Dutch-German Border Research Articles

Source mechanism of the 1992 Roermond earthquake from surface-wave inversion of regional data

SUMMARY The Dutch—German border region near the city of Roermond, The Netherlands was hit by a rather strong crustal earthquake at 1:20 UT, 1992 April 13. The epicentre is located within the Roer Valley Graben, a region currently undergoing extension. The centroidal source mechanism of this event has been retrieved by moment tensor inversion of broad-band long-period surface waves recorded at regional distances (100–1500 km). The double-couple contribution of the moment tensor corresponds to almost pure normal faulting (rake: 262°) on a steeply south-westward dipping fault (dip: 58°) with a NW-SE trend (strike: 138°). This result is consistent with local tectonics but violates some first-motion P-wave polarity data. The deduced seismic moment is 9.2 × 1016 N m corresponding to a moment magnitude of 5.3. A centroidal depth of 18 km fits slightly better than 13 km; however, the differences are small and other methods are necessary to constrain the depth further. It is now possible to access a number of broad-band three-component seismic stations in Europe via phone line (e.g. German Regional Seismic Network) and the ORFEUS data centre (i.e. Global Digital Seismic Network). This allows retrieval of waveform data immediately after an earthquake. In this paper we present a potentially fast and reliable procedure for extracting the moment tensor from low-frequency surface waves using the Roermond earthquake as an example. Detailed knowledge of the velocity-depth structure along the travel paths seems unnecessary with our procedure. Further testing is required on all future moderate to strong earthquakes in Europe using rapidly accessible stations to investigate the procedure's usefulness and possible limitations as a tool for rapid moment tensor estimation.

The institutionalization of transboundary cooperation in Europe: Recent development on the Dutch‐German Border

Paying particular attention to legal and organizational aspects, this article attempts to analyze transboundary institution-building within the context of European integration and changes in European regional policy. Based on a short case study of the Dutch-German EUREGIO, it is argued that new EC regional development programs and national government support have helped this border area association define strategies enabling it to circumvent legal technicalities, establishing defacto (although not dejure) public agencies responsible for coordinating transboundary cooperation efforts. Additionally, the EUREGIO and other Dutch-German border area associations have vigorously pursued transboundary economic development schemes that have tended to cement working relationships and elicit central government support. Europe's progress in transboundary cooperation must be viewed in the context of developments taking place there, especially the growth of a unitary market and political and economic union. Nevertheless, it is suggested that North American border regions may be able to learn from European experience - particularly in the light of the North American Trade Agreement - developing strategies that mobilize local political sentiment and help overcome the influence of ideologies of national sovereignty at regional, state and national levels.

The Mayfly,Ephoron Virgo (Olivier), back in the Dutch parts of the rivers Rhine and Meuse

Due to severe water pollution, the mayflyEphoron virgo (Olivier) disappeared from the Dutch parts of the rivers Rhine and Meuse in the first half of this century. In August 1991, however, larvae were found in the littoral zone of the Rhine near the Dutch-German border. Later, other stages were found along the Rhine branches and a small section of the Meuse. The occurrence in The Netherlands is the result of further expansion from the upstream regions of the Rhine.

Simulation of disulfoton fate in the river rhine with the toxfate model

In 1986, a chemical spill occurred at the Sandoz AG plant in Basel, Switzerland. Several chemicals entered the River Rhine and were transported downstream. In this paper we model the fate of one of the eight chemicals, Disulfoton, found in the German section of the River Rhine, with TOXFATE, a TOXic contaminants FATE model. Simulations show that the TOXFATE model can describe the fate of Disulfoton in the River Rhine. The main problem is that the model has to be calibrated by adjusting the shape of the river sections at different localities. Inputs to the model are Disulfoton concentrations at Maxau and five physico-chemical properties, namely molecular weight, water solubility, octanol/water partition coefficient ( K ow), soil/adsorption coefficient ( K oc), and vapour pressure or Henry's Law constant. Simulations are compared with Disulfoton data. TOXFATE predicts concentrations in the water column as well as volatilization and transport rates. Predicted and observed concentrations agree well at most locations. At Lobith, on the Dutch-German border, however, predicted concentrations are double the observed concentrations. Two explanations can be brought forward to explain this discrepancy, but neither can be verified with field data. Thus, the model is not modified any further to improve its prediction capability at Lobith.

A Geographical Study of the Dutch-German Border

A Geographical Study of the Dutch-German Border