bluuebunny/crossref_metadata_2025_split huggingface dataset:
The West Victorian Uplands of Southeastern Australia: Origin and history
Authors: Joyce E. B. 
Published: February 2007

AbstractThe West Victorian Uplands is a region of low relief, gentle gradients, young volcanicity and local domal uplift. These characteristics distinguish it from the rest of the Eastern Highlands of Australia. The origin of the West Victorian Uplands dates back to uplift in the Cretaceous, but elevation and relief have always remained low. Further uplift, extending westwards from central Victoria, may have begun raising the West Victorian Uplands in Middle Tertiary times. Doming, fault activity, earthquakes and volcanism are extending progressively westwards. Not only may the Eastern Highlands of Victoria have grown in this way in the past, but the area may also provide a view of the early evolution of the Eastern Highlands of Australia.
An experimental study of sapped drainage network development
Authors: Gomez Basil , Mullen Victor T. 
Published: February 2007

AbstractIn a basin developed on a stream table, effluent subsurface flow supported a channel network that evolved by a combination of headward growth, lateral widening and divide decay. The area occupied by the developing network increased with time. Circularity was used to characterize network evolution which occurred in three phases (initiation, extension and abstraction). Basin sediment discharge declined exponentially with time. Pronounced quasi‐cyclic variability was superimposed upon this general trend. Some of the variability was directly linked to changes in the amount of sediment supplied to the channel. The variation of mean network sediment yield (mean sediment discharge scaled by network area) with time adequately described the general decline in sediment discharge as the network evolved.
The variation of soil erodibility with slope position in a cultivated canadian prairie landscape
Authors: Martz Lawrence W. 
Published: February 2007

AbstractThis study examined the variation in soil erodibility along hillslopes in a Prairie landscape. The soil loss produced by simulated rainfall on undisturbed soils was used as an index of relative soil erodibility. Relative erodibility, and several soil properties, were measured at the summit, shoulder, midslope footslope and toeslope of 11 slope transects in an area of cultivated grassland soils on hummocky glacial till. The variation of erodibility with slope position was statistically significant, and slope position explained about 40 per cent of the variation in the erodibility measurements. Erodibility was 14 per cent higher on the shoulder and midslope, and 21 per cent lower on the toeslope, than on the summit and footslope. Local variation in erodibility along slopes was considered to be an important control on patterns of soil erosion in the landscape. The variation of erodibility along the slopes reflected soil property trends. The greatest erodibility was associated with upper slope positions where soils tended to be shallow, coarse, poorly leached and low in organic matter, while lower erodibility was found at lower slope positions with deep, organic‐rich and leached soils. Of the individual soil properties considered, silt and sand content were the most highly correlated with erodibility. The results, together with results from other studies, also suggest that net erosion and erodibility are positively related.
Mobilization of aluminium in the wathering profiles of the African surface in Malawi
Authors: McFarlane M. J. , Bowden D. J. 
Published: February 2007

AbstractLeaching of aluminium from the weathering profile of the African surface in Malawi was deduced from the chemistry of a vadose profile. Its loss occurs where congruent kaolinite dissolution results in saprolite collapse, leaving a weakly lateritized, sandy residual mantle. This leaching is a contemporary process, as shown by the precipitation of aluminosilicate evaporites in the dambos (seasonally waterlogged bottomlands). This paper presents the results of determinations, by ICP‐OES and AAS‐graphite furnace, of aluminium levels in groundwaters, examining the effects of a variety of pretreatments. Filtration (0.45 μm) substantially reduces the levels of total aluminium, showing it to be in particulate form. Subsequent acidification causes precipitation of < 0.45 μm forms of aluminium, further reducing the apparent levels to below ICP‐OES detection limit. This is consistent with mobilization in organically bound forms which are destabilized at low pH, and accords with earlier work which showed that indigenous micro‐organisms can cause dissolution of kaolinite. Organically bound mobilization provides an explanation for aluminium leaching at near‐neutral pH in conjunction with the presence of silica in solution.The identification of this mechanism of kaolinite dissolution and aluminium evacuation from vadose profiles provides a realistic process for the levelling of extensive planation surfaces; the contingent collapse of the kaolinized saprolite would lower the interfluves, progressively narrowing the vadose zone until the landsurface approaches the planar form of the stable, regional water‐table.
Analysis and interpretation of patterns within and between hydroclimatological time series in an alpine glacier basin
Authors: Gurnell A. M. , Clark M. J. , Hill C. T. 
Published: February 2007

