Crustal strain in Switzerland 1870–1970     

W. I. Reilly  E. Gubler 《Geophysical Journal International》1990,103(1):251-256

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Predictive ground motion scaling in Switzerland: Best estimates and uncertainties     

Francesca?Bay  Stefan?WiemerEmail author  Donat?F?h  Domenico?Giardini 《Journal of Seismology》2005,9(2):223-240

Spectral ground motion (1 to 15 Hz) as a function of distance is modeled for events spanning 3.0 <M_w ≤ 7.0 in Switzerland. The parameters required to simulate ground motion with a stochastic approach are inverted from 2958 horizontal and vertical component waveforms of small to moderate size events (2.0 ≤ M_{L} ≤ 5.2) in the distance range 10 to 300 km recorded on hard rock sites. Using a Monte Carlo simulation, we establish a significantly different amplification of about a factor of 1.9 between the Alpine Foreland and the Alps. To assess the trade-off between the free parameters of our stochastic model and their influence on the predictive ground motion relationship, we perform a grid search over the five-dimensional solution space. The uncertainties are separated into epistemic and aleatory parts; the main epistemic uncertainty is attributed to the lack of data forM > 5. To constrain the viable models at large magnitudes, results from worldwide scaling studies are evaluated in light of the Swiss data. The model that explains best the low observed stress drops at small magnitudes (Δσ ≅ 3 bar) yet matches observed intensities of historical earthquakes assumes a stress drop increasing with moment asM₀^0.25. For three sites in Switzerland we evaluate the sensitivity of the epistemic uncertainty by computing probabilistic hazard curves. Our model offers the most comprehensive and detailed study of spectral ground motion for Switzerland to date.  相似文献   

Rockfalls into forests: Analysis and simulation of rockfall trajectories — considerations with respect to mountainous forests in Switzerland   总被引：3，自引：1，他引：2  

Simone?PerretEmail author  Fabian?Dolf  Hans?Kienholz 《Landslides》2004,1(2):123-130

Rockfalls are a major threat to settlements and transportation routes in many places. Although the general protective effect of forests against rockfalls is currently not questioned, little is known about the ideal properties of a forest stand that provides good protection. Therefore, in this study the question was assessed of how mountainous forests may influence rockfalls of single boulders. An actual rockfall trajectory was measured, recorded, analysed and simulated with a rockfall model. Rockfalls into different forest scenarios were also modelled for the site. Results showed that the actual rockfall event can be well simulated. Furthermore, a completely forested slope reduces velocity and energy of the falling blocks much better than a sparsely forested slope. For the profile discussed in this paper, the largest effect upon falling 3 m³ blocks was obtained with a high forest containing 350 trees per ha. The results confirmed common assumptions on ideal properties of a protective forest stand against rockfalls.  相似文献   

Morphology and curvature of delta slopes in Swiss lakes: lessons for the interpretation of clinoforms in seismic data   总被引：1，自引：0，他引：1  

Erwin W. Adams  Wolfgang Schlager  & Flavio S. Anselmetti 《Sedimentology》2001,48(3):661-679

Seismic surveys were conducted and bathymetric data obtained from four alpine lakes in Switzerland. The curvature of the delta slopes was analysed with mathematical equations. Linear or exponential profiles are observed, representing planar or concave morphologies respectively. Planar profiles are interpreted to represent sediment that rests at the angle-of-repose. The slope angle of these profiles shows a correlation with sediment calibre. Exponential profiles do not show a clear correlation between sediment calibre and slope angle; they do not rest at the angle-of-repose, and different kinds of sediment can rest at the same slope angle. At the transition from lower slope to toe- of-slope, the exponential equation fails to predict the present-day morphology. The toe-of-slope lies above the predicted trend. This is attributed to a drastic increase in turbidite deposition that provides additional sediment and raises the basin-floor profile above the predicted trend. The breaks between delta plain and slope are sharp, reflecting an abrupt change from transport by river flow and waves to gravity-driven transport. In these lakes, the base-level fluctuations relative to supply are small and insufficient to alter this sharp topographic break. The absence of sigmoidal profiles on the Swiss deltas is attributed to the high rate of progradation coupled with small fluctuations in base level.  相似文献   

