bluuebunny/crossref_metadata_2025_split huggingface dataset:
The application of erosion slowness theory to hillslope formation
Authors: Carter G. , Nobes M. J. 
Published: February 2007

AbstractA method of analysis for predicting the time development of hillslope profiles is presented. The technique is based upon the assumption of weathering limited erosion and assumes that the local surface normal erosion rate is dependent upon the local flux of erosional agent and a function of the local slope gradient. This technique has been previously applied with success to analogous erosional processes in the sand blasting, chemical and energetic atom bombardment induced ablation of solids. The analysis shows how linearly segmented profiles can develop from initially curved surfaces and indicates the progress of profiles to stable end forms. Actual application to geomorphological situations is limited by lack of knowledge of micro‐environmental erosion fluxes and the gradient dependence of erosion and it is suggested that field observations and laboratory simulations could be helpful in determining the utility of the analysis technique outlined here.
The role of topography in controlling throughflow generation: A discussion
Authors: Speight J. Garry 
Published: February 2007

AbstractThe distributions of specific catchment area and specific dispersal area values over the hillside studied by Anderson and Burt (1978) relate much more closely to the observed distributions of soil water matric potential than do the occurrences of contour concavity on which the authors rely. Highest potential always occurred in the zone of large specific catchment area except immediately after rainfall, when it occurred in the zone of small dispersal area. Isolines of low potential persistently conformed to those of specific dispersal area.
Processes of accelerated pluvial erosion on desert hillslopes modified by vehicular traffic
Authors: Iverson Richard M. 
Published: February 2007

AbstractAccelerated pluvial erosion on hillslopes modified by off‐road vehicles (ORVs) is analysed using results from 50 rainfall simulation experiments conducted in the Mojave Desert, California. Sediment yield from 1 m2 hillslope plots subjected to intense, 20‐minute rainfalls is typically increased 10 to 20‐fold following ORV use. Salient effects of vehicle traffic, which reduce infiltration, increase runoff sediment transport efficiency, and enhance gully formation, are further studied by combining simple theoretical relations with experimental data. This analysis helps identify factors controlling erosion on natural desert hillslopes, as well as those used by ORVs.Erosion of natural or vehicle‐used desert surfaces is heavily influenced by runoff hydraulics. Calculated Darcy‐Weisbach friction factors decrease by an average of 13‐fold following vehicular slope modification, whereas runoff Reynolds numbers increase by an average of 5 1/2‐fold. The capacity of overland flow to transport sediment is related to runoff power and its degree of localization, which usually increase considerably following ORV activity; however, the ability of overland flow to move large grains (competency) is related to a combination of factors not always systematically influenced by ORV use. Kinematic runoff routing, which is used to extrapolate experimental results to longer slope lengths, leads to the suggestion that the hydraulic roughness of desert hillslopes strongly influences their erosional behaviour.
First‐order drainage basin morphology—definition and distribution
Authors: Marcus Alan 
Published: February 2007

AbstractFirst‐order drainage basin morphology consists of two complementary regions: a headwater region, the valley head; and a stream region, the channelway (Figure 1). Each subbasin's morphology is represented by a set of principal components factors that include the properties of area, length, slope, relief, elongation, and plan curvature. The channelway region is a highly‐integrated morphological unit that is dominated by a size‐shape factor, indicative of an organized flow system and the presence of a permanent channel. The valley head region shows little integration of its morphological factor set, and this is reflected by its lack of a permanent channel. The valley head‐channelway definition is utilized to classify first‐order basins into three morphological groups or types. Basin type is related to basin location within the larger drainage network, and this relation helps to explain variations in subbasin morphology. The channelway's morphologic properties are influenced by the location of the first‐order basin's bifurcation or junction within the higher‐ordered network; and valley head morphology is related to the location of the basin's divide position within the drainage net.
Options listings and individual equity volatility
Authors: Jubinski Daniel , Tomljanovich Marc 
Published: February 2007