AbstractThis paper explores patterns within and between climatological and hydrological time series from an alpine glacier basin. Time series recorded in the basin of the Haut Glacier d'Arolla over the 1989 ablation season are subdivided into five subperiods. Box‐Jenkins ARIMA (AutoRegressive Integrated Moving Average) and TFN (Transfer Function‐Noise) models are estimated for each of the five subperiods and differences between the models are interpreted in the context of changing glacier hydrology, particularly the changing nature and extent of the glacier drainage network.
Fan and playa areas in southern California and adjacent parts of Nevada
Authors: Jansson Peter , Jacobson Douglas , Le Hooke Roger B. 
Published: February 2007

AbstractIn bolsons in the desert regions of southern California and adjacent parts of Nevada, the area underlain by alluvial fan gravels and playa sediments is generally ˜1·2 times the area being eroded to produce those sediments. In certain larger basins in the vicinity of Death Valley, however, the depositional area is only about half the size of the erosional area. This reflects the more active tectonic environment in these bolsons.Of the areas underlain by recent sediments in these bolsons, playas make up 2–6 per cent. Smaller playas are found in the Mojave region, and seem to be associated with sedimentary terranes. Conversely, igneous terranes support larger playas. Larger deviations of playa area from these averages are attributable to incorrect identification of bolson boundaries. Fine sediment is either able to pass through the bolson to the next down stream, or is being collected from areas upstream that were not considered to be part of the system. For example, the playa in Death Valley is unusually large. This is in part because the Death Valley playa has been deformed tectonically so parts of it are now eroding, and in part because the outlet of Lake Tecopa was downcut in the geologically recent past, so sediment once trapped there now reaches Death Valley. The size of the playa in Death Valley is still adjusting to these changes.
Physical modelling of gelifluction and frost creep: Some results of a large‐scale laboratory experiment
Authors: Harris Charles , Gallop Michael , Coutard Jean‐Pierre 
Published: February 2007

AbstractAn experimental slope was constructed in a 5 m × 5 m square refrigerated tank. The slope was formed of four sections, each consisting of regolith (soil) collected from a distinct bedrock lithology. The four lithologies utilized were granite, limestone, mudstone and slate. The slope was subjected to freezing and thawing from the surface downwards. Water was supplied at the base of the soil during freezing. Frost heaving and surface downslope soil movement were determined after each of 15 freezing cycles, and the profiles of soil movement with depth for each soil type were measured at the end of the 15th cycle. The experimental soils were non‐cohesive; those derived from granite and limestone were respectively sandy and gravelly in texture, while those derived from mudstone and slate were silt‐rich. Mass movement in the granite and limestone soils was due mainly to frost creep and was associated with the growth of needle ice. In the mudstone and slate soils, gelifluction was dominant as a result of high moisture contents caused by the melting of segregation ice. Mean per cycle rates of downslope soil transport for the granite, limestone, mudstone and slate soils were 5·8 cm3 cm−1, 6·9 cm3 cm−1, 21·2 cm3 cm−1 and 31·2 cm3 cm−1 respectively, units referring to the volume of soil passing a unit width of slope per cycle. Mass movement rates were shown to be strongly related to the silt content of the soils.
Discussion. Denudational isostatic rebound of intraplate highlands: The Lachlan river valley, Australia
Authors: Fabel Derek , Webb John , Finlayson Brian 
Published: February 2007

