scholarly journals Recent movement pattern of the Lower Rhine Embayment from tilt, gravity and GPS data

2002 ◽  
Vol 81 (2) ◽  
pp. 223-230 ◽  
Author(s):  
J. Campbell ◽  
H.-J. Kümpel ◽  
M. Fabian ◽  
D. Fischer ◽  
B. Görres ◽  
...  
Keyword(s):  
Movement Pattern ◽  
Research Centre ◽  
Rift System ◽  
Gravity Gradients ◽  
Eurasian Plate ◽  
Mining Areas ◽  
Yield Information ◽  
Order Of Magnitude ◽  
Lower Rhine Embayment ◽  
Lower Rhine

AbstractAs part of the activities of the Collaborative Research Centre ‘SFB 350’, measurements of geodetic and geodynamic changes in the area of the Lower Rhine Embayment and the Rhenish Shield are being performed at different scales in space and time. Continuous borehole tilt measurements and repeated microgravimetric surveys yield information on the local stability of the ground and changes in horizontal gravity gradients that are both dominated by seasonal fluctuations. Results of more than seven years of regular GPS campaigns are discussed in terms of vertical and horizontal point motions. The most prominent motions are man-induced effects occurring in or near the browncoal mining areas, where groundwater withdrawal produces subsidence of up to 2.2 cm/y in the area under investigation. Horizontal and vertical motions at other GPS points are smaller by one order of magnitude and in most cases are only marginally detectable. The eastward motion of two points in the Bergisches Land and the westward motion of two points in the Eifel near the Belgian border may be interpreted as a result of the ongoing extension of the Cenozoic rift system in the western part of the Eurasian plate.

scholarly journals Patterns in river channel sinuosity of the Meuse, Roer and Rhine rivers in the Lower Rhine Embayment rift-system, are they tectonically forced?

Geomorphology ◽  
2021 ◽  
Vol 375 ◽  
pp. 107550
Author(s):  
H.A.G. Woolderink ◽  
K.M. Cohen ◽  
C. Kasse ◽  
M.G. Kleinhans ◽  
R.T. Van Balen
Keyword(s):  
River Channel ◽  
Rift System ◽  
Lower Rhine Embayment ◽  
Lower Rhine

Robust, an Earthquake Early Warning System in the Lower Rhine Embayment, Germany

2021 ◽  
Author(s):  
Bita Najdahmadi ◽  
Marco Pilz ◽  
Dino Bindi ◽  
Hoby Njara Tendrisoa Razafindrakoto ◽  
Adrien Oth ◽  
...  
Keyword(s):  
Early Warning ◽  
Early Warning System ◽  
Warning System ◽  
Earthquake Early Warning ◽  
Optimization Approach ◽  
Ground Acceleration ◽  
Earthquake Early Warning System ◽  
Scenario Earthquakes ◽  
Lower Rhine Embayment ◽  
Lower Rhine

<p>The Lower Rhine Embayment in western Germany is one of the most important areas of earthquake recurrence north of the Alps, facing a moderate level of seismic hazard in the European context but a significant level of risk due to a large number of important industrial infrastructures. In this context, the project ROBUST aims at designing a user-oriented hybrid earthquake early warning and rapid response system where regional seismic monitoring is combined with smart, on-site sensors, resulting in the implementation of decentralized early warning procedures.<br><br>One of the research areas of this project deals with finding an optimal regional seismic network arrangement. With the optimally compacted network, strong ground movements can be detected quickly and reliably. In this work simulated scenario earthquakes in the area are used with an optimization approach in order to densify the existing sparse network through the installation of additional decentralized measuring stations. Genetic algorithms are used to design efficient EEW networks, computing optimal station locations and trigger thresholds in recorded ground acceleration. By minimizing the cost function, a comparison of the best earthquake early warning system designs is performed and the potential usefulness of existing stations in the region is considered as will be presented in the meeting.</p>

A Note on the China-Film Technique for Boundary Layer Indication

1956 ◽  
Vol 60 (548) ◽  
pp. 543-544
Author(s):  
R. J. Stalker
Keyword(s):  
Flow Direction ◽  
Air Flow ◽  
Vertical Surface ◽  
Surface Shear Stress ◽  
Surface Shear ◽  
Carrier Liquid ◽  
China Clay ◽  
Yield Information ◽  
Volatile Liquid ◽  
Order Of Magnitude

The “ China-Film ” technique was developed by Murphy and Phinney from the “ China Clay” technique for indicating transition originated by Richards and Burstall. It consists in applying a suspension of china clay in a volatile liquid to a surface subsequently subjected to air flow. Not only is transition indicated, but when all the liquid has evaporated, the china clay remains deposited on the surface in patterns which may be interpreted to yield information on the direction of air flow near the surface and the incidence of shocks thereon.Experiments were carried out, at supersonic and subsonic air speeds, to determine the process by which the patterns form and to establish the aerodynamic meaning of the “ flow lines ” of the pattern. The influence of the viscosity of the carrier liquid was also studied. Indications of flow direction were found to be unreliable near a trailing edge, on a vertical surface at low speeds and in regions where the surface shear stress is only of the same order of magnitude as the product of pressure gradient and film thickness.

scholarly journals The confluence area of Rhine, Meuse, and Belgian rivers: Late Pliocene and Early Pleistocene fluvial history of the northern Lower Rhine Embayment

2008 ◽  
Vol 87 (1) ◽  
pp. 107-125 ◽  
Author(s):  
W.E. Westerhoff ◽  
H.A. Kemna ◽  
W. Boenigk
Keyword(s):  
Marked Change ◽  
Early Pleistocene ◽  
River Systems ◽  
Accommodation Space ◽  
Lower Pleistocene ◽  
Roer Valley Graben ◽  
History Of ◽  
Lithological Composition ◽  
Lower Rhine Embayment ◽  
Lower Rhine