AbstractThis article examines the effect of options introduction on the conditional volatility of 1,576 individual firms over the 1973–1996 time period. With the use of a GJR‐GARCH specification for daily volatility, it is found, for the majority of firms, that option listing does not impact the underlying equity security. Listing effects are identified for a small subset of firms, specifically smaller firms with high trading volume and/or volatility. For these firms there is evidence of a change in the conditional volatility process after option listing, and it is concluded that options continue to provide additional information about the underlying equity for these companies. © 2007 Wiley Periodicals, Inc. Jrl Fut Mark 27: 1–27, 2007
Effects of single SNPs, haplotypes, and whole‐genome LD maps on accuracy of association mapping
Authors: Maniatis Nikolas , Collins Andrew , Morton Newton E 
Published: February 2007

AbstractWe describe an association mapping approach that utilizes linkage disequilibrium (LD) maps in LD units (LDU). This method uses composite likelihood to combine information from all single marker tests, and applies a model with a parameter for the location of the causal polymorphism. Previous analyses of the poor drug metabolizer phenotype provided evidence of the substantial utility of LDU maps for disease gene association mapping. Using LDU locations for the 27 single nucleotide polymorphisms (SNPs) flanking the CYP2D6 gene on chromosome 22, the most common functional polymorphism within the gene was located at 15 kb from its true location. Here, we examine the performance of this mapping approach by exploiting the high‐density LDU map constructed from the HapMap data. Expressing the locations of the 27 SNPs in LDU from the HapMap LDU map, analysis yielded an estimated location that is only 0.3 kb away from the CYP2D6 gene. This supports the use of the high marker density HapMap‐derived LDU map for association mapping even though it is derived from a much smaller number of individuals compared to the CYP2D6 sample. We also examine the performance of 2‐SNP haplotypes. Using the same modelling procedures and composite likelihood as for single SNPs, the haplotype data provided much poorer localization compared to single SNP analysis. Haplotypes generate more autocorrelation through multiple inclusions of the same SNPs, which could inflate significance in association studies. The results of the present study demonstrate the great potential of the genome HapMap LDU maps for high‐resolution mapping of complex phenotypes. Genet. Epidemiol. 2007. © 2007 Wiley‐Liss, Inc.
Tectonostratigraphy and kinematics of the eastern end of the Sivas Basin (central eastern Turkey): Implications for the so‐called ‘Anatolian block’
Authors: Temiz Haluk , Guezou Jean Claude , Poisson Andre M. , Tutkun Zeki 
Published: February 2007

AbstractThe eastern end of the Sivas Basin, just west of Erzincan, is known as the Kemah Basin. The lithostratigraphy of the Kemah Basin thus corresponds with the general characteristics described for the Sivas Basin: the upper stratigraphic sequence begins with the Kemah Limestones of Burdigalian age. Above these, the sediments (grey limy marls, sandstones and conglomerates) are not yet dated, but probably span Late Miocene to Plio‐Quaternary times. The lower sequence is made of (Late Oligocene?) non‐fossiliferous, mainly continental deposits (variegated clays, silts and gypsum at the base; conglomerates, sandstones and some volcanics in the footwall of the limestones).Both the basin deposits and substratum (arc volcanics, volcanoclastics and ophiolites) are involved in thrust systems with displacements consistently directed to the SSE. The sequence of thrusting deduced from the geometrical pattern of the imbricate zone and from the stratigraphic record includes at least two stages of thrust propagation. The sequence shows the rise of successive waves of active new thrusts and folds from the north, cutting through earlier thrusts in a general ‘break‐back’ sequence. The southern edge of the Neogene basin against the ophiolites covering the Munzur Limestones (Taurides) shows a moderate northward tilting.A first attempt at a (incomplete) balanced cross‐section and restoration along the Burdigalian limestones as datum gives a minimum displacement of 11 km along a section length of 12 km. The kinematics and the contraction ratio question the concept of an ‘Anatolian block’ and related displacement models during the Late Neogene.
Remobilization of two mélanges in Central Anatolia
Authors: Norman Teoman N. 
Published: February 2007

