imply a significant sensitivity of the wais and the coastal margins of the eais to orbital oscillations in insolation during the mid pliocene period of relative global warmth sea level oscillations of 10 30m were paced by obliquity

probabilistic tsunami hazard assessment at seaside oregon for near and far field seismic sources 1 the first probabilistic tsunami flooding maps have been developed the methodology called probabilistic tsunami hazard assessment ptha integrates tsunami inundation modeling with methods of probabilistic seismic hazard assessment psha application of the methodology to seaside oregon has yielded estimates of the spatial distribution of 100 and 500 year maximum tsunami amplitudes i e amplitudes with 1 and 0 2 annual probability of exceedance the 100 year tsunami is generated most frequently by far field sources in the alaska aleutian subduction zone and is characterized by maximum amplitudes that do not exceed 4 m with an inland extent of less than 500 m in contrast the 500 year tsunami is dominated by local sources in the cascadia subduction zone and is characterized by maximum amplitudes in excess of 10 m and an inland extent of more than 1 km the primary sources of uncertainty in these results include those associated with interevent time estimates modeling of background sea level and accounting for temporal changes in bathymetry and topography nonetheless ptha represents an important contribution to tsunami hazard assessment techniques viewed in the broader context of risk analysis ptha provides a method for quantifying estimates of the likelihood and severity of the tsunami hazard which can then be combined with vulnerability and exposure to yield estimates of tsunami risk

experimental study of tsunami induced scour around a monopile foundation abstract this paper presents an experimental study of the tsunami induced scour process around a monopile foundation representative of those commonly used for offshore wind farms the scour process is studied by subjecting the monopile to a time varying current which enables a properly down scaled experiment from the boundary layer and scour perspective it is shown how the scaled experiments corresponds to real life idealized tsunami cases with periods ranging from 10 to 40 min it is then shown that the boundary layers of the model tsunami are well described by recently developed empirical relations for tsunami boundary layers by subjecting the monopile to several successive tsunami waves the scour process is shown to occur in a stepwise cumulative fashion with the final equilibrium scour depth tending to the depth limited steady current limit it is shown that the entire scour development can reasonably be predicted by a recently developed simple engineering model finally the experimental results are compared to a fully coupled hydrodynamic and morphologic cfd model and a good correspondence is obtained

process based modeling of tsunami inundation and sediment transport 1 the infrequent and unpredictable nature of tsunamis precludes the use of field experiments to measure the hydrodynamic and sediment transport processes that occur instead these processes are often approximated from laboratory numerical and theoretical studies or inferred from observations of the resultant sediment deposits here delft3d a three dimensional numerical model is used to simulate the inundation and sediment transport of a tsunami similar in magnitude to the 26 december 2004 indian ocean tsunami over one measured and three idealized morphologies the model is first shown to match well the observations taken at kuala meurisi sumatra and then used to examine in detail the processes that occur during the tsunami the model predicts that at a given cross shore location the onshore flow accelerates rapidly to a maximum as the wavefront passes and then gradually decelerates before reversing direction and flowing offshore the onshore flow does not tend to zero everywhere at maximum inundation but instead flow reversal occurs near the shoreline even as the wavefront continues to inundate landward while some sediment is eroded by the passing wavefront the suspension of sandy sediment is dominated by the long duration high velocity backwash that occurs along the beach face and offshore of the shoreline some of the sediment suspended during backwash is advected shoreward by the subsequent wave creating large spatial gradients in the suspended sediment concentrations which may not be in equilibrium with the local hydrodynamics the inundation and transport of sediment during a tsunami can be affected by complexities in the morphological profile and interactions between multiple waves and many of the hydrodynamic and sediment transport processes predicted here are similar to analogous processes previously observed in the swash zone