Gendered labour arrangements in Switzerland: Structures, cultures, meanings: statistical evidence and biographical narratives     

Elisabeth Bühler  Verena Meier Kruker 《GeoJournal》2002,56(4):305-313

In this paper we explore the role of culture in the reproduction of gendered labour arrangements. Using Switzerland as an example, we first analyse statistical data on paid and unpaid labour. We look at differences between women and men, but also between different types of regions. Patterns emerge to support our hypothesis that beyond structures of economic opportunity, economic cycles and welfare state provisions, local (gender) culture might explain some of the particularities of gendered labour arrangements. The argument is reinforced by data on regional voting patterns in a recent referendum on the issue of maternity leave. In the second part, we further explore these issues by looking at a particular place and re-telling work-life-stories that show how two women navigate between different working culture environments in accordance with their life-cycle needs and individual ideas and values. Finally, we discuss issues of scale and methodology and reflect on the significance of varying local working environments. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

The relationship between air and water temperatures in lakes of the Swiss Plateau: a case study with pal\sgmaelig;olimnological implications     

David M. Livingstone  André F. Lotter 《Journal of Paleolimnology》1998,19(2):181-198

In pal\sgmaelig;olimnological studies, inference models based on aquatic organisms are frequently used to estimate summer lake surface water temperatures. However, the calibration of such models is often unsatisfactory because of the sparseness of measured water temperature data. This study investigates the feasibility of using air temperature data, usually available at much higher resolution, to calibrate such models by comparing regional air temperatures with surface water temperatures in 17 lakes on the Swiss Plateau. Results show that altitude-corrected air temperatures are sufficiently uniform over the entire Swiss Plateau to allow local air temperatures at any particular lake site to be adequately estimated from standard composite air temperature series. In early summer, day-to-day variability in air temperature is reflected extremely well in the temperature of the uppermost metre of the water column, while monthly mean air temperatures correspond well, with respect to both absolute value and interannual variations, with water temperatures in most of the epilimnion. Standardised altitude-corrected air temperature series may therefore be a useful alternative to surface water temperatures for the purposes of calibrating lake temperature inference models. In Northern Hemisphere temperate regions, mean air and water temperatures are likely to correspond most closely in July, suggesting that calibration and reconstruction efforts be concentrated on this month.  相似文献   

Development of a System for 3D High-resolution Seismic Reflection Profiling on Lakes   总被引：2，自引：0，他引：2  

M. Scheidhauer  F. Marillier  D. Dupuy 《Marine Geophysical Researches》2005,26(2-4):183-195

A high-resolution three-dimensional (3D) seismic reflection system for small-scale targets in lacustrine settings has been developed. Its main characteristics include navigation and shot-triggering software that fires the seismic source at regular distance intervals (max. error of 0.25 m) with real-time control on navigation using differential GPS (Global Positioning System). Receiver positions are accurately calculated (error<0.20 m) with the aid of GPS antennas attached to the end of each of three 24-channel streamers. Two telescopic booms hold the streamers at a distance of 7.5 m from each other. With a receiver spacing of 2.5 m, the bin dimension is 1.25 m in inline and 3.75 m in crossline direction. To test the system, we conducted a 3D survey of about 1 km² in Lake Geneva, Switzerland, over a complex fault zone. A 5-m shot spacing resulted in a nominal fold of 6. A double-chamber bubble-cancelling 15/15 in³ air gun (40–650 Hz) operated at 80 bars and 1 m depth gave a signal penetration of 300 m below water bottom and a best vertical resolution of 1.1 m. Processing followed a conventional scheme, but had to be adapted to the high sampling rates, and our unconventional navigation data needed conversion to industry standards. The high-quality data enabled us to construct maps of seismic horizons and fault surfaces in three dimensions. The system proves to be well adapted to investigate complex structures by providing non-aliased images of reflectors with dips up to 30°.  相似文献   