AbstractEpisodic terrace cutting cannot be a complex response to the steady isostatic rebound forecast by an elastic flexure model because three terraces match epiphreatic passage levels in nearby caves. There is also some doubt about how fluvial incision rates should be extrapolated to catchment‐wide rates. At the local scale of the Lachlan River highlands, active tectonic compression may be more important than flexure, which is more important at a regional scale.
Erosion rather than plant dieback as the mechanism of marsh loss in an estuarine marsh
Authors: Nyman J. A. , Carloss M. , Delaune R. D. , Patrick W. H. 
Published: February 2007

AbstractCoastal marsh loss in Louisiana is attributed to plane dieback caused by processes that stress vegetation, and a common landscape pattern is broken marsh that expands at the expense of surrounding unbroken marsh. We tested the hypothesis that vegetation is more stressed in broken marsh than in adjacent unbroken marsh, as indicated by vegetation aboveground biomass, species diversity and soil Eh, on transects that extended from broken marsh to unbroken marsh at Marsh Island, Louisiana. Soil Eh, vegetation above‐ground biomass and species diversity did not differ between broken marsh and unbroken marsh, and above‐ground biomass was similar to that reported from other marshes. Thus, we rejected the hypothesis that marsh loss is related to vegetation stress. Two factors were related to vegetation vigour: soil drainage and soil bulk density. Surprisingly, significant soil drainage occurred in broken marsh but not in unbroken marsh. Above‐ground biomass of the dominant plant, Spartina patens (Aiton) Muhl., was lowest where soil bulk density was less than 0‐08 gcm−3, which illustrated the importance of mineral matter accumulation in submerging coastal marshes. The mechanism of marsh loss appeared to be erosion below the living root zone, as indicated by the vertical and often undercut marsh‐water interface, and by the separation of sod clasts. This is different from more rapid marsh loss associated with plant stress which we observed in other Louisiana marshes only 135 km away, indicating that marsh loss mechanisms can vary spatially even within a relatively small region.
Gravel transport and morphological change in braided sunwapta river, Alberta, Canada
Authors: Goff James R. , Ashmore Peter 
Published: February 2007

AbstractThe relation between morphological change and patterns of variation in bedload transport rate in braided streams was observed by repeated, daily topographic surveys over a 25 day study period in a 60 m reach of the proglacial Sunwapta River, Alberta, Canada. There are two major periods of morphological change, each lasting several days and each involving the complete destruction and reconstruction of bar complexes. Bar complex destruction was caused by redirection of the flow and by downstream extension of the confluence scour zone upstream. Reconstruction involved accretion of unit bars on bar head, flank and tail and in one case was initiated by disection of a large, lobate unit bar. High rates of sediment movement, measured from net scour and fill of the cross‐sections, coincided with these morphological changes. Sediment was supplied from both bed and bank erosion, and patterns and distances of transfer were highly variable. Rates of transport estimated by matching upstream erosional volumes with downstream deposition were much greater than those estimated from either a step‐length approach or a sediment budget. Measurements of scour and fill and observations of morphological change indicate that step lengths (virtual transport distances) were typically 40–100m during a diurnal discharge cycle. Shorter step lengths occurred when transfer was confined to a single anabranch and longer steps involved channel changes at the scale of the entire reach. Sediment budgeting was used to describe the spatial patterns of sediment transport associated with the morphological changes and to estimate minimum daily reach‐averaged transport rates. Mean bedload transport rates correlate with discharge, but with considerable scatter. The largest deviations from the mean relation can be tied to phases of channel incision, bank erosion, scour hole migration, bar deposition and channel filling apparently controlled by changes and fluctuations in sediment supply from upstream, independent of discharge. These are interpreted as field evidence of ‘autopulses’ or ‘macropulses’ in bedload transport, previously observed only in laboratory models of braided streams.
Comments on richards: The problems of ‘real’ geomorphology
Authors: Bassett K. 
Published: February 2007

AbstractA number of comments are made as a response to the editorial “Real” geomorphology' (Richards, 1990). The call for more involvement by geomorphologists in current philosophical debate is welcomed and the adoption of a broadly realist scientific approach is supported. Some contentious issues arise from this debate and these are outlined and discussed.
Cave levels and cave development in the mitchell plain following base‐level lowering
Authors: Johnson P. A. , Gomez Basil 
Published: February 2007