a simple model for calculating tsunami flow speed from tsunami deposits abstract this paper presents a simple model for tsunami sedimentation that can be applied to calculate tsunami flow speed from the thickness and grain size of a tsunami deposit the inverse problem for sandy tsunami deposits where grain size and thickness vary gradually in the direction of transport tsunami sediment transport is modeled as a steady spatially uniform process the amount of sediment in suspension is assumed to be in equilibrium with the steady portion of the long period slowing varying uprush portion of the tsunami spatial flow deceleration is assumed to be small and not to contribute significantly to the tsunami deposit tsunami deposits are formed from sediment settling from the water column when flow speeds on land go to zero everywhere at the time of maximum tsunami inundation there is little erosion of the deposit by return flow because it is a slow flow and is concentrated in topographic lows variations in grain size of the deposit are found to have more effect on calculated tsunami flow speed than deposit thickness the model is tested using field data collected at arop papua new guinea soon after the 1998 tsunami speed estimates of 14 m s at 200 m inland from the shoreline compare favorably with those from a 1 d inundation model and from application of bernoulli s principle to water levels on buildings left standing after the tsunami as evidence that the model is applicable to some sandy tsunami deposits the model reproduces the observed normal grading and vertical variation in sorting and skewness of a deposit formed by the 1998 tsunami

impulse waves in reservoirs generated by landslides into shallow water abstract landslides sliding into shallow water often block watercourses and in addition landslide induced impulse waves may result in risks to the safety of the reservoir or waterways over a wide area such impulse waves differ from those from landslides into deep water which slide underwater completely this study conducted twenty five groups of orthogonal experiments of landslide induced impulse waves in shallow water where the froude numbers ranged between 0 6 and 2 0 based on the experimental results dimensionless functions of the parameters such as amplitude wavelength and jet flow height of the initial landslide induced waves in shallow water were derived the predictions from these formulae are very close to those obtained from the experiments further a source model of landslide induced waves in shallow water was built based on formulae derived from the experiments and wave propagation and run up were calculated with the boussinesq type equations model the newly built model of landslide induced waves in shallow water was used to calculate and analyze two representative examples from landslides in the three gorges in china namely the qianjiangping landslide induced impulse wave event and the xintan landslide induced impulse wave event comparison of the calculations with data from multiple sources indicated that our model for landslide induced waves in shallow water had high accuracy our model for landslide induced waves in shallow water may help in the predictive analysis of impulse waves and mitigation works for this type of event in reservoirs worldwide

late quaternary transgressive regressive sequences from taranaki continental shelf western new zealand abstract interpretation of seismic reflection profiles 3 5 khz airgun and piston core and borehole stratigraphic logs collected from mid outer shelf depths 50 130 m on the taranaki continental shelf western new zealand have delineated at least 4 alternating late quaternary seismic and lithologic couplets each couplet comprises an acoustically transparent upper silty unit that overlies a highly reflective sandy unit characterised by a channelised erosive base radiocarbon and biostratigraphic nannofloral dating of selected samples provides chronostratigraphic control for the succession indicating that the entire sequence is probably late quaternary in age based mainly on nannofossil paleoenvironmental interpretations and seismic reflection characteristics it is proposed that the silty units represent interglacial highstand deposits and that the intervening sandy units were deposited either as glacial lowstand or transgressive nearshore deposits that developed under rising sea level conditions erosive irregular basal unconformities were probably developed during relative sea level fall and represent type 1 sequence boundaries there may also have been a component of wave planation during the subsequent transgression high amplitude channel fill seismic units are possibly fluvial and or paralic sediments deposited during the sea level lowstand and or the ensuing transgression tentative correlation of late quaternary units on the taranaki shelf is made to the deep sea oxygen isotope stage curve to provide temporal resolution of the stratigraphic section four possible sedimentation models are considered based on different temporal interpretations of the observed litho and seismic stratigraphy estimated sedimentation rates for each model are compared to existing data sets as a validation tool the data are inconclusive but appear to support scenario 1 which is characterised by moderate average sedimentation rates over the past 300 000 years typically 0 57 m kyr with an anomalous phase of slow deposition or non deposition and or erosion during stage 6

unified view of sediment transport by currents and waves i initiation of motion bed roughness and bed load transport attention is given to the properties of sediment beds over the full range of conditions silts to gravel in particular the effect of fine silt on the bed composition and on initiation of motion critical conditions is discussed high quality bed load transport data sets are identified and analyzed showing that the bed load transport in the sand range is related to velocity to power 2 5 the bed load transport is not much affected by particle size the prediction of bed roughness is addressed and the prediction of bed load transport in steady river flow is extended to coastal flow applying an intrawave approach simplified bed load transport formulas are presented which can be used to obtain a quick estimate of bed load transport in river and coastal flows it is shown that the sediment transport of fine silts to coarse sand can be described in a unified model framework using fairly simple expressions the proposed model is fully predictive in the sense that only the basic hydrodynamic parameters dep