AbstractMélanges are usually dated from the ages of contained blocks and of the oldest unconformably overlying cover rocks. Anomalies associated with this approach are illustrated in this study of the principal mélange belts developed in Anatolia.The Karakaya Mélange belt of supposed Middle Triassic inception and the Ophiolitic Mélange belt of supposed Late Cretaceous age are readily distinguished in western Turkey but their outcrops converge eastwards, the two belts merging in Central Anatolia and becoming intermingled further east, near Sivas, where the ages and natures of the mélange belts are problematic. Thus parts of the mélange attributed to the Karakaya belt contain blocks of younger limestone (Jurassic to Early Cretaceous or even younger), whereas outcrops attributed to the Ophiolitic Mélange include blocks of clastics of Late Palaeocene‐Early Eocene or even Mio‐Pliocene age. This situation confers apparently ‘younger’ ages of formation on these mélanges. It is suggested that such anomalies result from contamination by younger blocks as a result of local remobilization of the mélanges during subsequent tectonic disturbances.A north‐south oriented area, 45 km long and 20 km wide, crossing the complex mélange zone east of Sivas, has been mapped at a 1:25 000 scale and provides critical evidence on this question. It appears that the Karakaya Mélange (or its equivalent) may have been remobilized at least four times and the Ophiolitic Mélange at least three times since their inception. During each subsequent tectonic event the mélanges have incorporated some parts of the younger deposits which formed on top of them in the intervening geological periods.
Surface deformation and tectonic setting of the 13 March 1992 Erzincan earthquake, Eastern Turkey
Authors: Tatar O. , Temiz H. , Tutkun S. Z. , Park R. G. , Stimpson I. G. 
Published: February 2007

AbstractThe earthquake of 13 March 1992 (Ms = 6·8) in the densely populated Erzincan region of eastern Turkey resulted in about 500 deaths, at least 2000 people injured and widespread destruction of buildings. The results are presented of field observations carried out within the Erzincan Basin immediately after the earthquake. The main area of surface deformation is about 55 km2 in extent and lies 15 km south‐east of Erzincan. Surface fractures with significant displacements were observed with orientations as follows: strike‐slip 095–110° (dextral), 040° (sinistral) and 090° (sinistral); extensional 150–180°. Most of the observed fractures are consistent with the Harvard centroid moment tensor solution for the main shock, which indicates north‐south compressional and east‐west extensional principal horizontal stress axes. It is suggested that the earthquake probably occurred as a result of dextral strike‐slip motion on a segment of the North Anatolian Fault Zone.
Morphology and structural setting of Quaternary travertines at Pamukkale, Turkey
Authors: Altunel E. , Hancock P. L. 
Published: February 2007

AbstractPamukkale (Cotton Castle), in the west Anatolian sector of the Aegean extensional province, is so named because snow white travertines are accumulating there. Travertine deposition at Pamukkale, one of Turkey's most important tourist destinations, has been in progress for at least the last 400 000 years, and has partially overwhelmed the Roman city and necropolis of Hierapolis. The travertine originates from hot waters that emerge at 35–56°C from open fissures and at least one fault zone. The five principal morphological varieties of travertine mass are: (1) terraced‐mound travertines; (2) fissure‐ridge travertines; (3) range‐front travertines; (4) eroded‐sheet travertines; and (5) self‐built channel travertines. The first two varieties are similar to those reported from well known travertines at Tivoli, east of Rome, and Mammoth Hot Springs, Wyoming, but the last three varieties have not previously been reported.The orientations of fissure‐ridge travertines directly reflect neotectonic directions of stretching that are north‐south in the south and north‐east‐south‐west in the north of the Pamukkale plateau. The deposition of about 10 km2 of travertines at Pamukkale is attributed to the presence beneath Pamukkale of carbonate bedrocks and an anastomosing network of fissures intersecting at numerous nodes that provide conduits for the escape of water. These fissures are parallel to the normal faults framing the west‐trending Menderes graben and the north‐west trending Gediz graben, whose confluence is near Pamukkale.
Geological setting, petrographic and geochemical characteristics of the Cretaceous and Tertiary igneous rocks in the Hekimhan‐Hasançelebi area, north‐west Malatya, Turkey
Authors: Yilmaz Sabah , Boztui̇ Durmuş , Öztürk Ali 
Published: February 2007