AbstractMultiple levels evolved in Buddha–Christian's Cave and in Donaldson's–Bronson's–Twin Cave in a subtly different manner to that normally associated with the development of multilevel caves adjacent to entrenched river valleys. It is often assumed that lower cave levels are generated by successive phases of valley entrenchment; however, multiple levels may also be induced by progressive adjustments in groundwater flow paths. Such adjustments occur as the effects of a change in base level propagate up‐basin. In the Mitchell Plain much of the late Pleistocene drop in the elevation of the principal drainage (the East Fork of the White River) was accommodated by entrenchment along the lower reaches of tributary valleys. Caves initially developed in the mid‐sections of tributary basins at relatively shallow depths. In the vicinity of the cave exit, the piezometric surface gradually steepened and was eventually lowered through a combination of valley headwall retreat and the incremental concentration of flow through master conduits. Upper‐level passages were abandoned once the original high‐level flow paths were replaced by lower‐level routes.
Automated mapping of land components from digital elevation data
Authors: Dymond J. R. , Derose R. C. , Harmsworth G. R. 
Published: February 2007

AbstractAn algorithm for automating the mapping of land components from digital elevation data is described. Land components are areas of relatively uniform slope and aspect and often correspond with ridge crests, shoulders, head slopes, back slopes or foot slopes. Aspect regions, which generally span from stream to ridge, are first identified by generalizing an aspect map derived from digital elevation data. The aspect regions are then split successively into land components by grouping pixels above or below an automatically determined contour of elevation or ‘distance from stream’. The contour approximates a slope break. The land components mapped in this way give a complete polygonization of a hilly landscape and are a reasonable approximation of manually mapped land components.
A simulation study of the role of raindrop erosion in the formation of desert pavements
Authors: Wainwright John , Parsons Anthony J. , Abrahams Athol D. 
Published: February 2007

AbstractA simple model of raindrop erosion—the combined effects of the detachment of sediment by raindrops and its transport by splash or by overland flow—is developed to examine the role of this process in the formation of desert pavements. Application of the model to soils in areas of existing pavement initially simulates the formation of pavements, but the changing sediment size distributions lead to the subsequent destruction of these modelled surfaces. An improved model that accounts for the feedback effects of the changing size distributions on infiltration and microtopography is then developed. Incorporating these effects allows simulated pavements to be maintained over longer periods. The model yields desert pavements whose particle size compositions differ in response to differences in initial soil characteristics, slope and rainfall intensity. This model is tested against empirical data from a site where there is intershrub pavement and associated mounds of fines beneath desert shrubs. The results successfully predict the accumulation of fines under shrubs but underestimate the development of the pavement between shrubs. These findings suggest that the raindrop erosion mechanism on its own cannot account for the development of the pavement and that some other mechanism leading to the surface concentration of coarse particles must also be operating.
Design and calibration of a recording bedload trap
Authors: Harris T. , Richards K. S. 
Published: February 2007

AbstractThis paper reports design modifications to the recording bedload trap developed by Reid et al. (1980), and rigorous calibration procedures followed both before and after installation. An unexpected temperature dependence of the trap and stage pressure transducer records is identified and corrected. The consequences of this dependence for the interpretation of a bedload‐transport event are discussed.
Problems associated with quantitative magnetic sourcing of sediments of the scarborough to mablethorpe coast, Northeast England, U.K.
Authors: Lees J. A. , Pethick J. S. 
Published: February 2007