the runup of solitary waves this is a study of the runup of solitary waves on plane beaches an approximate theory is presented for non breaking waves and an asymptotic result is derived for the maximum runup of solitary waves a series of laboratory experiments is described to support the theory it is shown that the linear theory predicts the maximum runup satisfactorily and that the nonlinear theory describes the climb of solitary waves equally well different runup regimes are found to exist for the runup of breaking and non breaking waves a breaking criterion is derived for determining whether a solitary wave will break as it climbs up a sloping beach and a different criterion is shown to apply for determining whether a wave will break during rundown these results are used to explain some of the existing empirical runup relationships

unified view of sediment transport by currents and waves iv application of morphodynamic model the tr2004 transport formulations for clay silt and sand as proposed in parts 1 and 2 have been implemented in morphodynamic models to predict bed level changes these models have been verified using various laboratory and field data cases concerning coastal flow in offshore and near shore zones furthermore the model has been applied to two complicated sediment environments concerning the flow around a spurdike in a river and the tidal flow of cohesive sediments in the yangtze estuary in china overall it is concluded that the morphodynamic models using default settings performs reasonably well the applied scaling factors of the sediment transport model are in the generally accepted range of 0 5 2

phased array compaction cell for measurement of the transversely isotropic elastic properties of compacting sediments sediments undergoing compaction typically exhibit transversely isotropic ti elastic properties we present a new experimental apparatus the phased array compaction cell for measuring the ti elastic properties of clay rich sediments during compaction this apparatus uses matched sets of p and s wave ultrasonic transducers located along the sides of the sample and an ultrasonic p wave phased array source together with a miniature p wave receiver on the top and bottom ends of the sample the phased array measurements are used to form plane p waves that provide estimates of the phase velocities over a range of angles from these measurements the five ti elastic constants can be recovered as the sediment is compacted without the need for sample unloading recoring or reorienting this paper provides descriptions of the apparatus the data processing and an application demonstrating recovery of the evolving ti properties of a compacting marine sediment sample

preferred orientation of phyllosilicates in phyllonites and ultramylonites abstract x ray texture goniometry operated in the transmission mode has been applied to fine grained phyllosilicate rich sc mylonites from the santa rosa mylonite zone california the whipple mountains core complex california and the austroalpine nappes of the eastern alps austria basal planes 001 phyllosilicate pole figures depart in two respects from orthorhombic symmetry a the maximum pole density deviates from the pole to the mylonitic foliation and lies along a great circle which is normal to the foliation and contains the mylonitic lineation and b the contours of equal pole density are more widely spaced on one side of the 001 maximum than on the other measured along the mylonitic lineation optical microscopy reveals s and c surfaces and sets of shear bands sb characteristic of non coaxial deformation the pole figures are used for two purposes a the first is strain estimation after the march model by imposing orthorhombic symmetry the resulting march strains are more or less the same in all californian samples this is interpreted as evidence for a steady state foliation b the second is shear sense determination it is demonstrated that consistently asymmetric preferred orientations reflect structures which are typical of non coaxial deformation it is concluded that x ray analysis of phyllosilicate rich mylonites can in addition to providing an estimate of total strain give information about deformation regime and shear sense furthermore the study documents the heterogeneous nature of deformation on macroscopic and microscopic scales and the importance of non coaxial deformation in accommodating large strains

an amalgamated meter thick sedimentary package enabled by the 2011 tohoku tsunami in el garrapatero galapagos islands abstract tsunamis and storms instigate sedimentological and geomorphological changes to the coastal system both long term and ephemeral to accurately predict future coastal hazards one must identify the records that are generated by the processes associated with these hazards and recognize what will be preserved using eyewitness accounts photographs and sedimentology this study documents pre and post tsunami conditions and constrains the timing and process of depositional events during and following the 11 march 2011 tohoku tsunami in the coastal system at el garrapatero galapagos islands while the tsunami acted as both an erosional and depositional agent the thick fan like sand sheet in el garrapatero was primarily emplaced by overwash deposition during high tide from swell waves occurring between 19 25 march and 17 22 april 2011 the swell waves were only able to access the terrestrial coastal system via a channel carved by the 2011 tohoku tsunami through the barrier sand dune this combined deposit could result in an overestimation of the hazard if interpreted to be the result of only one event either tsunami or wind generated waves an analogous sand layer younger than 1390 1530 cal yr bp may record a similar prior event