AbstractThe fluvial history of the northern Lower Rhine Embayment shows interplay of three main river systems: Rhine, Meuse and smaller rivers draining the central and northern part of Belgium.The Pliocene and Early Pleistocene (pre-)Rhine and Meuse river systems had their conjunction in the southern part of the Roer Valley Graben between Aachen and Jülich. Despite slight differences in the heavy-mineral assemblages the lithological composition of the Pliocene deposits of the three river systems shows close resemblance and therefore they cannot be mapped separately. However, due to a marked change of the petrographical composition the Upper Pliocene and Lower Pleistocene deposits of the Rhine are easily recognised and as a result Rhine and Meuse deposits can be mapped separately upstream of their confluence.The Lower Pleistocene deposits of Rhine, Meuse and the Belgian rivers show a clear interrelationship. They are bounded by two regional well-mapable unconformities and are preserved in from west to east changing lithostratigraphical sequences. Revision of the lithostratigraphical schemes in Germany and the Netherlands and the better defined lithostratigraphical position of Meuse deposits in Germany now strongly constrain the correlation of the various fluvial deposits. As a result existing reconstructions of the fluvial deposition and tectonic history of the southern Roer Valley Graben can be evaluated and re-adjusted.It is concluded that the main course of the Meuse was aligned through the so-called East Meuse valley during the larger part of the Early Pleistocene. Available pollen data do not conflict with this conclusion. At the same time the Rhine ceased to enter the southern part of the Roer Valley Graben. Instead, the Meuse accumulated here a series of deposits derived from the East-Meuse valley. Simultaneously, the Belgian rivers filled available accommodation space in the Roer Valley Graben of the southern Netherlands. The conclusions are based primarily on the revised lithostratigraphical framework. In general they simplify the picture of fluvial and tectonic behaviour of the area.

Continental Hotspots Tracks from Analysis of GOCE Gravity Gradients Data

2020 ◽  
Author(s):  
Marianne Greff-Lefftz ◽  
Isabelle Panet ◽  
Jean Besse
Keyword(s):  
North Africa ◽  
Spatial Scales ◽  
Thermal Anomaly ◽  
Current Data ◽  
Data Detection ◽  
Gravity Gradients ◽  
Fixed Direction ◽  
Lithospheric Plates ◽  
Order Of Magnitude ◽  
Characteristic Signal

<p> Hotspots are thermal instabilities that originate in the mantle and manifest themselves on the surface by volcanism, continental breaks or "traces" observed in the oceans. Theirs effects under the continents are still debated: in addition to a phase of activity associated with surface volcanism, a residual thermal anomaly could persist durably under the lithosphere along the trajectory of the hotspot. For a simple model of thermal anomaly (a parallelogram aligned in a fixed direction), we compute the perturbations of the geoid, of the gravity vector and of the associated gravity gradients, and show that in a coordinate system aligned with the parallelogram, the gravity gradients exhibit a characteristic signal, with an order of magnitude of a few hundred mEotvös, well above the current data detection level. Thus considering four real cases :in North Africa (with Hoggar, Tibesti, Darfur and Cameroon hotspots), in Greenland (Iceland), in Australia (Cosgrove) and in Europe (Eifel), we calculate the paleo-positions of the hotspots for 100 Myr in a reference frame linked to the lithospheric plates, and we build maps of the Bouguer gravity gradients filtered on the spatial scale of a few hundred kilometers (the scale of the hotspot) and oriented along the direction of these trajectories. We clearly detect, in the scale-orientation diagrams, signals aligned in the direction of the movement of the plates on spatial scales of a few hundred kilometers. These preliminary results are very enthusiastic: gradiometric data indeed allow us to follow the tracks of hotspots in the continental lithosphere, for at least 20 Myr.</p>

scholarly journals The impact of faults on the hydrogeological conditions in the Roer Valley Rift System: an overview

2003 ◽  
Vol 82 (1) ◽  
pp. 41-54 ◽  
Author(s):  
V.F. Bense ◽  
R.T. Van Balen ◽  
J.J. De Vries
Keyword(s):  
Groundwater Flow ◽  
Hydraulic Properties ◽  
Great Influence ◽  
Hydraulic Head ◽  
Transport Processes ◽  
Rift System ◽  
Near Surface ◽  
Mining Areas ◽  
Vertical Permeability ◽  
The Impact

AbstractThe hydrogeology of the Roer Valley Rift System is strongly influenced by the hydraulic properties of faults. The hydrogeological impact of faults is illustrated by examples from the SE Netherlands and the adjacent lignite mining areas within the Roer Valley Rift System, near Bonn in Germany. Hydraulic head discontinuities over the main faults in the latter area can be up to tens of meters as a result of extremely large groundwater extractions in combination with the relatively low conductivity of the main faults. Within the Netherlands, outside the mining areas, such large groundwater extractions do not take place, and groundwater fluxes are smaller. In this situation natural hydraulic head differences over the main faults are limited to several meters. Hydraulic head profiles over faults provide a first estimate of fault hydraulic properties that can be quantified using simple analytical solutions. The impact of faults on near surface processes is reflected in vegetation patterns and the structure of drainage networks, aquifer structure and hydraulic head patterns. Faults can thus be of great influence on transport processes in the subsurface as well as on water-related phenomena at the surface, and should accordingly be taken into consideration in studies related to water-management, contamination and environmental impact. Faults that have an enhanced vertical permeability are difficult to detect when horizontal groundwater flow is studied, which is probably the main reason why they are rarely described. Though, these faults may form important preferential paths to vertical groundwater flow.

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