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A ground motion logic tree for seismic hazard analysis in the stable cratonic region of Europe
(2020)
Regions of low seismicity present a particular challenge for probabilistic seismic hazard analysis when identifying suitable ground motion models (GMMs) and quantifying their epistemic uncertainty. The 2020 European Seismic Hazard Model adopts a scaled backbone approach to characterise this uncertainty for shallow seismicity in Europe, incorporating region-to-region source and attenuation variability based on European strong motion data. This approach, however, may not be suited to stable cratonic region of northeastern Europe (encompassing Finland, Sweden and the Baltic countries), where exploration of various global geophysical datasets reveals that its crustal properties are distinctly different from the rest of Europe, and are instead more closely represented by those of the Central and Eastern United States. Building upon the suite of models developed by the recent NGA East project, we construct a new scaled backbone ground motion model and calibrate its corresponding epistemic uncertainties. The resulting logic tree is shown to provide comparable hazard outcomes to the epistemic uncertainty modelling strategy adopted for the Eastern United States, despite the different approaches taken. Comparison with previous GMM selections for northeastern Europe, however, highlights key differences in short period accelerations resulting from new assumptions regarding the characteristics of the reference rock and its influence on site amplification.
Wallfahrten und Pilgerreisen, allgemein der religiös motivierte Tourismus erfreut sich in Europa heute aus unterschiedlichen Motiven wachsender Zustimmung. Die Motivation hierzu wurzelt letztendlich im Bereich der religiösen Emotionalität. Untersucht wird diese Form spiritueller Orientierung in der religiösen Gegenwartskultur auch in seiner Auswirkung auf die religiösen Institutionen. Die Möglichkeit zu religiös motiviertem Reisen kommt dem Bedürfnis nach mehr Religiosität entgegen, ohne daß der Pilgertourist gezwungen ist, sich längerfristig an kirchliche Strukturen binden zu müssen. Der christliche Religionstourismus ist ein bedeutender Globalisierungsfaktor und zahlenmäßig die größte Mobilisierung von Religion.
In Auseinandersetzung mit dem Konzept kollektiver Identität werden drei Bürgerschafts-Modelle (republikanisches, liberales und cäsarisches) diskutiert. Bürgerschaft wird im Sinne von citizenship anstelle von Staatsbürgerschaft wegen deren etatistischer Konnotation in der deutschen Sprache verwendet. Abschließend wird die europäische Bürgerschaft sowie deren korrespondierende kollektive Identität betrachtet.
To understand past flood changes in the Rhine catchment and in particular the role of anthropogenic climate change in extreme flows, an attribution study relying on a proper GCM (general circulation model) downscaling is needed. A downscaling based on conditioning a stochastic weather generator on weather patterns is a promising approach. This approach assumes a strong link between weather patterns and local climate, and sufficient GCM skill in reproducing weather pattern climatology. These presuppositions are unprecedentedly evaluated here using 111 years of daily climate data from 490 stations in the Rhine basin and comprehensively testing the number of classification parameters and GCM weather pattern characteristics. A classification based on a combination of mean sea level pressure, temperature, and humidity from the ERA20C reanalysis of atmospheric fields over central Europe with 40 weather types was found to be the most appropriate for stratifying six local climate variables. The corresponding skill is quite diverse though, ranging from good for radiation to poor for precipitation. Especially for the latter it was apparent that pressure fields alone cannot sufficiently stratify local variability. To test the skill of the latest generation of GCMs from the CMIP5 ensemble in reproducing the frequency, seasonality, and persistence of the derived weather patterns, output from 15 GCMs is evaluated. Most GCMs are able to capture these characteristics well, but some models showed consistent deviations in all three evaluation criteria and should be excluded from further attribution analysis.
This article presents comparisons among the five ground-motion models described in other articles within this special issue, in terms of data selection criteria, characteristics of the models and predicted peak ground and response spectral accelerations. Comparisons are also made with predictions from the Next Generation Attenuation (NGA) models to which the models presented here have similarities (e.g. a common master database has been used) but also differences (e.g. some models in this issue are nonparametric). As a result of the differing data selection criteria and derivation techniques the predicted median ground motions show considerable differences (up to a factor of two for certain scenarios), particularly for magnitudes and distances close to or beyond the range of the available observations. The predicted influence of style-of-faulting shows much variation among models whereas site amplification factors are more similar, with peak amplification at around 1s. These differences are greater than those among predictions from the NGA models. The models for aleatory variability (sigma), however, are similar and suggest that ground-motion variability from this region is slightly higher than that predicted by the NGA models, based primarily on data from California and Taiwan.