AbstractThere are many problems associated with beach tracing and sand provenance in coastal studies over short and long timescales. Here, an attempt has been made to trace the source sediments of the beaches along the Holderness and Humberside coastline of northeast England, between Scarborough and Mablethorpe, using rapid field and laboratory magnetic techniques. The methodology employed involves classification and modelling of sediment sources and mixtures based on their magnetic properties. Focus is given to a strong ferrimagnetic black sand (heavy mineral) which dominates the magnetic signal of the beach mixtures. Delimiting the spatial extent, quantifying and tracing of this mineral may give a good indication of wave energy and sediment movement processes along this coastline. This paper represents results obtained during a short‐time‐scale survey.
Seabed stress determinations using the inertial dissipation method and the turbulent kinetic energy method
Authors: Stapleton K. R. , Huntley D. A. 
Published: February 2007

AbstractDirect measurements of seabed stress are difficult, especially in field conditions. Several methods for estimating these stresses using current meter data are available. Two of these methods, the Inertial Dissipation Method and the Turbulent Kinetic Energy Method, are described below, and a Matlab program is used to analyse data from a wave‐current environment.
Discrete modeling of the air‐gap field of synchronous machines for computation of torque and radial forces
Authors: Bekemans Marc , Matagne Ernest , Labrique Francis 
Published: February 2007

AbstractIn this paper, we exploit the multiple symmetries and the discrete character of the current distribution to express the torque and the radial forces in a PM synchronous machine. Under some assumptions, the magnetic field can be built with a limited number of discrete functions. These functions can constitute an orthogonal base of a vector space for the representation of the machine magnetic state. The representation of the stator and rotor fields as vectors of this space makes it possible to interpret the torque and the radial forces from the concept of distance between these vectors. The proposed method for torque and radial forces computation is well suited for a real‐time evaluation and can be used for a generalization of the Field‐Oriented Control to machines with non‐sinusoidal flux distribution. Copyright © 2007 John Wiley & Sons, Ltd.
A model of the unsteady response of a backward‐facing compliant step
Authors: Gerber A. G. , Holloway A. G. L. , Ng C. 
Published: February 2007

AbstractA large number of industrial surface coating and continuous casting operations require a fluid to flow from a reservoir, over a compliant step, onto a moving substrate. The contact line between the compliant step and substrate in such cases generally responds in an unsteady manner, depending on flow conditions, which can have an important influence on the surface quality of the final product. This work describes the development of a computational fluid dynamics (CFD) model for predicting this unsteady response, with a particular emphasis on isolating the natural frequency of the contact line in a backward‐facing step configuration. The compliant step was developed and implemented in the context of a pressure‐based finite‐element/finite‐volume CFD solution, implicit in time, and considers in‐surface forces based on a surface tension coefficient or an elastic membrane. Copyright © 2007 John Wiley & Sons, Ltd.
Inference on haplotype/disease association using parent‐affected‐child data: the projection conditional on parental haplotypes method
Authors: Allen Andrew S. , Satten Glen A. 
Published: February 2007

AbstractWe develop a method that allows inference on parameters in log‐linear models of the relative risk of disease given an individual's haplotypes, that can be used to analyze case‐parent trio data. Our methods are robust to population stratification and can also be used for inference on the effect of interactions between haplotypes and environmental covariates. We compare our results with the family‐based association test (FBAT) of Horvath et al. ([2004] Genet. Epidemiol. 26:61–69), and discuss when marginal tests, such as those available in FBAT, can be misleading. Our approach generalizes previous results of Allen et al. ([2005] Biometrika 92:559–571), allowing for missing genotype data and haplotype × environment interactions. Additional computational simplifications are also discussed. Genet. Epidemiol. 2007. Published 2007 Wiley‐Liss, Inc.
The relationship of the Bowland shales to the pendleside limestone in the Clitheroe, Slaidburn and Sykes Anticlines
Authors: Parkinson D. 
Published: February 2007

AbstractThe Pendleside Limestone is redefined as comprising the B1 (S2) zone and the lower part of the B2 (D1) zone. It is argued that the Bowland Shales, including the basal beds of upper B2 age, transgress the Pendleside Limestone northwards from Clitheroe, following a shallow earth‐movement with axes crossing the Ashnott Anticline, the Slaidburn Anticline and the Sykes Anticline. The Slaidburn Breccia is shown to be of lower B2 age. There is unconformable overlap locally of the Lower Bowland Shales.