Morphology of the Ebro fan valleys from SeaMARC and sea beam profiles

The northern continental slope off the Ebro Delta has a badland topography indicating major slope erosion and mass movement of material that deposits sediment into a ponded lobe. The southern slope has a low degree of mass movement activity and slope valleys feed channel levee-complexes on a steep continental rise. The last active fan valley is V-shaped with little meandering and its thalweg merges downstream with the Valencia Valley. The older and larger inactive channel-levee complex is smoother, U-shaped, and meanders more than the active fan valley.     

Die Tektonik der Scholle von Kudowa

Zusammenfassung Die jungsaxonischen Störungen der Kudowaer Kreidescholle, insbesondere ihre tektonischen Ränder, sind durch Querverwerfungen stellenweise gegliederte Flexuren. Sie folgen zum Teil nachweislich, zum Teil wahrscheinlich jungvariscischen Verwerfungen, deren Verlauf durch Strukturzüge der kaledonischen Gebirgsbildung und der variscischen Intrusion vorgezeichnet ist. Der Bewegungssinn der vertikalen Schollenverschiebungen verkehrte sich in der südlichen Randfuge der Innersudetischen Mulde schon in variscischer Zeit, im Bereich der Kudowaer Scholle erst mit Einsetzen der jungsaxonischen Tektonik. Bei deren Ablauf war ein tangentialer Schub von NNW und ihm zugeordnet ein Ausweichen in östlicher bis südöstlicher Richtung wirksam. Damit lebte der Gebirgsdruck der kaledonischen Zeit im gleichen Sinne aber in sehr abgeschwächter Form wieder auf, während in der variscischen Tektonik lokal bedingte vertikale Ausgleichsbewegungen vorherrschten.     

Geologische Beobachtungen an der Küste und auf dem Schelf von Kephallinia (Ionische Inseln)

The largest Ionian island Cephalonia is situated on the edge of the Greek shelf. To the west the slope (20% average) extends to the Ionian fault scarp. This area is characterized by young tectonic activity (last disastrous earthquake in 1953) with dominant N-S and NE-SW fault directions. This paper constitutes the first account of the marine and Quaternary geology of Cephalonia. Late Pleistocene (? Tyrrhen III) red algae-rich limestones - up to 6,5 m thick - with interbedded sand layers transgress steeply folded Plio-Pleistocene and Eocene sediments. In addition, relative sea level changes in Quaternary time are indicated by a submarine platform at ?26 m NN. and 5 elevated shorelines, partly with wave-cut notches and borings, at heights of about 15 m, 45 m, 90 m, 150 m and 190 m, whose correlation with other so-called high-sea-levels of the Mediterranean area is doubtful. Shore- and nearshore sediments mainly consist of eroded coast material and reworked Pliocene which locally crops out on the sea floor, The outer shelf sedimentation is characterized by the deposition of marly foraminiferal ooze which undergoes bioturbation. Because of strong currents the ridge between Cephalonia and Zante is free of recent sediment. A swash mark entirely composed of the tests of sessil foraminiferas (Miniacina miniacea) is described.     

Evolution of extreme temperatures in Belgium since the 1950s

The objective of the present study is to apply a wide range of efficient trend estimation methods for understanding how temperature extremes are locally changing. Temporal patterns of changes in extreme daily maximum or minimum temperature at homogeneous climate stations located in Belgium and their associations with changes in climate means are examined for the period 1952/1953 until present. A considerable amount of work is devoted to the formulation of extreme value models in the presence of non-stationarity. The covariate process is considered to be linear in time or/and in the North Atlantic Oscillation index as well. Additional insights on historical changes in frequency and amplitude of temperature extremes are obtained with the non-parametric quantile-perturbation approach.     

The collision singularity in a perturbedN-body problem

Celestial Mechanics and Dynamical Astronomy - Consider the perturbedN-body problem $$Z_k = - \gamma \sum\limits_{\mathop {j \ne k}\limits^{j = 1} }^N {\frac{{Z_k - Zj}}{{|Z_k - Zj|^3 }}} + P_k...     

Modelling floodplain sedimentation using particle tracking

Both climate change and river rehabilitation projects induce changes in floodplain sedimentation. Notably along the lower River Rhine, the sediment deposition patterns and rates are subject to change. To assess the magnitude of these changes, we developed the MoCSED model, a floodplain sedimentation model within a geographical information system for the lower Rhine River. We based MoCSED on the ‘method of characteristics’ (MoC), a particle tracking method that minimizes numerical dispersion. We implemented the MoCSED model in the PCRaster dynamic modelling language. The model input comprises initial suspended sediment concentrations, water levels, flow velocities, and longitudinal and transverse dispersivities. We used a combination of the Krone and Chen concepts to calculate the subsequent sedimentation (SED routine). We compared the model results with sediment trap data for the Bemmel floodplain along the Dutch Waal River during the 2003 inundation. This comparison showed that MoCSED was able to simulate the pattern of sediment deposition. In addition, the model proved to be an improvement in comparison with a conventional raster‐based floodplain sedimentation model for the lower River Rhine. In future, MoCSED may serve well to study the impact of a changing discharge regime due to climate change and floodplain rehabilitation plans on deposition of sediments. Copyright © 2006 John Wiley & Sons, Ltd.     

Runoff production processes in small alpine catchments within the unconsolidated Pleistocene sediments of the Lainbach area (Upper Bavaria)

In the Lainbach catchment, unconsolidated Pleistocene moraine sediments are widely distributed. Because of the great natural risk of floods, together with extreme loads of sediments, investigations of runoff production processes have been conducted in this area. At hillslope scale three test sites with different states of soil development and vegetation cover were instrumented with V‐shaped weirs, precipitation gauges and measurement devices for electrical conductivity (EC) of discharge water. The EC has been used as a geochemical tracer for hydrograph separation, since the statistical relationship between content of dissolved Ca²⁺, Mg²⁺ cations and EC is highly significant for different stages of runoff. This method allows hydrograph separation at high temporal resolution for both the rising and falling limb of the hydrograph. The following results of the investigations can be resumed. If relief conditions are similar, the effectiveness of runoff production decreases with an increasing density of vegetation cover. The runoff delivery ratio decreases as well as the peaks of runoff. In contrast, concentration times of hillslope catchments are equal, even if vegetation cover is of great density and soils are well developed. As a reason for the short reaction times, different runoff production processes have been detected. On bare ground, infiltration excess overland flow intensified by surface sealing processes is the main source for quick runoff. On hillslopes well covered by vegetation, translatory flow processes indicated by soil water with high solute contents force a rapid runoff reaction only a few minutes after rainfall has begun. It is to be assumed that translatory flow is a runoff production process typical for hillslopes covered by vegetation in a steep alpine relief. By means of the areal distribution of the topographic index, concentration of runoff production on a small part of the catchment has been demonstrated for hillslopes densely covered by vegetation. The investigations have shown that there is a lack of studies on runoff production processes in steep alpine relief, as well as a deficit of methods to quantify hydraulic properties of coarse‐grained soils with a wide grain size distribution. Copyright © 2003 John Wiley & Sons, Ltd.