sediment transport due to the 2011 tohoku oki tsunami at sendai results from numerical modeling abstract numerical modeling of sediment transport on the sendai plain in northeast japan which was caused by the 2011 tohoku oki tsunami was performed to investigate why onshore tsunami deposits included small amounts of marine materials and to explain the gap between the maximum inland extent of the recognizable sand layer and the limit of inundation the simulation results generally corresponded with the thicknesses of the deposits observed in the field by previous studies the simulation revealed that the tsunami caused a significant amount of erosion on the beach and in the coastal forest however erosion was significantly limited on the offshore seafloor in addition the bore of the highest tsunami wave offshore limited the amount of suspended sediment due to a steep bathymetric profile of the shoreface and a moderate initial drop in water level prior to the arrival of the bore this resulted in limited suspension and shoreward advection of the sediments and a minor contribution of the seafloor sediments to the onshore tsunami deposit visualization of the onshore sediment transport indicated that the sediment transport was significantly affected by artificial topographic features the flow speed and height varied across the topographic highs and sediments were trapped on the seaward side of these highs in coastal areas the sediment supply was limited due to the presence of engineered dikes along the coast in inland areas embankments of paved roadways caused increased deposition on the seaward sides of the embankments and less deposition on the leeward sides of the embankments although some aspects of the relevant physics were not fully implemented in the model in which uncertainties exist the results may explain the processes and consequences of sedimentation from a tsunami event

effects of fringing reefs on tsunami inundation american samoa abstract a numerical model of tsunami inundation delft3d which has been validated for the 29 september 2009 tsunami in tutuila american samoa is used to better understand the impact of fringing coral reefs and embayments on tsunami wave heights inundation distances and velocities the inundation model is used to explore the general conditions under which fringing reefs act as coastal buffers against incoming tsunamis of particular interest is the response of tsunamis to reefs of varying widths depths and roughness as well as the effects of channels incised in the reef and the focusing effect of embayments model simulations for conditions similar to tutuila yet simplified to be uniform in the alongshore suggest that for narrow reefs less than about 200 m wide the shoaling owing to shallow water depths over the fringing reef dominates inducing greater wave heights onshore under some conditions and farther inundation inland as the reef width increases wave dissipation through bottom friction begins to dominate and the reef causes the tsunami wave heights to decrease and the tsunami to inundate less far inland a sensitivity analysis suggests that coral reef roughness is important in determining the manner in which a fringing reef affects tsunami inundation smooth reefs are more likely to increase the onshore velocity within the tsunami compared to rough reefs a larger velocity will likely result in an increased impact of the tsunami on structures and buildings simulations developed to explore 2d coastal morphology show that incised channels similar to those found around tutuila as well as coastal embayments also affect tsunami inundation allowing larger waves to penetrate farther inland the largest effect is found for channels located within embayments and for embayments that narrow landward these simulations suggest that embayments that narrow landward such as fagafue bay on the north side of tutuila and that have an incised deep channel can cause a significant increase in tsunami wave heights inundation distances and velocities wide embayments similar in size to massacre bay induce some tsunami amplification but not as much as for the narrowing embayment

validating velocities in the geoclaw tsunami model using observations near hawaii from the 2011 tohoku tsunami the ability to measure predict and compute tsunami flow velocities is of importance in risk assessment and hazard mitigation substantial damage can be done by high velocity flows particularly in harbors and bays even when the wave height is small moreover advancing the study of sediment transport and tsunami deposits depends on the accurate interpretation and modeling of tsunami flow velocities and accelerations until recently few direct measurements of tsunami velocities existed to compare with model results during the 11 march 2011 tohoku tsunami 328 current meters were in place around the hawaiian islands usa that captured time series of water velocity in 18 locations in both harbors and deep channels at a series of depths we compare several of these velocity records against numerical simulations performed using the geoclaw numerical tsunami model based on solving the depth averaged shallow water equations with adaptive mesh refinement to confirm that this model can accurately predict velocities at nearshore locations model results demonstrate tsunami current velocity is more spatially variable than waveform or height and therefore may be a more sensitive variable for model validation