AbstractUpper Cretaceous to Tertiary igneous rocks outcrop in the Hekimhan‐Hasançelebi area, about 80 km to the north‐west of Malatya, Central‐Eastern Anatolia. These igneous rocks consist of Maastrichtian Bahçedam volcanics, the Palaeocene(?) Hasançelebi pluton and the Neogene Yamadaǧ volcanics. These latter rocks are subdivided into, from bottom to top, the Karadaǧ volcanics, Leylekdaǧ volcanics and Koçasar volcanics. The Hasançelebi pluton consists mainly of syenite, quartz syenite, monzonite and quartz monzonite. According to chemical criteria, the Hasançelebi pluton is classified as an alkaline oversaturated subtype of the cafemic association with a felsic I‐type character. Some trace element data indicate an apparent within‐plate origin. The Bahçedam volcanics are made up of tephrite basanite, basalts, trachybasalt and basaltic trachyandesite with an alkaline character. Other trace element criteria indicate both an arc and within‐plate origin. Mid‐ocean ridge basalt normalized distribution patterns of some incompatible elements indicate some conspicuous enrichment in the concentrations of K, Rb, Ba, Th and Nb; a slight enrichment in Zr; and some depletion in Sr, P and Ti. The Karadaǧ volcanics are composed mainly of alkaline trachyandesites. The Leylekdaǧ and Koçasar volcanics consist essentially of calc‐alkaline andesitic rocks. Some trace element discrimination diagrams reveal a possible arc origin for both sets of volcanics. The Hasançelebi pluton is assumed to be part of the Cretaceous‐Palaeogene Central‐Eastern Anatolian alkaline province. The Leylekdaǧ and Koçasar volcanics can be considered to be collision‐related igneous rocks by taking into account the regional tectonic regime in Central‐Eastern Anatolia. However, their trace element discrimination patterns indicate an arc origin. It is suggested that a study of the absolute age dates, rare earth element determinations and isotope geochemistry would lead to a better understanding of the tectonomagmatic evolution of this area.
Magnetic crustal character in Central Ireland
Authors: Morris P. , Max M. D. 
Published: February 2007

AbstractThe simplest magnetic model for the upper 20 km of crust in central Ireland is of two layers. A thin, weakly magnetic upper layer carrying a number of magnetic bodies that can be related to surface geology overlies a magnetic crustal zone whose gross magnetization increases towards the north. The deeper trace of the lapetus Suture in central Ireland forms the boundary between a more magnetic northern crustal area and a less magnetic southern area. A pre‐Carboniferous major dextral offset of this suture boundary occurs in the Limerick area. The suture is traced beneath the Dingle peninsula in the far south‐west of Ireland.In east‐central Ireland, between the Iapetus Suture and Southern Upland Line, the crust contains a large, south‐dipping magnetic body with no surface expression, which produces the Virginia magnetic anomaly.The development of magnetic bodies — in particular, volcanic rocks of Carboniferous age — has been controlled by regional stress patterns. The major volcanic centre at Limerick lies at the intersection of two major Caledonian block fault systems just to the north of the surface trace of the Hercynian Front.
Evaluation of the ventilated chamber for measuring evaporation from a forest
Authors: Dunin F. X. , Greenwood E. A. N. 
Published: February 2007

AbstractEvaporation from a regenerating forest was determined concurrently by atmospheric measurements of the Bowen ratio, soil water depletion, and by weighing lysimeter. The methods agreed closely over 18 days in spring and 11 days in summer. Accordingly, the Bowen ratio technique was then used as the control against which any effect on evaporation by enclosure of the lysimeter with a chamber of varied ventilation rate could be quantified hourly and daily. Accuracy of gas analysis was checked against lysimeter values.Daily evaporation by the lysimeter was generally unaffected by enclosure—on a few afternoons there was a statistically significant enhancement of hourly values by the chamber. This was accounted for by difference in turbulence between chamber and forest. The general agreement in daytime hourly values is attributed to the frequent occurrence of equilibrium evaporation (rate at which evaporation is independent of ventilation). At night, evaporation was higher during enclosure. Comparisons were not possible with rain or dew. Determination of evaporation by gas analysis agreed within about 5 per cent of lysimeter values during a dry period.We conclude that the ventilated chamber as used provides realistic estimates of evaporation by forests. We show how periods of bias can be anticipated and corrected by theory.
A review of aridity and groundwater
Authors: Lloyd J. W. 
Published: February 2007