Sedimentological and palynological constraints on the basal Triassic sequence in Central Switzerland     

Christian Gisler  Peter A. Hochuli  Karl Ramseyer  Hansruedi Bläsi  Fritz Schlunegger 《Swiss Journal of Geoscience》2007,100(2):263-272

In Central Switzerland, Mesozoic sedimentation began after erosion and peneplainisation of the Hercynian relief and late Paleozoic continental deposition in SW-NE striking pull-apart basins. The first Triassic sedimentary sequence overlaying a weathered crystalline basement consists of a relatively thin (<10 m), lithologically highly variable unit with coarse-grained siliciclastic deposits at the base, grading into a mixed sandstone/shale-dolomite sequence followed by well-bedded dolomites with chert nodules.Sedimentary texture analyses and petrological investigations revealed four different sedimentary units starting at the base with a regolith unit that represents the weathered crystalline basement. It is overlain by terrestrial plain deposits, followed by mixed siliciclastic-carbonaceous sediments and a sequence of dolomites, deposited between the supralittoral and eulittoral zones of a tidal flat (Mels-Formation), and the eulittoral to sublittoral zones of a carbonate tidal flat environment (Röti-Dolomit), respectively.Palynological data from four localities in Central Switzerland indicate a heterochronous early Anisian age (Aegean – Bithynian/Pelsonian) for the supra- to eulittoral mixed siliciclastic-carbonaceous sediments. These new biostratigraphic ages suggest that the first Triassic marine transgression in Central Switzerland is time equivalent with those of the basal Wellendolomit in Northern Switzerland but slightly older than in the Germanic Basin. Consequently, Central Switzerland was located at this time at the northern shoreline of the Tethys and not on the southern limit of the Germanic Basin.  相似文献   

Echinoids from the Belpberg Beds (Obere Meeresmolasse, Middle Burdigalian) in the area of Bern (Switzerland)   总被引：1，自引：0，他引：1  

Andreas Kroh  Ursula Menkveld-gfeller 《Eclogae Geologicae Helvetiae》2006,99(2):193-203

The present paper deals with the echinoid fauna of the Belpberg Beds, a lithostratigraphic unit in the Upper Marine Molasse cropping out southeast of Bern (Switzerland). In this unit, echinoids, in contrast to mollusks, are rare and of low diversity. The scarcity of echinoids is related to the environmental setting dominated by monotonous siliciclastic deposits and strong diagenetic alteration. The echinoid fauna consists of three species Psammechinus dubius dubius, Echinocardium deikei and Hemipatagus ocellatus? Psammechinus dubius dubius and H. ocellatus typically occur in Burdigalian sediments in the Paratethys and help to confirm the dating obtained from the microfossils and molluscs of the Belpberg Beds. Furthermore, the Belpberg echinoid fauna is especially relevant for the palaeobiogeography with species common to both the Rh?ne Basin and the Central Paratethyan faunas.

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Zusammenfassung. Die vorliegende Arbeit besch?ftigt sich mit der Echinidenfauna der Belpberg Schichten (Obere Meeresmolasse) bei Bern. Im Gegensatz zu den Mollusken sind die Echiniden selten und wenig divers. Dies kann einerseits auf das sediment?re Regime, und andererseits auf diagenetische Ursachen zurückgeführt werden. Insgesamt konnten drei Arten nachgewiesen werden (Psammechinus dubius dubius, Echinocardium deikei und Hemipatagus ocellatus?). Zwei davon treten in der Paratethys charakteristischerweise im Burdigalium auf und lassen ein ebensolches Alter für die Belpberg Schichten als wahrscheinlich erscheinen. Aus pal?obiogeographischer Sicht ist die Belpberg-Echinidenfauna von besonderem Interesse, das sie ein Bindeglied zwischen Rh?ne Becken und Zentraler Paratethys darstellt.

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The Valais earthquake of December 9, 1755   总被引：1，自引：0，他引：1  

Monika Gisler  Donat Fäh  Nicholas Deichmann 《Eclogae Geologicae Helvetiae》2004,97(3):411-422

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