The Eastern Mediterranean is the most seismically active region in Europe due to the complex interactions of the Arabian, African, and Eurasian tectonic plates. Deformation is achieved by faulting in the brittle crust, distributed flow in the viscoelastic lower-crust and mantle, and Hellenic subduction, but the long-term partitioning of these mechanisms is still unknown. We exploit an extensive suite of geodetic observations to build a kinematic model connecting strike-slip deformation, extension, subduction, and shear localization across Anatolia and the Aegean Sea by mapping the distribution of slip and strain accumulation on major active geological structures. We find that tectonic escape is facilitated by a plate-boundary-like, translithospheric shear zone extending from the Gulf of Evia to the Turkish-Iranian Plateau that underlies the surface trace of the North Anatolian Fault. Additional deformation in Anatolia is taken up by a series of smaller-scale conjugate shear zones that reach the upper mantle, the largest of which is located beneath the East Anatolian Fault. Rapid north-south extension in the western part of the system, driven primarily by Hellenic Trench retreat, is accommodated by rotation and broadening of the North Anatolian mantle shear zone from the Sea of Marmara across the north Aegean Sea, and by a system of distributed transform faults and rifts including the rapidly extending Gulf of Corinth in central Greece and the active grabens of western Turkey. Africa-Eurasia convergence along the Hellenic Arc occurs at a median rate of 49.8mm yr(-1) in a largely trench-normal direction except near eastern Crete where variably oriented slip on the megathrust coincides with mixed-mode and strike-slip deformation in the overlying accretionary wedge near the Ptolemy-Pliny-Strabo trenches. Our kinematic model illustrates the competing roles the North Anatolian mantle shear zone, Hellenic Trench, overlying mantle wedge, and active crustal faults play in accommodating tectonic indentation, slab rollback and associated Aegean extension. Viscoelastic flow in the lower crust and upper mantle dominate the surface velocity field across much of Anatolia and a clear transition to megathrust-related slab pull occurs in western Turkey, the Aegean Sea and Greece. Crustal scale faults and the Hellenic wedge contribute only a minor amount to the large-scale, regional pattern of Eastern Mediterranean interseismic surface deformation.
In 2010, project CoCoCo (incipient COntinent-COntinent COllision) recorded a 650 km long amphibian N-S wide-angle seismic profile, extending from the Anatolian plateau across southern Turkey and Cyprus to just south of the Eratosthenes Seamount (ESM). The aim of the project is to reveal the impact of the transition from subduction to continent-continent collision of Africa with Anatolia. Arrival picking, finite-differences ray-tracing and inversion of the offshore and on-offshore data produced a tomographic model across southern Cyprus, the accretionary wedge and the ESM. The main features of this model are (1) crustal P-velocities predominantly lower than 6.5 km/s beneath the ESM, (2) crustal thickness between 28 and 37 km, (3) an upper crustal reflection at 5 km depth beneath the ESM, (4) the likely presence of oceanic crust south of the ESM and a transform margin north of it and (5) a 12 km thick ophiolite sequence on Cyprus. Land shots on Turkey, also recorded on Cyprus, gravity data and geological and previous seismic investigations allow to derive a layered velocity model beneath Anatolia and the northern part of Cyprus. The main features of this model are (1) Moho depths of 38–45 km beneath the Anatolian plateau, (2) an upper and lower crust with large lateral changes in velocity and thickness, (3) a north-dipping subducting plate below Cyprus with a steepening of the dip-angle of the plate at about 45 km depth. Thus, the wide-angle seismic and gravity data provide detailed insights into the 2-D geometry and velocity structures associated with the Cyprus Arc collision zone. Finally, integrated analysis of the geophysics and geology allows a comprehensive interpretation of the crustal structure related to the collision process.
Die deutsche Außenpolitik hat seit dem 19. Jahrhundert bis zur Gegenwart viele Veränderungen erlebt. Lange stand Deutschland in einem angespannten Verhältnis zu den europäischen Ordnungen, doch nun ist es ein wichtiger Akteur der internationalen Gemeinschaft. Manfred Görtemaker, Professor für Neuere Geschichte aus Potsdam, zeichnet die wichtigsten Stationen dieser Entwicklung in seinem Beitrag nach.
Seit 1990 ist die vereinte, wieder souveräne Bundesrepublik Deutschland auf der Suche nach ihrer Rolle in der Welt. Auch die akademische Debatte um die Orientierung deutscher Außenpolitik und die ihr zugrundeliegenden Interessen hält seitdem an. In welchem Verhältnis stehen Normen und Werte einerseits und pragmatische, meist wirtschaftliche Interessen andererseits zueinander? Wie verhält sich die deutsche Außenpolitik zur europäischen? Beeinflusst oder dominiert die deutsche Position gar die europäische? Am Beispiel der deutschen Außenpolitik gegenüber den zentralasiatischen Staaten Kasachstan, Kirgisistan, Tadschikistan, Turkmenistan und Usbekistan werden diese Fragen diskutiert.
Anfang des Jahres 2008 erkannte die Bundesrepublik Deutschland den Kosovo als souveränen Staat an, während sich die Europäische Union mit dieser Entscheidung zurückhielt. Die Politikwissenschaftlerin Franziska Krämer untersucht in ihrer Arbeit „Die Politik Deutschlands in der Kosovofrage“ das Spannungsverhältnis zwischen eigenständiger deutscher und europäischer Außenpolitik. Am Beispiel des Kosovo wird die Problematik der Verflechtung von deutschen und europäischen Politikebenen diskutiert. Die Autorin kommt zu dem Ergebnis, dass die deutsche Kosovopolitik als Beispiel einer neuen deutschen Außenpolitik und nicht als der Beginn einer Europäisierung deutscher Außenpolitik zu sehen ist.