AbstractSurface hydrological studies are seen as inadequate in hyperarid and arid areas to provide reliable estimates of recharge. In most such areas surface discharges are not present so that assessments of groundwater resources are dependent upon ground interpretation and denied the flow control found in assessments elsewhere. Groundwater models show that gradients are sustained by long‐term dewatering and very small amounts of modern indirect recharge. Recharge indications are well within the error of a hydrological balance. Discharges appear equally small.The development of groundwater in arid areas frequently faces problems of salination due to recycling of irrigation water and rising groundwater heads. Abstraction is often inadequately managed so that uncontrolled mining of groundwater occurs. The advantage that groundwater has, however, is that it offers staged development and staged appraisal.
Electronic acquisition of hydrologic data from intensively instrumented hillslopes
Authors: Durham I. H. , O'Loughlin E. M. , Moore I. D. 
Published: February 2007

AbstractA new concept in recording data from a large network of transducers in the field is described. Each transducer is equipped with an addressable switching unit enabling parallel connection by a single four wire cable and sequential interrogation from a micro‐computer controlled data logger. A simple water level transducer suitable for both large stilling wells and piezometers, which returns an audio frequency signal with pulse width proportional to water level, is described. The use of audio frequency signals enables telephone grade circuits to be used and avoids many of the problems associated with direct current signals, whether current or voltage, commonly used at present.A field installation of 30 piezometers, a tipping bucket raingauge, a weir‐stage recorder and logger controlled water sampler is described and examples given of the data collected from a single piezometer transect during a major storm event.
Vegetation characteristics and the prediction of runoff: Analysis of an experiment in the New Forest, Hampshire
Authors: Gurnell A. M. , Gregory K. J. 
Published: February 2007

AbstractVegetation characteristics have not been sufficiently utilized in catchment runoff models. An analysis of storm hydrograph data from nested subareas of the Highland Water catchment, New Forest, U.K., indicates that depth of runoff and peak discharge from areas under heathland cover is substantially greater than from areas under woodland cover at several spatial scales. The significance of heath vegetation composition in the identification of runoff contributing areas is illustrated by an analysis of vegetation composition, water table depth, baseflow discharge and storm runoff from areas predominantly covered by heathland. Methods are proposed to employ the hydrological characteristics of heathland to refine and develop the Flood Studies Approach to discharge estimation in ungauged heathland catchments. Such an approach is greatly facilitated by the use of remotely‐sensed data.
Soil water dye tracing, with special reference to the use of rhodamine WT, lissamine FF and amino G acid
Authors: Trudgill S. T. 
Published: February 2007

AbstractThree fluorescent dyes (Rhodamine WT, Lissamine FF and Amino G Acid) are compared for use in soil water tracing. Severe limitations are evident, but practical applications are possible. Background fluorescence, adsorption, desorption, pH and other non‐adsorptive effects are reviewed in the contexts of soil column work and field tracing of soil water. Lissamine FF and Amino G Acid are to be preferred for soil column work because of their lower adsorption; Rhodamine WT exhibits higher adsorption but is useful in field situations where organic fluorescence backgrounds are high. Semi‐quantitative work may be undertaken in soil columns once a priming and flushing procedure has been adopted.
Scale effects in fluvial sediment‐associated chemical data
Authors: Ongley E. D. 
Published: February 2007

AbstractAssessment of man's impact on fluvial systems frequently involves extrapolation in time and space from data collected as part of a water quality network. Extrapolation represents information transfer and is used for scenario building and risk assessment. Transfer functions for non‐conservative quality variables are poorly understood. Metals, phosphorus, and organic contaminants, which are preferentially transported in association with suspended sediment, are especially susceptible to extrapolation errors. Information loss, which is inherent in extrapolation procedures, is characterized for sediment‐associated substances by examining the assumptions and limitations of the sediment delivery ratio. A practical demonstration of scale effects and interpretive difficulties is provided using data from the Bow River, Alberta. Guidelines for data assessment and extrapolation are summarized for temporal effects and for three different spatial scales.