constraints on deformation of the southern andes since the cretaceous from anisotropy of magnetic susceptibility the southernmost segment of the andean cordillera underwent a complex deformation history characterized by alternation of contractional extensional and strike slip tectonics key elements of southern andean deformation that remain poorly constrained include the origin of the orogenic bend known as the patagonian orocline here renamed as patagonian arc and the exhumation mechanism of an upper amphibolite facies metamorphic complex currently exposed in cordillera darwin here we present results of anisotropy of magnetic susceptibility ams from 22 sites in upper cretaceous to upper eocene sedimentary rocks within the internal structural domain of the magallanes fold and thrust belt in tierra del fuego argentina ams parameters from most sites reveal a weak tectonic overprint of the original magnetic fabric which was likely acquired upon layer parallel shortening soon after sedimentation magnetic lineation from 17 sites is interpreted to have formed during compressive tectonic phases associated to a continuous n s contraction our data combined with the existing ams database from adjacent areas show that the early cretaceous late oligocene tectonic phases in the southern andes yielded continuous contraction variable from e w in the patagonian andes to n s in the fuegian andes which defined a radial strain field a direct implication is that the exhumation of the cordillera darwin metamorphic complex occurred under compressive rather than extensional or strike slip tectonics as alternatively proposed if we agree with recent works considering the curved magallanes fold and thrust belt as a primary arc i e no relative vertical axis rotation of the limbs occurs during its formation then other mechanisms different from oroclinal bending should be invoked to explain the documented radial strain field we tentatively propose a kinematic model in which reactivation of variably oriented jurassic faults at the south american continental margin controlled the late cretaceous to cenozoic evolution of the magallanes fold and thrust belt yielding the observed deformation pattern

kinematics of breaking tsunami wavefronts a data set from large scale laboratory experiments abstract this paper provides an overview of a new large scale laboratory data set on the kinematics of breaking tsunami wavefronts the aim of the experiments was to provide an open access data set for model testing calibration and verification with particular emphasis on fluid kinematics in the wave breaking and run up swash zones the experiments were performed over a composite slope in the tsunami wave basin at the o h hinsdale wave research laboratory at oregon state university data for ten different wave conditions were collected including non breaking and breaking waves and both shore breaks and fully developed long bores surface elevation and fluid kinematics were measured with a closely spaced array of surface piercing wave gauges non contact ultrasonic wave gauges and four 3 d side looking acoustic doppler velocimeters the array was traversed from the nearshore depth 0 2 m to the middle and upper run up zone providing kinematic data at 30 cross shore locations video was also recorded from 4 cameras covering the propagation breaking and run up zones surface elevation flow velocities and the wave maker displacement were also recorded to provide offshore boundary conditions the experiments include conditions with wave heights up to 0 55 m notional wave periods up to 20 s and run up lengths of up to 15 2 m on a 1 30 slope in terms of the slope in the shoaling and breaker zones the data correspond to iribarren numbers in the range of 0 26 5 6 raw calibrated and processed data are stored with open access within the osu tsunami wave basin experiment notebook which provides full access to all the wave maker control signals data instrument coordinates and processing and plotting software this paper serves as an introduction to the data set demonstrates data quality and provides an initial analysis of some key parameters that govern the impact of tsunami events including run up versus offshore wave conditions and nearshore bore height the maximum inundation depths at the original shoreline position and the time to maximum inundation depth and flow reversal examples of temporal and convective accelerations and turbulent flow components are also presented to illustrate further details of the kinematics

preferred orientation and elastic anisotropy in shales anisotropy in shales is becoming an important issue in exploration and reservoir geophysics in this study the crystallographic preferred orientation of clay platelets that contributes to elastic anisotropy was determined quantitatively by hard monochromatic x ray synchrotron diffraction in two different shales from drillholes off the coast of nigeria to analyze complicated diffraction images with five different phases illite smectite kaolinite quartz siderite feldspar and many overlapping peaks we applied a methodology based on the crystallographic rietveld method the goal was to describe the intrinsic physical properties of the sample phase composition crystallographic preferred orientation crystal structure and microstructure and compute macroscopic elastic properties by averaging single crystal properties over the orientation distribution for each phase our results show that elastic anisotropy resulting from crystallographic preferred orientation of the clay particles can be determined quantitatively this provides a possible way to compare measured seismic anisotropy and texture derived anisotropy and to estimate the contribution of the low aspect ratio pores aligned with bedding